CN113097992B - Droop control method and device for direct-current micro-grid and computer storage medium - Google Patents
Droop control method and device for direct-current micro-grid and computer storage medium Download PDFInfo
- Publication number
- CN113097992B CN113097992B CN202110469819.2A CN202110469819A CN113097992B CN 113097992 B CN113097992 B CN 113097992B CN 202110469819 A CN202110469819 A CN 202110469819A CN 113097992 B CN113097992 B CN 113097992B
- Authority
- CN
- China
- Prior art keywords
- energy storage
- storage unit
- current
- value
- soc
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J1/00—Circuit arrangements for dc mains or dc distribution networks
- H02J1/10—Parallel operation of dc sources
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
- H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
- H02J7/00302—Overcharge protection
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
- H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
- H02J7/00306—Overdischarge protection
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
- H02J7/0047—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with monitoring or indicating devices or circuits
- H02J7/0048—Detection of remaining charge capacity or state of charge [SOC]
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
- H02J7/007—Regulation of charging or discharging current or voltage
- H02J7/00712—Regulation of charging or discharging current or voltage the cycle being controlled or terminated in response to electric parameters
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Charge And Discharge Circuits For Batteries Or The Like (AREA)
- Secondary Cells (AREA)
Abstract
The invention relates to a droop control method, a droop control device and a computer storage medium for a direct-current micro-grid, wherein the droop control method for the direct-current micro-grid comprises the following steps: acquiring a first output current value of a converter corresponding to a current energy storage unit in real time, and acquiring a first charge state value of the current energy storage unit at the same time; calculating to obtain a first droop coefficient corresponding to the current energy storage unit according to the first output current value and the first state of charge value; carrying out droop control on the current energy storage unit according to the first droop coefficient; and respectively calculating a corresponding first droop coefficient for each energy storage unit of the direct current microgrid by adopting the steps, and performing droop control. By means of the method, the size of the droop coefficient is changed in real time according to the charge state value of the current energy storage unit, the charge state values of the energy storage units are finally balanced, and the problems of over-charging and over-discharging of the energy storage units and unbalance of the charge state values are avoided.
Description
Technical Field
The invention relates to the technical field of direct-current micro-grid energy storage, in particular to a droop control method and device for a direct-current micro-grid and a computer storage medium.
Background
In recent years, the concept of a dc microgrid which is composed of a distributed power supply such as photovoltaic and fan, an energy storage system, ac/dc loads, a converter connected with an ac power grid and a control system has been proposed. The direct-current micro-grid only has a balance relation between direct-current bus voltage and active power, and the fluctuation condition of the bus voltage reflects the power balance relation in the system, so that the aim of inhibiting the bus fluctuation is fulfilled by applying reasonable control on an energy storage system. The parallel energy storage unit power distribution method generally adopts droop control, and the droop control is widely applied due to the fact that the droop control is simple in control structure and does not depend on interconnection communication among the energy storage units, and reliability is high. However, the droop coefficient of the droop control is fixed after being determined, and when the droop control is adopted to adjust the converter at the interface of the energy storage unit, the fixed droop coefficient brings certain problems, and when the energy storage element in the energy storage unit, such as a storage battery, is excessively charged or discharged, the service life of the battery is reduced, and the deep discharge can cause the direct paralysis of the storage battery. However, the conventional droop control method does not have the capability of adjusting the magnitude of the droop coefficient in real time according to the state of charge (SOC) of the energy storage unit, a single charging speed may cause the energy storage unit with a high SOC to be overcharged, and the same single discharging speed may cause the energy storage unit with a low SOC to be overdischarged and the electric quantity of other energy storage units to be insufficiently utilized. Therefore, when the energy storage units are connected in parallel for charging and discharging, the problems of over-charging and over-discharging of the energy storage units and unbalanced charged state values may occur when the existing droop control is adopted.
Disclosure of Invention
In order to solve the problems that an energy storage unit of a direct current micro-grid is overcharged and overdischarged and the state of charge value is unbalanced due to an existing droop control method, the invention provides a droop control method and device for the direct current micro-grid and a computer storage medium.
In a first aspect, to solve the above technical problem, the present invention provides a droop control method for a dc micro grid, including:
acquiring a first output current value of a converter corresponding to a current energy storage unit in real time, and acquiring a first charge state value of the current energy storage unit at the same time;
calculating to obtain a first droop coefficient corresponding to the current energy storage unit according to the first output current value and the first state of charge value;
performing droop control on the current energy storage unit according to the first droop coefficient;
and respectively calculating a corresponding first droop coefficient for each energy storage unit of the direct current micro-grid by adopting the steps, and performing droop control.
