CN111200307A

CN111200307A - Energy balance control device, battery system and energy balance control method thereof

Info

Publication number: CN111200307A
Application number: CN202010049353.6A
Authority: CN
Inventors: 刘兆斌; 宋爱; 朱晓蒙; 单成龙
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2020-01-16
Filing date: 2020-01-16
Publication date: 2020-05-26
Also published as: WO2021143263A1

Abstract

The invention discloses an energy balance control device, a battery system and an energy balance control method thereof, wherein the device comprises: the selection unit is used for gating one path of electric core which needs energy balance control in the electric core group; the transformation unit is used for realizing a first energy transformation process between the gated battery cell and the storage battery; and the transformer is used for realizing a second energy conversion process between the gated electric core and the storage battery. According to the scheme, the problem that the implementation difficulty of the transformer is high due to the fact that the number of the secondary windings of the transformer is increased along with the increase of the number of the battery cores in the battery balancing technology can be solved, and the effect that the implementation difficulty of the transformer is reduced due to the fact that the number of the secondary windings of the transformer is increased along with the increase of the number of the battery cores is avoided.

Description

Energy balance control device, battery system and energy balance control method thereof

Technical Field

The invention belongs to the technical field of batteries, and particularly relates to an energy balance control device, a BATTERY system and an energy balance control method thereof, in particular to an active balance topology of a BATTERY management system (BATTERY MANAGEMENT SYSTEM, BMS), the BATTERY system with the BATTERY management system and the energy balance control method of the BATTERY system.

Background

With the development of economy, the use amount of fossil fuels such as petroleum is increasing, and environmental problems are becoming more serious. The main way to solve the environmental problem is to find clean energy with little pollution. The electric vehicle replaces a fuel vehicle to be the main trend of the current social development, and the battery is indispensable as an energy storage device of the electric vehicle, and the performance of the battery is directly related to the performance of the electric vehicle, thereby determining the development prospect of the electric vehicle and having an important role in reducing the environmental pollution. However, in some battery equalization techniques, the number of secondary windings of the transformer needs to be correspondingly increased along with the increase of the number of battery cells, so that the difficulty in implementing the transformer is high.

The above is only for the purpose of assisting understanding of the technical aspects of the present invention, and does not represent an admission that the above is prior art.

Disclosure of Invention

The invention aims to provide an energy balance control device, a battery system and an energy balance control method thereof, aiming at overcoming the problems that the realization difficulty of a transformer is higher because the number of secondary windings of the transformer is increased along with the increase of battery cores in the battery balance technology, and achieving the effect of avoiding the increase of the number of secondary windings of the transformer along with the increase of the battery cores and reducing the realization difficulty of the transformer.

The invention provides an energy balance control device, comprising: the transformer comprises a transformer, a transformation unit and a selection unit, wherein a winding is arranged on the secondary side of the transformer; the selection unit is used for gating one path of electric core which needs energy balance control in the electric core group; the transformation unit is used for realizing a first energy transformation process between the gated battery cell and the storage battery; the first energy conversion process, comprising: the first energy conversion processing is carried out between the one path of the battery cell arranged on the first side of the conversion unit and the second side of the conversion unit; the transformer is used for realizing a second energy conversion process between one path of gated battery cell and the storage battery; the second energy conversion process, comprising: a second energy conversion process between a second side of the conversion unit arranged on the secondary side of the transformer and a storage battery arranged on the primary side of the transformer; the first energy conversion process and the second energy conversion process form an energy balance process between the gated electric core and the storage battery.

Optionally, the primary side of the transformer is provided with two windings; a transformation unit which is a bidirectional transformation unit; an energy balancing process between a gated cell and a battery, comprising: the two-way energy balance process between the electric core of the way of selecting for use and the battery, this two-way energy balance process specifically includes: under the condition that the voltage of one path of gated battery cell is higher than the set voltage, one path of gated battery cell charges the storage battery so as to realize the discharging process of discharging; and under the condition that the voltage of the gated electric core is lower than the set voltage, the gated electric core is charged from the storage battery, so that the charging process is realized.

Optionally, the primary side of the transformer is provided with two windings, including: a first winding and a second winding; the synonym end of the first winding is connected with the synonym end of the second winding, and the synonym end of the first winding are respectively connected to the anode and the cathode of the storage battery; a first group of control switches are arranged on the homonymous end lead of the first winding, and a second group of control switches are arranged on the heteronymous end lead of the second winding; the first group of control switches and the second group of control switches are used for controlling the switching of the working states of a first winding and a second winding of a primary side of the transformer; the first winding and the second winding are two independent windings, or the first winding and the second winding are two windings with a center tap and one winding divided by the center tap; and a third group of control switches are arranged on the homonymous end lead of the secondary side winding of the transformer.

Optionally, a bidirectional conversion unit, comprising: a bidirectional BUCK-BOOST circuit; the bidirectional BUCK-BOOST circuit is provided with an inductor, a fourth group of control switches and a fifth group of control switches; the first end of the fourth group of control switches is connected with the first end of the fifth group of control switches, the second end of the fourth group of control switches is connected to the homonymous end of the secondary winding of the transformer, and the second end of the fifth group of control switches is respectively connected with the second terminal of the first side of the transformation unit and the synonym end of the secondary winding of the transformer; an inductance is connected between the first terminal of the first side of the varying unit and the first terminal of the fourth set of control switches.

Optionally, the electric core group comprises: the battery comprises N single-section battery cores, wherein the N single-section battery cores are arranged in parallel, and N is a natural number; the positive leads of the N single-section battery cells are connected to a first wiring terminal on the first side of the transformation unit, and the negative leads of the N single-section battery cells are connected to a second wiring terminal on the first side of the transformation unit; a selection unit comprising: the sixth group of control switches are arranged on the positive lead of each battery cell, and the seventh group of control switches are arranged on the negative lead of each battery cell; and adjacent stages in the positive and negative electrodes of two adjacent battery cells share one group of control switches.

Optionally, any one of the first, second, third, fourth, fifth, sixth and seventh sets of control switches comprises: a first switch body, a second switch body, a first body diode and a second body diode; the first body diode is arranged between the first control end and the second control end of the first switch body in parallel, and the second body diode is arranged between the first control end and the second control end of the second switch body in parallel; and in any group of control switches, the anode of the first body diode and the anode of the second body diode are oppositely arranged.

Optionally, any one of the first switch body and the second switch body includes: MOS tube, IGBT or relay.

Optionally, the method further comprises: a voltage stabilizing and filtering unit; the number of the voltage stabilizing filter units is more than one, and the more than one voltage stabilizing filter units are arranged on one side of the primary side of the transformer, one side of the secondary side of the transformer and/or the first side of the conversion unit.

Optionally, the step of charging the battery by the gated one of the battery cells to realize a discharging process includes: if the gated electric core is the electric core with odd-numbered arrangement sequence in the electric core group, under the condition of receiving a discharge instruction, controlling a fifth group of control switches and a sixth group of control switches on the positive and negative leads of the electric core to be simultaneously switched on so as to enable the positive and negative electrodes of the electric core to be respectively connected to a first terminal and a second terminal on the first side of the transformation unit; controlling a fourth group of control switches in the conversion unit to be turned on for a set time to charge an inductor in the conversion unit, so that the conversion unit outputs a first voltage which is positive and negative up and down after the conversion unit realizes boosting processing; the first voltage is the sum of the voltage of the battery cell and the voltage of an inductor in the conversion unit; and a third group of control switches on the homonymous end outgoing line of the secondary winding of the control transformer are turned on for a set time and then turned off, and a second group of control switches on the heteronymous end outgoing line of the secondary winding of the primary winding of the control transformer are turned on, so that the battery cell charges a storage battery at the secondary winding of the primary winding of the control transformer.

Optionally, the gated one of the battery cells charges the storage battery to realize a discharging process of discharging, further including: if the gated electric core in one path is the electric core with an even number of arrangement sequence in the electric core group, under the condition of receiving a discharge instruction, controlling a fifth group of control switches and a sixth group of control switches on the positive and negative leads of the electric core to be simultaneously switched on so as to enable the positive and negative electrodes of the electric core to be respectively connected to a first terminal and a second terminal on the first side of the transformation unit; controlling a fourth group of control switches in the conversion unit to be turned on for a set time to charge an inductor in the conversion unit, so that the conversion unit outputs a second voltage with a positive upper voltage, a negative lower voltage and a positive lower voltage after the conversion unit realizes boosting processing; the second voltage is the sum of the voltage of the battery cell and the voltage of an inductor in the conversion unit; and a third group of control switches on the homonymous end outgoing line of the winding on the secondary side of the control transformer are turned on for a set time and then turned off, and a first group of control switches on the homonymous end outgoing line of the first winding on the primary side of the control transformer are controlled to be turned on, so that the battery cell charges a storage battery at the first winding on the primary side of the control transformer.

Optionally, the charging process of charging the battery by charging the battery with the selected one path of battery cells includes: if the gated electric core is the electric core with odd-numbered arrangement sequence in the electric core group, under the condition of receiving a charging instruction, controlling a fifth group of control switches and a sixth group of control switches on the positive and negative leads of the electric core to be simultaneously switched on so as to enable the positive and negative electrodes of the electric core to be respectively connected to a first terminal and a second terminal of the first side of the transformation unit; and a second group of control switches on the different-name end outgoing line of the second winding on the primary side of the control transformer are turned off after being turned on for a set time, and a third group of control switches on the same-name end outgoing line of the winding on the secondary side of the control transformer are turned on, so that the winding on the secondary side of the control transformer outputs a third voltage, and the third voltage is charged to the battery cell after being subjected to voltage reduction processing by the conversion unit.

