阅读说明：本技术 一种控制双向储能变流器的方法及双向储能变流器 (Method for controlling bidirectional energy storage converter and bidirectional energy storage converter ) 是由 张政权 张耀文 刘庆想 欧伟丽 于 2020-07-27 设计创作，主要内容包括：本发明提供了一种控制双向储能变流器的方法及双向储能变流器,其中,方法包括：依据工况与控制策略的对应关系得到获取的当前工况对应的当前控制策略,依据当前控制策略计算三相电压指令值；查询预先存储的电压指令值与工作区间的映射关系,得到三相电压指令值映射的当前工作区间,并依据三相电压指令值计算电压参数；依据电压参数计算等效直流合成电压,依据储能器侧电压与等效直流合成电压,确定双向储能变流器的工作模式；依据当前工况、确定的工作模式、电压参数计算开关周期中每个工作过程的导通时长；依据开关周期中每个工作过程的导通时长,生成驱动脉冲信号,以控制当前工作区间中对应开关的导通。可以提高双向储能变流器的利用效率。(The invention provides a method for controlling a bidirectional energy storage converter and the bidirectional energy storage converter, wherein the method comprises the following steps: obtaining a current control strategy corresponding to the obtained current working condition according to the corresponding relation between the working condition and the control strategy, and calculating a three-phase voltage instruction value according to the current control strategy; inquiring a mapping relation between a prestored voltage command value and a working interval to obtain a current working interval mapped by the three-phase voltage command value, and calculating a voltage parameter according to the three-phase voltage command value; calculating equivalent direct current synthetic voltage according to the voltage parameters, and determining the working mode of the bidirectional energy storage converter according to the side voltage of the energy accumulator and the equivalent direct current synthetic voltage; calculating the conduction duration of each working process in the switching period according to the current working condition, the determined working mode and the voltage parameter; and generating a driving pulse signal according to the conduction duration of each working process in the switching period so as to control the conduction of the corresponding switch in the current working interval. The utilization efficiency of the bidirectional energy storage converter can be improved.)

1. A bi-directional energy storage converter, comprising: an energy storage, a DC-AC converter, a transformer, a resonator, a switching assembly, a filtering assembly, wherein,

the energy accumulator is connected with the DC-AC converter, the DC-AC converter is also connected with the transformer, the transformer is also connected with the resonator, the resonator is also connected with the switch component, and the switch component is also connected with the filter component;

when the bidirectional energy storage converter is used for supplying energy, the energy accumulator outputs direct current, the direct current-alternating current converter performs direct current-alternating current conversion on the direct current output by the energy accumulator to obtain alternating current, the alternating current is output to the transformer, the transformer transforms the input alternating current to obtain transformation alternating current and outputs the transformation alternating current to the resonator, the resonator performs resonance conversion on the transformation alternating current to obtain resonance alternating current, the resonance alternating current is output to the switch assembly, the switch assembly performs on-off control on the resonance alternating current to obtain three-phase alternating current, the three-phase alternating current is output to the filtering assembly, and the filtering assembly filters the three-phase alternating current and then outputs the;

when the bidirectional energy storage converter is used for storing energy, a power grid outputs three-phase alternating current, the filtering assembly filters the three-phase alternating current and outputs the three-phase alternating current to the switch assembly, the switch assembly converts the filtered three-phase alternating current into alternating current signals and outputs the alternating current signals to the resonator, the resonator performs resonance transformation on the alternating current signals to obtain resonance alternating current, the resonance alternating current is output to the transformer, the transformer transforms the input resonance alternating current to obtain transformation alternating current, the transformation alternating current is output to the direct current-alternating current converter, the direct current-alternating current converter performs alternating current-direct current transformation on the transformation alternating current to obtain direct current, the direct current is output to the energy storage device.

2. The bidirectional energy storage converter of claim 1, further comprising: a first controller and a second controller, wherein,

the first controller outputs first control information to control the on-off of a switch in the direct current-alternating current converter;

the second controller outputs second control information to control the on-off of the switch in the switch assembly.

3. The bidirectional energy storage converter of claim 1, wherein said dc-ac converter comprises: a first switch, a second switch, a third switch, and a fourth switch, wherein,

the first end of the first switch is respectively connected with the first end of the third switch and one end of the energy accumulator, and the second end of the first switch is respectively connected with the first end of the second switch and one end of the primary winding of the transformer;

the second end of the second switch is respectively connected with the second end of the fourth switch and the other end of the energy accumulator;

the first end of the third switch is respectively connected with the first end of the fourth switch and the other end of the primary winding of the transformer;

and the third ends of the first switch, the second switch, the third switch and the fourth switch are respectively connected with the output end of the first controller.

4. The bidirectional energy storage converter of claim 2, wherein said switching assembly comprises: a fifth switch, a sixth switch, a seventh switch, an eighth switch, a ninth switch, a tenth switch, an eleventh switch, a twelfth switch, a thirteenth switch, a fourteenth switch, a fifteenth switch, and a sixteenth switch, wherein,

the first end of the fifth switch is respectively connected with the first end of the seventh switch, the first end of the ninth switch and the first output end of the resonator, and the second end of the fifth switch is connected with the second end of the sixth switch;

the second end of the seventh switch is connected with the second end of the eighth switch;

the second end of the ninth switch is connected with the second end of the tenth switch;

the first end of the eleventh switch is connected with the first end of the sixth switch and the third input end of the filtering component respectively, and the second end of the eleventh switch is connected with the second end of the twelfth switch;

a first end of the thirteenth switch is connected with a first end of the eighth switch and a second input end of the filtering component respectively, and a second end of the thirteenth switch is connected with a second end of the fourteenth switch;

a first end of the fifteenth switch is connected with a first end of the tenth switch and a first input end of the filtering component respectively, and a second end of the fifteenth switch is connected with a second end of the sixteenth switch;

a first end of the twelfth switch is connected with a first end of the fourteenth switch, a first end of the sixteenth switch and a second output end of the resonator respectively;

and the third ends of the fifth switch, the sixth switch, the seventh switch, the eighth switch, the ninth switch, the tenth switch, the eleventh switch, the twelfth switch, the thirteenth switch, the fourteenth switch, the fifteenth switch and the sixteenth switch are respectively connected with the output end of the second controller.

5. A bidirectional energy storing converter as claimed in claim 3 or 4, wherein said first terminal is a drain, said second terminal is a source and said third terminal is a gate.

6. A bi-directional energy storage converter as claimed in claim 3 or 4 wherein said first, second, third and fourth switches are unidirectional switches and each switch in said switch assembly is a bi-directional switch.