The invention has the beneficial effects that: and changing the size of the droop coefficient in real time according to the charge state value of the current energy storage unit, and finally enabling the charge state values of the energy storage units to tend to be balanced to realize overcharge and overdischarge protection.
On the basis of the technical scheme, the invention can be improved as follows.
Further, the calculating process of the first droop coefficient includes:
according to the formula
Calculating to obtain an adjusting factor d i Wherein, soc i Is the first state of charge value, soc A Is the average charge state value of all energy storage units of the direct current micro-grid, n is a preset control parameter, i dci Is the first output current value;
according to the formula R (soc) i )＝R 0 *d i And calculating to obtain the first sag coefficient R (soc) i ) Wherein R is 0 A preset initial droop coefficient, d, corresponding to the current energy storage unit i Is the regulatory factor.
The beneficial effect who adopts above-mentioned improvement scheme is: by adjusting said adjustment factor d i The preset control parameter n in (1) can control the equalization speed of the state of charge value, and further can increase the equalization speed of the state of charge value by increasing the preset control parameter n.
Further, the first sag factor R (soc) i ) Satisfy the requirement of
Wherein, Δ u dcmax Allowing the maximum fluctuation range value i of the DC bus voltage of the DC micro-grid dcmax And the maximum allowable output current value of the converter corresponding to the current energy storage unit is obtained.
The beneficial effect who adopts above-mentioned improvement scheme is: further ensuring the normal work of the direct current microgrid, and avoiding the first droop coefficient R (soc) caused by excessively increasing the preset control parameter n i ) The selection of the voltage exceeds the allowable dropping range of the direct current bus voltage, so that the whole direct current micro-grid system loses stability.
Further, the average state of charge value soc A The calculation process of (2) includes:
according to the formula
Calculating to obtain the average state of charge value soc A Wherein, soc j The number is the charge state value of the energy storage unit with the serial number j, and N is the total number of all the energy storage units of the direct current micro-grid.
The beneficial effect who adopts above-mentioned improvement scheme is: the droop coefficient is combined with the charge state values of all the energy storage units, so that the droop coefficient is reasonably changed, the charge state values of the energy storage units are balanced, the over-charge and over-discharge of the energy storage units are avoided, and the method is easy to realize.
Further, before the first droop coefficient corresponding to the current energy storage unit is obtained through calculation according to the first output current value and the first state of charge value, the method further includes:
judging a first state of charge value soc of the current energy storage unit i Whether the soc is more than or equal to 20 percent i Less than or equal to 80 percent to obtain a first judgment result;
and when the first judgment result is negative, stopping performing droop control on the current energy storage unit, performing charging/discharging treatment until the current energy storage unit meets a preset condition, stopping the charging/discharging treatment, and performing droop control on the current energy storage unit again.
The beneficial effect who adopts above-mentioned improvement scheme is: and each energy storage unit is processed according to the state of charge value, so that the working stability of the direct-current microgrid is further improved.
Further, the preset conditions are the real-time state of charge value soc of the current energy storage unit and the real-time average state of charge value of all energy storage units of the direct current microgrid
Equal to, wherein soc k The real-time state of charge value of the energy storage units with the serial number k is obtained, and N is the total number of all the energy storage units of the direct current micro-grid.
The beneficial effect who adopts above-mentioned improvement scheme is: the energy storage units with the charge state values not within the range of 20% to 80% do not adopt droop control, but the energy storage units are subjected to droop control when the charge state values of the energy storage units are adjusted to the average charge state values of all the energy storage units by using charge and discharge processing, so that the system stability of a direct-current micro-grid is ensured, the charge state values of the energy storage units tend to be balanced, and overcharge and overdischarge protection is realized.
Further, the current energy storage unit is a storage battery pack, and the first state of charge value soc i The calculation process of (2) comprises:
according to the formula
Calculating to obtain the first state of charge value soc i Wherein, C bat Is the cell capacity of the battery pack, i L Is the output current value of the battery pack, soc i0 And the initial state of charge value of the storage battery pack.
The beneficial effect who adopts above-mentioned improvement scheme is: and calculating the state of charge value of the storage battery pack according to the sampled output current value of the storage battery pack, wherein the calculation is simple and easy to realize.