Optionally, the charging process of charging the battery by charging the battery with the selected one path of battery cells includes: if the gated electric core in one path is the electric core with an even number of arrangement sequence in the electric core group, under the condition of receiving a charging instruction, controlling a fifth group of control switches and a sixth group of control switches on the positive and negative leads of the electric core to be simultaneously switched on so as to enable the positive and negative electrodes of the electric core to be respectively connected to a first terminal and a second terminal on the first side of the transformation unit; and a first group of control switches on the homonymous end outgoing line of the first winding on the primary side of the control transformer are turned off after being turned on for a set time, and a third group of control switches on the homonymous end outgoing line of the winding on the secondary side of the control transformer are turned on, so that the winding on the secondary side of the control transformer outputs a fourth voltage, and the fourth voltage is charged to the battery cell after being subjected to voltage reduction processing by the conversion unit.

In accordance with another aspect of the present invention, there is provided a battery system including: the energy balance control device is described above.

In accordance with the above battery system, a further aspect of the present invention provides an energy balance control method for a battery system, including: selecting one path of electric core needing energy balance control in the electric core group through a selection unit; a first energy conversion process between one path of gated battery cell and the storage battery is realized through a conversion unit; the first energy conversion process, comprising: the first energy conversion processing is carried out between the one path of the battery cell arranged on the first side of the conversion unit and the second side of the conversion unit; a second energy conversion process between one path of gated battery cell and the storage battery is realized through a transformer; the second energy conversion process, comprising: a second energy conversion process between a second side of the conversion unit arranged on the secondary side of the transformer and a storage battery arranged on the primary side of the transformer; the first energy conversion process and the second energy conversion process form an energy balance process between the gated electric core and the storage battery.

Optionally, an energy balancing process between the gated one of the cells and the battery includes: the two-way energy balance process between the electric core of the way of selecting for use and the battery, this two-way energy balance process specifically includes: under the condition that the voltage of one path of gated battery cell is higher than the set voltage, one path of gated battery cell charges the storage battery so as to realize the discharging process of discharging; and under the condition that the voltage of the gated electric core is lower than the set voltage, the gated electric core is charged from the storage battery, so that the charging process is realized.

According to the scheme of the invention, the number of the windings on the secondary side of the high-frequency transformer is reduced by the flyback converter with the primary side of the high-frequency transformer being provided with two windings and the secondary side of the high-frequency transformer being provided with one winding, so that the number of the windings on the secondary side of the high-frequency transformer can be obviously reduced, and the difficulty in realizing the high-frequency transformer is correspondingly reduced.

Furthermore, according to the scheme of the invention, the number of windings on the secondary side of the high-frequency transformer is reduced by the flyback converter with the primary side of the high-frequency transformer being provided with two windings and the secondary side of the high-frequency transformer being provided with one winding, so that the volume of the transformer can be reduced, and the implementation cost of the transformer can be reduced.

Furthermore, according to the scheme of the invention, the number of the windings on the secondary side of the high-frequency transformer is reduced by the flyback converter with the primary side of the high-frequency transformer being provided with two windings and the secondary side of the high-frequency transformer being provided with one winding, so that the magnetic coupling between the windings is enhanced, the leakage inductance is greatly reduced, the stability and the reliability of the topological work can be improved, and the power conversion efficiency is greatly improved.

Therefore, according to the scheme of the invention, the number of the windings on the secondary side of the high-frequency transformer is reduced by the flyback converter with the primary side of the high-frequency transformer being two windings and the secondary side of the high-frequency transformer being one winding, so that the problem that the implementation difficulty of the transformer is higher because the number of the secondary windings of the transformer is increased along with the increase of the electric cores in the battery equalization technology is solved, and the effects of avoiding the increase of the number of the secondary windings of the transformer along with the increase of the electric cores and reducing the implementation difficulty of the transformer are achieved.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.

Drawings

Fig. 1 is a schematic structural diagram of an embodiment of an energy balance control device according to the present invention;

FIG. 2 is a schematic diagram of an active equalization topology;

fig. 3 is a schematic structural diagram of an active equalization topology according to an embodiment of the battery system of the present invention;

fig. 4 is a schematic structural diagram of a cell selection switch array according to an embodiment of the battery system of the present invention;

fig. 5 is a schematic diagram illustrating an operation process of a discharging flyback converter of a first battery cell according to an embodiment of the battery system of the present invention;

fig. 6 is a schematic diagram illustrating an operation process of a second cell discharging flyback converter according to an embodiment of the battery system of the present invention;

FIG. 7 is a flowchart illustrating an energy balance control method according to an embodiment of the present invention;

fig. 8 is a schematic flow chart of an embodiment of a first discharging process in which cells arranged in an odd number in the cell group are discharged to the storage battery for one channel of cells gated in the method of the present invention;

fig. 9 is a schematic flow chart of an embodiment of a second discharging process in which cells arranged in an even number in the cell group are discharged to the storage battery, in which one cell to be gated is in the method of the present invention;

fig. 10 is a schematic flow chart of an embodiment of a first charging process in which cells arranged in an odd number in the cell group are charged to the storage battery for one channel of cells gated in the method of the present invention;

fig. 11 is a flowchart illustrating an embodiment of a second charging process in which cells in an even-numbered cell group are charged into a storage battery in one channel of cells gated in the method of the present invention.

The reference numbers in the embodiments of the present invention are as follows, in combination with the accompanying drawings:

1-a first electrical core; 2-a second cell.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the specific embodiments of the present invention and the accompanying drawings. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

According to an embodiment of the present invention, there is provided an energy balance control apparatus. Referring to fig. 1, a schematic diagram of an embodiment of the apparatus of the present invention is shown. The energy balance control apparatus may include: the transformer, the transformation unit and the selection unit, the secondary side of the transformer is provided with a winding, the number of windings of the transformer is reduced, the size is reduced, the cost is reduced, the indirect PCB is also reduced, the size of the controller is reduced, and the product can be produced in a quantitative mode. Specifically, the transformer, the transforming unit, and the selecting unit may be connected in sequence. For example: the transformer may be a transformer with a set frequency, such as a high frequency transformer. The conversion unit can be a voltage boosting circuit or a voltage reducing circuit. The selection unit may be a cell selection switch array, and the cell selection switch array may be disposed between the cell and the transformation unit.

Specifically, the selection unit is arranged between the electric core group and the first side of the transformation unit, and can be used for gating one path of electric cores which need to be subjected to energy balance control in the electric core group in an energy balance control process. For example: and selecting any electric core in the electric core group, and opening a connecting passage between the selected electric core and the first side of the transformation unit so as to realize gating or switching-off control between any electric core in the electric core group and the first side of the transformation unit.

Specifically, the transformation unit may be configured to implement a first energy transformation process in an energy balance control process between the gated electric core and the battery based on the gated electric core. The first energy conversion process may include: and the first energy conversion processing is carried out between the one path of the battery cell arranged on the first side of the conversion unit and the second side of the conversion unit. The first side of the conversion unit is communicated with the selection unit, and the second side of the conversion unit is communicated with the secondary side of the transformer.

Specifically, the transformer may be configured to implement a second energy conversion process in an energy balance control process between the gated one of the battery cells and the battery. The second energy conversion process may include: and a second energy conversion process between the second side of the conversion unit arranged on the secondary side of the transformer and the storage battery arranged on the primary side of the transformer. The storage battery is arranged on the primary side of the transformer, and the secondary side of the transformer is arranged on the second side of the conversion unit.

The first energy conversion process and the second energy conversion process form an energy balance process between the one path of gated battery cell and the storage battery, namely, form an energy balance process capable of realizing energy balance control between the one path of gated battery cell and the storage battery.

For example: the secondary side of the high-frequency transformer is provided with one winding, so that the number of windings of the high-frequency transformer can be obviously reduced, and the problem of more secondary windings of the transformer can be at least solved. Furthermore, the windings of the high-frequency transformer can be obviously reduced, so that the problems of difficult manufacture, high cost and large volume of the transformer caused by more windings can be solved, the manufacture cost and the volume of the transformer are greatly reduced, the manufacture is easy, the automatic production can be realized, and the efficiency is high. Furthermore, because the number of windings is reduced, the magnetic coupling between the windings is favorably enhanced, the leakage inductance is greatly reduced, the problems of unstable topology work and low power efficiency caused by large leakage inductance of the transformer can be solved, the stability and the reliability of the topology work are improved, and the power conversion efficiency is greatly improved.

Therefore, the number of windings of the transformer is obviously reduced by arranging one winding on the secondary side of the transformer, so that the realization difficulty of the transformer is obviously reduced; and moreover, the selection unit and the transformation unit are matched, so that an energy balance control process between one path of gated electric core in the electric core group and the storage battery can be realized, and the control difficulty of one energy balance control process between one path of gated electric core in the electric core group and the storage battery can be reduced.

In an alternative example, the primary side of the transformer is provided with two windings. And the transformation unit is a bidirectional transformation unit. An energy balancing process between the gated cell and the battery may include: the bidirectional energy balancing process between the selected one-way battery core and the battery specifically may include: and a bidirectional process of bidirectional energy balance in the discharging control process or the charging control process of the gated one path of battery cell. Specifically, the method may include: under the condition that the voltage of one path of gated battery cell is higher than the set voltage, one path of gated battery cell charges the storage battery so as to realize the discharging process of discharging; and under the condition that the voltage of the gated electric core is lower than the set voltage, the gated electric core is charged from the storage battery, so that the charging process is realized.

Wherein the set voltage and the set voltage may be the same. Of course, the setting voltage and the setting voltage may be different, for example, the setting voltage may be an upper limit of a setting voltage range, and the setting voltage may be a lower limit of a setting voltage range.

For example: the primary side of the high-frequency transformer is a winding with a center tap, namely the flyback transformer with the primary side of 2 windings and the secondary side of one winding, so that the windings of the high-frequency transformer can be obviously reduced, and the problem of more secondary windings of the transformer can be at least solved. Furthermore, the windings of the high-frequency transformer can be obviously reduced, so that the problems of difficult manufacture, high cost and large volume of the transformer caused by more windings can be solved, the manufacture cost and the volume of the transformer are greatly reduced, the manufacture is easy, the automatic production can be realized, and the efficiency is high. Furthermore, because the number of windings is reduced, the magnetic coupling between the windings is favorably enhanced, the leakage inductance is greatly reduced, the problems of unstable topology work and low power efficiency caused by large leakage inductance of the transformer can be solved, the stability and the reliability of the topology work are improved, and the power conversion efficiency is greatly improved.