7. A method of controlling a bidirectional energy storage converter, comprising:

acquiring the current working condition of the bidirectional energy storage converter according to external scheduling, and calculating a three-phase voltage instruction value according to a current control strategy corresponding to the current working condition;

inquiring a mapping relation between a prestored voltage command value and a working interval to obtain a current working interval mapped by the three-phase voltage command value, and calculating a voltage parameter according to the three-phase voltage command value;

calculating equivalent direct current synthetic voltage according to the voltage parameters, and determining the working mode of the bidirectional energy storage converter according to the side voltage of the energy accumulator and the equivalent direct current synthetic voltage;

calculating the conduction duration of each working process in the switching period according to the current working condition, the determined working mode and the voltage parameter;

and generating a driving pulse signal according to the conduction duration of each working process in the switching period so as to control the conduction of the corresponding switch in the current working interval.

8. The method of claim 7, wherein calculating the on-time for each operation in the switching cycle according to the voltage parameter comprises:

determining basic parameters of a state plan according to the current working condition, the determined working mode, the high line voltage of the voltage parameter, the low line voltage and the charge distribution ratio;

and calculating the conduction time length of each working process in the switching period according to the basic parameters of the obtained state plan.

9. An electronic device, comprising: a processor, a memory and a bus, the memory storing machine readable instructions executable by the processor, the processor and the memory communicating over the bus when the electronic device is running, the machine readable instructions when executed by the processor performing the steps of the method of controlling a bidirectional energy storage converter as claimed in claim 7 or 8.

10. A computer-readable storage medium, characterized in that a computer program is stored thereon, which computer program, when being executed by a processor, performs the steps of the method of controlling a bidirectional energy storage converter as claimed in claim 7 or 8.

Technical Field

The invention relates to the technical field of electrical control, in particular to a method for controlling a bidirectional energy storage converter and the bidirectional energy storage converter.

Background

With the rapid development of power electronic technology and the proposal of new energy development planning, the application of generating power by using new energy is more and more extensive, but because the continuity and stability of new energy power generation are poor, most of the new energy is intermittent energy, after the new energy is connected into a power grid, a bidirectional energy storage converter is required to be arranged as an energy storage and supply system to improve the power quality of the power grid and stabilize the power fluctuation in the power grid, thereby realizing the bidirectional flow of electric energy on the side of the power grid and the bidirectional energy storage converter, effectively regulating the electric energy balance between the side of the power grid and the side of a load during peak valley period, and playing a role of peak clipping and valley filling, wherein the regulating performance of the bidirectional energy storage converter directly determines the working performance of the whole energy storage system.

At present, in a bidirectional energy storage converter at home and abroad, a bidirectional Direct Current-Direct Current (DC-DC) converter with high frequency isolation is adopted at a Direct Current side, namely an energy storage side, to perform voltage boosting and reducing, and a bidirectional (DC-AC) converter is adopted at an Alternating Current side, namely a power grid side, to perform Direct Current-Alternating Current conversion, so that two-stage conversion exists between the power grid side and the energy storage side, partial power is consumed by the two-stage conversion, the utilization efficiency of the bidirectional energy storage converter is influenced, and the manufacturing cost of the bidirectional energy storage converter is higher due to the two-stage Current conversion.

Disclosure of Invention

In view of the above, the present invention provides a method for controlling a bidirectional energy storage converter and a bidirectional energy storage converter, so as to improve the utilization efficiency of the bidirectional energy storage converter.

In a first aspect, an embodiment of the present invention provides a bidirectional energy storage converter, including: an energy storage, a DC-AC converter, a transformer, a resonator, a switching assembly, a filtering assembly, wherein,

the energy accumulator is connected with the DC-AC converter, the DC-AC converter is also connected with the transformer, the transformer is also connected with the resonator, the resonator is also connected with the switch component, and the switch component is also connected with the filter component;

when the bidirectional energy storage converter is used for supplying energy, the energy accumulator outputs direct current, the direct current-alternating current converter performs direct current-alternating current conversion on the direct current output by the energy accumulator to obtain alternating current, the alternating current is output to the transformer, the transformer transforms the input alternating current to obtain transformation alternating current and outputs the transformation alternating current to the resonator, the resonator performs resonance conversion on the transformation alternating current to obtain resonance alternating current, the resonance alternating current is output to the switch assembly, the switch assembly performs on-off control on the resonance alternating current to obtain three-phase alternating current, the three-phase alternating current is output to the filtering assembly, and the filtering assembly filters the three-phase alternating current and then outputs the;

when the bidirectional energy storage converter is used for storing energy, a power grid outputs three-phase alternating current, the filtering assembly filters the three-phase alternating current and outputs the three-phase alternating current to the switch assembly, the switch assembly converts the filtered three-phase alternating current into alternating current signals and outputs the alternating current signals to the resonator, the resonator performs resonance transformation on the alternating current signals to obtain resonance alternating current, the resonance alternating current is output to the transformer, the transformer transforms the input resonance alternating current to obtain transformation alternating current, the transformation alternating current is output to the direct current-alternating current converter, the direct current-alternating current converter performs alternating current-direct current transformation on the transformation alternating current to obtain direct current, the direct current is output to the energy storage device.

With reference to the first aspect, an embodiment of the present invention provides a first possible implementation manner of the first aspect, where the method further includes: a first controller and a second controller, wherein,

the first controller outputs first control information to control the on-off of a switch in the direct current-alternating current converter;

the second controller outputs second control information to control the on-off of the switch in the switch assembly.

With reference to the first aspect, an embodiment of the present invention provides a second possible implementation manner of the first aspect, where the dc-ac converter includes: a first switch, a second switch, a third switch, and a fourth switch, wherein,

the first end of the first switch is respectively connected with the first end of the third switch and one end of the energy accumulator, and the second end of the first switch is respectively connected with the first end of the second switch and one end of the primary winding of the transformer;

the second end of the second switch is respectively connected with the second end of the fourth switch and the other end of the energy accumulator;

the first end of the third switch is respectively connected with the first end of the fourth switch and the other end of the primary winding of the transformer;

and the third ends of the first switch, the second switch, the third switch and the fourth switch are respectively connected with the output end of the first controller.

