Cascading type energy storage rapid interphase equalization control method and system

Abstract

The invention belongs to the technical field of energy storage balance control, and particularly discloses a cascade type energy storage fast interphase balance control method and system, and the method comprises the steps: injecting a zero-sequence voltage into a three-phase modulation signal outputted by a power control loop, and constructing an interphase power deviation model; taking the actually measured three-phase output current as input, and obtaining zero-sequence voltage for realizing inter-phase output power balance by taking the output current phasor as a reference; replacing a balance object with the SOC mean value of each phase of battery cluster to obtain zero sequence voltage required for realizing inter-phase SOC balance by taking the output current phasor as a reference; and superposing the zero-sequence voltage and a three-phase modulation signal output by the power control loop, and generating a PWM control signal of each switching device by adopting a carrier phase-shifting modulation mode. According to the method, the zero-sequence voltage injection model is constructed based on the current phasor synthesis principle, calculation is simple, and rapid inter-phase equalization under different operation conditions such as bidirectional charging and discharging and reactive power supporting is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy storage equalization control, and particularly relates to a cascaded energy storage fast inter-phase equalization control method and system. BACKGROUND

[0002] The statements in this section merely provide background information related to the present application and do not necessarily constitute the prior art.

[0003] The cascaded H-bridge battery energy storage system (CHB-BESS) has become an important technical route in the field of large-scale energy storage due to its modularity, high-voltage output capability, and direct access to medium-voltage distribution networks. However, it generally faces the problem of battery cluster SOC imbalance during operation.

[0004] According to the spatial relationship of the affected battery pack, the battery cluster SOC imbalance of the cascaded H-bridge energy storage system can be divided into two categories: in-phase SOC imbalance and inter-phase SOC imbalance. The inter-phase SOC imbalance is caused by multiple factors such as manufacturing differences, temperature changes, battery aging, and asymmetric three-phase loads. If not timely suppressed, it will lead to decreased utilization of sub-modules, limited modulation duty ratio, compressed charging and discharging intervals, and even trigger over-modulation and potential battery failure risks. Therefore, achieving fast and stable inter-phase SOC equalization is of great significance to improve the reliability, safety, and energy utilization rate of CHB-BESS.

[0005] Existing inter-phase SOC equalization methods usually adopt a zero-sequence voltage injection strategy, which adjusts the common components of three-phase modulation signals to produce controllable differences in three-phase output power, thereby achieving SOC balance. However, this method requires trigonometric function calculations for zero-sequence voltage amplitude and phase, resulting in high control algorithm complexity. Moreover, traditional zero-sequence voltage often adopts a fixed amplitude mode, limiting the equalization speed. The over-modulation boundary is not fully considered during the equalization process, and the equalization coefficient selection does not have a theoretical upper limit. SUMMARY

[0006] To solve the above problems, the present application proposes a cascaded energy storage fast inter-phase equalization control method and system, which can effectively reduce the computational load of the controller and improve the real-time control capability of the system. By selecting the optimal inter-phase equalization coefficient within the modulation constraint range, fast inter-phase SOC convergence is achieved under different operating conditions.

[0007] In some embodiments, the following technical solutions are adopted: A cascaded energy storage fast inter-phase equalization control method, comprising: obtaining the SOC information, output voltage and current information of each phase battery cluster of the cascaded energy storage system; injecting a zero sequence voltage with a set amplitude and phase into a three-phase modulation signal output by a power control loop u 0, constructing a phase-to-phase power deviation model; obtaining a zero sequence voltage for achieving phase-to-phase output power balance with reference to output current phasors, by taking measured three-phase output currents as input; establishing a relationship between reference output power of each phase and average SOC of corresponding battery cluster, replacing the balancing object with the average SOC of each phase battery cluster, to obtain a zero sequence voltage required for achieving phase-to-phase SOC balance with reference to output current phasors; superimposing the zero sequence voltage on a three-phase modulation signal output by the power control loop, and generating a PWM control signal for each switching device using carrier phase-shift modulation.

[0008] As a further scheme, the phase-to-phase power deviation model is specifically: ; wherein, is the increased output power of each phase, denotes the total reference output power of the system, denotes the reference output power of the jth phase, I g is the root mean square value of the output current of the cascaded energy storage system, denotes the amplitude of the zero sequence voltage u 0 in the direction of the three-phase output current.

[0009] As a further scheme, the zero sequence voltage for achieving phase-to-phase output power balance with reference to output current phasors is specifically: ; wherein, denotes the given apparent power, denotes the total reference output power of the system, denotes the reference output power of the jth phase, 、 、 are the instantaneous currents of the ABC three-phase output of the cascaded energy storage system, respectively.

[0010] As a further scheme, the relationship between reference output power of each phase and average SOC of corresponding battery cluster is specifically: ; wherein, denotes the total reference output power of the system, denotes the reference output power of the jth phase, SOC avj denotes the average SOC value of the jth phase battery cluster, SOCT Representing all SOC avj The sum, .

[0011] As a further solution, the balancing object is replaced with the average SOC of each battery cluster, resulting in the zero-sequence voltage required to achieve inter-phase SOC balance based on the output current phasor, specifically: ; in, K 1 represents the phase equilibrium coefficient, which determines the equilibrium speed; Represents the given apparent power. This represents the total reference output power of the system. I g It is the root mean square value of the output current of the cascaded energy storage system; SOC avj This represents the average SOC value of the j-th phase battery cluster. SOC T Representing all SOC avj The sum of .

[0012] As a further solution, the interphase balance coefficient K 1. Adjust according to actual operating conditions. In order to achieve rapid phase-to-phase SOC balance and prevent overmodulation, the zero-sequence voltage needs to meet the following conditions: ; in, express j The modulation signal after phase injection of zero-sequence voltage, Indicates the output of the power control loop. j The phase modulation signal, This indicates the number of H-bridge submodules contained in each phase of a cascaded energy storage system. This indicates the voltage of the DC-side battery cluster of the H-bridge submodule.

[0013] As a further solution, the interphase balance coefficient K The range of values ​​for 1 is: ; in, Where is the grid voltage amplitude, and S represents the overall phase-to-phase SOC imbalance of the cascaded energy storage system. Let S be the amplitude. In other embodiments, the following technical solutions are adopted: A cascaded energy storage rapid phase-to-phase equalization control system includes: a data acquisition module configured to acquire SOC information, output voltage and current information of each phase battery cluster of the cascade energy storage system; a power deviation construction module configured to inject a zero sequence voltage with a set amplitude and phase into a three-phase modulation signal output by a power control loop u 0, construct an inter-phase power deviation model; take the measured three-phase output current as input to obtain a zero sequence voltage for achieving inter-phase output power balance based on the output current phasor; an equalization conversion module configured to establish a relationship between the reference output power of each phase and the average SOC of the corresponding battery cluster, replace the equalization object with the average SOC of each phase battery cluster, and obtain a zero sequence voltage required for achieving inter-phase SOC balance based on the output current phasor; a switch control module configured to superimpose the zero sequence voltage on a three-phase modulation signal output by the power control loop u j superimpose and generate a PWM control signal of each switching device by using a carrier phase-shifted modulation method.

[0014] In some other embodiments, the following technical solutions are adopted: A terminal device includes a processor and a memory, the processor is used to implement instructions; the memory is used to store a plurality of instructions, the instructions are suitable for being loaded and executed by the processor to implement the cascade energy storage fast inter-phase equalization control method.

[0015] In some other embodiments, the following technical solutions are adopted: A computer readable storage medium, wherein a plurality of instructions are stored, the instructions are suitable for being loaded and executed by the processor of the terminal device to implement the cascade energy storage fast inter-phase equalization control method.

[0016] Compared with the prior art, the beneficial effects of the present application are: (1) The present application constructs a zero sequence voltage injection model based on the current phasor synthesis principle, selects the optimal inter-phase equalization coefficient within the modulation constraint range, and realizes the fast inter-phase SOC convergence under different operating conditions; and the inter-phase SOC equalization can be kept stable and effective under the scenes of bidirectional power flow and reactive power support.

[0017] (2) The zero sequence voltage calculation of the present application only depends on the basic algebraic operation, avoids the complex trigonometric function operation in the traditional method, thereby effectively reduces the calculation amount of the controller and improves the real-time control ability of the system. The method is constructed based on the current phasor model and can be applied to the operating mode containing reactive power support, is not affected by the active and reactive coupling characteristics, and has strong operating condition adaptability.

[0018] (3) The application can reduce the risk of overcharge and overdischarge of the battery cluster, improve the energy utilization rate and operation safety of the energy storage system, and further improve the overall efficiency, service life and reliability of the system by realizing the rapid convergence of the average SOC of the three-phase battery cluster.

[0019] Other features and advantages of the present application will be in part apparent and in part pointed out in the description which follows. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 A schematic diagram of the main circuit structure of the cascaded H-bridge energy storage system in the embodiment of the application is shown in the figure. Figure 2 A schematic diagram of the three-phase voltage and current phasor relationship after injecting zero sequence voltage in the embodiment of the application is shown in the figure. Figure 3 A schematic diagram of the three-phase voltage and current phasor relationship after injecting zero sequence voltage in the embodiment of the application is shown in the figure. K 1max The change curve of the grid voltage amplitude V m and the inter-phase SOC imbalance degree S. Figure 4 A schematic diagram of the superposition of the zero sequence voltage and the modulation signal output by the power control loop of the cascaded energy storage system in the embodiment of the application is shown in the figure. Figure 5 The simulation results of the fast inter-phase SOC balancing method of the embodiment of the application under the condition of 10kV, 4MW (active power) and 3MW (reactive power) are shown in the figure. DETAILED DESCRIPTION

[0021] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the application. Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the application pertains.

[0022] It should be noted that the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the exemplary embodiments according to the application. As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and furthermore, it should be understood that when the terms "comprise" and / or "include" are used in the specification, there is a presence of the features, steps, operations, devices, components and / or combinations thereof.

[0023] Embodiment one In one or more embodiments, a cascaded energy storage fast inter-phase balancing control method is disclosed, which specifically includes the following processes: S101: Obtain the SOC information, output voltage and current information of each phase battery cluster of the cascaded energy storage system.

[0024] Specifically, Figure 1 The main circuit topology of the cascaded H-bridge energy storage system is shown in FIG. 1. The system adopts a star structure, and is connected to a power grid through a filter inductor Lf. L f Each phase is composed of N sub-modules, and each sub-module includes a group of battery clusters, a DC side filter inductor, a DC side filter capacitor, and an H-bridge structure composed of four power switching devices.

[0025] wherein SOC jk represents the state of charge of the battery cluster of the kth sub-module in the jth phase (j∈{a, b, c}), which can be obtained by a battery management system; the output current of each phase is i j the grid voltage of each phase is v j which can be obtained by a current sensor and a voltage sensor, respectively.

[0026] S102: outputting three-phase modulation signals to a power control loop u j a zero sequence voltage with a set amplitude and phase is injected into each of the phases (j∈{a, b, c}) u 0, a phase-to-phase power deviation model is constructed; the measured three-phase output current is taken as input, and a zero sequence voltage for realizing phase-to-phase output power balance based on the output current phase is obtained.

[0027] In this embodiment, in order to realize phase-to-phase SOC balance, a zero sequence voltage with a specific amplitude and phase needs to be injected into the three-phase output modulation signal u 0, the phase diagram of the energy storage system after injecting the zero sequence voltage is shown in FIG. 2. Figure 2

[0028] Based on the power balance principle, a phase-to-phase power deviation model is constructed according to the phase relationship between the output voltage and the output current of the cascaded energy storage system as follows: The output power increased by each phase can be represented as: (1) wherein represents the total reference output power of the system, represents the reference output power of the jth phase, is the root mean square value of the output current of the cascaded energy storage system, represents the projection of the output current of the jth phase in the direction of the three-phase output current.

[0029] According to the three-phase power balance principle, the zero sequence voltage in the direction of the three-phase output current is: (2)​​ where, is the effective value of grid voltage, represents the phase angle between three-phase output current and grid voltage, represents the given apparent power.

[0030] Therefore, the zero-sequence voltage in the projection of three-phase instantaneous output current direction can be expressed as: (3) where, is the phasor, which can represent the direction of the output current of the energy storage system to some extent.

[0031] With the measured three-phase output current as input, according to the phasor synthesis, the zero-sequence voltage required to realize the inter-phase output power balance based on the output current phasor is: (4) where, , , are the instantaneous currents of the ABC three-phase output of the cascaded energy storage system, respectively.

[0032] S103: Establish the relationship between the reference output power of each phase and the average SOC of the corresponding battery cluster, replace the balancing object with the average SOC of each phase battery cluster, and obtain the zero-sequence voltage required to realize the inter-phase SOC balance based on the output current phasor.

[0033] In this embodiment, on the basis of realizing the inter-phase output power balance, in order to further realize the inter-phase SOC balance among the battery groups, the relationship between the output power of each phase and the average SOC of the corresponding battery group is established as follows: (5) where, SOC avj represents the average SOC value of the jth phase battery group, SOC T represents the sum of all SOC avj , .

[0034] Replacing the power balance with the SOC balance, the zero-sequence voltage required to realize the inter-phase SOC balance based on the output current phasor is: is: (6) where, Zeta j is the inter-phase imbalance factor, which represents the degree of inter-phase SOC imbalance; K1 is the phase-to-phase balance coefficient, which determines the balancing speed. Its value is limited by the overshoot boundary and the power output capability of the submodule.

[0035] During the charging process of the grid to the energy storage system, the zero-sequence voltage synthesized in this embodiment This zero-sequence voltage is dynamically generated based on the SOC and output current information of each phase battery cluster. The polarity of this zero-sequence voltage is automatically adjusted according to the direction of the output current, ensuring that during charging, when the SOC of a certain phase is low... The phase with a higher SOC receives a larger charging current, while the phase with a lower SOC receives a smaller charging current. This mechanism effectively promotes SOC balance among battery clusters during charging. Therefore, the phase-to-phase SOC balancing method proposed in this embodiment is applicable not only to the discharge process but also to the scenario of the grid charging the battery.

[0036] In addition, to achieve rapid interphase SOC balancing and prevent overmodulation, the interphase balance coefficient needs to be adjusted appropriately according to the actual operating conditions. K 1. However, the following conditions must be met: (7) in, express j The modulation signal after phase injection of zero-sequence voltage, Indicates the output of the power control loop. j The phase modulation signal, This indicates the number of H-bridge submodules contained in each phase of a cascaded energy storage system. This indicates the voltage of the DC-side battery cluster of the H-bridge submodule.

[0037] when With any v i When the directions are consistent, the result is K 1. Ensure and v i Arbitrary phase differences can exist without causing overmodulation. Therefore, K The range of values ​​for 1 is: (8) Among them, V m Here, S represents the grid voltage amplitude, and S indicates the degree of phase-to-phase SOC imbalance. S m Let S be the amplitude.

[0038] This embodiment achieves rapid interphase SOC convergence under different operating conditions by selecting the optimal interphase equalization coefficient within the modulation constraint range.

[0039] Figure 3 Showing K1 with V m and S m The changing trend. The degree of phase imbalance can be obtained, which significantly affects the maximum achievable value. K 1max To achieve rapid phase equilibrium, K 1 should be as close as possible K 1max However, in practical applications, a certain modulation margin needs to be reserved to cope with sudden events such as grid disturbances and power fluctuations.

[0040] S104: Combines the zero-sequence voltage with the three-phase modulation signal output from the power control loop. u j The signals are superimposed and a carrier phase-shift modulation method is used to generate the PWM control signal for each switching device.

[0041] Figure 4 The overall control strategy of the cascaded energy storage system is demonstrated, including: a power control loop, an intra-phase SOC equalization control loop, and an inter-phase SOC equalization control loop. The power control loop is based on a reference active power... P reactive power Q Grid voltage v gi and current feedback i j Output three-phase modulated signal u j The intra-phase SOC equalization control loop is based on the SOC value of each battery cluster. SOC jk Output phase equalization compensation signal u jnk To achieve consistency in the State of Charge (SOC) of each battery cluster within the same phase; the proposed inter-phase SOC equalization control loop is based on the inter-phase SOC difference and the angle of the rotating coordinate system. Omega t and dq axis current i d , i q Output phase equalization signal u 0, used to regulate energy distribution between different phases. Power control loop output signal. u j After being superimposed with the intra-phase equalization signal, it is then combined with the inter-phase equalization signal. u The zeros are superimposed to form the final modulation signals for each phase. u mjk The modulation signal, after being modulated by carrier phase-shift PWM, generates the switching signals required by the H-bridge power devices in the submodule. S jk, to realize the precise control of the cascaded energy storage system. Through the above control strategy, the SOC balance within and between phases can be effectively coordinated while realizing fast power response, thereby improving the operation stability and service life of the energy storage system.

[0042] Figure 5 For a 10kV power grid environment, the output active power is 4MW, the reactive power is 3MW, the number of sub-modules per phase N=13, the battery cluster rated voltage is 768V, 5Ah, and the grid-side inductance L f For an 8mH environment, the initial SOC of phases A, B and C is 70%, 80% and 90% respectively. The simulation results of the fast inter-phase balancing method of the embodiment are shown in the table. At the initial time, the state is discharging. At the 20th second, the state is switched to charging. At the 30th second, the state is switched to discharging again. The average SOC of each phase can converge with linear characteristics throughout the process. At the 42nd second, the inter-phase balance state is reached, indicating that the method proposed in the embodiment has a significant effect on achieving fast inter-phase SOC balance of the cascaded energy storage battery cluster.

[0043] The embodiment synthesizes the ideal zero sequence voltage required for fast inter-phase balancing based on the converter output current phasor through the power balancing method, and can realize inter-phase SOC balancing of the cascaded energy storage battery cluster in a scenario containing reactive power output. At the same time, considering the hard constraint condition of modulation saturation limitation, the limit balancing coefficient under different balancing degrees and grid voltages is obtained to realize fast SOC balancing. Based on the method of the embodiment, the energy utilization rate of the energy storage system can be effectively improved, the economy can be improved, and the overcharge and overdischarge of the battery cluster can be effectively avoided, thereby improving the safety of the energy storage system.

[0044] Embodiment two In one or more embodiments, a cascaded energy storage fast inter-phase balancing control system is disclosed, comprising: A data acquisition module configured to acquire the SOC information of each phase battery cluster of the cascaded energy storage system and the output voltage and current information; A power deviation construction module configured to inject a zero sequence voltage with a set amplitude and phase into the three-phase modulation signal output to the power control loop u j A zero sequence voltage with a set amplitude and phase is injected into the three-phase modulation signal output to the power control loop u 0, a model of inter-phase power deviation is constructed; the measured three-phase output current is taken as input to obtain a zero sequence voltage for realizing inter-phase output power balancing based on the output current phasor; An equalization conversion module configured to establish a relationship between the reference output power of each phase and the average SOC of the corresponding battery cluster, and replace the equalization object with the average SOC of each phase battery cluster to obtain a zero sequence voltage required for realizing inter-phase SOC balancing based on the output current phasor; A switch control module configured to combine the zero sequence voltage with a three-phase modulation signal output by a power control loop u j The superposition is performed, and a carrier phase-shift modulation mode is used to generate a PWM control signal of each switching device.

[0045] It should be noted that the specific implementation of each module has been described in Embodiment One, which will not be described in detail here.

[0046] Embodiment Three In one or more embodiments, a terminal device is disclosed, which includes a processor and a memory, the processor is configured to implement instructions; the memory is configured to store a plurality of instructions, which are suitable for being loaded and executed by the processor to implement the cascade energy storage fast inter-phase balancing control method described in Embodiment One.

[0047] It should be understood that in the embodiments, the processor can be a central processing unit CPU, and the processor can also be other general-purpose processors, digital signal processors DSP, application-specific integrated circuits ASIC, ready programmable gate arrays FPGA or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor.

[0048] The memory can include read-only memory and random access memory, and provide instructions and data to the processor, and a portion of the memory can also include non-volatile random access memory. For example, the memory can also store device type information.

[0049] In the implementation process, each step of the above method can be completed by integrated logic circuits of hardware in the processor or instructions in the form of software.

[0050] Embodiment Four In one or more embodiments, a computer readable storage medium is disclosed, which stores a plurality of instructions, the instructions are suitable for being loaded and executed by a processor of a terminal device to implement the cascade energy storage fast inter-phase balancing control method described in Embodiment One.

[0051] Although the specific embodiments of the application are described above with reference to the drawings, the description is not a limitation on the scope of protection of the application, and those skilled in the art should understand that various modifications or changes made on the basis of the technical solutions of the application without creative labor are still within the protection scope of the application.

Claims

1. A method for controlling a cascade energy storage fast inter-area power oscillation equalizer, characterized in that, The method comprises the following steps: obtaining the SOC information of each phase battery cluster of the cascaded energy storage system and the output voltage and current information; Injecting a zero sequence voltage of a set amplitude and phase into a three-phase modulation signal output to a power control loop u 0, constructing an inter-phase power deviation model; taking the measured three-phase output current as input, obtaining a zero sequence voltage for realizing inter-phase output power balance with the output current phasor as reference; establishing the relationship between the reference output power of each phase and the average SOC of the corresponding battery cluster, replacing the balancing object with the average SOC of each phase battery cluster, and obtaining the zero sequence voltage required for realizing the inter-phase SOC balance based on the output current phasor; superimposing the zero sequence voltage and the three-phase modulation signal output by the power control loop, and generating the PWM control signal of each switching device by using the carrier phase-shift modulation method.

2. The method of claim 1, wherein the method is characterized by, The inter-phase power deviation model is specifically: ； wherein the output power added for each phase, denotes the total reference output power of the system, denotes the reference output power of the jth phase, I g is the root mean square value of the output current of the cascaded energy storage system, denotes the zero sequence voltage u 0 the amplitude of the projection of the three-phase output current in the direction of the zero sequence voltage.

3. The cascade-type energy storage fast inter-area equalization control method of claim 1, wherein, obtaining the zero sequence voltage required for realizing the inter-phase output power balance based on the output current phasor, specifically: ； wherein, denotes the given apparent power, denotes the total reference output power of the system, denotes the reference output power of the jth phase, , , are the instantaneous currents of the three-phase output of the cascaded energy storage system ABC, respectively.

4. The cascade-type energy storage fast inter-area equalization control method of claim 1, wherein, establishing the relationship between the reference output power of each phase and the average SOC of the corresponding battery cluster, specifically: ； wherein, represents the total reference output power of the system, represents the reference output power of the jth phase, SOC avj represents the average SOC value of the jth phase battery cluster, SOC T represents the sum of all SOC avj .​ 5. The cascade-type energy storage fast inter-area equalization control method of claim 1, wherein, replacing the balancing object with the average SOC of each phase battery cluster, and obtaining the zero sequence voltage required for realizing the inter-phase SOC balance based on the output current phasor, specifically: ； wherein, K 1 is the inter-phase balance coefficient, which determines the balance speed; denotes the given apparent power, denotes the total reference output power of the system, I g is the root mean square value of the output current of the cascaded energy storage system; SOC avj denotes the average SOC value of the jth phase battery cluster, SOC T represents the sum of all SOC avj the sum of all 6. The cascade-type energy storage fast inter-area equalization control method of claim 5, wherein, The inter-phase balance coefficient K 1. According to the actual operating conditions adjustment, in order to realize the fast inter-phase SOC balance and prevent over-modulation, the zero sequence voltage needs to meet the following conditions: ； wherein, represents j the modulation signal after injection of the phase zero sequence voltage, represents the power control loop output j the modulation signal of the phase, represents the number of H-bridge sub-modules contained in each phase of the cascaded energy storage system, represents the voltage of the battery cluster at the DC side of the H-bridge sub-module.

7. The cascade-type energy storage fast inter-area equalization control method of claim 5, wherein, the inter-phase balance coefficient K 1 is in the range of values: ； wherein, is the grid voltage amplitude, S represents the total inter-phase SOC imbalance degree of the cascaded energy storage system, is the amplitude of S.

8. A cascade energy storage fast inter-area equalization control system, characterized in that, The method comprises the following steps: a data acquisition module configured to obtain the SOC information of each phase battery cluster of the cascaded energy storage system and the output voltage and current information; a power deviation building module configured to inject a zero sequence voltage of a set amplitude and phase into a three-phase modulation signal output to a power control loop u 0, building a phase-to-phase power deviation model; taking the measured three-phase output current as input, obtaining a zero sequence voltage for achieving phase-to-phase output power balance with reference to the output current phasor; an equalization conversion module configured to establish the relationship between the reference output power of each phase and the average SOC of the corresponding battery cluster, replace the balancing object with the average SOC of each phase battery cluster, and obtain the zero sequence voltage required for realizing the inter-phase SOC balance based on the output current phasor. a switch control module configured to combine the zero sequence voltage with a three-phase modulation signal output by a power control loop u j Superposition is performed, and a carrier phase-shift modulation method is used to generate a PWM control signal for each switching device.

9. A terminal device comprising a processor and a memory, the processor configured to implement instructions; the memory configured to store a plurality of instructions, the terminal device characterized by, The instructions are adapted to be loaded and executed by the processor to perform the cascaded energy storage fast inter-phase equalization control method of any one of claims 1-7.

10. A computer readable storage medium having stored therein a plurality of instructions, wherein the instructions, when executed by a processor, cause the processor to perform the method of any one of claims 1-9. The instructions are adapted to be loaded and executed by the processor of the terminal device to perform the cascaded energy storage fast inter-phase equalization control method of any one of claims 1-7.

Images