For example: the active equalization can be realized by exchanging energy between the 24V storage battery on the electric vehicle and the battery cells in the battery cell group. And the exchange or conversion of energy is realized by a transformer. Wherein, the effect of transformer: firstly, the isolation function is realized; the second is energy conversion and is bidirectional. That is, if the voltage of the battery cell is too high, the energy of the battery cell is required to be transmitted to the storage battery, that is, the battery cell discharges; on the contrary, if the voltage of the battery cell is too low, or if the voltage of the battery is too high, the energy of the battery is required to be transferred to the battery cell direction, that is, the battery cell is charged.

Therefore, the primary side of the transformer is provided with two windings, and the secondary side of the transformer is provided with one winding, so that the number of the windings of the transformer is not reduced, and the realization difficulty of the transformer is obviously reduced; and moreover, the selection unit and the transformation unit are matched, so that a bidirectional energy balance control process between one path of gated electric core in the electric core group and the storage battery can be realized, and the control difficulty of one bidirectional energy balance control process between one path of gated electric core in the electric core group and the storage battery can be reduced.

In an optional specific example, when the voltage of the gated one of the battery cells is higher than the set voltage, the gated one of the battery cells charges the storage battery to realize a discharging process of discharging, which may include: the one path of gated battery cells is a first discharge process in which the battery cells arranged in the odd number in the battery cell group discharge to the storage battery, or the one path of gated battery cells is a second discharge process in which the battery cells arranged in the even number in the battery cell group discharge to the storage battery, which may be specifically referred to as an exemplary description in any one of the following discharge situations.

First discharge case: the gated electric core is a first discharging process of discharging the electric cores arranged in the odd number in the electric core group to the storage battery, and the first discharging process specifically includes the following steps:

on one hand, if one path of the gated battery cells is the battery cells with odd arrangement sequence in the battery cell group, such as the first battery cell 1, the third battery cell 3, and the like, under the condition of receiving a discharge instruction, the fifth group of control switches and the sixth group of control switches on the positive and negative leads of the battery cell are controlled to be simultaneously turned on, so that the positive and negative electrodes of the battery cell are respectively connected to the first terminal and the second terminal on the first side of the transformation unit.

For example: if the voltage of the first battery cell 1 is too high, discharge equalization is required. The controller sends out a command, so that the selection switches on two sides of the first battery cell 1, such as power tubes or switching tubes Q1, Q3, Q3 and Q4, are simultaneously turned on, at this time, the first terminal BUS1 is connected with the positive electrode of the first battery cell 1, and the second terminal BUS2 is connected with the negative electrode of the first battery cell 1. Thereafter, the BUSs (i.e., first terminal BUS1, second terminal BUS2) are coupled to the bidirectional BUCK-BOOST circuit.

Further, the conversion unit is controlled to be in a boosting state, and in the boosting process, a fourth group of control switches in the conversion unit are controlled to be turned on for a set time length, such as turning-on time T, so as to charge an inductor in the conversion unit, so that the conversion unit outputs a first voltage which is positive, negative and up after the conversion unit realizes boosting processing. The first voltage is the sum of the voltage of the battery cell and the voltage of the inductor in the conversion unit.

For example: under the condition that the voltage of the first battery cell 1 is too high and needs to be balanced, the first terminal BUS1 of the first battery cell 1 is connected with the positive electrode of the first battery cell 1, the second terminal BUS2 is connected with the negative electrode of the first battery cell 1, and then BUSs (namely the first terminal BUS1 and the second terminal BUS2) are connected to the bidirectional BUCK-BOOST circuit. First, when the first cell 1 is discharged, the BUCK-BOOST operates in the BOOST mode, so that the output voltage of the inverter is higher than the voltage of the first cell 1. The output voltage of the converter is V1, namely, the voltage drop across the capacitor C2 is V1, and the voltage is positive, negative and up. And (3) boosting: and controlling the conduction time T of the power tubes K6 and K7, charging the inductor L for T, and then disconnecting the power tubes K6 and K7, wherein the inductance induction voltage of the inductor L is left negative and right positive. The output voltage of the converter is equal to the voltage of the inductor L plus the voltage of the first cell 1, and therefore is a boost circuit.

And further, a third group of control switches on the homonymous end outgoing line of the secondary winding of the control transformer are turned off after being turned on for a set time, for example, the third group of control switches is turned off after being turned on for T1, and then a second group of control switches on the heteronymous end outgoing line of the secondary winding of the primary winding of the control transformer are turned on, so that the battery cell charges a storage battery at the secondary winding of the primary winding of the control transformer.

For example: when the voltage of the first battery cell 1 is too high and requires discharge equalization, the voltage of the first battery cell 1 is subjected to voltage boosting processing by a conversion unit such as a bidirectional BUCK-BOOST circuit, and then a voltage V1 is output. The voltage V1 generated by boosting is connected to the bidirectional flyback converter, and first, the power tubes K4 and K5 are on for a time T1, and their on voltage drops are ignored, so that the dotted end of the secondary side of the high-frequency transformer (as shown by black dots in fig. 2, 4, and 5) is the positive electrode, and the other end is the negative electrode. Current flows from the same-name end to excite the secondary winding, then the power tubes K4 and K5 are turned off, the direction of induced voltage of the secondary winding is up-negative and down-positive, the polarity of the primary-side same-name end is negative, the other end is positive, and after the power tubes K4 and K5 are turned off, the switching tubes K3 and K2 must be controlled to be conducted (for example, the switching tubes K3 and K2 can be conducted by enabling the MCU to send out high-frequency PWM waves), and the storage battery is charged. And finally, the energy of the first battery cell 1 is transferred to the storage battery, the voltage of the first battery cell 1 is reduced, and the aim of balancing is fulfilled.

The second discharge case: the gated electric core is a second discharging process of discharging the electric cores with even number of arrangement sequence in the electric core group to the storage battery, and the second discharging process specifically comprises the following steps:

on the other hand, if one of the strobed battery cells is the battery cell with an even number of arrangement sequence in the battery cell group, such as the second battery cell 2, the fourth battery cell 4, and the like, under the condition that the discharging instruction is received, the fifth group of control switches and the sixth group of control switches on the positive and negative leads of the battery cell are controlled to be simultaneously turned on, so that the positive and negative electrodes of the battery cell are respectively connected to the first terminal and the second terminal on the first side of the transformation unit.

For example: if the voltage of the second battery cell 2 is too high, the battery needs to be discharged. And the MCU sends out a control signal, switches on the switching tubes Q3 and Q4, and switches on the switching tubes Q5 and Q6, and selects the second battery cell 2 to be connected into the bidirectional BUCK-BOOST circuit.

Further, the conversion unit is controlled to be in a boosting state, and in the boosting process, a fourth group of control switches in the conversion unit are controlled to be turned on for a set time length, such as turning-on time T, so as to charge an inductor in the conversion unit, so that the conversion unit outputs a second voltage which is positive up and negative down after the boosting process is realized. The second voltage is the sum of the voltage of the battery cell and the voltage of the inductor in the conversion unit.

For example: when the voltage of the second battery cell 2 is too high and needs to be balanced, the second battery cell 2 is connected into the bidirectional BUCK-BOOST circuit, and then the bidirectional BUCK-BOOST circuit is used for boosting. Different from the discharge of the first battery cell 1, after passing through the BUCK-BOOST circuit, the generated voltage V2 is generated, and the voltage values of V2 and V1 are the same and have opposite polarities, that is, the same-name end of the secondary side of the access transformer is a negative electrode, and the other end of the secondary side of the access transformer is a positive electrode.

And further, a third group of control switches on the homonymous end outgoing line of the winding on the secondary side of the control transformer are turned off after being turned on for a set time, for example, the third group of control switches is turned off after being turned on for T1, and then a first group of control switches on the homonymous end outgoing line of the first winding on the primary side of the control transformer are controlled to be turned on, so that the battery cell charges the storage battery at the first winding on the primary side of the control transformer.

For example: when the voltage of the second battery cell 2 is too high and requires discharge equalization, the voltage of the second battery cell 2 is subjected to voltage boosting processing by a conversion unit such as a bidirectional BUCK-BOOST circuit, and then a voltage V2 is output. MCU sends signal control switch tube K4 and K5 and switches on simultaneously, at this moment, the negative pole of second electric core 2 is connected with the vice limit synonym end of transformer, the other end is connected to the positive pole, when switch tube K4 and K5 disconnection, the voltage that the vice limit winding produced is upper and lower burden, must switch on switch tube K1 and K this moment, make the energy transfer of vice limit primary side, through adjusting switch tube K, K1, K4, the PWM ripples duty cycle of K5, second electric core 2 accomplishes the discharge to the battery, realize balanced control.

In an optional specific example, when the voltage of the gated one of the cells is lower than the set voltage, the gated one of the cells is charged from the battery to realize a charging process of charging, which may include: the one-way gated battery cell is a first charging process in which the battery cells arranged in the odd number in the battery cell group charge the storage battery, or the one-way gated battery cell is a second charging process in which the battery cells arranged in the even number in the battery cell group charge the storage battery, which can be specifically referred to as an exemplary description in any one of the following charging situations.

First charging situation: the gated electric core is a first charging process of charging the storage battery by the electric cores arranged in the electric core group in an odd number, and the first charging process specifically comprises the following steps:

on one hand, if one path of the gated battery cells is the battery cells with odd arrangement sequence in the battery cell group, such as the first battery cell 1, the third battery cell 3, and the like, under the condition of receiving a charging instruction, the fifth group of control switches and the sixth group of control switches on the positive and negative leads of the battery cell are controlled to be simultaneously turned on, so that the positive and negative electrodes of the battery cell are respectively connected to the first wiring end and the second wiring end of the first side of the transformation unit.

For example: if the voltage of the first battery cell 1 is too low, charge equalization is required. If the voltage of the first battery cell 1 is too low, a storage battery is needed to charge the first battery cell. Selective switches such as power tubes Q1, Q2, Q3 and Q4 on two sides of the first battery cell 1 are turned on, so that the first battery cell 1 is connected into an equalizing circuit.