With reference to the first possible implementation manner of the first aspect, an embodiment of the present invention provides a third possible implementation manner of the first aspect, where the switch assembly includes: a fifth switch, a sixth switch, a seventh switch, an eighth switch, a ninth switch, a tenth switch, an eleventh switch, a twelfth switch, a thirteenth switch, a fourteenth switch, a fifteenth switch, and a sixteenth switch, wherein,

the first end of the fifth switch is respectively connected with the first end of the seventh switch, the first end of the ninth switch and the first output end of the resonator, and the second end of the fifth switch is connected with the second end of the sixth switch;

the second end of the seventh switch is connected with the second end of the eighth switch;

the second end of the ninth switch is connected with the second end of the tenth switch;

the first end of the eleventh switch is connected with the first end of the sixth switch and the third input end of the filtering component respectively, and the second end of the eleventh switch is connected with the second end of the twelfth switch;

a first end of the thirteenth switch is connected with a first end of the eighth switch and a second input end of the filtering component respectively, and a second end of the thirteenth switch is connected with a second end of the fourteenth switch;

a first end of the fifteenth switch is connected with a first end of the tenth switch and a first input end of the filtering component respectively, and a second end of the fifteenth switch is connected with a second end of the sixteenth switch;

a first end of the twelfth switch is connected with a first end of the fourteenth switch, a first end of the sixteenth switch and a second output end of the resonator respectively;

and the third ends of the fifth switch, the sixth switch, the seventh switch, the eighth switch, the ninth switch, the tenth switch, the eleventh switch, the twelfth switch, the thirteenth switch, the fourteenth switch, the fifteenth switch and the sixteenth switch are respectively connected with the output end of the second controller.

With reference to the second possible implementation manner or the third possible implementation manner of the first aspect, an embodiment of the present invention provides a fourth possible implementation manner of the first aspect, wherein the first terminal is a drain, the second terminal is a source, and the third terminal is a gate.

With reference to the second possible implementation manner or the third possible implementation manner of the first aspect, an embodiment of the present invention provides a fifth possible implementation manner of the first aspect, where the first switch, the second switch, the third switch, and the fourth switch are unidirectional switches, and each switch in the switch assembly is a bidirectional switch.

In a second aspect, an embodiment of the present invention further provides a method for controlling a bidirectional energy storage converter, including:

acquiring the current working condition of the bidirectional energy storage converter, inquiring the corresponding relation between the pre-stored working condition and the control strategy to obtain the current control strategy corresponding to the current working condition, and calculating a three-phase voltage command value according to the current control strategy;

inquiring a mapping relation between a prestored voltage command value and a working interval to obtain a current working interval mapped by the three-phase voltage command value, and calculating a voltage parameter according to the three-phase voltage command value;

calculating equivalent direct current synthetic voltage according to the voltage parameters, and determining the working mode of the bidirectional energy storage converter according to the side voltage of the energy accumulator and the equivalent direct current synthetic voltage;

calculating the conduction duration of each working process in the switching period according to the current working condition, the determined working mode and the voltage parameter;

and generating a driving pulse signal according to the conduction duration of each working process in the switching period so as to control the conduction of the corresponding switch in the current working interval.

With reference to the second aspect, an embodiment of the present invention provides a first possible implementation manner of the second aspect, where the calculating, according to the voltage parameter, the on-time of each working process in the switching period includes:

determining basic parameters of a state plan according to the current working condition, the determined working mode, the high line voltage of the voltage parameter, the low line voltage and the charge distribution ratio;

and calculating the conduction time length of each working process in the switching period according to the basic parameters of the obtained state plan.

In a third aspect, an embodiment of the present application provides a computer device, which includes a memory, a processor, and a computer program stored on the memory and executable on the processor, and the processor implements the steps of the above method when executing the computer program.

In a fourth aspect, the present application provides a computer-readable storage medium, on which a computer program is stored, and the computer program, when executed by a processor, performs the steps of the method described above.

The embodiment of the invention provides a method for controlling a bidirectional energy storage converter and the bidirectional energy storage converter, wherein the bidirectional energy storage converter comprises the following steps: the device comprises an energy storage device, a direct current-alternating current converter, a transformer, a resonator, a switch component and a filter component, wherein the energy storage device is connected with the direct current-alternating current converter, the direct current-alternating current converter is also connected with the transformer, the transformer is also connected with the resonator, the resonator is also connected with the switch component, and the switch component is also connected with the filter component; when the bidirectional energy storage converter is used for supplying energy, the energy accumulator outputs direct current, the direct current-alternating current converter performs direct current-alternating current conversion on the direct current output by the energy accumulator to obtain alternating current, the alternating current is output to the transformer, the transformer transforms the input alternating current to obtain transformation alternating current and outputs the transformation alternating current to the resonator, the resonator performs resonance conversion on the transformation alternating current to obtain resonance alternating current, the resonance alternating current is output to the switch assembly, the switch assembly performs on-off control on the resonance alternating current to obtain three-phase alternating current, the three-phase alternating current is output to the filtering assembly, and the filtering assembly filters the three-phase alternating current and then outputs the; when the bidirectional energy storage converter is used for storing energy, a power grid outputs three-phase alternating current, the filtering assembly filters the three-phase alternating current and outputs the three-phase alternating current to the switch assembly, the switch assembly converts the filtered three-phase alternating current into alternating current signals and outputs the alternating current signals to the resonator, the resonator performs resonance transformation on the alternating current signals to obtain resonance alternating current, the resonance alternating current is output to the transformer, the transformer transforms the input resonance alternating current to obtain transformation alternating current, the transformation alternating current is output to the direct current-alternating current converter, the direct current-alternating current converter performs alternating current-direct current transformation on the transformation alternating current to obtain direct current, the direct current is output to the energy storage device. Therefore, a direct current-direct current converter is not required to be arranged, the frequency of electric energy conversion is reduced, and the utilization efficiency of the bidirectional energy storage converter can be effectively improved.

In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 shows a schematic structural diagram of a bidirectional energy storage converter provided by an embodiment of the invention;

fig. 2 is a schematic flow chart of a method for controlling a bidirectional energy storage converter according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a computer device 300 according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.

In the existing bidirectional energy storage converter, a DC-DC converter is adopted at a direct current side for voltage increase and reduction, and a DC-AC converter is adopted at an alternating current side for direct current and alternating current conversion. In the embodiment of the invention, the DC-AC converter is adopted for direct current-alternating current conversion, the transformer and the resonator are utilized for voltage boosting and reducing, the energy storage and energy supply of the bidirectional energy storage converter are realized by controlling the on-off duration of the switch assembly, and the power consumption of the resonator is far less than that of the DC-DC converter, so that the utilization efficiency of the bidirectional energy storage converter can be effectively improved.

The embodiment of the invention provides a method for controlling a bidirectional energy storage converter and the bidirectional energy storage converter, which are described by the following embodiments.

Fig. 1 shows a schematic structural diagram of a bidirectional energy storage converter provided in an embodiment of the present invention. As shown in fig. 1, the bidirectional energy storage converter comprises: an energy storage 01, a DC-AC converter 02, a transformer 03, a resonator 04, a switch component 05 and a filter component 06, wherein,

the energy storage device 01 is connected with the DC-AC converter 02, the DC-AC converter 02 is also connected with the transformer 03, the transformer 03 is also connected with the resonator 04, the resonator 04 is also connected with the switch component 05, and the switch component 05 is also connected with the filter component 06.

In the embodiment of the invention, when the bidirectional energy storage converter is powered, the energy storage device 01 outputs direct current, the direct current-alternating current converter 02 performs direct current-alternating current conversion on the direct current output by the energy storage device 01 to obtain alternating current, the alternating current is output to the transformer 03, the transformer 03 performs voltage transformation on the input alternating current to obtain voltage transformation alternating current, the voltage transformation alternating current is output to the resonator 04, the resonator 04 performs resonance conversion on the voltage transformation alternating current to obtain resonance alternating current, the resonance alternating current is output to the switch assembly 05, the switch assembly 05 performs on-off control on the resonance alternating current to obtain three-phase alternating current, the three-phase alternating current is output to the filter assembly 06, and the filter assembly 06 filters the three.

When the bidirectional energy storage converter is in energy storage, a three-phase alternating current is output by a power grid, the three-phase alternating current is filtered by the filtering component 06 and then output to the switching component 05, the three-phase alternating current after being filtered is converted into an alternating current signal by the switching component 05 and output to the resonator 04, the resonator 04 performs resonance transformation on the alternating current signal to obtain a resonance alternating current, the resonance alternating current is output to the transformer 03, the transformer 03 transforms the input resonance alternating current to obtain a transformation alternating current, the transformation alternating current is output to the direct current-alternating current converter 02, the direct current-alternating current converter 02 performs alternating current-direct current transformation on the transformation alternating current to obtain a direct current, the direct current is output to the energy storage device. Therefore, by adopting the novel electric energy conversion structure, the intermediate direct current storage link can be saved, the electric energy conversion times are reduced, the power density and the utilization efficiency of the bidirectional energy storage converter can be effectively improved, and the cost can be reduced.

In this embodiment of the present invention, as an optional embodiment, the bidirectional energy storage converter further includes: a first controller and a second controller (not shown), wherein,

the first controller outputs first control information to control the on-off of a switch in the direct current-alternating current converter 02;

the second controller outputs second control information to control the on/off of the switch in the switch assembly 05.

In this embodiment of the present invention, as an alternative embodiment, the dc-ac converter 02 includes: a first switch V1, a second switch V2, a third switch V3, and a fourth switch V4, wherein,

a first end of the first switch V1 is connected to a first end of the third switch V3 and one end of the energy storage device 01, respectively, and a second end is connected to a first end of the second switch V2 and one end of the primary winding of the transformer 03, respectively;

a second end of the second switch V2 is connected to a second end of the fourth switch V4 and the other end of the energy storage device 01;

a first end of the third switch V3 is connected to a first end of the fourth switch V4 and the other end of the primary winding of the transformer 03, respectively;

and third ends of the first switch V1, the second switch V2, the third switch V3 and the fourth switch V4 are respectively connected with an output end of the first controller.

In the embodiment of the present invention, as an optional embodiment, the switch includes but is not limited to: a Metal Oxide Semiconductor (MOS) Transistor, an Insulated Gate Bipolar Transistor (IGBT) Transistor, a triode, and a field effect Transistor. The first end is a drain electrode, the second end is a source electrode, and the third end is a grid electrode.

In the embodiment of the present invention, as an alternative embodiment, the first switch V1, the second switch V2, the third switch V3, and the fourth switch V4 are unidirectional switches. The first control signal output by the first controller turns on the first switch V1 and the fourth switch V4 and turns off the second switch V2 and the third switch V3, or turns on the second switch V2 and the third switch V3 and turns off the first switch V1 and the fourth switch V4.

In this embodiment of the present invention, as an optional embodiment, the resonator 04 includes: a resonant capacitor Cr and a resonant inductor Lr, wherein,

one end of the resonant capacitor Cr is connected with one end of the secondary winding of the transformer 03, and the other end is connected with a first input end of the switch component 05;

one end of the resonant inductor Lr is connected to the other end of the secondary winding of the transformer 03, and the other end is connected to the second input terminal of the switching element 05.

In the embodiment of the present invention, as an optional embodiment, the transformer 03 is a power electronic transformer 03, which has a small volume and a light weight.

In this embodiment of the present invention, as an optional embodiment, the switch module 05 includes: a fifth switch V5, a sixth switch V6, a seventh switch V7, an eighth switch V8, a ninth switch V9, a tenth switch V10, an eleventh switch V11, a twelfth switch V12, a thirteenth switch V13, a fourteenth switch V14, a fifteenth switch V15, and a sixteenth switch V16, wherein,

a first terminal of the fifth switch V5 is connected to a first terminal of the seventh switch V7, a first terminal of the ninth switch V9, and a first output terminal of the resonator 04, respectively, and a second terminal is connected to a second terminal of the sixth switch V6;

a second terminal of the seventh switch V7 is connected to a second terminal of the eighth switch V8;

a second terminal of the ninth switch V9 is connected to a second terminal of the tenth switch V10;

a first terminal of the eleventh switch V11 is connected to the first terminal of the sixth switch V6 and the third input terminal of the filter module 06, respectively, and a second terminal is connected to the second terminal of the twelfth switch V12;

a first terminal of the thirteenth switch V13 is connected to the first terminal of the eighth switch V8 and the second input terminal of the filter module 06, respectively, and a second terminal is connected to the second terminal of the fourteenth switch V14;

a first terminal of the fifteenth switch V15 is connected to the first terminal of the tenth switch V10 and the first input terminal of the filter module 06, respectively, and a second terminal is connected to the second terminal of the sixteenth switch V16;

a first end of the twelfth switch V12 is connected to a first end of the fourteenth switch V14, a first end of the sixteenth switch V16, and a second output terminal of the resonator 04, respectively;

third ends of a fifth switch V5, a sixth switch V6, a seventh switch V7, an eighth switch V8, a ninth switch V9, a tenth switch V10, an eleventh switch V11, a twelfth switch V12, a thirteenth switch V13, a fourteenth switch V14, a fifteenth switch V15 and a sixteenth switch V16 are respectively connected with the output end of the second controller.

In the embodiment of the present invention, as an optional embodiment, each switch in the switch assembly 05 is a bidirectional switch, so that bidirectional flow of energy can be realized.

In this embodiment of the present invention, as an optional embodiment, the filtering component 06 includes: a first capacitor Ca, a second capacitor Cb, a third capacitor Cc, a first inductor La, a second inductor Lb, and a third inductor Lc;

one end of the first capacitor Ca is connected to one end of the first inductor La and the first end of the tenth switch V10, respectively, and the other end is connected to the power grid;

one end of the second capacitor Cb is connected to one end of the second inductor Lb and the first end of the eighth switch V8, respectively, and the other end is connected to the power grid;

one end of the third capacitor Cc is connected to one end of the third inductor Lc and the first end of the sixth switch V6, respectively, and the other end is connected to the power grid.

In the embodiment of the present invention, as an optional embodiment, the filtering component 06 is a second-order low-pass filter composed of three inductors and three capacitors.

In the embodiment of the invention, under the off/grid-connected working condition, the energy storage device 01 is in a discharging state, the voltage output by discharging is inverted into high-frequency alternating current through the DC/AC converter, and then is modulated into three-phase alternating current with specific amplitude, frequency and phase required by a load or a power grid through the transformer 03, the resonance component, the switching component 05 and the filtering component 06. Under the charging working condition, the energy storage device 01 is in a charging state, three-phase alternating current of a power grid is modulated into single-phase alternating current through the filtering component 06 and the switching component 05, and then is rectified by the DC/AC converter through the resonance component and the transformer 03 to output direct current voltage meeting the charging amplitude of the energy storage device 01.

Fig. 2 shows a flow chart of a method for controlling a bidirectional energy storage converter according to an embodiment of the present invention. The structure of the bidirectional energy storage converter is shown in fig. 1, and as shown in fig. 2, the method comprises the following steps:

step 201, obtaining the current working condition of a bidirectional energy storage converter according to external scheduling, and calculating a three-phase voltage instruction value according to a current control strategy corresponding to the current working condition and the current control strategy;

in the embodiment of the present invention, as an optional embodiment, the working conditions include, but are not limited to: the control strategy comprises a grid-connected working condition, an off-grid working condition and a charging working condition, wherein the control strategy corresponding to the grid-connected working condition is active power and reactive Power (PQ) control, the control strategy corresponding to the off-grid working condition is voltage Frequency (V/F) conversion control, and the control strategy corresponding to the charging working condition is voltage outer ring current inner ring control.

In the embodiment of the present invention, if the current operating condition is a grid-connected operating condition, the current control strategy is active power and reactive power control, and as an optional embodiment, the calculating of the three-phase voltage command value according to the current control strategy includes:

a11, acquiring three-phase alternating current of a power grid, and acquiring an active power value, a reactive power value, an active current value and a reactive current value according to the three-phase alternating current;

a12, performing power loop calculation on the obtained active power value and reactive power value and preset active power reference value and reactive power reference value to obtain an active current reference value and a reactive current reference value;

a13, obtaining an active voltage instruction value and a reactive voltage instruction value according to the active current value, the reactive current value, the active current reference value and the reactive current reference value;

and A14, acquiring a voltage phase angle of the three-phase alternating current of the power grid, and acquiring a three-phase voltage instruction value according to the active voltage instruction value, the reactive voltage instruction value and the voltage phase angle.

In the embodiment of the invention, the three-phase alternating current of the power grid is subjected to power calculation and decoupling to obtain an active power value P and a reactive power value Q. Through the active power value P, the reactive power value Q and the preset active power reference value P_refReference value of reactive power Q_refCalculating to obtain an active current reference value I_drefAnd a reactive current reference value I_qref。

The three-phase alternating current of the power grid is subjected to coordinate transformation to obtain the actual active current value I_dAnd a value of reactive current I_qFor active current value I by using preset current regulator_dValue of reactive current I_qReference value of active current I_drefAnd a reactive current reference value I_qrefRegulating to obtain an active voltage command value V_d ^*And a reactive voltage command value V_q ^*。

In the embodiment of the invention, three-phase alternating current is output through the phase-locked loop, a voltage phase angle theta can be obtained, and the voltage phase angle theta and an active voltage instruction value V are obtained_d ^*And a reactive voltage command value V_q ^*Coordinate inverse transformation is carried out to obtain a three-phase voltage command value V_a ^*、V_b ^*、V_c ^*。

In the embodiment of the present invention, if the current operating condition is an off-grid operating condition, the current control strategy is voltage-frequency conversion control, and as an optional embodiment, the calculating of the three-phase voltage command value according to the current control strategy includes:

a21, acquiring three-phase alternating current of a load, and acquiring a quadrature-direct axis active voltage value and a quadrature-direct axis reactive voltage value according to the three-phase alternating current;

a22, obtaining an active voltage instruction value and a reactive voltage instruction value according to the obtained quadrature-direct axis active voltage value, the quadrature-direct axis reactive voltage value, and a preset quadrature-direct axis active voltage reference value and a preset quadrature-direct axis reactive voltage reference value;

and A23, integrating the three-phase alternating current of the load to obtain a voltage phase angle, and obtaining a three-phase voltage command value according to the active voltage command value, the reactive voltage command value and the voltage phase angle.

In the embodiment of the invention, the voltage of the three-phase alternating current of the load is utilized to carry out coordinate transformation decoupling to obtain the actual active voltage value V of the alternating current and direct current axes_dAnd the reactive voltage value V of the quadrature axis and the direct axis_q。

Will be the active voltage value V of the quadrature-direct axis_dReactive voltage value V of AC/DC axis_qAnd a preset active voltage reference value V of the quadrature-direct axis_drefReactive voltage reference value V of quadrature-direct axis_qrefThe input voltage regulator obtains an active voltage command value V_d ^*And a reactive voltage command value V_q ^*。

In the embodiment of the invention, the frequency of the three-phase alternating current of the load is given by the outside, the three-phase alternating current is integrated to obtain the voltage phase angle theta, and the voltage phase angle theta is obtainedPhase angle theta and active voltage command value V_d ^*And a reactive voltage command value V_q ^*Coordinate inverse transformation is carried out to obtain a three-phase voltage command value V_a ^*、V_b ^*、V_c ^*。

In the embodiment of the present invention, the current operating condition is a charging operating condition, and the current control strategy is voltage outer loop current inner loop control, and as an optional embodiment, the calculating of the three-phase voltage command value according to the current control strategy includes:

a31, obtaining an active current reference value and a reactive current reference value according to the side voltage of the energy storage and the preset charging voltage;

a32, carrying out coordinate transformation on the three-phase alternating current of the power grid to obtain an active current value and a reactive current value;

a33, obtaining an active voltage instruction value and a reactive voltage instruction value according to the active current reference value, the reactive current reference value, the active current value and the reactive current value;

and A34, acquiring a voltage phase angle of the three-phase alternating current of the power grid, and acquiring a three-phase voltage instruction value according to the active voltage instruction value, the reactive voltage instruction value and the voltage phase angle.