In a second aspect, the invention provides a droop control device for a direct current microgrid, which comprises an acquisition module, a calculation module and a control module;
the acquisition module is used for acquiring a first output current value of a converter corresponding to the current energy storage unit in real time and acquiring a first charge state value of the current energy storage unit at the same time;
the calculation module is used for calculating and obtaining a first droop coefficient corresponding to the current energy storage unit according to the first output current value and the first state of charge value;
and the control module is used for carrying out droop control on the current energy storage unit according to the first droop coefficient.
Further, the computing module comprises a first computing module and a second computing module;
the first calculation module is used for calculating according to a formula
Calculating to obtain an adjusting factor d i Wherein, soc i Is the first state of charge value, soc A Is the average charge state value of all energy storage units of the direct current micro-grid, n is a preset control parameter, i dci Is the first output current value;
the second calculation module is used for calculating the formula R (soc) i )＝R 0 *d i And calculating to obtain the first sag coefficient R (soc) i ) Wherein R is 0 A preset initial droop coefficient, d, corresponding to the current energy storage unit i Is the regulatory factor.
In a third aspect, the present invention further provides a computer-readable storage medium, where instructions are stored, and when the instructions are executed on a terminal device, the terminal device is caused to execute any one of the above-mentioned droop control methods for a dc microgrid.
Drawings
Fig. 1 is a schematic flowchart of a droop control method for a dc microgrid according to an embodiment of the present invention;
fig. 2 is a schematic circuit diagram of a parallel battery pack in a dc micro-grid according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of a droop control apparatus for a dc microgrid according to an embodiment of the present invention;
fig. 4 is a schematic structural diagram of a droop control apparatus for a dc microgrid according to another embodiment of the present invention.
Detailed Description
The following examples are further illustrative and supplementary to the present invention and do not limit the present invention in any way.
A droop control method for a dc microgrid according to an embodiment of the present invention is described below with reference to the accompanying drawings.
Referring to fig. 1, the present invention provides a droop control method for a dc microgrid, including:
s1, acquiring a first output current value of a converter corresponding to the current energy storage unit in real time, and acquiring a first state of charge value of the current energy storage unit at the same time;
s2, calculating to obtain a first droop coefficient corresponding to the current energy storage unit according to the first output current value and the first state of charge value;
s3, carrying out droop control on the current energy storage unit according to the first droop coefficient;
and S4, calculating a corresponding first droop coefficient for each energy storage unit of the direct current microgrid by adopting the steps, and performing droop control.
According to the droop control method for the direct-current micro-grid, the droop coefficient and the charge state value of the energy storage unit are combined, the magnitude of the droop coefficient is changed in real time according to the current charge state value of the energy storage unit, and finally the charge state value of the energy storage unit tends to be balanced, so that the problems of over-charge and over-discharge of the energy storage unit and unbalance of the charge state value are solved.
It can be understood that a plurality of energy storage units may be provided in the energy storage system of the dc microgrid, the plurality of energy storage units are respectively connected in parallel to a dc bus of the dc microgrid through a converter, and the energy storage units may be energy storage elements such as a storage battery or a storage battery pack.
Specifically, in this embodiment, in order to promote the equalization of the state of charge values of the energy storage units, the calculated first droop coefficient should be such that the energy storage unit with a high state of charge value absorbs less electric quantity and the energy storage unit with a low state of charge value absorbs more electric quantity during the charging process; in the discharging process, the energy storage unit with a high charge state value releases more electric quantity, and the energy storage unit with a low charge state value releases less electric quantity, so that the charge state values of the energy storage units are balanced.
Preferably, the calculation process of the first droop coefficient comprises:
according to the formula
Calculating to obtain an adjusting factor d i Wherein, soc i Is said first state of charge value, soc A Is the average charge state value of all energy storage units of the direct current micro-grid, n is a preset control parameter, i dci Is the first output current value;
according to the formula R (soc) i )＝R 0 *d i And calculating to obtain the first sag coefficient R (soc) i ) Wherein R is 0 A preset initial droop coefficient, d, corresponding to the current energy storage unit i Is the regulatory factor.
In this embodiment, the adjustment factor d is adjusted i The preset control parameter n in (1) can control the equalization speed of the state of charge value, so that the equalization speed of the state of charge value can be increased by increasing the preset control parameter n.
Further, the average state of charge value soc A The calculation process of (2) includes:
according to the formula
Calculating to obtain the average state of charge value soc A Wherein, soc j Of energy-storing cells of sequence number jAnd the charge state value N is the total number of all energy storage units of the direct current microgrid.
It is understood that the calculation of the droop coefficient should be divided into two cases, the charge and discharge states. i all right angle dci If the energy storage unit is in a discharge state more than 0, the state of charge value of the energy storage unit is larger than the average value, such as soc i ＞soc A Then, the first sag factor R (soc) calculated at this time is known i )＜R 0 I.e. compared to a predetermined initial sag factor R 0 If the value of the state of charge is smaller than the average value, the energy storage unit provides a smaller load current than the energy storage unit without the adjustment factor; when i is dci If the charge state value of the energy storage unit is greater than the average value, namely soc i ＞soc A Then there is R (soc) i )＞R 0 The energy storage unit will absorb a smaller load current than without the addition of the adjustment factor, thus knowing that if the state of charge value is less than the average value, the energy storage unit will absorb a larger load current than without the addition of the adjustment factor.
Therefore, the droop coefficient calculated by the adjusting factor can realize the state of charge value balance and overcharge and overdischarge protection of the energy storage unit.
Optionally, in one embodiment, the first sag factor R (soc) i ) Satisfy the requirements of
Wherein, Δ u dcmax Allowing the maximum fluctuation range value i for the DC bus voltage of the DC micro-grid dcmax And the maximum allowable output current value of the converter corresponding to the current energy storage unit is obtained.
In the droop control, the computed droop coefficient R (soc) i ) If the value is too large, the deviation between the bus voltage and the actual reference value is possibly large, so that the whole direct-current micro-grid system is unstable, and the corresponding droop coefficient is selectedThe selection rule in the discharge state is:
the charging state is as follows:
wherein R is 0 And setting the initial droop coefficient for the preset initial droop coefficient.
Further, in an embodiment, before the calculating, according to the first output current value and the first state of charge value, a first droop coefficient corresponding to the current energy storage unit, the method further includes:
judging a first state of charge value soc of the current energy storage unit i Whether the soc is more than or equal to 20 percent i Less than or equal to 80 percent to obtain a first judgment result;
and when the first judgment result is negative, stopping droop control on the current energy storage unit, performing charging/discharging treatment, and stopping the charging/discharging treatment and performing droop control on the current energy storage unit again when the current energy storage unit meets the preset conditions.
Preferably, the preset conditions are the current real-time state of charge value soc of the energy storage unit and the real-time average state of charge value of all energy storage units of the direct current microgrid
Equal to, wherein soc k The real-time charge state value of the energy storage unit with the serial number k is shown, and N is the total number of all the energy storage units of the direct-current micro-grid.
It should be noted that, the optimal applicable condition of the droop control method is that when the state of charge value of the energy storage unit is within the range of 20% to 80%, when there is an energy storage unit with a state of charge value greater than 80%, the energy storage unit should be prohibited from charging, and only allowed to operate in a discharging state, that is, the energy storage unit is subjected to discharging processing; when the energy storage units with the state of charge values smaller than 20% exist, the energy storage units are forbidden to discharge, the energy storage units are only allowed to work in a charging state, namely, the energy storage units are charged, the energy storage units which are charged/discharged are not subjected to the droop control method, and the energy storage units are subjected to the droop control method until the state of charge values of the energy storage units are adjusted to the average state of charge of all the current energy storage units, and are synchronously charged and discharged with other energy storage units.
Further, in one embodiment, the current energy storage unit is a battery pack, and the first state of charge value soc i The calculation process of (2) comprises:
according to the formula
Calculating to obtain the first state of charge value soc i Wherein, C bat Is the cell capacity of the battery pack, i L Is the output current value of the battery pack soc i0 And the initial state of charge value of the storage battery pack.
Specifically, in this embodiment, the battery packs may be connected in parallel to the DC bus via a bidirectional DC/DC converter (bidirectional DC-DC converter).
For example, in one embodiment, referring to fig. 2, the battery pack 1 and the battery pack 2 are respectively connected in parallel to a dc bus through a converter to supply power to a load; u. u bat1 、u bat2 Respectively, the output voltage of the storage battery pack 1 and the output voltage of the storage battery pack 2, i L1 、i L2 Output currents, S, of the battery pack 1 and the battery pack 2, respectively 1 、S 2 、S 3 、S 4 Is IGBT (insulated gate bipolar transistor), R is load resistance, wherein, the inductance L 1 Insulated gate bipolar transistor S 1 And S 2 And a capacitor C 1 A converter 1 corresponding to the storage battery 1, an inductor L 2 Insulated gate bipolar transistor S 3 And S 4 And a capacitor C 2 Constituting a converter 2, u corresponding to said battery pack 2 dc1 、u dc2 Output voltages, i, of converters 1 and 2, respectively dc1 、i dc2 Respectively, a converter 1 andthe converter 2 outputs a current;
further, in this embodiment, for the secondary battery pack 1, the output current value i of the inverter 1 is detected first dc1 And calculating the current state of charge value soc of the storage battery pack 1 1 ，soc 1 The calculation formula of (c) is:
wherein, C bat1 Is the cell capacity, soc, of the battery pack 1 10 Simultaneously carrying out similar calculation steps on the storage battery pack 2 to obtain a state of charge value soc for the initial state of charge value of the storage battery pack 1 2 (ii) a Obtaining soc through calculation 1 、soc 2 Post-detection soc 1 、soc 2 Whether the battery pack is in the range of 20% to 80%, when the battery pack with the state of charge value larger than 80% exists in the parallel battery packs, the charging of the battery pack should be prohibited, and the battery pack is only allowed to work in a discharging state; when the state of charge value in the storage battery pack is less than 20%, the storage battery pack should be prohibited from discharging, and only the storage battery pack is allowed to work in a charging state, and the discharging and charging modes of the storage battery pack in the two cases do not adopt the droop control method, and a traditional charging and discharging mode can be adopted. When the state of charge value of the storage battery pack is adjusted to the average state of charge value of the storage battery, the storage battery pack and other storage battery packs are charged and discharged together;
if soc 1 、soc 2 In the range of 20% to 80%, the soc is first calculated A The calculation formula is
When N is 2;
at the same time, i for battery packs 1 and 2, respectively dc1 、i dc2 Judging the positive and negative of the signal; for the battery pack 1, when i dc1 If the voltage is more than 0, the storage battery pack 1 is in a discharge state, the factor d is adjusted 1 Comprises the following steps:
when i is dc1 If the storage battery pack 1 is in a charging state, the factor d is adjusted 1 Comprises the following steps:
performing similar calculation steps on the storage battery pack 2 to obtain an adjusting factor d 2 The balance of the state of charge values can be accelerated by adjusting a preset control parameter n in the adjustment factor, but the adjustment factor is in a range of bus voltage allowed to drop;
finally, the formula R (soc) 1 )＝R 01 *d 1 、R(soc 2 )＝R 02 *d 2 To obtain the adjusted sag factor R (soc) of the battery packs 1 and 2 1 )、R(soc 2 ) So that the states of charge of the storage battery packs 1 and 2 tend to be balanced, and overcharge and overdischarge are avoided, wherein R 01 、R 02 Respectively presetting initial droop coefficients corresponding to the storage battery pack 1 and the storage battery pack 2; further, the droop control method is adopted for the storage battery pack 1 and the storage battery pack 2, and specifically, the relevant parameters of corresponding converters are adjusted according to the adjusted droop coefficients so that the outputs of the two storage battery packs meet a droop formula: u. of dc1 ＝u dcref -i dc1 R(soc 1 )、u dc2 ＝u dcref -i dc2 R(soc 2 ) And
wherein u is dcref Is a direct current bus reference voltage.
The droop control method for the direct-current microgrid is simple and easy to understand and realize, and has a good application prospect.
In the foregoing embodiments, although the steps are numbered as S1, S2, etc., but only the specific embodiments are given in this application, and those skilled in the art may adjust the execution order of S1, S2, etc. according to the actual situation, which is also within the protection scope of the present invention, and it is understood that some embodiments may include some or all of the above embodiments.
As shown in fig. 3, a droop control apparatus 10 for a dc microgrid according to an embodiment of the present invention includes an acquisition module 20, a calculation module 30, and a control module 40;
the acquisition module 20 is configured to acquire a first output current value of a converter corresponding to a current energy storage unit in real time, and acquire a first state of charge value of the current energy storage unit at the same time;
the calculating module 30 is configured to calculate and obtain a first droop coefficient corresponding to the current energy storage unit according to the first output current value and the first state of charge value;
the control module 40 is configured to perform droop control on the current energy storage unit according to the first droop coefficient.
Optionally, in one embodiment, the calculation module 30 includes a first calculation module and a second calculation module;
the first calculation module is used for calculating according to a formula
Calculating to obtain an adjusting factor d i Wherein, soc i Is said first state of charge value, soc A Is the average charge state value of all energy storage units of the direct current micro-grid, n is a preset control parameter, i dci Is the first output current value;
the second calculation module is used for calculating the formula R (soc) i )＝R 0 *d i And calculating to obtain the first sag coefficient R (soc) i ) Wherein R is 0 A preset initial droop coefficient, d, corresponding to the current energy storage unit i Is the regulatory factor.
Preferably, said first sag factor R (soc) i ) Satisfy the requirements of
Wherein, Δ u dcmax Allowing the maximum fluctuation range value i of the DC bus voltage of the DC micro-grid dcmax And the maximum allowable output current value of the converter corresponding to the current energy storage unit is obtained.
Optionally, in one embodiment, the calculation module 30 further includes a third calculation module; the third calculation module is used for calculating according to a formula
Calculating to obtain the average state of charge value soc A Wherein, soc j The number is the charge state value of the energy storage unit with the serial number j, and N is the total number of all the energy storage units of the direct current micro-grid.
Optionally, in an embodiment, as shown in fig. 4, the energy storage system further includes a determining module 50, where the determining module 50 is configured to determine the first state of charge soc of the current energy storage unit i Whether the soc is more than or equal to 20 percent i Less than or equal to 80 percent to obtain a first judgment result; and when the first judgment result is negative, stopping performing droop control on the current energy storage unit, performing charging/discharging treatment until the current energy storage unit meets a preset condition, stopping the charging/discharging treatment, and performing droop control on the current energy storage unit again.
Preferably, the preset conditions are the current real-time state of charge value soc of the energy storage unit and the real-time average state of charge value of all energy storage units of the direct current microgrid
Equal to, wherein soc k The real-time charge state value of the energy storage unit with the serial number k is shown, and N is the total number of all the energy storage units of the direct-current micro-grid.
Optionally, in an embodiment, the current energy storage unit is a storage battery pack, and the acquisition module 20 is specifically configured to obtain the energy according to a formula
Calculating to obtain the secondA state of charge value soc i Wherein, C bat Is the cell capacity of the battery pack, i L Is the output current value of the battery pack soc i0 And the initial state of charge value of the storage battery pack.
An embodiment of the present invention further provides a computer-readable storage medium, where instructions are stored in the computer-readable storage medium, and when the instructions are executed on a terminal device, the terminal device is enabled to execute the parameters and the steps in the foregoing embodiment of the droop control method for the dc microgrid, which are not described herein again.
As will be appreciated by one skilled in the art, the present invention may be embodied as an apparatus, method or computer program product. Accordingly, the present disclosure may be embodied in the form of: the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a "circuit," module "or" device. Furthermore, in some embodiments, the invention may also be embodied in the form of a computer program product in one or more computer-readable media having computer-readable program code embodied in the medium.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.
Claims (8)
1. A droop control method for a direct current micro-grid is characterized by comprising the following steps:
acquiring a first output current value of a converter corresponding to a current energy storage unit in real time, and acquiring a first charge state value of the current energy storage unit at the same time;
calculating to obtain a first droop coefficient corresponding to the current energy storage unit according to the first output current value and the first state of charge value;
carrying out droop control on the current energy storage unit according to the first droop coefficient;
respectively calculating a corresponding first droop coefficient for each energy storage unit of the direct current microgrid by adopting the steps, and performing droop control;
before the first droop coefficient corresponding to the current energy storage unit is obtained through calculation according to the first output current value and the first state of charge value, the method further includes:
judging a first state of charge value soc of the current energy storage unit i Whether the soc is more than or equal to 20 percent i Less than or equal to 80 percent to obtain a first judgment result;
when the first judgment result is negative, stopping droop control on the current energy storage unit, and performing charging/discharging treatment, and when the current energy storage unit meets a preset condition, stopping the charging/discharging treatment, and performing droop control on the current energy storage unit again;
the preset conditions are the current real-time state of charge value soc of the energy storage unit and the real-time average state of charge value of all the energy storage units of the direct-current microgrid
Equal to, wherein soc k The real-time state of charge value of the energy storage units with the serial number k is obtained, and N is the total number of all the energy storage units of the direct current micro-grid.
2. The droop control method for the direct-current microgrid according to claim 1, characterized in that the calculation process of the first droop coefficient comprises:
according to the formula
Calculating to obtain an adjusting factor d i Wherein, soc i Is said first state of charge value, soc A Is the average charge state value of all energy storage units of the direct current micro-grid, n is a preset control parameter, i dci Is the first output current value;
according to the formula R (soc) i )＝R 0 *d i And calculating to obtain the first sag coefficient R (soc) i ) Wherein R is 0 A preset initial droop coefficient, d, corresponding to the current energy storage unit i Is the regulatory factor.
3. The droop control method for the direct current microgrid of claim 2, characterized in that the first droop coefficient R (soc) i ) Satisfy the requirements of
Wherein, Δ u dcmax Allowing the maximum fluctuation range value i for the DC bus voltage of the DC micro-grid dcmax And the maximum allowable output current value of the converter corresponding to the current energy storage unit is obtained.
4. The droop control method for the direct current microgrid of claim 2, characterized in that the average state of charge value soc A The calculation process of (2) comprises:
according to the formula
Calculating to obtain the average state of charge value soc A Wherein, soc j The number is the charge state value of the energy storage unit with the serial number j, and N is the total number of all the energy storage units of the direct current micro-grid.
5. The droop control method for the direct current microgrid according to any one of claims 1 to 4, characterized in that the current energy storage unit is a storage battery, and the first state of charge value soc i The calculation process of (2) includes:
according to the formula
Calculating to obtain the first state of charge value soc i Wherein, C bat Is the cell capacity of the battery pack, i L Is the output current value of the battery pack, soc i0 And the initial state of charge value of the storage battery pack is obtained.
6. A droop control device for a direct current micro-grid is characterized by comprising an acquisition module, a calculation module, a judgment module and a control module;
the acquisition module is used for acquiring a first output current value of a converter corresponding to the current energy storage unit in real time and acquiring a first charge state value of the current energy storage unit at the same time;
the calculation module is used for calculating and obtaining a first droop coefficient corresponding to the current energy storage unit according to the first output current value and the first state of charge value;
the control module is used for carrying out droop control on the current energy storage unit according to the first droop coefficient;
the judging module is used for judging the current first state of charge (soc) value of the energy storage unit i Whether the soc is more than or equal to 20 percent i Less than or equal to 80 percent to obtain a first judgment result; when the first judgment result is negative, stopping the current energy storage unitPerforming droop control, performing charge/discharge treatment until the current energy storage unit meets a preset condition, stopping the charge/discharge treatment, and performing droop control on the current energy storage unit again; the preset conditions are the real-time charge state value soc of the current energy storage unit and the real-time average charge state value of all the energy storage units of the direct-current micro-grid
Equal to, wherein soc k The real-time charge state value of the energy storage unit with the serial number k is shown, and N is the total number of all the energy storage units of the direct-current micro-grid.
7. The droop control device for the direct current microgrid according to claim 6, characterized in that the calculation module comprises a first calculation module and a second calculation module;
the first calculation module is used for calculating according to a formula
Calculating to obtain an adjusting factor d i Wherein, soc i Is the first state of charge value, soc A Is the average charge state value of all energy storage units of the direct current micro-grid, n is a preset control parameter, i dci Is the first output current value;
the second calculation module is used for calculating the formula R (soc) i )＝R 0 *d i And calculating to obtain the first sag coefficient R (soc) i ) Wherein R is 0 A preset initial droop coefficient, d, corresponding to the current energy storage unit i Is the regulatory factor.
8. A computer-readable storage medium having stored therein instructions that, when run on a terminal device, cause the terminal device to perform the droop control method for a dc microgrid of any of claims 1-5.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110469819.2A CN113097992B (en) | 2021-04-28 | 2021-04-28 | Droop control method and device for direct-current micro-grid and computer storage medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110469819.2A CN113097992B (en) | 2021-04-28 | 2021-04-28 | Droop control method and device for direct-current micro-grid and computer storage medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113097992A CN113097992A (en) | 2021-07-09 |
| CN113097992B true CN113097992B (en) | 2022-07-26 |
Family
ID=76681003
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110469819.2A Active CN113097992B (en) | 2021-04-28 | 2021-04-28 | Droop control method and device for direct-current micro-grid and computer storage medium |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113097992B (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105870911A (en) * | 2016-05-17 | 2016-08-17 | 国网浙江省电力公司电力科学研究院 | Multi-source coordination control method for direct-current microgrid |
| CN109713660A (en) * | 2019-03-07 | 2019-05-03 | 上海禧龙科技股份有限公司 | Direct-current grid parallel connection energy-storage battery state-of-charge balance control method and device |
| CN109742749A (en) * | 2019-02-21 | 2019-05-10 | 太原理工大学 | A kind of improvement droop control method based on SOC for direct-current grid |
| CN110137992A (en) * | 2019-04-26 | 2019-08-16 | 上海电力学院 | A kind of isolated island direct-current grid stable coordination progress control method |
| CN111969693A (en) * | 2020-08-28 | 2020-11-20 | 广东电网有限责任公司佛山供电局 | Multi-agent lithium battery cluster energy storage system |
| CN112350357A (en) * | 2020-10-29 | 2021-02-09 | 南京工程学院 | SoC balance control method for distributed grid-connected electric automobile |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101809784B1 (en) * | 2014-01-27 | 2018-01-18 | 엘에스산전 주식회사 | method for controlling charging and discharging of battery energy storage system and the same |
| CA2923930C (en) * | 2015-03-19 | 2019-09-17 | Battelle Memorial Institute | Primary frequency control through simulated droop control with electric loads |
-
2021
- 2021-04-28 CN CN202110469819.2A patent/CN113097992B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105870911A (en) * | 2016-05-17 | 2016-08-17 | 国网浙江省电力公司电力科学研究院 | Multi-source coordination control method for direct-current microgrid |
| CN109742749A (en) * | 2019-02-21 | 2019-05-10 | 太原理工大学 | A kind of improvement droop control method based on SOC for direct-current grid |
| CN109713660A (en) * | 2019-03-07 | 2019-05-03 | 上海禧龙科技股份有限公司 | Direct-current grid parallel connection energy-storage battery state-of-charge balance control method and device |
| CN110137992A (en) * | 2019-04-26 | 2019-08-16 | 上海电力学院 | A kind of isolated island direct-current grid stable coordination progress control method |
| CN111969693A (en) * | 2020-08-28 | 2020-11-20 | 广东电网有限责任公司佛山供电局 | Multi-agent lithium battery cluster energy storage system |
| CN112350357A (en) * | 2020-10-29 | 2021-02-09 | 南京工程学院 | SoC balance control method for distributed grid-connected electric automobile |
Non-Patent Citations (4)
| Title |
|---|
| 基于混合储能的直流微电网电压控制研究;文波;《中国优秀硕士学位论文全文数据库工程科技Ⅱ辑》;20160831;第45-47页 * |
| 改进SOC下垂控制的分布式储能***负荷电流分配方法;李鹏程;《中国电机工程学报》;20170705;第37卷(第13期);第3747-3749页 * |
| 林嘉伟等.独立直流微电网中考虑不同容量的分布式储能***能量控制策略.《电力自动化设备》.2020,(第10期), * |
| 独立直流微电网中考虑不同容量的分布式储能***能量控制策略;林嘉伟等;《电力自动化设备》;20201031(第10期);第140-141页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113097992A (en) | 2021-07-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP3503282B1 (en) | Quick charging method for parallel battery pack, and related device | |
| AU2018355632B2 (en) | Method for charging or discharging an energy store | |
| US8957625B2 (en) | Systems and methods for cell balancing | |
| TWI751229B (en) | Control device, control system, power storage device, and computer readable media | |
| KR100415747B1 (en) | Apparatus for controlling elevator | |
| US7193391B2 (en) | Method for cell balancing for lithium battery systems | |
| US20040222768A1 (en) | System and method for battery charge control based on charge capacity headroom | |
| US20130187466A1 (en) | Power management system | |
| US10355320B2 (en) | Power storage device for a battery group and connection control of capacitor and switching device | |
| WO2020049824A1 (en) | Electricity storage device and charging method | |
| CN103715722A (en) | Power battery pack equalization maintenance system and method | |
| CN107681733A (en) | Battery balanced module and distributed battery energy storage balancer | |
| CN111987759B (en) | Active equalization topology and method based on high-frequency power electronic transformer | |
| Hou et al. | A battery power bank of serial battery power modules with buck-boost converters | |
| CN105607003A (en) | Energy storage unit capacity test method | |
| CN115441487A (en) | SOC (system on chip) balancing method and terminal of common DC bus energy storage system | |
| TW202040909A (en) | Electricity storage system | |
| US20200203956A1 (en) | Method and device for charging aluminum battery | |
| JPH09200968A (en) | Charge controller for battery set | |
| JPWO2019081084A5 (en) | ||
| CN113097992B (en) | Droop control method and device for direct-current micro-grid and computer storage medium | |
| CN201854071U (en) | Battery pack charging management system | |
| JP2022045843A (en) | Method, rated voltage adjustment device, and power storage device | |
| KR20190071459A (en) | Battery charging system, and method for controlling maximum capacity charging in battery module using the same | |
| CN115800420B (en) | Energy storage system and method for regulating an energy storage system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |