CN109921636B

CN109921636B - Train and control method and device of bidirectional DC-DC converter of train

Info

Publication number: CN109921636B
Application number: CN201711316236.6A
Authority: CN
Inventors: 邬白贺; 王兴辉; 王超
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2017-12-12
Filing date: 2017-12-12
Publication date: 2021-01-19
Anticipated expiration: 2037-12-12
Also published as: CN109921636A

Abstract

The invention discloses a train and a control method and a control device of a bidirectional DC-DC converter of the train, wherein the bidirectional DC-DC converter comprises a first conversion branch, a second conversion branch and a third conversion branch which are mutually connected in parallel, each conversion branch of the first conversion branch, the second conversion branch and the third conversion branch comprises an upper bridge switching tube and a lower bridge switching tube, and the control method comprises the following steps: acquiring power to be output of the bidirectional DC-DC converter; judging a power interval in which the power to be output is positioned; when the power to be output is in a first power interval, the upper bridge switching tube and the lower bridge switching tube are controlled so that the first conversion branch, the second conversion branch and the third conversion branch sequentially work in turn in a circulating mode, wherein the working time of the first conversion branch, the second conversion branch and the third conversion branch is the same in each circulation, so that the working time of the switching tubes is effectively shortened, the working life of the switching tubes in the conversion branches is prolonged, and the life cycle of the bidirectional DC-DC converter can be further prolonged.

Description

Train and control method and device of bidirectional DC-DC converter of train

Technical Field

The present invention relates to the field of vehicle technologies, and in particular, to a control method of a bidirectional DC-DC converter, a non-transitory computer-readable storage medium, a control apparatus of a bidirectional DC-DC converter, and a train.

Background

The bidirectional DC-DC converter has been an important component in the power electronics field, and with the development of the vehicle field, the DC-DC converter has also become one of the important parts on the train. In the related art, a bidirectional DC-DC converter usually adopts three Boost topological structures, namely, the output power of the bidirectional DC-DC converter is improved in a mode that three Boost conversion branches are connected in parallel, and the total power is divided equally by the three Boost conversion branches in the working process of the bidirectional DC-DC converter. Therefore, the related art has a problem that the three Boost conversion branches work simultaneously no matter the target output power, so that circuit elements are in a working state for a long time, and the working life of the switching tube is influenced.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the art described above. Therefore, a first objective of the present invention is to provide a control method for a bidirectional DC-DC converter, which can enable three conversion branches to work in turn when the output power is in a first power interval, thereby improving the service life of a switching tube in the conversion branch.

A second object of the invention is to propose a non-transitory computer-readable storage medium. A third object of the present invention is to provide a bidirectional DC-DC converter. A fourth object of the present invention is to provide a control device for a bidirectional DC-DC converter. A fifth object of the present invention is to provide a bidirectional DC-DC converter. A sixth object of the invention is to propose a train.

In order to achieve the above object, an embodiment of an aspect of the present invention provides a control method for a bidirectional DC-DC converter, where the bidirectional DC-DC converter includes a first converting branch, a second converting branch, and a third converting branch, the first converting branch, the second converting branch, and the third converting branch are connected in parallel, and each of the first converting branch, the second converting branch, and the third converting branch includes an upper bridge switching tube and a lower bridge switching tube, the control method includes the following steps: acquiring the power to be output of the bidirectional DC-DC converter; judging a power interval in which the power to be output is positioned, wherein the output power of the bidirectional DC-DC converter is divided into a first power interval, a second power interval and a third power interval, the power corresponding to the second power interval is larger than the power corresponding to the first power interval, and the power corresponding to the third power interval is larger than the power corresponding to the second power interval; and when the power to be output is in the first power interval, controlling the upper bridge switching tube and the lower bridge switching tube so as to enable the first conversion branch, the second conversion branch and the third conversion branch to work in turn in a circulating mode, wherein in each circulation, the working time of the first conversion branch, the working time of the second conversion branch and the working time of the third conversion branch are the same.

According to the control method of the bidirectional DC-DC converter provided by the embodiment of the invention, the bidirectional DC-DC converter comprises a first conversion branch, a second conversion branch and a third conversion branch which are mutually connected in parallel, each conversion branch comprises an upper bridge switching tube and a lower bridge switching tube, the function rate interval of the power to be output is judged by obtaining the power to be output of the bidirectional DC-DC converter, when the power to be output is in the first power interval, the upper bridge switching tube and the lower bridge switching tube are controlled so as to enable the first conversion branch, the second conversion branch and the third conversion branch to work in turn in a circulating mode, wherein in each circulation, the working time of the first conversion branch, the working time of the second conversion branch and the working time of the third conversion branch are the same, thereby effectively reducing the working time of the switching tubes and prolonging the working life of the switching tubes in the conversion branches, thereby prolonging the life cycle of the bidirectional DC-DC converter.

To achieve the above object, a non-transitory computer-readable storage medium is provided in an embodiment of a second aspect of the present invention, on which a computer program is stored, and the computer program realizes the control method of the bidirectional DC-DC converter when being executed by a processor.

According to the non-transitory computer readable storage medium of the embodiment of the invention, by implementing the control method of the bidirectional DC-DC converter, the first conversion branch, the second conversion branch and the third conversion branch can be controlled to sequentially work in a cycle manner when the power to be output is in the first power interval, and in each cycle, the working time of the first conversion branch, the second conversion branch and the third conversion branch is the same, so that the working time of the switching tube is effectively reduced, the working life of the switching tube in the conversion branch is prolonged, and the life cycle of the bidirectional DC-DC converter can be further prolonged.

In order to achieve the above object, a bidirectional DC-DC converter according to an embodiment of a third aspect of the present invention includes a first converting branch, a second converting branch, and a third converting branch, where the first converting branch, the second converting branch, and the third converting branch are connected in parallel, each of the first converting branch, the second converting branch, and the third converting branch includes an upper switching tube and a lower switching tube, the bidirectional DC-DC converter further includes a memory, a processor, and a control program of the bidirectional DC-DC converter stored in the memory and operable on the processor, and the control program of the bidirectional DC-DC converter, when executed by the processor, implements a control method of the bidirectional DC-DC converter.

According to the bidirectional DC-DC converter provided by the embodiment of the invention, the control method of the bidirectional DC-DC converter can be realized, the first conversion branch, the second conversion branch and the third conversion branch are controlled to sequentially work in turn in a circulating mode when the power to be output is in the first power interval, and the working time of the first conversion branch, the second conversion branch and the third conversion branch is the same in each circulation, so that the working time of a switching tube is effectively reduced, the working life of the switching tube in the conversion branch is prolonged, and the life cycle of the bidirectional DC-DC converter can be further prolonged.

In order to achieve the above object, a control device for a bidirectional DC-DC converter according to an embodiment of a fourth aspect of the present invention is provided, where the bidirectional DC-DC converter includes a first converting branch, a second converting branch, and a third converting branch, the first converting branch, the second converting branch, and the third converting branch are connected in parallel, and each of the first converting branch, the second converting branch, and the third converting branch includes an upper bridge switching tube and a lower bridge switching tube, and the control device includes: the acquisition module is used for acquiring the power to be output of the bidirectional DC-DC converter; the judging module is used for judging a power interval in which the power to be output is positioned, wherein the output power of the bidirectional DC-DC converter is divided into a first power interval, a second power interval and a third power interval, the power corresponding to the second power interval is larger than the power corresponding to the first power interval, and the power corresponding to the third power interval is larger than the power corresponding to the second power interval; and the control module is used for controlling the upper bridge switching tube and the lower bridge switching tube when the power to be output is in the first power interval so as to enable the first conversion branch, the second conversion branch and the third conversion branch to work in turn in a circulating mode, wherein the working time of the first conversion branch, the second conversion branch and the third conversion branch is the same in each circulation.

According to the control device of the bidirectional DC-DC converter, the bidirectional DC-DC converter comprises a first conversion branch, a second conversion branch and a third conversion branch which are connected in parallel, each conversion branch comprises an upper bridge switching tube and a lower bridge switching tube, power to be output of the bidirectional DC-DC converter is obtained through an obtaining module, a judging module judges a power interval where the power to be output is located, and a control module carries out alternate work on the upper bridge switching tube and the lower bridge switching tube when the power to be output is in the first power interval, wherein in each cycle, the working time of the first conversion branch, the working time of the second conversion branch and the working time of the third conversion branch are the same, so that the working time of the switching tubes is effectively shortened, the working life of the switching tubes in the conversion branches is prolonged, and the life cycle of the bidirectional DC-DC converter can be further prolonged.

In order to achieve the above object, a bidirectional DC-DC converter according to an embodiment of a fifth aspect of the present invention includes the control device of the bidirectional DC-DC converter.

According to the bidirectional DC-DC converter provided by the embodiment of the invention, the control device of the bidirectional DC-DC converter can control the first conversion branch, the second conversion branch and the third conversion branch to sequentially work in a circulation mode when the power to be output is in the first power interval, and the working time of the first conversion branch, the second conversion branch and the third conversion branch is the same in each circulation, so that the working time of a switching tube is effectively reduced, the working life of the switching tube in the conversion branch is prolonged, and the life cycle of the bidirectional DC-DC converter can be further prolonged.

In order to achieve the above object, a sixth embodiment of the present invention provides a train, including the bidirectional DC-DC converter.

According to the train provided by the embodiment of the invention, the bidirectional DC-DC converter is utilized, the first conversion branch, the second conversion branch and the third conversion branch can be controlled to sequentially work in a circulation mode when the power to be output is in the first power interval, and the working time of the first conversion branch, the second conversion branch and the third conversion branch is the same in each circulation, so that the working time of a switching tube is effectively shortened, the working life of the switching tube in the conversion branch is prolonged, and the life cycle of the bidirectional DC-DC converter can be further prolonged.

Drawings

FIG. 1 is a circuit schematic of a bi-directional DC-DC converter according to one embodiment of the present invention;

FIG. 2 is a flow chart of a method of controlling a bi-directional DC-DC converter according to an embodiment of the present invention;

FIG. 3 is a flow chart of a method of controlling a bi-directional DC-DC converter according to an embodiment of the present invention;

FIG. 4 is a block schematic diagram of a control arrangement for a bi-directional DC-DC converter according to an embodiment of the present invention;

FIG. 5 is a block schematic diagram of a bidirectional DC to DC converter according to an embodiment of the present invention;

fig. 6 is a block schematic diagram of a train according to an embodiment of the invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

A control method of a bidirectional DC-DC converter, a control device of a bidirectional DC-DC converter, and a train according to an embodiment of the present invention will be described below with reference to the drawings.

As shown in fig. 1, a bidirectional DC-DC converter according to an embodiment of the present invention includes a first converting branch, a second converting branch and a third converting branch, the first converting branch, the second converting branch and the third converting branch are connected in parallel with each other, each of the first converting branch, the second converting branch and the third converting branch includes an upper bridge switching tube and a lower bridge switching tube, namely, the first conversion branch comprises a first upper bridge switching tube Q11 and a first lower bridge switching tube Q12, a first node J1 is arranged between the first upper bridge switching tube Q11 and the first lower bridge switching tube Q1, the second conversion branch comprises a second upper bridge switching tube Q21 and a second lower bridge switching tube Q22, a second node J2 is arranged between the second upper bridge switching tube Q21 and the second lower bridge switching tube Q22, the third conversion branch comprises a third upper bridge switching tube Q31 and a third lower bridge switching tube Q32, and a third node J3 is arranged between the third upper bridge switching tube Q31 and the third lower bridge switching tube Q32.

As shown in fig. 1, the bidirectional DC-DC converter further includes a first inductor L1, a second inductor L2, a third inductor L3, and a first capacitor C1, wherein one end of the first inductor L1 is connected to the first node J1, one end of the second inductor L2 is connected to the second node J2, one end of the third inductor L3 is connected to the third node J3, the other end of the third inductor L3 is connected to both the other end of the first inductor L1 and the other end of the second inductor L2, and the first capacitor C1 is connected to the output terminal of the bidirectional DC-DC converter.

When the bidirectional DC-DC converter works in a forward direction, the first upper bridge switching tube Q11, the second upper bridge switching tube Q21 and the third upper bridge switching tube Q31 are controlled to be switched on and off, when the first upper bridge switching tube Q11, the second upper bridge switching tube Q21 and the third upper bridge switching tube Q31 are controlled to be switched on, the first upper bridge switching tube Q11, the second upper bridge switching tube Q21 and the third upper bridge switching tube Q31 respectively charge the first inductor L1, the second inductor L2 and the third inductor L3, and when the first upper bridge switching tube Q11, the second upper bridge switching tube Q21 and the third upper bridge switching tube Q31 are controlled to be switched off, the first inductor L1, the second inductor L2 and the third inductor L3 respectively pass through the first lower bridge switching tube Q12, the second lower bridge switching tube Q22 and the third lower bridge switching tube Q32 to reduce voltage. On the contrary, when the bidirectional DC-DC converter works reversely, the first lower bridge switching tube Q12, the second lower bridge switching tube Q22 and the third lower bridge switching tube Q32 are controlled to be turned on and off, when the first lower bridge switching tube Q12, the second lower bridge switching tube Q22 and the third lower bridge switching tube Q32 are controlled to be turned on, the first lower bridge switching tube Q12, the second lower bridge switching tube Q22 and the third lower bridge switching tube Q32 are controlled to be turned on to respectively charge the first inductor L1, the second inductor L2 and the third inductor L3, and the first lower bridge switching tube Q12, the second lower bridge switching tube Q22 and the third lower bridge switching tube Q32 are controlled to be turned on, and the first inductor L1, the second inductor L2 and the third inductor L3 are respectively controlled to be turned on through the first upper bridge switching tube Q11, the second upper bridge switching tube Q21 and the third upper bridge switching tube Q31.

In an embodiment of the present invention, as shown in fig. 2, the control method of the bidirectional DC-DC converter includes the following steps:

s1: and acquiring the power to be output of the bidirectional DC-DC converter.

S2: and judging the power interval where the power to be output is located. The output power of the bidirectional DC-DC converter is divided into a first power interval, a second power interval and a third power interval, wherein the power corresponding to the second power interval is larger than the power corresponding to the first power interval, and the power corresponding to the third power interval is larger than the power corresponding to the second power interval. For example, the first power interval may be 0kw-100kw, the second power interval may be 100kw-200kw, and the third power interval may be 200kw-300 kw.

S3: when the power to be output is in a first power interval, the upper bridge switching tube and the lower bridge switching tube are controlled so that the first conversion branch, the second conversion branch and the third conversion branch work in turn in a circulating mode, wherein the working time of the first conversion branch, the second conversion branch and the third conversion branch is the same in each circulation.

The control of the upper bridge switching tube and the lower bridge switching tube can be the on-off control of the upper bridge switching tube and the lower bridge switching tube. Specifically, when the power to be output is in a first power interval, the first conversion branch, the second conversion branch and the third conversion branch sequentially work in turn by controlling the upper bridge switching tube and the lower bridge switching tube. For example, when the first conversion branch circuit works, the first upper bridge switching tube and the first lower bridge switching tube of the first conversion branch circuit can be controlled to be switched on or switched off, to control the first conversion branch to work, and at the same time, to control the upper bridge switch tube and the lower bridge switch tube of the second conversion branch and the third conversion branch to be both switched off, when the second conversion branch circuit is controlled to work, the second upper bridge switching tube and the second lower bridge switching tube of the second conversion branch circuit can be controlled to be switched on or switched off, to control the second conversion branch to work, and at the moment, to control the upper bridge switch tube and the lower bridge switch tube of the first conversion branch and the third conversion branch to be both switched off, and when controlling the third conversion branch circuit to work, controlling the third upper bridge switch tube and the third lower bridge switch tube of the third conversion branch circuit to be switched on or switched off, and controlling the third control branch to work, and controlling the upper bridge switching tube and the lower bridge switching tube of the first conversion branch and the second conversion branch to be switched off at the moment. When the upper bridge switching tube and the lower bridge switching tube are controlled to be switched on or switched off, the upper bridge switching tube can be controlled to be switched on or switched off during forward work, and the lower bridge switching tube can be controlled to be switched on or switched off during reverse work.

That is to say, when the bidirectional DC-DC converter operates, the power to be output is obtained, the power interval where the power to be output is located is determined, and if the power to be output is in the first power interval, the upper bridge switching tube and the lower bridge switching tube of the bidirectional DC-DC converter are controlled to be turned on or off, so that the first conversion branch, the second conversion branch and the third conversion branch sequentially operate in turn in a cyclic manner, for example, the first conversion branch → the second conversion branch → the third conversion branch → the first conversion branch, where in each cycle, the operating time of the first conversion branch, the second conversion branch and the third conversion branch is the same.

Specifically, the to-be-output power can be set to work for a first preset time in each cycle conversion branch when the to-be-output power is in a first power interval. When the power to be output belongs to a first power interval, firstly controlling a first conversion branch to work for a first preset time, when the working time of the first conversion branch reaches the first preset time, controlling the first conversion branch to stop working and controlling a second conversion branch to work for the first preset time, when the working time of the second conversion branch reaches the first preset time, controlling the second conversion branch to stop working and controlling a third conversion branch to work for the first preset time, when the working time of the third conversion branch reaches the first preset time, controlling the third conversion branch to stop working and controlling the first conversion branch to work for the first preset time, and so on, so that the first conversion branch, the second conversion branch and the third conversion branch work in a circulation mode in turn, and in each circulation, the working time of the first conversion branch, the second conversion branch and the third conversion branch is the same, i.e. for a first preset time of operation.

According to an embodiment of the present invention, when the first conversion branch, the second conversion branch and the third conversion branch sequentially perform alternate operation in a cyclic manner, if the bidirectional DC-DC converter stops operating or jumps out of the current power interval, the remaining time of the currently operating conversion branch and the currently operating conversion branch is obtained, so that the cycle is performed after the remaining time of the currently operating conversion branch is continuously completed when the bidirectional DC-DC converter sequentially performs alternate operation with the first conversion branch, the second conversion branch and the third conversion branch next time.

That is, the flag bits of the conversion branches may be set, for example, the flag bit of the first conversion branch is a, the flag bit of the second conversion branch is b, and the flag bit of the third conversion branch is c. When the bidirectional DC-DC converter stops working or jumps out of the current power interval, acquiring a flag bit of a currently working conversion branch to determine the currently working conversion branch and simultaneously acquiring the remaining time of the currently working conversion branch, wherein the remaining time of the currently working conversion branch can be acquired by acquiring the working time of the currently working conversion branch and then calculating the first preset time to subtract the working time of the currently working conversion branch; in addition, when the conversion branch works, the remaining time of the current work can be calculated in a countdown mode, so that the circulation is performed after the remaining time of the conversion branch of the current work is continuously completed when the first conversion branch, the second conversion branch and the third conversion branch sequentially work in turn next time of the bidirectional DC-DC converter, namely, according to the flag bit of the conversion branch of the current work and the remaining time of the conversion branch of the current work, when the power to be output of the bidirectional DC-DC converter is in the first power interval again, the conversion branch of the current work is controlled to continuously work and work the remaining time of the conversion branch of the current work, and then the next conversion branch is controlled to run for the first preset time.

For example, when the bidirectional DC-DC converter operates, the power to be output of the bidirectional DC-DC converter is obtained, when the power to be output for the first time is in the first power interval, the first converting branch is controlled to operate, when the first converting branch operates for the first preset time, the first converting branch is controlled to stop operating and the second converting branch is controlled to operate, the second converting branch operates for a period of remaining operating time Tp1, at this time, the bidirectional DC-DC converter stops operating or jumps out of the current power interval, the flag bit of the currently operating converting branch is obtained as b and the remaining operating time Tp1 of the currently operating converter are obtained, when the power to be output of the bidirectional DC-DC converter is in the first power interval again, the second converting branch is controlled to operate for the remaining operating time Tp1, and then the third converting branch is controlled to operate.

Therefore, the control method of the bidirectional DC-DC converter provided by the embodiment of the invention can realize that the first conversion branch, the second conversion branch and the third conversion branch are controlled to work in turn when the power to be output is in the first power interval, thereby effectively reducing the working time of the switching tube, prolonging the working life of the switching tube in the conversion branch and further prolonging the life cycle of the bidirectional DC-DC converter.

According to one embodiment of the invention, when the power to be output is in the second power interval, the upper bridge switching tube and the lower bridge switching tube are controlled, so that two of the first conversion branch, the second conversion branch and the third conversion branch are grouped into one group and sequentially work in turn in a circulating manner, wherein the working time of each group of conversion branches is the same in each circulation.

It should be noted that the first conversion branch and the second conversion branch may form a first conversion branch group, the first conversion branch and the third conversion branch may form a second conversion branch group, and the second conversion branch and the third conversion branch may form a third conversion branch group. When the power to be output is in the second power interval, the upper bridge switching tube and the lower bridge switching tube of the conversion branch group are controlled, two of the first conversion branch, the second conversion branch and the third conversion branch can be sequentially in a group to work in turn, for example, when the first conversion branch group works, the first upper bridge switching tube and the lower bridge switching tube of the first conversion branch and the second upper bridge switching tube and the second lower bridge switching tube of the second conversion branch can be controlled to be switched on or off, so that the first conversion branch and the second conversion branch are controlled to work, and the upper bridge switching tube and the lower bridge switching tube of the third conversion branch are controlled to be switched off at the moment; when the second conversion branch group works, the first upper bridge switching tube and the first lower bridge switching tube of the first conversion branch and the third upper bridge switching tube and the third lower bridge switching tube of the third conversion branch can be controlled to be switched on or switched off to control the first conversion branch and the third conversion branch to work, and at the moment, the upper bridge switching tube and the lower bridge switching tube of the second conversion branch are controlled to be switched off; when the third conversion branch group works, the second upper bridge switching tube and the second lower bridge switching tube of the second conversion branch and the third upper bridge switching tube and the third lower bridge switching tube of the third conversion branch can be controlled to be switched on or switched off to control the second conversion branch and the third conversion branch to work, and at the moment, the upper bridge switching tube and the lower bridge switching tube of the first conversion branch are controlled to be switched off. When the upper bridge switching tube and the lower bridge switching tube are controlled to be switched on or switched off, the upper bridge switching tube can be controlled to be switched on or switched off during forward work, and the lower bridge switching tube can be controlled to be switched on or switched off during reverse work.

That is to say, when the bidirectional DC-DC converter operates, the power to be output is obtained, the power interval where the power to be output is located is determined, and if the power to be output is in the second power interval, the on/off of the upper bridge switching tube and the lower bridge switching tube of the bidirectional DC-DC converter is controlled, so that the first conversion branch, the second conversion branch and the third conversion branch are grouped into one group in a cycle manner to operate in turn, for example, the first conversion branch and the second conversion branch → the first conversion branch and the third conversion branch → the second conversion branch and the third conversion branch → the first conversion branch and the second conversion branch are operated in a cycle manner, wherein the operating time of each group of conversion branches is the same in each cycle.

Specifically, when the power to be output is in the second power interval, each group of conversion branches may be set to operate for a second preset time in each cycle. When the power to be output belongs to a second power interval, firstly, the first conversion branch and the second conversion branch are controlled to work for a first preset time at the same time, when the working time of the first conversion branch and the second conversion branch reaches a second preset time, the first conversion branch and the second conversion branch are controlled to stop working, the first conversion branch and the third conversion branch are controlled to work for a second preset time at the same time, when the working time of the first conversion branch and the third conversion branch reaches the second preset time, the first conversion branch and the third conversion branch are controlled to stop working, the second conversion branch and the third conversion branch are controlled to work for the second preset time at the same time, when the working time of the second conversion branch and the third conversion branch reaches the second preset time, the second conversion branch and the third conversion branch are controlled to stop working, and the first conversion branch and the second conversion branch are controlled to work for the second preset time at the same time, therefore, the first transformation branch, the second transformation branch and the third transformation branch are grouped into a group in pairs and work in turn in a circulating mode, wherein the working time of each group of transformation branches is the same in each circulation.

According to an embodiment of the present invention, when two of the first conversion branch, the second conversion branch and the third conversion branch are sequentially operated in a cyclic manner, if the bidirectional DC-DC converter stops operating or jumps out of the current power interval, the remaining time of the currently operating conversion branch group and the currently operating conversion branch group is obtained, so that the bidirectional DC-DC converter continues to complete the remaining time of the currently operating conversion branch group when the bidirectional DC-DC converter sequentially operates in a cyclic manner next time with two of the first conversion branch, the second conversion branch and the third conversion branch.

That is, flag bits of the conversion branches may be set, for example, the flag bit of the first conversion branch group is a ', the flag bit of the second conversion branch group is b ', and the flag bit of the third conversion branch group is c '. When the bidirectional DC-DC converter stops working or jumps out of the current power interval, acquiring the zone bits of the currently working group of conversion branches to determine the currently working group of conversion branches, and acquiring the remaining time of the currently working group of conversion branches, wherein the operating time of the currently operating group of conversion branches can be obtained, and then the remaining time of the currently operating group of conversion branches can be obtained by subtracting the operating time of the currently operating group of conversion branches from the second preset time, and in addition, the remaining time of the current operation can be calculated by the conversion branches in a countdown mode, therefore, circulation is carried out after the remaining time of the currently working conversion branch group is continuously finished when the bidirectional DC-DC converter sequentially works in turn next time by taking two of the first conversion branch, the second conversion branch and the third conversion branch as a group.

For example, when the bidirectional DC-DC converter is running, the power to be output of the bidirectional DC-DC converter is obtained, when the power to be output for the first time is in the second power interval, the first converting branch group is controlled to operate, that is, the first converting branch and the second converting branch operate simultaneously, when the first converting branch group operates for the second preset time, the first converting branch group is controlled to stop operating and the second converting branch group is controlled to operate, that is, the first converting branch and the second converting branch are controlled to stop operating and the first converting branch and the third converting branch are controlled to operate, the second branch group operates for a period of time, and then the remaining operating time Tp2 is left, at this time, the bidirectional DC-DC converter stops operating or jumps out of the current power interval, and the flag bit of the currently operating converting branch is b' and the remaining operating time Tp2 of the currently operating converting branch group are obtained, when the power to be output of the bidirectional DC-DC converter is in the second power interval again, the working time Tp2 of the second conversion branch group when working is remained is controlled, namely the working time Tp2 of the first conversion branch and the third conversion branch which work together is controlled, and then the third conversion branch group (namely the second conversion branch and the third conversion branch) is controlled to work for a second preset time.

According to one embodiment of the invention, when the power to be output is in the third power interval, the upper bridge switching tube and the lower bridge switching tube are controlled, so that the first conversion branch, the second conversion branch and the third conversion branch work simultaneously.

That is to say, when the power to be output is in the third power interval, the first conversion branch, the second conversion branch and the third conversion branch of the bidirectional DC-DC conversion branch operate simultaneously, wherein the first conversion branch, the second conversion branch and the third conversion branch equally divide the power to be output.

Specifically, when the power to be output is in a third power interval, the upper bridge switching tube and the lower bridge switching tube of the first conversion branch, the second conversion branch and the third conversion branch can be controlled to be switched on or switched off simultaneously, so that the first conversion branch, the second conversion branch and the third conversion branch work simultaneously. For example, the first upper bridge switching tube of the first conversion branch, the second upper bridge switching tube of the second conversion branch and the third upper bridge switching tube of the third conversion branch can be controlled to be switched on or switched off when the DC-DC converter works in the forward direction, and the first lower bridge switching tube of the first conversion branch, the second lower bridge switching tube of the second conversion branch and the lower bridge switching tube of the third conversion branch can be controlled to be switched on or switched off when the DC-DC converter works in the reverse direction.

According to an embodiment of the present invention, as shown in fig. 3, the control method of the bidirectional DC-DC converter includes the following steps:

s101: when the bidirectional DC-DC converter is started to work.

S102: and acquiring the power to be output of the bidirectional DC-DC converter.

S103: and judging the power interval where the power to be output is located.

If the power interval in which the power to be output is located is the first power interval, executing step S104;

if the power interval in which the power to be output is located is the second power interval, executing step S107;

if the power interval in which the power to be output is located is the third power interval, step S108 is executed.

S104: and controlling the first transformation branch, the second transformation branch and the third transformation branch to work in turn in a circulating mode.

S105: stopping working or jumping out of the first power interval by the power to be output, and acquiring the zone bit of the currently working conversion branch and the remaining time of the currently working conversion branch.

S106: and controlling the remaining time of the current branch of the currently working conversion branch, and returning to the step S104.

S107: and controlling two of the first transformation branch, the second transformation branch and the third transformation branch to be a group, and sequentially performing alternate work in a circulating mode.

S108: stopping working or jumping out of the second power interval by the power to be output, and acquiring the zone bit of the group of currently working conversion branches and the remaining time of the group of currently working conversion branches.

S109: the currently active set of conversion legs is controlled to complete the remaining time of the current set of legs and returns to step S107.

S110: and controlling the first conversion branch, the second conversion branch and the third conversion branch to work simultaneously.

In summary, according to the control method of the bidirectional DC-DC converter of the embodiment of the present invention, the bidirectional DC-DC converter includes the first converting branch, the second converting branch and the third converting branch which are connected in parallel, each converting branch includes the upper bridge switching tube and the lower bridge switching tube, the functional rate interval where the power to be output is located is determined by obtaining the power to be output of the bidirectional DC-DC converter, when the power to be output is in the first power interval, the upper bridge switching tube and the lower bridge switching tube are controlled to make the first converting branch, the second converting branch and the third converting branch sequentially operate in turn in a cyclic manner, wherein in each cycle, the operating time of the first converting branch, the second converting branch and the third converting branch is the same, thereby effectively reducing the operating time of the switching tubes and improving the operating life of the switching tubes in the converting branches, thereby prolonging the life cycle of the bidirectional DC-DC converter.

Embodiments of the present invention also provide a non-transitory computer-readable storage medium on which a computer program is stored, the program, when executed by a processor, implementing a method of controlling a bidirectional DC-DC converter.

The embodiment of the invention also provides a bidirectional DC-DC converter, which comprises a first conversion branch, a second conversion branch and a third conversion branch, wherein the first conversion branch, the second conversion branch and the third conversion branch are connected in parallel, each of the first conversion branch, the second conversion branch and the third conversion branch comprises an upper bridge switching tube and a lower bridge switching tube, the bidirectional DC-DC converter further comprises a memory, a processor and a control program of the bidirectional DC-DC converter, the control program of the bidirectional DC-DC converter is stored on the memory and can be operated on the processor, and the control method of the bidirectional DC-DC converter is realized when the control program of the bidirectional DC-DC converter is executed by the processor.

Fig. 4 is a block schematic diagram of a control apparatus of a bidirectional DC-DC converter according to an embodiment of the present invention. The bidirectional DC-DC converter comprises a first conversion branch, a second conversion branch and a third conversion branch, wherein the first conversion branch, the second conversion branch and the third conversion branch are connected in parallel, and each conversion branch comprises an upper bridge switching tube and a lower bridge switching tube.

As shown in fig. 4, the control device of the bidirectional DC-DC converter according to the embodiment of the present invention includes: the device comprises an acquisition module 10, a judgment module 20 and a control module 30.

The obtaining module 10 is configured to obtain power to be output of the bidirectional DC-DC converter; the determining module 20 is configured to determine a power interval in which power to be output is located, where the output power of the bidirectional DC-DC converter is divided into a first power interval, a second power interval, and a third power interval, where power corresponding to the second power interval is greater than power corresponding to the first power interval, and power corresponding to the third power interval is greater than power corresponding to the second power interval; the control module 30 is configured to control the upper bridge switching tube and the lower bridge switching tube when the power to be output is in the first power interval, so that the first conversion branch, the second conversion branch, and the third conversion branch sequentially work in turn in a cyclic manner, where in each cycle, the working time of the first conversion branch, the second conversion branch, and the third conversion branch is the same.

The Control module 30 may be an MCU (Micro Control Unit).

Specifically, the controlling of the upper bridge switching tube and the lower bridge switching tube may be controlling the on and off of the upper bridge switching tube and the lower bridge switching tube. More specifically, when the power to be output is in the first power interval, the first conversion branch, the second conversion branch and the third conversion branch can work in turn by controlling the upper bridge switching tube and the lower bridge switching tube. For example, when the first conversion branch circuit works, the first upper bridge switching tube and the first lower bridge switching tube of the first conversion branch circuit can be controlled to be switched on or switched off, to control the first conversion branch to work, and at the same time, to control the upper bridge switch tube and the lower bridge switch tube of the second conversion branch and the third conversion branch to be both switched off, when the second conversion branch circuit is controlled to work, the second upper bridge switching tube and the second lower bridge switching tube of the second conversion branch circuit can be controlled to be switched on or switched off, to control the second conversion branch to work, and at the moment, to control the upper bridge switch tube and the lower bridge switch tube of the first conversion branch and the third conversion branch to be both switched off, and when controlling the third conversion branch circuit to work, controlling the third upper bridge switch tube and the third lower bridge switch tube of the third conversion branch circuit to be switched on or switched off, and controlling the third control branch to work, and controlling the upper bridge switching tube and the lower bridge switching tube of the first conversion branch and the second conversion branch to be switched off at the moment. When the upper bridge switching tube and the lower bridge switching tube are controlled to be switched on or switched off, the upper bridge switching tube can be controlled to be switched on or switched off during forward work, and the lower bridge switching tube can be controlled to be switched on or switched off during reverse work.

That is to say, when the bidirectional DC-DC converter operates, the obtaining module 10 obtains power to be output, the determining module 20 determines a power interval in which the power to be output is located, and if the power to be output is in the first power interval, the control module 30 controls the upper bridge switching tube and the lower bridge switching tube of the bidirectional DC-DC converter to be turned on or off, so that the first converting branch, the second converting branch and the third converting branch sequentially operate in a cyclic manner, for example, the first converting branch → the second converting branch → the third converting branch → the first converting branch alternately operates, where in each cycle, the operating time of the first converting branch, the second converting branch and the third converting branch is the same.

Specifically, the to-be-output power can be set to work for a first preset time in each cycle conversion branch when the to-be-output power is in a first power interval. When the power to be output belongs to a first power interval, firstly, the control module 30 controls the first conversion branch to work for a first preset time, when the working time of the first conversion branch reaches the first preset time, the control module 30 controls the first conversion branch to stop working and controls the second conversion branch to work for the first preset time, when the working time of the second conversion branch reaches the first preset time, the control module 30 controls the second conversion branch to stop working and controls the third conversion branch to work for the first preset time, when the working time of the third conversion branch reaches the first preset time, the control module 30 controls the third conversion branch to stop working and controls the first conversion branch to work for the first preset time, so that the first conversion branch, the second conversion branch and the third conversion branch work in turn in a cycle mode, and in each cycle, the first conversion branch, The working time of the second conversion branch circuit is the same as that of the third conversion branch circuit, namely the second conversion branch circuit works for the first preset time.

According to an embodiment of the present invention, the control module 30 is further configured to, when the first converting branch, the second converting branch and the third converting branch sequentially perform the alternate operation in a cyclic manner, if the bidirectional DC-DC converter stops operating or jumps out of the current power interval, obtain the remaining time of the currently operating converting branch and the currently operating converting branch, so as to continue to complete the remaining time of the currently operating converting branch when the bidirectional DC-DC converter sequentially performs the alternate operation with the first converting branch, the second converting branch and the third converting branch next time, and then perform the cycle again.

That is, the flag bits of the conversion branches may be set, for example, the flag bit of the first conversion branch is a, the flag bit of the second conversion branch is b, and the flag bit of the third conversion branch is c. When the bidirectional DC-DC converter stops working or jumps out of the current power interval, acquiring a flag bit of a currently working conversion branch to determine the currently working conversion branch and simultaneously acquiring the remaining time of the currently working conversion branch, for example, acquiring the operating time of the currently working conversion branch, and then calculating the first preset time to subtract the operating time of the currently working conversion branch to acquire the remaining time of the currently working conversion branch; for another example, when the conversion branch works, the remaining time of the current work can be calculated in a countdown manner, so that when the bidirectional DC-DC converter works next time in turn with the first conversion branch, the second conversion branch and the third conversion branch, the remaining time of the conversion branch working currently is continuously completed, and then circulation is performed, that is, according to the flag bit of the conversion branch working currently and the remaining time of the conversion branch working currently, when the power to be output of the bidirectional DC-DC converter is in the first power interval again, the conversion branch working currently is controlled to work continuously and work the remaining time of the conversion branch working currently, and then the next conversion branch is controlled to operate for the first preset time.

Therefore, the control device of the bidirectional DC-DC converter provided by the embodiment of the invention can control the first conversion branch, the second conversion branch and the third conversion branch to work in turn when the power to be output is in the first power interval, so that the working time of the switching tube is effectively reduced, the working life of the switching tube in the conversion branch is prolonged, and the life cycle of the bidirectional DC-DC converter can be further prolonged.

According to an embodiment of the present invention, the control module 30 is further configured to control the upper bridge switching tube and the lower bridge switching tube when the power to be output is in the second power interval, so that two of the first conversion branch, the second conversion branch and the third conversion branch are grouped into one group and sequentially operate in a cycle manner, where in each cycle, the operating time of each group of conversion branches is the same.

According to an embodiment of the present invention, the control module 30 is further configured to, when two of the first conversion branch, the second conversion branch and the third conversion branch sequentially perform alternate operation in a cyclic manner, if the bidirectional DC-DC converter stops operating or jumps out of the current power interval, obtain remaining time of the currently operating conversion branch group and the currently operating conversion branch group, so as to continue to complete the remaining time of the currently operating conversion branch group when the bidirectional DC-DC converter sequentially performs alternate operation in two of the first conversion branch, the second conversion branch and the third conversion branch next time, and then perform the cycle.

According to an embodiment of the present invention, the control module 30 is further configured to control the upper bridge switching tube and the lower bridge switching tube when the power to be output is in the third power interval, so that the first conversion branch, the second conversion branch, and the third conversion branch operate simultaneously.

That is to say, when the power to be output is in the third power interval, the control module 30 controls the first converting branch, the second converting branch and the third converting branch of the bidirectional DC-DC converting branch to work simultaneously, wherein the first converting branch, the second converting branch and the third converting branch equally divide the power to be output.

In summary, according to the control apparatus of the bidirectional DC-DC converter in the embodiment of the present invention, the bidirectional DC-DC converter includes the first converting branch, the second converting branch and the third converting branch which are connected in parallel, each converting branch includes the upper bridge switching tube and the lower bridge switching tube, the power to be output of the bidirectional DC-DC converter is obtained through the obtaining module, the judging module judges the power interval where the power to be output is located, the control module carries out alternate work on the upper bridge switching tube and the lower bridge switching tube when the power to be output is in the first power interval, wherein, in each cycle, the working time of the first conversion branch, the second conversion branch and the third conversion branch is the same, therefore, the working time of the switching tube is effectively reduced, the working life of the switching tube in the conversion branch is prolonged, and the life cycle of the bidirectional DC-DC converter can be further prolonged.

The embodiment of the invention also provides a bidirectional DC-DC converter.

Fig. 5 is a block schematic diagram of a bidirectional DC-DC converter according to an embodiment of the invention. As shown in fig. 5, the bidirectional DC-DC converter 200 according to the embodiment of the present invention includes the control device 100 of the bidirectional DC-DC converter.

The embodiment of the invention also provides a train.

Fig. 6 is a block schematic diagram of a train according to an embodiment of the invention. As shown in fig. 6, the train 300 of the embodiment of the present invention includes a bidirectional DC-DC converter 200.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

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

1. A control method of a bidirectional DC-DC converter is characterized in that the bidirectional DC-DC converter comprises a first conversion branch, a second conversion branch and a third conversion branch, the first conversion branch, the second conversion branch and the third conversion branch are connected in parallel, each of the first conversion branch, the second conversion branch and the third conversion branch comprises an upper bridge switching tube and a lower bridge switching tube, and the control method comprises the following steps:

acquiring the power to be output of the bidirectional DC-DC converter;

judging a power interval in which the power to be output is positioned, wherein the output power of the bidirectional DC-DC converter is divided into a first power interval, a second power interval and a third power interval, the power corresponding to the second power interval is larger than the power corresponding to the first power interval, and the power corresponding to the third power interval is larger than the power corresponding to the second power interval;

when the power to be output is in the first power interval, controlling the upper bridge switching tube and the lower bridge switching tube to enable the first conversion branch, the second conversion branch and the third conversion branch to work in turn in a circulating mode, wherein the working time of the first conversion branch, the second conversion branch and the third conversion branch is the same in each circulation;

when the first conversion branch, the second conversion branch and the third conversion branch work in turn in a circulating mode, if the bidirectional DC-DC converter stops working or jumps out of the current power interval, the remaining time of the conversion branch working at present and the remaining time of the conversion branch working at present are obtained, so that circulation is performed after the remaining time of the conversion branch working at present is continuously completed when the first conversion branch, the second conversion branch and the third conversion branch work in turn next time by the bidirectional DC-DC converter, wherein the remaining time of the conversion branch working at present is calculated in a countdown mode.

2. The method according to claim 1, wherein when the power to be output is in the second power interval, the upper bridge switching tube and the lower bridge switching tube are controlled so that two of the first conversion branch, the second conversion branch and the third conversion branch are sequentially operated in a cyclic manner, and the operation time of each conversion branch is the same in each cycle.

3. The method according to claim 1 or 2, wherein when the power to be output is in the third power interval, the up-bridge switching tube and the down-bridge switching tube are controlled so that the first conversion branch, the second conversion branch and the third conversion branch operate simultaneously.

4. The method according to claim 2, wherein when two of the first, second, and third conversion branches sequentially operate in a cyclic manner, if the bidirectional DC-DC converter stops operating or jumps out of the current power range, the remaining time of the currently operating conversion branch group and the currently operating conversion branch group is obtained, so that the bidirectional DC-DC converter continues to complete the remaining time of the currently operating conversion branch group when the bidirectional DC-DC converter sequentially operates in a group of two of the first, second, and third conversion branches next time.

5. A non-transitory computer-readable storage medium having stored thereon a computer program, characterized in that the program, when executed by a processor, implements the control method of the bidirectional DC-DC converter according to any one of claims 1 to 4.

6. A bidirectional DC-DC converter, characterized in that it further comprises a memory, a processor and a control program of the bidirectional DC-DC converter stored on the memory and executable on the processor, the control program of the bidirectional DC-DC converter, when executed by the processor, implementing the control method of the bidirectional DC-DC converter according to any one of claims 1-4.

7. A control device of a bidirectional DC-DC converter is characterized in that the bidirectional DC-DC converter comprises a first conversion branch, a second conversion branch and a third conversion branch, the first conversion branch, the second conversion branch and the third conversion branch are connected in parallel, each of the first conversion branch, the second conversion branch and the third conversion branch comprises an upper bridge switching tube and a lower bridge switching tube, and the control device comprises:

the acquisition module is used for acquiring the power to be output of the bidirectional DC-DC converter;

the judging module is used for judging a power interval in which the power to be output is positioned, wherein the output power of the bidirectional DC-DC converter is divided into a first power interval, a second power interval and a third power interval, the power corresponding to the second power interval is larger than the power corresponding to the first power interval, and the power corresponding to the third power interval is larger than the power corresponding to the second power interval;

the control module is used for controlling the upper bridge switching tube and the lower bridge switching tube when the power to be output is in the first power interval so as to enable the first conversion branch, the second conversion branch and the third conversion branch to work in turn in a circulating mode, wherein the working time of the first conversion branch, the second conversion branch and the third conversion branch is the same in each circulation; and if the bidirectional DC-DC converter stops working or jumps out of the current power interval, acquiring the remaining time of the current working conversion branch and the remaining time of the current working conversion branch so as to circulate after the remaining time of the current working conversion branch is continuously finished when the bidirectional DC-DC converter sequentially works in turn by the first conversion branch, the second conversion branch and the third conversion branch next time, wherein the remaining time of the current working conversion branch is calculated in a countdown mode.

8. The apparatus according to claim 7, wherein the control module is further configured to control the upper bridge switching tube and the lower bridge switching tube when the power to be output is in the second power interval, so that two of the first conversion branch, the second conversion branch and the third conversion branch are sequentially operated in a cyclic manner, and in each cycle, the operation time of each conversion branch is the same.

9. The apparatus according to claim 7 or 8, wherein the control module is further configured to control the upper switching tube and the lower switching tube to operate the first converting branch, the second converting branch and the third converting branch simultaneously when the power to be output is in the third power interval.

10. The apparatus according to claim 8, wherein the control module is further configured to, when two of the first, second, and third transforming branches sequentially operate in a cyclic manner, if the bidirectional DC-DC converter stops operating or jumps out of the current power interval, obtain the remaining time of the currently operating transforming branch group and the currently operating transforming branch group, so as to continue to complete the remaining time of the currently operating transforming branch group when the bidirectional DC-DC converter next operates in a cyclic manner with two of the first, second, and third transforming branches sequentially operating in a cyclic manner.

11. A bidirectional DC-DC converter, characterized by comprising a control device of the bidirectional DC-DC converter according to any one of claims 7 to 10.

12. Train, characterized in that it comprises a bidirectional DC-DC converter according to claim 6 or 11.