In the embodiment of the invention, the voltage V at the side of the energy storage device is used_dcAnd a charging voltage V_dcrefPerforming voltage outer-loop conversion to obtain an active current reference value I_drefAnd a reactive current reference value I_qref。

The actual active current value I is obtained by carrying out coordinate transformation on the three-phase alternating current of the power grid_dAnd a value of reactive current I_q。

Reference value I of active current_drefReference value of reactive current I_qrefActive current value I_dAnd a value of reactive current I_qInputting the current regulator to obtain an active voltage command value V_d ^*And a reactive voltage command value V_q ^*。

Three-phase alternating current of a power grid is output through a phase-locked loop, a voltage phase angle theta can be obtained, and the voltage phase angle theta and an active voltage instruction value V are obtained_d ^*And a reactive voltage command value V_q ^*Coordinate inverse transformation is carried out to obtain a three-phase voltage command value V_a ^*、V_b ^*、V_c ^*。

Step 202, inquiring a mapping relation between a prestored voltage command value and a working interval to obtain a current working interval mapped by the three-phase voltage command value, and calculating a voltage parameter according to the three-phase voltage command value;

in the embodiment of the present invention, as an optional embodiment, the voltage parameters include but are not limited to: high line voltage, low line voltage and charge sharing ratio.

In the embodiment of the present invention, as an optional embodiment, the three-phase voltage command values are divided into 12 working time intervals in advance according to the magnitude of the three-phase voltage command values. And in each working time interval, the magnitude and the positive-negative relation of the three-phase voltage command values are determined.

In the embodiment of the present invention, the relationship between the phase voltages in the 12 working time intervals is specifically:

operating time interval 1: v_c ^*>V_a ^*>V_b ^*,U_P＝V_a ^*,U_M＝V_c ^*,U_N＝V_b ^*；

Operating time interval 2: v_a ^*>V_c ^*>V_b ^*,U_P＝V_a ^*,U_M＝V_b ^*,U_N＝V_c ^*；

Operating time interval 3: v_a ^*>V_c ^*>V_b ^*,U_P＝V_a ^*,U_M＝V_c ^*,U_N＝V_b ^*；

Operating time interval 4: v_a ^*>V_b ^*>V_c ^*,U_P＝V_a ^*,U_M＝V_b ^*,U_N＝V_c ^*；

Operating time interval 5: v_a ^*>V_b ^*>V_c ^*,U_P＝V_c ^*,U_M＝V_b ^*,U_N＝V_a ^*；

Operating time interval 6: v_b ^*>V_a ^*>V_c ^*,U_P＝V_c ^*,U_M＝V_b ^*,U_N＝V_a ^*；

Operating time interval 7: v_b ^*>V_a ^*>V_c ^*,U_P＝V_b ^*,U_M＝V_a ^*,U_N＝V_c ^*；

Operating time interval 8: v_b ^*>V_c ^*>V_a ^*,U_P＝V_b ^*,U_M＝V_a ^*,U_N＝V_c ^*；

Operating time interval 9: v_b ^*>V_c ^*>V_a ^*,U_P＝V_a ^*,U_M＝V_b ^*,U_N＝V_c ^*；

Operating time interval 10: v_c ^*>V_b ^*>V_a ^*,U_P＝V_a ^*,U_M＝V_b ^*,U_N＝V_c ^*；

Operating time interval 11: v_c ^*>V_b ^*>V_a ^*,U_P＝V_c ^*,U_M＝V_b ^*,U_N＝V_a ^*；

Operating time interval 12: v_c ^*>V_a ^*>V_b ^*,U_P＝V_c ^*,U_M＝V_a ^*,U_N＝V_b ^*；

Wherein the content of the first and second substances,

U_pthe phase voltage command value with the maximum amplitude value, U, of the three-phase voltage command values_NPhase voltage command value, U, of next largest magnitude_MThe phase voltage command value having the smallest amplitude.

In the embodiment of the invention, the voltage parameter is calculated by using the following formula:

V_n＝|U_P-U_N|

V_m＝|U_P-U_M|

K＝U_M/U_N

in the formula (I), the compound is shown in the specification,

V_nis a high line voltage;

V_mis a low line voltage;

k is the charge distribution ratio.

Step 203, calculating an equivalent direct current synthetic voltage according to the voltage parameter, and determining a working mode of the bidirectional energy storage converter according to the side voltage of the energy storage device and the equivalent direct current synthetic voltage;

in the embodiment of the invention, high line voltage, low line voltage and charge distribution ratio are calculated according to the three-phase voltage of the alternating current side power grid of the bidirectional energy storage converter, and equivalent direct current synthetic voltage is calculated based on the high line voltage, the low line voltage and the charge distribution ratio. As an alternative embodiment, the equivalent dc composite voltage is calculated using the following equation:

in the formula (I), the compound is shown in the specification,

V_sis an equivalent dc composite voltage.

In the embodiment of the invention, under the off/grid-connected working condition, if the voltage of the energy storage side is smaller than the equivalent direct current synthetic voltage, the working mode of the bidirectional energy storage converter is determined to be a boost mode (boost), and if the voltage of the energy storage side is larger than the equivalent direct current synthetic voltage, the working mode of the bidirectional energy storage converter is determined to be a buck mode (buck).

Under the charging working condition, if the voltage of the energy storage side is greater than the equivalent direct-current synthetic voltage, the working mode of the bidirectional energy storage converter is determined to be a boosting mode, and if the voltage of the energy storage side is less than the equivalent direct-current synthetic voltage, the working mode of the bidirectional energy storage converter is determined to be a reducing mode.

Step 204, calculating the conducting duration of each working process in the switching period according to the current working condition, the determined working mode and the voltage parameter;

in this embodiment of the present invention, as an optional embodiment, calculating the on-time of each working process in the switching period according to the voltage parameter includes:

b11, determining basic parameters of the state plan according to the current working condition, the determined working mode, the high line voltage of the voltage parameter, the low line voltage and the charge distribution ratio;

in the embodiment of the present invention, as an optional embodiment, the basic parameters include: center of circle (O)₁、O₂、O₃) Radius (r)₁、r₂、r₃) And resonant capacitor voltage (V)_cro、V₁、V₂)。

In the embodiment of the invention, basic parameters of a state plan are calculated according to the working condition and the determined working mode, wherein the state plan comprises the following steps: the system comprises an off/grid-connected working condition voltage reduction mode state plan, an off/grid-connected working condition voltage boosting mode state plan, a charging working condition voltage reduction mode state plan and a charging condition voltage boosting mode state plan.

In the embodiment of the invention, for the state plan of the voltage reduction mode under the off/grid-connected working condition, the following formula is utilized to calculate the basic parameters of the state plan:

O₁＝V_dc/n-V_m(1)

O₂＝V_dc/n-V_n(2)

O₃＝-V_n(3)

r₁＝O₁+V_cro(4)

r₃＝V_cro-O₃(5)

V_cro＝(PT)/(4*C_r*V_s) (7)

in the formula (I), the compound is shown in the specification,

V_dcis the accumulator side voltage;

n is the transformer turn ratio;

C_ris a resonant capacitor;

L_ris a resonant inductor;

p is output power;

t is the resonance period.

Wherein the content of the first and second substances,

for the state plan of the boosting mode under the off-grid/grid-connected working condition, the basic parameters of the state plan are calculated by the following formula:

O₁＝V_dc/n (10)

O₂＝V_dc/n-V_m(11)

O₃＝V_dc/n-V_n(12)

r₁＝O₁+V_cro(13)

r₃＝V_cro-O₃(14)

V_cro＝(nPT)/(4*C_r*V_dc) (16)

for the charging condition step-down mode state plan, the basic parameters of the state plan are calculated by using the following formula:

O₁＝V_n-V_dc/n (19)

O₂＝V_m-V_dc/n (20)

O₃＝-V_dc(21)

r₁＝v_Cr+O₁(22)

r₃＝v_Cr-O₃(23)

V_cr＝(nPT)/(4*C_r*V_dc) (25)

for the boost mode state plan of the charging condition, the basic parameters of the state plan are calculated by the following formula:

O₁＝V_n(28)

O₂＝V_n-V_dc/n (29)

O₃＝V_m-V_dc/n (30)

r₁＝v_Cr+O₁(31)

r₃＝v_Cr-O₃(32)

V_cro＝(PT)/(4C_rV_s) (34)

and B12, calculating the conducting time length of each working process in the switching period according to the basic parameters of the obtained state plan.

In the embodiment of the invention, no matter what working condition or working mode the bidirectional energy storage converter is in, one switching cycle can be divided into 6 working processes, wherein the positive half cycle comprises 3 working processes, and the negative half cycle comprises 3 working processes.

In the embodiment of the invention, because the working process of the negative half period is similar to that of the positive half period, the duration of the 3 working processes of the negative half period is correspondingly the same as that of the 3 working processes of the positive half period.

In the embodiment of the invention, after the state plan is established, the angle corresponding to each working process can be solved according to the geometric relationship in the state plan, and further the conducting duration of each working process in the switching period is obtained.

In the embodiment of the invention, the setting theta₁、θ₂，θ₃Angles, t, corresponding to 3 working processes of the positive half cycle respectively₁、t₂、t₃The conduction time lengths are respectively corresponding to the 3 working processes of the positive half period.

For the state plan of the off/grid-connected working condition voltage reduction mode, the conduction time is calculated by the following formula:

θ₁＝cos^-1((O₁-V₁)/r₁) (37)

θ₂＝cos^-1((V₁-O₂)/r₂)-cos^-1((V₂-O₂)/r₂) (38)

θ₃＝cos^-1((V₂-O₃)/r₃) (39)

wherein the content of the first and second substances,

from θ ═ ω t, we can obtain:

t₁＝θ₁/ω (40)

t₂＝θ₂/ω (41)

t₃＝θ₃/ω (42)

in the formula (I), the compound is shown in the specification,

and omega is the angular frequency of the alternating current signal.

For the state plan of the boosting mode under the off/grid-connected working condition, the conduction time is calculated by the following formula:

θ₁＝cos^-1((O₁-V₁)/r₁) (43)

θ₂＝cos^-1((V₁-O₂)/r₂)-cos^-1((V₂-O₂)/r₂) (44)

θ₃＝cos^-1((O₃-V₂)/r₃) (45)

similarly, from θ ═ ω t, we can:

t₁＝θ₁/ω (46)

t₂＝θ₂/ω (47)

t₃＝θ₃/ω (48)

for the charging condition step-down mode state plan, the conduction time is calculated by using the following formula:

θ₁＝cos^-1((O₁-V₁)/r₁) (49)

θ₂＝cos^-1((V₁-O₂)/r₂))-cos^-1((V₂-O₂)/r₂)) (50)

θ₃＝cos^-1((O₃-V₂)/r₃)) (51)

from θ ═ ω t, we can obtain:

t₁＝θ₁/ω (52)

t₂＝(θ₁+θ₂)/ω (53)

t₃＝(θ₁+θ₂+θ₃)/ω (54)

for the charging condition boost mode state plan, the conduction time is calculated by the following formula:

θ₁＝cos^-1((O₁-V₁)/r₁) (55)

θ₂＝π-cos^-1((O₂-V₂)/r₂))-cos^-1((V₁-O₂)/r₂)) (56)

θ₃＝cos^-1((O₃-V₂)/r₃)) (57)

from θ ═ ω t, we can obtain:

t₁＝θ₁/ω (58)

t₂＝(θ₁+θ₂)/ω (59)

t₃＝(θ₁+θ₂+θ₃)/ω (60)

it should be noted that the conduction time of the 3 working processes in the negative half cycle is the same as the conduction time of the 3 working processes in the positive half cycle. In the conduction time length of the negative half period of 3 working processes, the conduction time length of the fourth working process is correspondingly the same as the conduction time length of the first working process and is t₁The conduction time length of the fifth working process is correspondingly the same as that of the second working process and is t₂The conduction time of the sixth working process is correspondingly the same as the conduction time of the third working process, and is t₃。

Step 205, according to the conducting duration of each working process in the switching period, a driving pulse signal is generated to control the conduction of the corresponding switch in the current working interval.

In the embodiment of the invention, a Pulse Width Modulation (PWM) driving Pulse signal is generated according to the determined current working interval and the calculated conducting time length of each working process, so as to control the conduction of the corresponding switch in the switch component.

In the embodiment of the invention, under different working conditions and different working modes, the corresponding relation tables of the on-off conditions of each switch in the switch assembly and the working interval and the working process are respectively shown in table 1, table 2, table 3 and table 4. The working time interval is simply called interval, and the working process is simply called process.

TABLE 1 Turn-on schematic table of each switch in switch assembly in each working time interval and each working process under voltage reduction mode under off/on-grid working condition

Table 2 on-state schematic table of each switch in the switch assembly in each operating time interval and each operating process in the off/on-grid boost mode

Chart 3 conducting schematic table of each switch in switch assembly in each working time interval and each working process under charging condition voltage reduction mode

Chart 4 schematic diagram of the conduction of each switch in the switch assembly during each operating time interval and each operating process in the boost mode under charging conditions

The following description will be made in detail with reference to a specific embodiment.

In the embodiment of the invention, as an optional embodiment, taking the bidirectional energy storage converter in a grid-connected working condition as an example, assuming that the Output power is 39kW, the voltage at the side of the energy storage device is 400-870V, the resonance inductance is 20uH, the resonance capacitance is 0.9uF, the Output filter inductor (Output filter inductor) is 400uH, the Output filter capacitor (Output filter capacitor) is 3uF, the turn ratio of the transformer is 1.5:1, the switching frequency is 37.5kHz, the frequency of a grid (load or grid) is 50Hz, the voltage of the grid is 380V, the phase resistance is 3.7 ohms, and the voltage at the side of the energy storage device is 400V.

The control strategy is PQ control because the energy storage converter is in a grid-connected working condition, and if the three-phase voltage command value is calculated according to the control strategy, the three-phase voltage command value V is supposed to be obtained at a certain time_a ^*、V_b ^*、V_c ^*300V, -200V, -100V respectively.

Obtaining the time belonging to the 3 rd working time interval according to the positive and negative relation of the three-phase voltage instruction values and the mapping relation of the prestored voltage instruction values and the working interval, and according to a formula:

V_n＝|U_P-U_N|

V_m＝|U_P-U_M|

K＝U_M/U_N

wherein, U_p＝300，U_N＝-200，U_M-100, to yield:

high line voltage V_n500, low line voltage V_mAt 400, the charge distribution ratio K is 0.5.

Equivalent direct current composite voltage:

the voltage on the accumulator side after passing through the transformer is:

since V is less than V_sAnd determining that the bidirectional energy storage converter is in a boost mode at the moment, namely the bidirectional energy storage converter is in the boost mode under the grid-connected working condition at the moment, and selecting equations (10) - (18) to calculate basic parameters of the state plan:

O₁＝V_dc/n＝266.67

O₂＝V_dc/n-V_m＝-133.34

O₃＝V_dc/n-V_n＝-233.34

r₁＝O₁+V_cro＝1.189×10³

r₃＝V_cro-O₃＝1.1548×10³

V_cro＝(nPT)/(4*C_r*V_dc)＝921.43

and calculating the conduction time of each working process according to the obtained basic parameters of the state plane. In the embodiment of the invention, because the bidirectional energy storage converter is in a grid-connected working condition boosting mode, the conduction duration corresponding to each working process is calculated by selecting the formulas (43) to (48):

θ₁＝cos^-1((O₁-V₁)/r₁)＝1.2917

θ₂＝cos^-1((V₁-O₂)/r₂)-cos^-1((V₂-O₂)/r₂)＝0.3191

θ₃＝cos^-1((O₃-V₂)/r₃)＝1.1679

t₁＝θ₁/ω＝0.2056(ms)

t₂＝θ₂/ω＝0.0508(ms)

t₃＝θ₃/ω＝0.1859(ms)

for the grid-connected working condition boost mode, the conduction meanings of each switch in the switch assembly in each working time interval and each working process are shown in table 2. As can be seen from table 2, in the 3 rd operating time interval, the conduction relationship of each operating process is specifically (taking one switching cycle as an example):

at 0 to t₁In time period, the switches V2, V3, V9 and V15 are turned on;

at t₁～t₁+t₂In the time period, the switches V2, V3, V9 and V11 are turned on, and the output voltage is V_m；

At t₁+t₂～t₁+t₂+t₃In the time period, the switches V2, V3, V9 and V13 are turned on, and the output voltage is V_n；

Until t₁+t₂+t₃At this moment, the 3 working processes of the positive half cycle are already executed and finished in sequence, and the execution process of the negative half cycle is similar to that of the positive half cycle, which is not described herein again.

In the embodiment of the invention, further, according to the parameters provided above, a simulation platform is built based on Matlab/Simulink software, and grid-connected output voltage and current waveforms at full power are obtained, and the simulation result shows that the power factor is close to 1, the frequency is 50HZ, and the utilization efficiency of the bidirectional energy storage converter is high.

As shown in fig. 3, an embodiment of the present application provides a computer device 300 for executing the method for controlling the bidirectional energy storage converter in fig. 1, the device includes a memory 301, a processor 302 and a computer program stored on the memory 301 and executable on the processor 302, wherein the processor 302 implements the steps of the method for controlling the bidirectional energy storage converter when executing the computer program.

Specifically, the memory 301 and the processor 302 can be general-purpose memory and processor, and are not limited to this, and when the processor 302 runs the computer program stored in the memory 301, the method for controlling the bidirectional energy storage converter can be executed.

Corresponding to the method for controlling the bidirectional energy storage converter in fig. 2, an embodiment of the present application further provides a computer readable storage medium, on which a computer program is stored, and the computer program, when executed by a processor, performs the steps of the above method for controlling the bidirectional energy storage converter.

In particular, the storage medium can be a general-purpose storage medium, such as a removable disk, a hard disk, etc., and when the computer program on the storage medium is executed, the method for controlling the bidirectional energy storage converter can be executed.

In the embodiments provided in the present application, it should be understood that the disclosed system and method may be implemented in other ways. The above-described system embodiments are merely illustrative, and for example, the division of the units is only one logical functional division, and there may be other divisions in actual implementation, and for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection of systems or units through some communication interfaces, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments provided in the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus once an item is defined in one figure, it need not be further defined and explained in subsequent figures, and moreover, the terms "first", "second", "third", etc. are used merely to distinguish one description from another and are not to be construed as indicating or implying relative importance.

Finally, it should be noted that: the above-mentioned embodiments are only specific embodiments of the present application, and are used for illustrating the technical solutions of the present application, but not limiting the same, and the scope of the present application is not limited thereto, and although the present application is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: any person skilled in the art can modify or easily conceive the technical solutions described in the foregoing embodiments or equivalent substitutes for some technical features within the technical scope disclosed in the present application; such modifications, changes or substitutions do not depart from the spirit and scope of the present disclosure, which should be construed in light of the above teachings. Are intended to be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.