And further, a second group of control switches on the different-name end outgoing line of the second winding on the primary side of the transformer are controlled to be turned off after being turned on for a set time, and a third group of control switches on the same-name end outgoing line of the winding on the secondary side of the transformer are controlled to be turned on, so that the winding on the secondary side of the transformer outputs a third voltage, and the third voltage is charged to the battery cell after being subjected to voltage reduction processing by the conversion unit.

For example: when the voltage of the first battery cell 1 is too low and charging equalization is needed, the first battery cell 1 is controlled to be connected into an equalization circuit. Since the end of the same name connected to the secondary winding of the first cell 1 is positive, when charging the first cell 1, the switching tubes K2 and K3 on the primary side need to be closed. The MCU sends out high level to control the switching tubes K2 and K3 to be conducted, at the moment, the primary winding is excited, after the primary winding is conducted for a period of time, the switching tubes K2 and K3 are closed, and meanwhile, the switching tubes K4 and K5 are opened. By adjusting the duty ratio of the PWM, a stable voltage V1 is output; then, the voltage V1 passes through the BUCK-BOOST circuit, and finally outputs a relatively stable current, so as to charge the first cell 1.

The second charging scenario: the gated electric core is a second charging process of charging the storage battery by the electric cores arranged in the electric core group in an even number, and the second charging process specifically comprises the following steps:

on the other hand, if one of the strobed battery cells is the battery cell with an even number of arrangement sequence in the battery cell group, such as the second battery cell 2, the fourth battery cell 4, and the like, under the condition that the charging instruction is received, the fifth group of control switches and the sixth group of control switches on the positive and negative leads of the battery cell are controlled to be simultaneously turned on, so that the positive and negative electrodes of the battery cell are respectively connected to the first terminal and the second terminal on the first side of the transformation unit.

For example: if the voltage of the second battery cell 2 is too low, charge equalization is required. If the voltage of the second battery cell 2 is too low, the battery is required to charge the second battery cell. And switching on selection switches such as power tubes Q1 and Q2, Q3 and Q4 on two sides of the second battery cell 2, so that the second battery cell 2 is connected into the equalizing circuit.

Further, the first group of control switches on the homonymous end outgoing line of the first winding on the primary side of the transformer are controlled to be turned off after being turned on for a set time, and the third group of control switches on the homonymous end outgoing line of the winding on the secondary side of the transformer are controlled to be turned on, so that the winding on the secondary side of the transformer outputs a fourth voltage, and the fourth voltage is charged to the battery cell after being subjected to voltage reduction processing by the conversion unit.

For example: and under the condition that the voltage of the second battery cell 2 is too low and charging equalization is needed, controlling the second battery cell 2 to be connected into an equalization circuit. Since the end of the same name connected to the secondary winding of the second cell 2 is the negative electrode, when charging the second cell 2, the switching tubes K and K1 on the primary side need to be closed. The MCU sends out high level to control the switch tubes K and K1 to be conducted, at the moment, the primary winding is excited, after the primary winding is conducted for a period of time, K and K1 are closed, and K4 and K5 are simultaneously opened. By adjusting the duty ratio of the PWM, a stable voltage V2 is output; then, the voltage V2 passes through the BUCK-BOOST circuit, and finally outputs a relatively stable current, so as to charge the second cell 2.

The operation process is described above by taking charging and discharging of the first battery cell 1 and the second battery cell 2 as an example. The charging and discharging of other battery cells are consistent with the working modes of the first battery cell 1 and the second battery cell 2, and the description is omitted here.

Therefore, through different control of the first group of control units to the seventh group of control units, charging and discharging control of the gated electric core in the electric core group with odd or even arrangement sequence can be realized, energy balance processing between the gated electric core and the storage battery is realized, and the realization difficulty is low and the cost is low.

Alternatively, the two windings of the primary side of the transformer may comprise: a first winding and a second winding. The synonym end of the first winding is connected with the synonym end of the second winding, and the synonym end of the first winding are respectively connected to the positive electrode and the negative electrode of the storage battery. And a first group of control switches are arranged on the homonymous end lead of the first winding, and a second group of control switches are arranged on the heteronymous end lead of the second winding. The first group of control switches and the second group of control switches can be used for controlling the switching of the working states of the first winding and the second winding of the primary side of the transformer. Wherein a first set of control switches, such as control switches K and K1. A second set of control switches, such as control switches K2 and K3.

The first winding and the second winding are two independent windings, or the first winding and the second winding are two windings with a center tap and one winding divided by the center tap; for example: the primary side of the high-frequency transformer is provided with one winding and a center tap, and can also be two independent windings.

For example: the primary side of the high-frequency transformer is connected with a power switch tube, so that the energy conversion is realized, and the high-frequency transformer can be used for selecting and switching the positive polarity and the negative polarity of a storage battery. That is to say, in the scheme of the invention, in the aspect of battery cell charging and discharging, the primary side of the flyback transformer performs winding switching, and the primary side winding of the flyback transformer is switched to realize charging and discharging with the storage battery due to the uncertain voltage polarity of the bus, so that the transformer is simple in design.

And a third group of control switches are arranged on the homonymous end lead of the secondary side winding of the transformer. Wherein the third set of control switches, such as control switches K4 and K5.

For example: the primary side of the high-frequency transformer is a winding with a center tap, namely, the primary side is a flyback transformer with 2 windings and the secondary side is a winding. A control switch is arranged on a primary winding of the transformer, and bidirectional flow of energy can be realized by switching on or off. Such as: the control switches K, K1, K2, K3, K4, K5 and the like can be all power MOSFET tubes, power switch tubes such as IGBTs can also be adopted for replacement, and bidirectional flow of energy can be realized by controlling the on or off of the power switch tubes.

The power switch tubes K4 and K5 act simultaneously, and the power switch tubes K2 and K3 act simultaneously, namely the power switch tubes K4 and K5 are switched simultaneously, and the power switch tubes K2 and K3 are switched simultaneously. However, the power switches K4 and K5 and the power switches K2 and K3 cannot be turned on simultaneously, otherwise the circuit cannot work normally.

Therefore, the first group of control switches and the second group of control switches are respectively arranged on the two windings on the primary side of the transformer, and the third control switch is arranged on one winding on the secondary side of the transformer, so that the switching of the working state can be controlled and realized, the bidirectional control is further realized, the bidirectional energy balance control can be realized between the gated electric core and the storage battery, and the switching of the working state in the bidirectional control is more convenient and reliable.

Optionally, the bidirectional transformation unit may include: bidirectional BUCK-BOOST circuit. For example: the transformation unit may be a bidirectional BUCK-BOOST circuit, and the bidirectional BUCK-BOOST circuit may be disposed at a rear end of the secondary side of the transformer. A bidirectional BUCK-BOOST circuit is additionally arranged at the rear end of the secondary side of the high-frequency transformer, and constant-current charging and discharging of a battery cell can be achieved.

The bidirectional BUCK-BOOST circuit is provided with an inductor, a fourth group of control switches and a fifth group of control switches. The first end of the fourth group of control switches is connected with the first end of the fifth group of control switches, the second end of the fourth group of control switches is connected to the homonymous end of the secondary winding of the transformer, and the second end of the fifth group of control switches is respectively connected with the second terminal of the first side of the transformation unit and the synonym end of the secondary winding of the transformer. An inductance is connected between the first terminal of the first side of the varying unit and the first terminal of the fourth set of control switches.

Specifically, in the bidirectional BUCK-BOOST circuit, an inductor (e.g., inductor L), a fourth set of control switches (e.g., control switches K6 and K7), and a fifth set of control switches (e.g., control switches K8 and K9) are provided. K6, K7, K8, K9 are all power MOSFET tubes, can also adopt power switch tubes such as IGBT to replace, through controlling its turn-on or turn-off, can realize the two-way flow of energy. The first end of the fourth group of control switches is connected with the first end of the fifth group of control switches, the second end of the fourth group of control switches is connected to the homonymous end of the secondary winding of the transformer, and the second end of the fifth group of control switches is respectively connected with the second terminal of the first side of the transformation unit and the synonym end of the secondary winding of the transformer. An inductance is connected between the first terminal of the first side of the varying unit and the first terminal of the fourth set of control switches. An inductor L in the bidirectional BUCK-BOOST circuit is an energy storage element, and BUCK-BOOST power conversion is realized when the switching tube is switched on and off.

For example: the primary side of the high-frequency transformer is a winding with a center tap, namely, the primary side is a flyback transformer with 2 windings and the secondary side is a winding. In addition, a power switch tube is connected to the primary side of the high-frequency transformer, so that energy conversion is realized, and the high-frequency transformer can be used for selective switching of the positive polarity and the negative polarity of the storage battery, so that the high-frequency transformer forms a bidirectional flyback converter such as bidirectional flyback DC/DC. The bidirectional flyback converter is used for realizing bidirectional transmission of energy to realize balance, and a bidirectional half-bridge type BUCK-BOOST circuit is added behind the bidirectional flyback converter to realize constant-current charging and discharging of the battery cell. Namely, a BUCK-BOOST circuit is added in the topology to realize constant current control, so that the balance current of the battery cell is a constant value, and the service life of the battery cell is prolonged. Therefore, constant current control can be realized, and the service life of the battery cell is prolonged.

Therefore, constant current control can be realized by sampling the bidirectional BUCK-BOOST circuit, so that the balance current of the battery cell is a constant value, and the service life of the battery cell is prolonged.

In an alternative example, the electric core group may include: n single section electric cores, N single section electric core parallel arrangement, N is the natural number. The positive leads of the N single-section battery cells are connected to a first wiring terminal on the first side of the transformation unit, and the negative leads of the N single-section battery cells are connected to a second wiring terminal on the first side of the transformation unit.

Specifically, the selection unit may include: and the sixth group of control switches and the seventh group of control switches are respectively arranged on the positive lead and the negative lead of each section of battery cell, namely, the sixth group of control switches are arranged on the positive lead of each section of battery cell, and the seventh group of control switches are arranged on the negative lead of each section of battery cell. And adjacent stages in the positive and negative electrodes of two adjacent battery cells share one group of control switches.

Wherein, the selection unit is arranged between the electric core group and the first side of the transformation unit. In the electric core group, more than one electric core branch road sets up in parallel. Each battery cell branch is provided with a single battery cell, and a group of control switches are respectively arranged on the positive and negative leads of the battery cell. In the electric core group, the positive lead of each cell is connected to a first terminal such as a BUS1 terminal, and the negative lead of each cell is connected to a second terminal such as a BUS2 terminal.

For example: the sixth group of control switches disposed on the positive and negative leads of the first cell in the cell group, for example, the first cell 1, may be, for example, control switches Q1 and Q2, the seventh group of control switches may be, for example, control switches Q3 and Q4, the sixth group of control switches disposed on the positive and negative leads of the second cell in the cell group, for example, the second cell 2, may be, for example, control switches Q3 and Q4, the seventh group of control switches may be, for example, control switches Q5 and Q6, the sixth group of control switches disposed on the positive and negative leads of the third cell in the cell group, for example, the third cell 3, may be, for example, control switches Q5 and Q6, and the seventh group of control switches may be, for example, other control switches similar to control switches Q5 and Q6. Such as: the control switches such as power switching tubes Q1, Q2, Q3 and Q4 are all cell selection switches. For example: power switching tubes Q1, Q2 and Q3, Q4 on both sides of the first cell 1, power switching tubes Q3, Q4 and Q5, Q6 on both sides of the second cell 2, and so on.

If the power switching tubes Q1 and Q2 and the power switching tubes Q3 and Q4 on both sides of the first battery cell 1 are turned on simultaneously, the positive and negative electrodes of the first battery cell 1 are connected with the BUS1 and the BUS2, and then the first battery cell 1 is selected and connected into the active balancing circuit. Of course, if the power switching tubes Q3 and Q4 and the power switching tubes Q5 and Q6 on both sides of the second battery cell 2 are turned on at the same time, the second battery cell 2 is selected, and since the positive and negative electrodes of the second battery cell 2 are also connected with the BUS1 and the BUS2, at this time, the second battery cell 2 is selected and connected to the active balancing circuit. By analogy, each battery cell can be accessed to an active equalization circuit by determining whether the battery cell is selected through the on or off of the power switches on the two sides of the battery cell.

For example: the cells can be selected by selecting the switch array and then connected to the bus, the polarity of the voltage of the bus is indefinite, the voltage can be negative, the voltage can be positive, and energy conversion can be carried out between the flyback converter and the on-vehicle storage battery according to the position change of the selected cells. The battery cells are selected through the selection switch array, and no matter how many battery cells are balanced, the battery cells can be balanced only by one high-frequency transformer, so that the cost is greatly reduced. Therefore, the problem that one high-frequency transformer cannot complete balance of all the battery cores can be solved.

Therefore, the selection unit can be used for connecting the electric core group to the transformation unit after one path of electric core needing energy equalization processing in the electric core group is selected, so that the energy equalization processing of any electric core in the electric core group under the condition that the secondary side of the transformer is only provided with one winding, and the difficulty and the cost of the energy equalization processing of the electric core group are greatly reduced.

Alternatively, any one of the first, second, third, fourth, fifth, sixth and seventh sets of control switches may include: the switch comprises a first switch body, a second switch body, a first body diode and a second body diode.

The first body diode is arranged between the first control end and the second control end of the first switch body in parallel, and the second body diode is arranged between the first control end and the second control end of the second switch body in parallel; and in any group of control switches, the anode of the first body diode and the anode of the second body diode are oppositely arranged.

For example: because of the bi-directional energy flow and because of the MOSFET parasitic body diode (i.e., the MOSFET is provided with a parasitic body diode), the process of energy flowing automatically from the body diode can occur with a MOSFET and is not controllable. Therefore, the power switches on any one side of the two sides of each battery cell are connected in series by adopting the two power MOSFETs, and the problem of uncontrollable influence of energy flowing from the body diode caused by the parasitic body diode of the MOSFETs is solved.

Therefore, two switch bodies are arranged in any group of control switches, and the two switch bodies are respectively connected with a pair of body diodes in opposite directions in parallel, so that the problem of uncontrollable energy in bidirectional energy control can be avoided, and the reliability and safety of the bidirectional energy control are realized.

More optionally, any one of the first switch body and the second switch body may include: MOS tube, IGBT or relay.

For example: K. k1, K2, K3, K4, K5, K6, K7, K8 and K9 are all power MOSFET tubes, and power switch tubes such as IGBTs can be adopted for replacement. As another example: the battery cell selection switch can be a switch such as a MOSFET, an IGBT, a relay and the like.

Therefore, through the switches in various forms, the setting of any group of control switches can be more flexible and convenient, and the control switch can also be suitable for control occasions with various requirements.

In an alternative embodiment, the method may further include: and the voltage stabilizing and filtering unit. The number of the voltage stabilizing filter units is more than one, and the more than one voltage stabilizing filter units are arranged on one side of the primary side of the transformer, one side of the secondary side of the transformer and/or the first side of the conversion unit.

For example: the more than one voltage stabilizing filter unit may include: a capacitor C1, a capacitor C2, and/or a capacitor C3.

Therefore, the voltage stabilization and filtering processing of the voltage at the set position is facilitated through the voltage stabilization filtering unit, and the stability and the reliability of the voltage are improved.

Through a large number of tests, the technical scheme of the invention is adopted, and the number of windings on the secondary side of the high-frequency transformer is reduced by the flyback converter which enables the primary side of the high-frequency transformer to be provided with two windings and the secondary side of the high-frequency transformer to be provided with one winding, so that the windings of the high-frequency transformer can be obviously reduced, and the realization difficulty of the high-frequency transformer is correspondingly reduced.

According to an embodiment of the invention, a battery system corresponding to the energy balance control device is also provided. The battery system may include: the energy balance control device is described above.

Because the battery is composed of a plurality of single battery cores connected in series and in parallel, the service life of the battery is closely related to each battery core. As batteries operate for a long time, the problem of inconsistency among a plurality of single battery cells in the batteries becomes more serious, and the service life of the whole batteries such as power batteries is greatly reduced over time. However, the best solution to the problem of non-uniformity among the individual cells in a battery is to find new materials that are more durable and consistent. But material innovation is very difficult. Therefore, measures are needed to improve the consistency of the battery cell, and the balancing technology is natural.

The equalization technology is divided into active equalization and passive equalization, and the passive equalization is used for supplementing the energy consumed by the battery of the high-voltage battery cell so as to reduce the voltage; however, the low-voltage battery cell cannot be supplemented, so that the limitation of passive balance is large and the efficiency is low. And active equalization can realize equalization of high and low voltage battery cells, and has lower power consumption and high efficiency. Therefore, the active equalization technology can well solve the problem of inconsistency of a plurality of single battery cells in the battery and prolong the service life of the battery. Such as a bidirectional flyback converter, may be used as a circuit topology to solve active equalization.

The active equalization is to equalize multiple electric cores, and the electric cores need to be selected during each equalization, so that a switch needs to be selected, the electric cores needing to be equalized need to be selected, and the DC/DC high-frequency transformer is matched to realize energy conversion.

Fig. 2 is a schematic structural diagram of an active equalization topology.

As shown in fig. 2, in an active equalization topology, it is obvious that the primary side of the transformer in the topology is a winding, and the secondary side of the transformer has N windings, and if the number of cells is increased, the number of secondary windings of the high-frequency transformer is also increased. Where N represents the number of the battery cells, and is a natural number, such as the first battery cell 1, the second battery cell 2, … …, the N-1 battery cell N-1, the N-1 battery cell N, and the like.

In fig. 2, a first battery cell 1, a second battery cell 2, … …, an N-1 battery cell N-1, and an N battery cell N are single battery cells in a power PACK (PACK), balancing is designed for these battery cells, and power switching tubes such as Q1 and Q2 may be used to select the battery cells that need balancing. The primary side of the high-frequency transformer is provided with one winding, and the corresponding secondary side is provided with a plurality of windings. If the cell voltage of the secondary side is low, the secondary side is charged by the storage battery; otherwise, the battery cell charges the storage battery.

In an alternative embodiment, at least to solve the problem of more secondary windings of the transformer, such as the problem of the secondary windings of the high-frequency transformer increasing with the increase of the number of the battery cells, the scheme of the present invention provides a BMS active equalization topology, i.e., an active equalization topology is designed to make the structure of the active equalization DC/DC high-frequency transformer simpler.

Specifically, in the scheme of the invention, a new active equalization topology is designed, and the primary side of the high-frequency transformer of the topology is a winding with a center tap, namely, a flyback transformer with 2 windings on the primary side and one winding on the secondary side, so that the number of windings of the high-frequency transformer can be obviously reduced, and the problem of more windings on the secondary side of the transformer can be at least solved.

The winding of the high-frequency transformer can be obviously reduced, so that the problems of difficult manufacture, high cost and large volume of the transformer caused by a plurality of windings can be solved, the manufacture cost and the volume of the transformer are greatly reduced, the manufacture is easy, the automatic production can be realized, and the efficiency is high.

In addition, because the windings are reduced, the magnetic coupling between the windings is favorably enhanced, the leakage inductance is greatly reduced, the problems of unstable topology work and low power efficiency caused by large leakage inductance of the transformer can be solved, the stability and the reliability of the topology work are improved, and the power conversion efficiency is greatly improved.

Further alternatively, in the solution of the present invention, the cells may be selected by selecting the switch array and then connected to the bus, and the polarity of the bus voltage is not fixed, may be negative, and may be positive, and according to the selected cell position change, the energy conversion is performed with the on-vehicle storage battery through the flyback converter. The battery cells are selected through the selection switch array, and no matter how many battery cells are balanced, the battery cells can be balanced only by one high-frequency transformer, so that the cost is greatly reduced. Therefore, the problem that one high-frequency transformer cannot complete balance of all the battery cores can be solved.

Further optionally, in the scheme of the invention, a power switching tube is connected to the primary side of the high-frequency transformer, so that not only is energy conversion realized, but also the power switching tube can be used for selecting and switching the positive polarity and the negative polarity of the storage battery. That is to say, in the scheme of the invention, in the aspect of battery cell charging and discharging, the primary side of the flyback transformer performs winding switching, and the primary side winding of the flyback transformer is switched to realize charging and discharging with the storage battery due to the uncertain voltage polarity of the bus, so that the transformer is simple in design.

Further optionally, in the scheme of the invention, not only the bidirectional flyback converter is used for realizing bidirectional transmission of energy to realize balance, but also a bidirectional half-bridge type BUCK-BOOST circuit is added behind the bidirectional flyback converter to realize constant-current charging and discharging of the battery cell. Namely, a BUCK-BOOST circuit is added in the topology to realize constant current control, so that the balance current of the battery cell is a constant value, and the service life of the battery cell is prolonged. Therefore, constant current control can be realized, and the service life of the battery cell is prolonged.

Fig. 3 is a schematic structural diagram of an active equalization topology of an embodiment of a battery system of the present invention.

In fig. 3, K, K1, K2, K3, K4, K5, K6, K7, K8, and K9 are all power MOSFET transistors, or power switching transistors such as IGBTs may be used instead, and by controlling the on or off of the power switching transistors, bidirectional flow of energy may be realized. The inductor L is an energy storage element, and when the switch tube is switched on and off, BUCK-BOOST power conversion is realized. The primary side of the high-frequency transformer is provided with one winding and a center tap, and can also be two independent windings. Compared with the transformer in the figure 2, the winding of the transformer in the figure 3 is reduced, the volume is reduced, the cost is reduced, the indirect PCB is also reduced, the volume of the controller is reduced, and the product can be produced in a quantized mode; in addition, in fig. 3, a bidirectional BUCK-BOOST circuit is added at the rear end of the secondary side of the high-frequency transformer, so that constant-current charging and discharging of the battery cell can be realized.

The BUCK-BOOST power conversion circuit is a BUCK-BOOST circuit. The BUCK circuit refers to a single tube with output voltage lower than input voltage and without isolation of direct current conversion. BOOST refers to single-tube non-isolated dc conversion with output voltage higher than input voltage.

Fig. 4 is a schematic structural diagram of a cell selection switch array according to an embodiment of the battery system of the present invention.

In fig. 4, power switching tubes Q1, Q2, Q3, Q4, and the like are all cell selection switches. For example: power switching tubes Q1, Q2 and Q3, Q4 on both sides of the first cell 1, power switching tubes Q3, Q4 and Q5, Q6 on both sides of the second cell 2, and so on.

Optionally, the cell selection switch may be a switch such as a MOSFET, an IGBT, or a relay.

Optionally, if the power switching tubes Q1 and Q2 and the power switching tubes Q3 and Q4 on the two sides of the first battery cell 1 are turned on simultaneously, since the positive and negative electrodes of the first battery cell 1 are connected to the BUS1 and the BUS2, then the first battery cell 1 is selected and connected to the active equalization circuit. Of course, if the power switching tubes Q3 and Q4 and the power switching tubes Q5 and Q6 on both sides of the second battery cell 2 are turned on at the same time, the second battery cell 2 is selected, and since the positive and negative electrodes of the second battery cell 2 are also connected with the BUS1 and the BUS2, at this time, the second battery cell 2 is selected and connected to the active balancing circuit. By analogy, each battery cell can be accessed to an active equalization circuit by determining whether the battery cell is selected through the on or off of the power switches on the two sides of the battery cell.

However, because of the bidirectional energy flow, and because of the MOSFET parasitic body diode (i.e., the MOSFET is provided with a parasitic body diode), if one MOSFET is used, the process of energy flowing automatically from the body diode occurs, which is not controllable. Therefore, the power switches on any one side of the two sides of each battery cell are connected in series by adopting the two power MOSFETs, and the problem of uncontrollable influence of energy flowing from the body diode caused by the parasitic body diode of the MOSFETs is solved.

Fig. 5 is a schematic diagram illustrating an operation process of the discharging flyback converter of the first battery cell 1 according to an embodiment of the battery system of the present invention. Fig. 6 is a schematic diagram illustrating an operation process of a second battery cell 2 discharging flyback converter according to an embodiment of the battery system of the present invention.

In fig. 5 and 6, the dotted line represents the power switch tube operation, and the solid line represents the power switch tube non-operation, i.e., the power switch tube is always in the off state.

Therefore, the scheme of the invention can realize active balance by exchanging energy between the 24V storage battery on the electric vehicle and the battery cells in the battery cell group. And the exchange or conversion of energy is realized by a transformer. Wherein, the effect of transformer: firstly, the isolation function is realized; the second is energy conversion and is bidirectional. That is, if the voltage of the battery cell is too high, the energy of the battery cell is required to be transmitted to the storage battery, that is, the battery cell discharges; on the contrary, if the voltage of the battery cell is too low, or if the voltage of the battery is too high, the energy of the battery is required to be transferred to the battery cell direction, that is, the battery cell is charged.

Specifically, referring to the examples shown in fig. 3 to fig. 6, in the scheme of the present invention, the following exemplary descriptions may be referred to for a process of implementing bidirectional energy conversion between the storage battery and the battery cell.

In an alternative specific example, if the voltage of the first battery cell 1 is too high, discharge equalization is required.

The controller sends out a command, so that the selection switches on two sides of the first battery cell 1, such as power tubes or switching tubes Q1, Q2, Q3 and Q4, are simultaneously turned on, at this time, the first terminal BUS1 is connected with the positive electrode of the first battery cell 1, and the second terminal BUS2 is connected with the negative electrode of the first battery cell 1.

Thereafter, the BUSs (i.e., first terminal BUS1, second terminal BUS2) are coupled to the bidirectional BUCK-BOOST circuit. First, when the first cell 1 is discharged, the BUCK-BOOST operates in the BOOST mode, so that the output voltage of the inverter is higher than the voltage of the first cell 1. The output voltage of the converter is V1, namely, the voltage drop across the capacitor C2 is V1, and the voltage is positive, negative and up.

And (3) boosting: and controlling the conduction time T of the power tubes K6 and K7, charging the inductor L for T, and then disconnecting the power tubes K6 and K7, wherein the inductance induction voltage of the inductor L is left negative and right positive. The output voltage of the converter is equal to the voltage of the inductor L plus the voltage of the first cell 1, and therefore is a boost circuit.

The voltage generated by boosting is connected to the bidirectional flyback converter, firstly, the power tubes K4 and K5 are conducted for a time T1, and the conduction voltage drop is neglected, so that the dotted end (as a black point in fig. 3, 5 and 6) of the secondary side of the high-frequency transformer is a positive electrode, and the other end is a negative electrode. Current flows from the same-name end to excite the secondary winding, then the power tubes K4 and K5 are turned off, the direction of induced voltage of the secondary winding is up-negative and down-positive, the polarity of the primary-side same-name end is negative, the other end is positive, and after the power tubes K4 and K5 are turned off, the switching tubes K3 and K2 must be controlled to be conducted (for example, the switching tubes K3 and K2 can be conducted by enabling the MCU to send out high-frequency PWM waves), and the storage battery is charged. And finally, the energy of the first battery cell 1 is transferred to the storage battery, the voltage of the first battery cell 1 is reduced, and the aim of balancing is fulfilled.

Optionally, if the voltage of the first battery cell 1 is too low, a storage battery is required to charge the first battery cell 1.

First, the selection switches on both sides of the first battery cell 1, such as the power transistors Q1 and Q2, Q3, and Q4, are turned on, so that the first battery cell 1 is connected to the equalization circuit. Since the end of the same name connected to the secondary winding of the first cell 1 is positive, when charging the first cell 1, the switching tubes K2 and K3 on the primary side need to be closed. The MCU sends out high level to control the switching tubes K2 and K3 to be conducted, at the moment, the primary winding is excited, after the primary winding is conducted for a period of time, the switching tubes K2 and K3 are closed, and meanwhile, the switching tubes K4 and K5 are opened. By adjusting the duty ratio of the PWM, a stable voltage V1 is output; then, the voltage V1 passes through the BUCK-BOOST circuit, and finally outputs a relatively stable current, so as to charge the first cell 1.

In an alternative specific example, if the voltage of the second battery cell 2 is too high, the battery needs to be discharged. As shown in fig. 4, the MCU sends out a control signal to turn on the switching tubes Q3 and Q4, Q5, and Q6, and selects the second cell 2 to be connected to the circuit. Different from the discharge of the first battery cell 1, after passing through the BUCK-BOOST circuit, the generated voltage V2 is generated, and the voltage values of V2 and V1 are the same and have opposite polarities, that is, the same-name end of the secondary side of the access transformer is a negative electrode, and the other end of the secondary side of the access transformer is a positive electrode. MCU sends signal control switch tube K4 and K5 and switches on simultaneously, at this moment, the negative pole of second electric core 2 is connected with the vice limit synonym end of transformer, the other end is connected to the positive pole, when switch tube K4 and K5 disconnection, the voltage that the vice limit winding produced is upper and lower burden, must switch on switch tube K1 and K this moment, make the energy transfer of vice limit primary side, through adjusting switch tube K, K1, K4, the PWM ripples duty cycle of K5, second electric core 2 accomplishes the discharge to the battery, realize balanced control.

Optionally, if the voltage of the second battery cell 2 is too low, the storage battery is required to charge the second battery cell. First, the cell selection switches Q3, Q4, Q5, and Q6 are turned on, so that the cells are connected to the equalization circuit. Since the end of the same name connected to the secondary winding of the second cell 2 is the negative electrode, when charging the second cell 2, the switching tubes K and K1 on the primary side need to be closed. The MCU sends out high level to control the switch tubes K and K1 to be conducted, at the moment, the primary winding is excited, after the primary winding is conducted for a period of time, K and K1 are closed, and K4 and K5 are simultaneously opened. By adjusting the duty ratio of the PWM, a stable voltage V2 is output; then, the voltage V2 passes through the BUCK-BOOST circuit, and finally outputs a relatively stable current, so as to charge the second cell 2.

Since the processes and functions implemented by the battery system of this embodiment substantially correspond to the embodiments, principles, and examples of the apparatus shown in fig. 1, reference may be made to the related descriptions in the foregoing embodiments without being detailed in the description of this embodiment.

Through a large number of tests, the technical scheme of the invention is adopted, and the number of windings on the secondary side of the high-frequency transformer is reduced by the flyback converter which enables the primary side of the high-frequency transformer to be two windings and the secondary side of the high-frequency transformer to be one winding, so that the volume of the transformer can be reduced, and the implementation cost of the transformer can be reduced.

According to an embodiment of the present invention, there is also provided an energy balance control method for a battery system corresponding to the battery system, as shown in fig. 7, which is a schematic flow chart of an embodiment of the method of the present invention. The energy balance control method of the battery system may include: step S110 to step S130.

In step S110, by the selection unit, in an energy balance control process, one path of the electric cells in the electric cell group that needs to be subjected to the energy balance control is gated. For example: and selecting any electric core in the electric core group, and opening a connecting passage between the selected electric core and the first side of the transformation unit so as to realize gating or switching-off control between any electric core in the electric core group and the first side of the transformation unit.

In step S120, a first energy conversion process in an energy balance control process between the gated one of the battery cells and the storage battery is implemented through the conversion unit based on the gated one of the battery cells. The first energy conversion process may include: and the first energy conversion processing is carried out between the one path of the battery cell arranged on the first side of the conversion unit and the second side of the conversion unit. The first side of the conversion unit is communicated with the selection unit, and the second side of the conversion unit is communicated with the secondary side of the transformer.

In step S130, a second energy conversion process in an energy balance control process between the gated one of the battery cells and the battery is implemented by the transformer. The second energy conversion process may include: and a second energy conversion process between the second side of the conversion unit arranged on the secondary side of the transformer and the storage battery arranged on the primary side of the transformer. The storage battery is arranged on the primary side of the transformer, and the secondary side of the transformer is arranged on the second side of the conversion unit.

An energy balancing process between the gated one-way battery cell and the storage battery may include: the bidirectional energy balancing process between the selected one-way battery core and the battery specifically may include: and a bidirectional process of bidirectional energy balance in the discharging control process or the charging control process of the gated one path of battery cell. Specifically, the method may include: under the condition that the voltage of one path of gated battery cell is higher than the set voltage, one path of gated battery cell charges the storage battery so as to realize the discharging process of discharging; and under the condition that the voltage of the gated electric core is lower than the set voltage, the gated electric core is charged from the storage battery, so that the charging process is realized.

Optionally, when the voltage of the gated one of the battery cells is higher than the set voltage, the gated one of the battery cells charges the storage battery to implement a discharging process, which may include: the one path of gated battery cells is a first discharge process in which the battery cells arranged in the odd number in the battery cell group discharge to the storage battery, or the one path of gated battery cells is a second discharge process in which the battery cells arranged in the even number in the battery cell group discharge to the storage battery, which may be specifically referred to as an exemplary description in any one of the following discharge situations.

First discharge case: the gated battery cells are the first discharging process that the battery cells arranged in the odd number in the battery cell group discharge to the storage battery.

With reference to the flow chart of an embodiment of a first discharging process in which cells arranged in an odd number in the cell core group are discharged to the storage battery in one path of cell gating in the method of the present invention shown in fig. 8, further explaining a specific process in which cells arranged in an odd number in the cell core group are discharged to the storage battery in one path of cell gating, which may include: step S210 to step S230.

Step S210, if one of the gated electric cores is an electric core in the electric core group with an odd number of arrangement sequences, such as the first electric core 1, the third electric core 3, and the like, under the condition that a discharge instruction is received, controlling the fifth group of control switches and the sixth group of control switches on the positive and negative leads of the electric core to be simultaneously turned on, so that the positive and negative electrodes of the electric core are respectively connected to the first terminal and the second terminal on the first side of the transformation unit.

Step S220, controlling the converting unit to be in a voltage boosting state, and in the voltage boosting process, controlling a fourth group of control switches in the converting unit to be turned on for a set time, such as an on time T, to charge an inductor in the converting unit, so that the converting unit outputs a first voltage which is positive, negative, and up after the converting unit realizes the voltage boosting process. The first voltage is the sum of the voltage of the battery cell and the voltage of the inductor in the conversion unit.

And step S230, turning on a third group of control switches on the homonymous end outgoing line of the secondary winding of the transformer for a set time, turning off the third group of control switches, turning on a second group of control switches on the heteronymous end outgoing line of the secondary winding of the transformer, and controlling the second group of control switches to be turned on to charge the storage battery at the second winding of the primary winding of the transformer by the battery cell if the third group of control switches is turned on for T1.

The second discharge case: and the gated electric cores are the second discharging process that the electric cores arranged in the electric core group in an even number are discharged to the storage battery.

With reference to the flow chart of an embodiment of the second discharging process in which the cells arranged in the even number in the cell core group are discharged to the storage battery in the one path of cells gated in the method of the present invention shown in fig. 9, further description is given to a specific process in which the cells arranged in the even number in the cell core group are discharged to the storage battery in the one path of cells gated in the method of the present invention, which may include: step S310 to step S330.

Step S310, if one of the gated electric cores is an electric core in the electric core group, such as the second electric core 2 and the fourth electric core 4, which are arranged in an even order, under the condition of receiving a discharge instruction, controlling the fifth group of control switches and the sixth group of control switches on the positive and negative leads of the electric core to be simultaneously turned on, so that the positive and negative electrodes of the electric core are respectively connected to the first terminal and the second terminal on the first side of the transformation unit.

And step S320, controlling the conversion unit to be in a boosting state, and controlling a fourth group of control switches in the conversion unit to be switched on for a set time length, such as switching-on time T, in the boosting process so as to charge an inductor in the conversion unit, so that the conversion unit outputs a second voltage which is positive, negative and positive. The second voltage is the sum of the voltage of the battery cell and the voltage of the inductor in the conversion unit.

And step S330, turning on a third group of control switches on the homonymous end outgoing line of the secondary winding of the control transformer for a set time, turning off the third group of control switches if the third group of control switches is turned on for T1, and then turning on a first group of control switches on the homonymous end outgoing line of the primary winding of the control transformer to charge the storage battery at the primary winding of the control transformer by the battery cell.

Optionally, when the voltage of the gated one of the cells is lower than the set voltage, the gated one of the cells is charged from the battery, so as to implement a charging process of charging, which may include: the one-way gated battery cell is a first charging process in which the battery cells arranged in the odd number in the battery cell group charge the storage battery, or the one-way gated battery cell is a second charging process in which the battery cells arranged in the even number in the battery cell group charge the storage battery, which can be specifically referred to as an exemplary description in any one of the following charging situations.

First charging situation: the gated battery cells are the first charging process of charging the storage battery by the battery cells arranged in the odd number in the battery cell group.

With reference to the flow chart of an embodiment of the first charging process in which the cells arranged in the odd number in the cell core group charge the storage battery, the cell of the first path gated in the method of the present invention shown in fig. 10 further illustrates that the cell of the first path gated in the cell core group is a specific process of the first charging process in which the cells arranged in the odd number in the cell core group charge the storage battery, and the specific process may include: step S410 and step S420.

Step S410, if one of the gated electric cores is an electric core in the electric core group, such as the first electric core 1, the third electric core 3, and the like, the fifth group of control switches and the sixth group of control switches on the positive and negative leads of the electric core are controlled to be simultaneously turned on under the condition that the charging instruction is received, so that the positive and negative electrodes of the electric core are respectively connected to the first terminal and the second terminal on the first side of the transformation unit.

Step S420, turning on a second group of control switches on the different-name-end outgoing line of the second winding on the primary side of the transformer for a set time period, and turning on a third group of control switches on the same-name-end outgoing line of the winding on the secondary side of the transformer, so that the winding on the secondary side of the transformer outputs a third voltage, and then charging the battery cell after voltage reduction processing by the conversion unit.

The second charging scenario: and the gated electric cores are the second charging process of charging the storage battery by the electric cores arranged in the electric core group in an even number.

With reference to the flow chart of an embodiment of the second charging process in which the cells that are arranged in the even number in the cell core group charge the storage battery, the cell of the first path gated in the method of the present invention shown in fig. 11 further describes that the cell of the first path gated is a specific process of the second charging process in which the cells that are arranged in the even number in the cell core group charge the storage battery, and the specific process may include: step S510 and step S520.

Step S510, if one of the gated electric cores is an electric core in the electric core group, such as the second electric core 2 and the fourth electric core 4, which are arranged in an even order, under the condition of receiving the charging instruction, controlling the fifth group of control switches and the sixth group of control switches on the positive and negative leads of the electric core to be simultaneously turned on, so that the positive and negative electrodes of the electric core are respectively connected to the first terminal and the second terminal on the first side of the transformation unit.

Step S520, a first group of control switches on the homonymous end outgoing line of the first winding on the primary side of the transformer are controlled to be turned off after being turned on for a set time, and a third group of control switches on the homonymous end outgoing line of the winding on the secondary side of the transformer are controlled to be turned on, so that the winding on the secondary side of the transformer outputs a fourth voltage, and the fourth voltage is charged to the battery cell after being subjected to voltage reduction processing by the conversion unit.

Since the processes and functions implemented by the method of the present embodiment substantially correspond to the embodiments, principles and examples of the battery system, reference may be made to the related descriptions in the foregoing embodiments without being detailed in the description of the present embodiment.

Through a large number of tests, the technical scheme of the embodiment is adopted, and the flyback converter which enables the primary side of the high-frequency transformer to be provided with two windings and the secondary side of the high-frequency transformer to be provided with one winding is adopted, so that the number of the windings of the secondary side of the high-frequency transformer is reduced, the magnetic coupling between the windings is enhanced, the leakage inductance is greatly reduced, the stability and the reliability of topological work can be improved, and the power conversion efficiency is greatly improved.

In summary, it is readily understood by those skilled in the art that the advantageous modes described above can be freely combined and superimposed without conflict.

The above description is only an example of the present invention, and is not intended to limit the present invention, and it is obvious to those skilled in the art that various modifications and variations can be made in the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. An energy balance control apparatus, comprising: the transformer comprises a transformer, a transformation unit and a selection unit, wherein a winding is arranged on the secondary side of the transformer; wherein the content of the first and second substances,

the selection unit is used for gating one path of electric core which needs energy balance control in the electric core group;

the transformation unit is used for realizing a first energy transformation process between the gated battery cell and the storage battery; the first energy conversion process, comprising: the first energy conversion processing is carried out between the one path of the battery cell arranged on the first side of the conversion unit and the second side of the conversion unit;

the transformer is used for realizing a second energy conversion process between one path of gated battery cell and the storage battery; the second energy conversion process, comprising: a second energy conversion process between a second side of the conversion unit arranged on the secondary side of the transformer and a storage battery arranged on the primary side of the transformer;

the first energy conversion process and the second energy conversion process form an energy balance process between the gated electric core and the storage battery.

2. The energy balance control device according to claim 1, wherein the primary side of the transformer is provided with two windings;

a transformation unit which is a bidirectional transformation unit;

an energy balancing process between a gated cell and a battery, comprising: the two-way energy balance process between the electric core of the way of selecting for use and the battery, this two-way energy balance process specifically includes:

under the condition that the voltage of one path of gated battery cell is higher than the set voltage, one path of gated battery cell charges the storage battery so as to realize the discharging process of discharging;

and under the condition that the voltage of the gated electric core is lower than the set voltage, the gated electric core is charged from the storage battery, so that the charging process is realized.

3. The energy balance control device according to claim 2, wherein the two windings of the primary side of the transformer comprise: a first winding and a second winding; the synonym end of the first winding is connected with the synonym end of the second winding, and the synonym end of the first winding are respectively connected to the anode and the cathode of the storage battery; a first group of control switches are arranged on the homonymous end lead of the first winding, and a second group of control switches are arranged on the heteronymous end lead of the second winding; the first group of control switches and the second group of control switches are used for controlling the switching of the working states of a first winding and a second winding of a primary side of the transformer;

the first winding and the second winding are two independent windings, or the first winding and the second winding are two windings with a center tap and one winding divided by the center tap;

and a third group of control switches are arranged on the homonymous end lead of the secondary side winding of the transformer.

4. The energy balance control device according to claim 2, wherein the bidirectional conversion unit includes: a bidirectional BUCK-BOOST circuit;

the bidirectional BUCK-BOOST circuit is provided with an inductor, a fourth group of control switches and a fifth group of control switches; the first end of the fourth group of control switches is connected with the first end of the fifth group of control switches, the second end of the fourth group of control switches is connected to the homonymous end of the secondary winding of the transformer, and the second end of the fifth group of control switches is respectively connected with the second terminal of the first side of the transformation unit and the synonym end of the secondary winding of the transformer; an inductance is connected between the first terminal of the first side of the varying unit and the first terminal of the fourth set of control switches.

5. The energy balance control device according to any one of claims 1 to 4, wherein the electric core group comprises: the battery comprises N single-section battery cores, wherein the N single-section battery cores are arranged in parallel, and N is a natural number; the positive leads of the N single-section battery cells are connected to a first wiring terminal on the first side of the transformation unit, and the negative leads of the N single-section battery cells are connected to a second wiring terminal on the first side of the transformation unit;

a selection unit comprising: the sixth group of control switches are arranged on the positive lead of each battery cell, and the seventh group of control switches are arranged on the negative lead of each battery cell; and adjacent stages in the positive and negative electrodes of two adjacent battery cells share one group of control switches.

6. The energy balance control device of claim 5 wherein any one of the first set of control switches, the second set of control switches, the third set of control switches, the fourth set of control switches, the fifth set of control switches, the sixth set of control switches, and the seventh set of control switches comprises: a first switch body, a second switch body, a first body diode and a second body diode; wherein the content of the first and second substances,

7. The energy balance control device according to claim 6, wherein any one of the first switch body and the second switch body comprises: MOS tube, IGBT or relay.

8. The energy balance control device according to any one of claims 1 to 4, characterized by further comprising: a voltage stabilizing and filtering unit; the number of the voltage stabilizing filter units is more than one, and the more than one voltage stabilizing filter units are arranged on one side of the primary side of the transformer, one side of the secondary side of the transformer and/or the first side of the conversion unit.

9. The energy balance control device according to claim 2, wherein the gated one of the cells charges the battery to realize a discharging process of discharging, and the discharging process comprises:

if the gated electric core is the electric core with odd-numbered arrangement sequence in the electric core group, under the condition of receiving a discharge instruction, controlling a fifth group of control switches and a sixth group of control switches on the positive and negative leads of the electric core to be simultaneously switched on so as to enable the positive and negative electrodes of the electric core to be respectively connected to a first terminal and a second terminal on the first side of the transformation unit;

controlling a fourth group of control switches in the conversion unit to be turned on for a set time to charge an inductor in the conversion unit, so that the conversion unit outputs a first voltage which is positive and negative up and down after the conversion unit realizes boosting processing; the first voltage is the sum of the voltage of the battery cell and the voltage of an inductor in the conversion unit;

and a third group of control switches on the homonymous end outgoing line of the secondary winding of the control transformer are turned on for a set time and then turned off, and a second group of control switches on the heteronymous end outgoing line of the secondary winding of the primary winding of the control transformer are turned on, so that the battery cell charges a storage battery at the secondary winding of the primary winding of the control transformer.

10. The energy balance control device according to claim 2, wherein the gated one of the cells charges the battery to realize a discharging process of discharging, further comprising:

if the gated electric core in one path is the electric core with an even number of arrangement sequence in the electric core group, under the condition of receiving a discharge instruction, controlling a fifth group of control switches and a sixth group of control switches on the positive and negative leads of the electric core to be simultaneously switched on so as to enable the positive and negative electrodes of the electric core to be respectively connected to a first terminal and a second terminal on the first side of the transformation unit;

controlling a fourth group of control switches in the conversion unit to be turned on for a set time to charge an inductor in the conversion unit, so that the conversion unit outputs a second voltage with a positive upper voltage, a negative lower voltage and a positive lower voltage after the conversion unit realizes boosting processing; the second voltage is the sum of the voltage of the battery cell and the voltage of an inductor in the conversion unit;

and a third group of control switches on the homonymous end outgoing line of the winding on the secondary side of the control transformer are turned on for a set time and then turned off, and a first group of control switches on the homonymous end outgoing line of the first winding on the primary side of the control transformer are controlled to be turned on, so that the battery cell charges a storage battery at the first winding on the primary side of the control transformer.

11. The energy balance control device according to claim 2, wherein the gated one of the cells is charged from the battery to realize a charging process of charging, and the charging process includes:

if the gated electric core is the electric core with odd-numbered arrangement sequence in the electric core group, under the condition of receiving a charging instruction, controlling a fifth group of control switches and a sixth group of control switches on the positive and negative leads of the electric core to be simultaneously switched on so as to enable the positive and negative electrodes of the electric core to be respectively connected to a first terminal and a second terminal of the first side of the transformation unit;

and a second group of control switches on the different-name end outgoing line of the second winding on the primary side of the control transformer are turned off after being turned on for a set time, and a third group of control switches on the same-name end outgoing line of the winding on the secondary side of the control transformer are turned on, so that the winding on the secondary side of the control transformer outputs a third voltage, and the third voltage is charged to the battery cell after being subjected to voltage reduction processing by the conversion unit.

12. The energy balance control device according to claim 2, wherein the gated one of the cells is charged from the battery to realize a charging process of charging, and the charging process includes:

if the gated electric core in one path is the electric core with an even number of arrangement sequence in the electric core group, under the condition of receiving a charging instruction, controlling a fifth group of control switches and a sixth group of control switches on the positive and negative leads of the electric core to be simultaneously switched on so as to enable the positive and negative electrodes of the electric core to be respectively connected to a first terminal and a second terminal on the first side of the transformation unit;

and a first group of control switches on the homonymous end outgoing line of the first winding on the primary side of the control transformer are turned off after being turned on for a set time, and a third group of control switches on the homonymous end outgoing line of the winding on the secondary side of the control transformer are turned on, so that the winding on the secondary side of the control transformer outputs a fourth voltage, and the fourth voltage is charged to the battery cell after being subjected to voltage reduction processing by the conversion unit.

13. A battery system, comprising: an energy balance control apparatus as claimed in any one of claims 1 to 12.

14. A method for controlling energy balance of a battery system according to claim 13, comprising:

selecting one path of electric core needing energy balance control in the electric core group through a selection unit;

a first energy conversion process between one path of gated battery cell and the storage battery is realized through a conversion unit; the first energy conversion process, comprising: the first energy conversion processing is carried out between the one path of the battery cell arranged on the first side of the conversion unit and the second side of the conversion unit;

a second energy conversion process between one path of gated battery cell and the storage battery is realized through a transformer; the second energy conversion process, comprising: a second energy conversion process between a second side of the conversion unit arranged on the secondary side of the transformer and a storage battery arranged on the primary side of the transformer;

15. The energy balance control method according to claim 14, wherein an energy balance process between the gated one of the cells and the battery includes: the two-way energy balance process between the electric core of the way of selecting for use and the battery, this two-way energy balance process specifically includes:

16. The energy balance control method according to claim 15, wherein the discharging process of charging the battery by the gated one of the cells to realize discharging comprises:

17. The energy balance control method according to claim 15, wherein the gated one of the cells charges the battery to realize a discharging process of discharging, further comprising:

18. The energy balance control method according to claim 15, wherein the gated one of the cells is charged from the battery to realize a charging process of charging, and the charging process includes:

19. The energy balance control method according to claim 15, wherein the gated one of the cells is charged from the battery to realize a charging process of charging, and the charging process includes: