Method and system for controlling state machine of photovoltaic energy storage system in multiple working condition modes

Abstract

The invention discloses a state machine control method and system for a photovoltaic energy storage system in a multi-working-condition mode. The state machine control method comprises the steps that collected signals are acquired to perform sequential control on an inversion module, a power conversion module and a direct current conversion module to enter different operation modes; and the operation modes of the inversion module, the power conversion module and the direct current conversion module are controlled through a time sequence to realize the switching of the whole mode. According to the main technical scheme and the main effects, seamless switching among multiple working condition modes is achieved, shutdown and restarting are not needed, and the problems that an existing system is incomplete in function and unstable in switching are fundamentally solved.

Description

Technical Field

[0001] The present invention relates to the photovoltaic field, and in particular to a state machine control method and system under multiple operating modes of a photovoltaic energy storage system. Background Art

[0002] Based on the diversification of the use scenarios of photovoltaic energy storage systems, the photovoltaic system itself has a variety of operating control modes. The photovoltaic energy storage system integrates the function of energy storage on the basis of grid-connected and off-grid inverters, which further increases the complexity of its mode control. Through the exhaustive classification of the system's working modes, the system has at least 12 steady-state working modes. Further considering the switching conditions under different modes, the system's working conditions increase exponentially. In this situation, if the photovoltaic energy storage system mode control is unreasonable, the entire system will bring a series of chain reactions such as safety risks, reduced efficiency, and reduced service life of the photovoltaic energy storage system due to these differences.

[0003] The existing solutions have the following main defects:

[0004] 1. Existing solar storage products on the market have incomplete coverage of working mode, and some specific steady-state working modes or switching between different steady-state modes are not supported;

[0005] 2. When switching between different working modes, there is a phenomenon of manual shutdown and restart, and seamless switching cannot be achieved;

[0006] 3. It is not possible to quickly achieve backward compatibility. For example, if the original system supports photovoltaic storage and charging and off-grid operation, if the battery function or photovoltaic module is cancelled, the software must be modified for adaptation. It is impossible to achieve direct downward compatibility from the beginning of the design. Summary of the invention

[0007] Purpose of the invention: The purpose of the present invention is to solve the defects in the prior art and provide a mode conversion module under multiple operating modes of a photovoltaic energy storage system, so as to achieve full coverage of all operating modes through the studied efficient state mode management strategy, and realize reliable switching under multiple operating modes based on the module switch timing management mechanism, thereby solving the challenges brought by the incomplete functions of the existing photovoltaic energy storage system and the unstable operating mode switching to the system control, and then realize the system control and unit energy density improvement of the photovoltaic energy storage system in different scenarios.

[0008] Technical solution:

[0009] This application proposes a state machine control method for a photovoltaic energy storage system in a multi-operating mode, including:

[0010] S101, acquiring collected signals to perform timing control so that the inverter module, the power conversion module and the DC conversion module enter different operation modes;

[0011] S102, switching of the overall mode is achieved by sequentially controlling the operation modes of the inverter module, the power conversion module and the DC conversion module.

[0012] Preferably, obtaining the collected signal to perform timing control on the DC conversion module to enter different operation modes includes:

[0013] After the DC conversion module is powered, the system starts initializing and generates an initialization flag;

[0014] When the initialization flag is effective, the DC conversion module enters the self-test module and generates a self-test flag;

[0015] When the self-check mark is effective, the DC conversion module enters the pre-charge mode, performs the pre-charge operation, and generates the pre-charge mark;

[0016] When the pre-charge flag is effective, the DC conversion module enters the standby mode. In the standby mode, when the power-on condition is met, it enters the working module;

[0017] When a fault signal is obtained, the DC conversion module enters a fault mode;

[0018] When a signal indicating that the DC conversion module cannot continue to work is obtained, the DC conversion module enters a shutdown mode.

[0019] Preferably, obtaining the collected signal to perform timing control so that the power conversion module enters different operation modes includes:

[0020] After the power conversion module is powered, the system starts to initialize and generates an initialization flag;

[0021] When the initialization flag is effective, the power conversion module enters the self-building module and generates a self-check flag;

[0022] When the self-check mark is effective, the power conversion module enters the pre-charge mode, performs the pre-charge operation, and generates the pre-charge mark;

[0023] When the pre-charge flag is effective, the power conversion module enters the standby mode. In the standby mode, when the power-on condition is met, it enters the working module;

[0024] When a fault signal is obtained, the power conversion module enters a fault mode;

[0025] When a signal indicating that the power conversion module cannot continue to work is obtained, the power conversion module enters a shutdown mode.

[0026] Preferably, obtaining the collected signals to perform timing control so that the inverter module enters different operation modes includes:

[0027] After power is supplied, the inverter module is initialized to generate an initialization flag;

[0028] When the initialization flag takes effect, the inverter module enters the self-test mode and generates a self-test flag when the self-test is completed;

[0029] When the self-check flag is effective, the inverter module enters the pre-charge mode, and generates a pre-charge flag when the pre-charge mode is completed;

[0030] When the pre-charge flag is effective, the inverter module enters standby mode;

[0031] In standby mode, the system judges whether the acquired signal meets the grid connection condition. If so, the system enters the grid connection working mode. If not, the system enters the off-grid working mode.

[0032] When a fault signal is obtained, the inverter module enters a fault mode;

[0033] When a signal is obtained indicating that the power conversion module cannot continue to work, the inverter module enters a shutdown mode.

[0034] Preferably, when a signal indicating that the DC conversion module cannot continue to work is obtained, the DC conversion module enters a shutdown mode, including:

[0035] When the single module active shutdown conditions are met, the system receives a sleep command, or a serious unrecoverable fault is detected, the system enters shutdown mode.

[0036] Preferably, when a fault signal is obtained, the DC conversion module enters a fault mode, including:

[0037] If the module detects any fault, it will automatically stop related functions and enter protection mode;

[0038] The module will take appropriate protection measures according to the fault type and continuously monitor whether the fault is restored;

[0039] When it is detected that the fault condition is eliminated, the module will automatically exit the fault state and resume normal operation.

[0040] Preferably, in the off-grid working mode, if it is necessary to switch to the grid-connected working mode, when the grid-connected conditions are met, the off-grid working mode state can be switched to the grid-connected working mode state;

[0041] In the grid-connected state, if it is necessary to switch to the off-grid working mode, when the off-grid working mode conditions are met, the grid-connected working mode can be switched to the off-grid working mode.

[0042] Preferably, the switching between the above different modes is realized according to specific conditions, and the specific conditions include:

[0043] Module power on / off enable, self-test status, module fault flag, signal correction completion status, initialization completion flag, sleep instruction, voltage, current and frequency range, and time sequence flag.

[0044] Preferably, the switching of the overall mode is realized by sequentially controlling the operation modes of the inverter module, the power conversion module and the DC conversion module, including:

[0045] S1, determine whether the inverter module, the power conversion module and the DC conversion module are in standby mode, if so, enter the system standby mode;

[0046] S2, obtain the battery status and determine whether the battery terminal can work normally. If so, the battery terminal is turned on; if not, the battery terminal is turned off;

[0047] S21, obtaining the photovoltaic status, when the battery end is turned off, judging whether the photovoltaic power is working normally, if so, the photovoltaic end is turned on, if not, returning to the system standby mode;

[0048] Get the inverter module status and determine whether the inverter module is working normally. If so, the grid end is turned on. If not, the system returns to standby mode.

[0049] S22, obtaining the photovoltaic status, when the battery end is turned on, judging whether the photovoltaic power is working normally, if so, the photovoltaic end is turned on, if not, returning to the system standby mode;

[0050] Get the inverter module status and determine whether the inverter module is working normally. If so, the grid end is turned on. If not, the system returns to standby mode.

[0051] In some embodiments, a state machine control system is provided according to a photovoltaic energy storage system in multiple working modes, including:

[0052] Mode conversion module, timing management module, inverter module, power conversion module and DC conversion module:

[0053] The mode conversion module and the timing management module are electrically connected to the inverter module, the power conversion module and the DC conversion module respectively;

[0054] The mode conversion module is used to obtain the collected signals to perform timing control on the inverter module, the power conversion module and the DC conversion module to enter different operation modes;

[0055] The timing management module is used to sequentially control the operation modes of the inverter module, the power conversion module and the DC conversion module to achieve overall mode switching.

[0056] Beneficial effects: To solve the problem of incomplete functions of existing systems, this patent proposes a complete multi-operating mode of photovoltaic energy storage system based on overall design, including 12 typical steady-state operating modes such as grid-connected, off-grid, energy storage, charging, and discharging. This design ensures that the system can adapt to the operation requirements of various scenarios, such as residential scenarios, industrial scenarios, and distributed power generation application scenarios. By realizing seamless switching between multiple operating modes without shutdown and restart, the problem of incomplete functions and unstable switching in existing systems is fundamentally solved;

[0057] Through distributed control logic and modular design, the operation of each module is independent of each other, avoiding system disorder caused by unsatisfied conditions during mode switching. The functional modules are independently controlled to avoid the coupling problem between modules in the existing system. The photovoltaic side, energy storage side, and ACDC module are each managed by an independent state machine to achieve autonomous control of the functional modules.

[0058] The system has strong scalability, which is convenient for adding functional modules or upgrading hardware equipment in the later stage. It can be compatible with single grid-connected or off-grid systems without energy storage functions, and can also adapt to traditional single-charge and discharge energy storage systems, and smoothly transition to multi-operating-condition intelligent energy storage systems;

[0059] It achieves full coverage of different modes and seamless switching between different modes, reduces the power switching delay caused by incomplete working modes and mode switching, and the voltage and current shocks caused by turning the machine on and off, and has better operating results. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 Provide a schematic diagram of the method framework for the present invention;

[0061] Figure 2 The present invention provides a schematic diagram of the startup process of a DC conversion module and a power conversion module;

[0062] Figure 3 Provides a schematic diagram of the inverter module startup process structure of the present invention;

[0063] Figure 4 Provide a schematic diagram of the timing control flow structure of the present invention;

[0064] Figure 5 A schematic diagram of the system structure is provided for the present invention. DETAILED DESCRIPTION

[0065] In order to make the technical solution of the present invention clearer, the present invention is further described in detail below with reference to the specific embodiments of the accompanying drawings.

[0066] Example 1

[0067] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be understood by people with general skills in the field to which the present invention belongs. "Including" and similar words used in this article mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0068] In view of the problems existing in the existing technology, such as Figure 1-5 As shown, the present application proposes a state machine control method for a photovoltaic energy storage system in a multi-operating mode, including:

[0069] Acquire the collected signals to perform timing control so that the inverter module, power conversion module and DC conversion module enter different operation modes;

[0070] The overall mode switching is achieved by sequentially controlling the operating modes of the inverter module, the power conversion module and the DC conversion module.

[0071] In some specific embodiments, conventional topology circuits that can be used in the DC conversion module and the power conversion module include BOOST boost DC conversion circuit, BUCK buck DC conversion circuit, BUCKBOOST buck-boost, LLC, CLLC, and DAB types.

[0072] In some specific embodiments, the inverter module realizes the conversion of DC into AC signals, and also supports the conversion of AC signals into DC signals. Conventional topology circuits that can be used include H4, H5, and H6 conversion circuit topologies. The present invention does not limit which conversion circuit is used to support two-stage power conversion requirements.

[0073] In some specific embodiments, the collected signals are acquired to perform timing control so that the DC conversion module enters different operation modes, including:

[0074] After the DC conversion module is powered, the system starts initializing and generates an initialization flag;

[0075] When the initialization flag is effective, the DC conversion module enters the self-test module and generates a self-test flag;

[0076] When the self-check mark is effective, the DC conversion module enters the pre-charge mode, performs the pre-charge operation, and generates the pre-charge mark;

[0077] When the pre-charge flag is effective, the DC conversion module enters the standby mode. In the standby mode, when the power-on condition is met, it enters the working module;

[0078] When a fault signal is obtained, the DC conversion module enters a fault mode;

[0079] When a signal indicating that the DC conversion module cannot continue to work is obtained, the DC conversion module enters a shutdown mode.

[0080] In some specific embodiments, the collected signals are acquired to perform timing control so that the power conversion module enters different operation modes, including:

[0081] After the power conversion module is powered, the system starts to initialize and generates an initialization flag;

[0082] When the initialization flag is effective, the power conversion module enters the self-building module and generates a self-check flag;

[0083] When the self-check mark is effective, the power conversion module enters the pre-charge mode, performs the pre-charge operation, and generates the pre-charge mark;

[0084] When the pre-charge flag is effective, the power conversion module enters the standby mode. In the standby mode, when the power-on condition is met, it enters the working module;

[0085] When a fault signal is obtained, the power conversion module enters a fault mode;

[0086] When a signal indicating that the power conversion module cannot continue to work is obtained, the power conversion module enters a shutdown mode.

[0087] In some specific embodiments, the collected signals are acquired to perform timing control so that the inverter module enters different operation modes, including:

[0088] After power is supplied, the inverter module is initialized to generate an initialization flag;

[0089] When the initialization flag takes effect, the inverter module enters the self-test mode and generates a self-test flag when the self-test is completed;

[0090] When the self-check flag is effective, the inverter module enters the pre-charge mode, and generates a pre-charge flag when the pre-charge mode is completed;

[0091] When the pre-charge flag is effective, the inverter module enters standby mode;

[0092] In standby mode, the system judges whether the acquired signal meets the grid connection condition. If so, the system enters the grid connection working mode. If not, the system enters the off-grid working mode.

[0093] When a fault signal is obtained, the inverter module enters a fault mode;

[0094] When a signal is obtained indicating that the power conversion module cannot continue to work, the inverter module enters a shutdown mode.

[0095] In some specific embodiments, when a signal indicating that the DC conversion module cannot continue to work is obtained, the DC conversion module enters a shutdown mode, including:

[0096] When the single module active shutdown conditions are met, the system receives a sleep command, or a serious unrecoverable fault is detected, the system enters shutdown mode.

[0097] In some specific embodiments, when a fault signal is obtained, the DC conversion module enters a fault mode, including:

[0098] If the module detects any fault, it will automatically stop related functions and enter protection mode;

[0099] The module will take appropriate protection measures according to the fault type and continuously monitor whether the fault is restored;

[0100] When it is detected that the fault condition is eliminated, the module will automatically exit the fault state and resume normal operation.

[0101] Preferably, in the off-grid working mode, if it is necessary to switch to the grid-connected working mode, when the grid-connected conditions are met, the off-grid working mode state can be switched to the grid-connected working mode state;

[0102] In the grid-connected state, if it is necessary to switch to the off-grid working mode, when the off-grid working mode conditions are met, the grid-connected working mode can be switched to the off-grid working mode.

[0103] In some specific embodiments, the switching between the above different modes is realized according to specific conditions, and the specific conditions include:

[0104] Module power on / off enable, self-test status, module fault flag, signal correction completion status, initialization completion flag, sleep instruction, voltage, current and frequency range, and time sequence flag.

[0105] In some specific embodiments, the switching of the overall mode is realized by sequentially controlling the operation modes of the inverter module, the power conversion module and the DC conversion module, including:

[0106] S1, determine whether the inverter module, the power conversion module and the DC conversion module are in standby mode, if so, enter the system standby mode;

[0107] S2, obtain the battery status and determine whether the battery terminal can work normally. If so, the battery terminal is turned on; if not, the battery terminal is turned off;

[0108] S21, obtaining the photovoltaic status, when the battery end is turned off, judging whether the photovoltaic power is working normally, if so, the photovoltaic end is turned on, if not, returning to the system standby mode;

[0109] Get the inverter module status and determine whether the inverter module is working normally. If so, the grid end is turned on. If not, the system returns to standby mode.

[0110] S22, obtaining the photovoltaic status, when the battery end is turned on, judging whether the photovoltaic power is working normally, if so, the photovoltaic end is turned on, if not, returning to the system standby mode;

[0111] Get the inverter module status and determine whether the inverter module is working normally. If so, the grid end is turned on. If not, the system returns to standby mode.

[0112] Specifically, the above-mentioned timing management module is introduced on the basis of mode conversion, and all working modes of the system are exhaustively enumerated, and different working mode situations can be obtained as shown in the following figure:

[0113] 1) MPPT, DCDC battery discharge, ACDC inverter grid connection, this is working condition cond1, in this state, photovoltaic power generation and battery discharge are transmitted to the grid, and no load is connected;

[0114] 2) MPPT, DCDC battery discharge, ACDC inverter off-grid, this is working condition cond2. In this state, photovoltaic power generation and battery discharge are used to power the load, and the grid does not intervene (equivalent to zero grid feed-in);

[0115] 3) MPPT, DCDC battery charging, ACDC rectification, this is working condition cond3, in this state, the grid + photovoltaic power together charge the battery;

[0116] 4) MPPT, DCDC battery charging, ACDC inverter grid connection, this is working condition cond4. In this state, photovoltaic charges the battery and the excess power is transmitted to the grid;

[0117] 5) MPPT, DCDC battery charging, ACDC inverter off-grid, this is working condition cond5. In this state, photovoltaic charges the battery, and the excess power is only given to the load;

[0118] 6) MPPT, DCDC battery charging, this is working condition cond6, in this state, the grid and load are not involved, the photovoltaic only charges the battery;

[0119] 7) MPPT, ACDC inverter and grid connection, this is working condition cond7;

[0120] 8) MPPT, ACDC inverter off-grid, this is working condition cond8;

[0121] 9) DCDC battery discharges and ACDC is inverter-connected to the grid, this is working condition cond9;

[0122] 10) DCDC battery discharge, ACDC inverter off-grid, this is working condition cond10;

[0123] 11) DCDC battery charging, ACDC rectification, this is working condition cond11;

[0124] 12) All are not working, this is working condition cond12;

[0125] The conversion of the above modes is realized through the timing management module;

[0126] 1) When the battery, photovoltaic modules, power grid and household loads are all working, the photovoltaic side is started up by combining the corresponding closed-loop control strategy under the control of the photovoltaic side DC conversion module;

[0127] Under the control of the DCDC state machine on the battery side, combined with the corresponding closed-loop control strategy, the battery side is turned on. Under the control of the ACDC state machine on the AC side, combined with the corresponding closed-loop control strategy, the AC side is turned on. Based on the differences in the settings of the charging and discharging conditions and the settings of the grid-connected and off-grid conditions, the mode combinations under the aforementioned working conditions cond1, cond2, cond3, cond4, and cond5 can be realized.

[0128] 2) When the battery end is not working, and the photovoltaic end, the grid end, and the load end are working, the mode combination under the above-mentioned working conditions cond7 and cond8 can be realized;

[0129] 3) When the photovoltaic module is not working, the battery end, the grid end and the load end can work, and the mode combination under the above-mentioned working conditions cond9, cond10 and cond11 can be realized;

[0130] 4) When the grid side and the load side are not working, and the battery side and the photovoltaic side are working, the mode combination under the aforementioned working condition cond6 can be realized;

[0131] 5) When all are not working, the mode under cond12 condition is realized.

[0132] In some embodiments, the DC conversion module, power conversion module and inverter module can realize effective control of the modes of independent functional modules. At the system level, a certain degree of functional decoupling is achieved, and the requirements for relatively independent control of power modules with different characteristic requirements are realized.

[0133] In some embodiments, a state machine control system is provided according to a photovoltaic energy storage system in multiple working modes, including:

[0134] Mode conversion module, timing management module, inverter module, power conversion module and DC conversion module:

[0135] The mode conversion module and the timing management module are electrically connected to the inverter module, the power conversion module and the DC conversion module respectively;

[0136] The mode conversion module is used to obtain the collected signals to perform timing control on the inverter module, the power conversion module and the DC conversion module to enter different operation modes;

[0137] The timing management module is used to sequentially control the operation modes of the inverter module, the power conversion module and the DC conversion module to achieve overall mode switching.

[0138] Specifically, the system is divided into three main conversion modules, namely, one AC-DC bidirectional inverter rectifier topology, at least one MPPT DC conversion circuit to realize photovoltaic module power conversion, and at least one buck-boost DC-DC conversion circuit to realize battery side charging and discharging. Among the three main objects, there are different combinations of control.

[0139] The above is only a specific implementation of the embodiment of the present invention, but the protection scope of the embodiment of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed in the embodiment of the present invention should be included in the protection scope of the embodiment of the present invention. Therefore, the protection scope of the embodiment of the present invention should be based on the protection scope of the claims.

Claims

1. A state machine control method for a photovoltaic energy storage system in multiple operating modes, characterized in that: include: Acquire the collected signals to perform timing control so that the inverter module, power conversion module and DC conversion module enter different operation modes; The overall mode switching is achieved by sequentially controlling the operating modes of the inverter module, the power conversion module and the DC conversion module.

2. The method according to claim 1, characterized in that The collected signals are obtained to control the DC conversion module to enter different operation modes, including: After the DC conversion module is powered, the system starts initializing and generates an initialization flag; When the initialization flag is effective, the DC conversion module enters the self-test module and generates a self-test flag; When the self-check mark is effective, the DC conversion module enters the pre-charge mode, performs the pre-charge operation, and generates the pre-charge mark; When the pre-charge flag is effective, the DC conversion module enters the standby mode. In the standby mode, when the power-on condition is met, it enters the working module; When a fault signal is obtained, the DC conversion module enters a fault mode; When a signal indicating that the DC conversion module cannot continue to work is obtained, the DC conversion module enters a shutdown mode.

3. The method according to claim 1, characterized in that The collected signals are obtained to control the timing of the power conversion module to enter different operation modes, including: After the power conversion module is powered, the system starts to initialize and generates an initialization flag; When the initialization flag is effective, the power conversion module enters the self-building module and generates a self-check flag; When the self-check mark is effective, the power conversion module enters the pre-charge mode, performs the pre-charge operation, and generates the pre-charge mark; When the pre-charge flag is effective, the power conversion module enters the standby mode. In the standby mode, when the power-on condition is met, it enters the working module; When a fault signal is obtained, the power conversion module enters a fault mode; When a signal indicating that the power conversion module cannot continue to work is obtained, the power conversion module enters a shutdown mode.

4. The method according to claim 1, characterized in that: The collected signals are obtained to perform timing control so that the inverter module enters different operation modes, including: After power is supplied, the inverter module is initialized to generate an initialization flag; When the initialization flag takes effect, the inverter module enters the self-test mode and generates a self-test flag when the self-test is completed; When the self-check flag is effective, the inverter module enters the pre-charge mode, and generates a pre-charge flag when the pre-charge mode is completed; When the pre-charge flag is effective, the inverter module enters standby mode; In standby mode, the system judges whether the acquired signal meets the grid connection condition. If so, the system enters the grid connection working mode. If not, the system enters the off-grid working mode. When a fault signal is obtained, the inverter module enters a fault mode; When a signal is obtained indicating that the power conversion module cannot continue to work, the inverter module enters a shutdown mode.

5. The method according to any one of claims 2 to 4, characterized in that: When a signal indicating that the DC conversion module cannot continue to work is obtained, the DC conversion module enters shutdown mode, including: When the single module active shutdown conditions are met, the system receives a sleep command, or a serious unrecoverable fault is detected, the system enters shutdown mode.

6. The method according to any one of claims 2 to 4, characterized in that: When a fault signal is received, the DC conversion module enters a fault mode, including: If the module detects any fault, it will automatically stop related functions and enter protection mode; The module will take appropriate protection measures according to the fault type and continuously monitor whether the fault is restored; When it is detected that the fault condition is eliminated, the module will automatically exit the fault state and resume normal operation.

7. The method according to claim 4, characterized in that In the off-grid working mode, if it is necessary to switch to the grid-connected working mode, when the grid-connected conditions are met, the off-grid working mode can be switched to the grid-connected working mode; In the grid-connected state, if it is necessary to switch to the off-grid working mode, when the off-grid working mode conditions are met, the grid-connected working mode can be switched to the off-grid working mode.

8. The method according to any one of claims 2 to 4, characterized in that: The above different modes are switched based on specific conditions, including: Module power on / off enable, self-test status, module fault flag, signal correction completion status, initialization completion flag, sleep instruction, voltage, current and frequency range, and time sequence flag.

9. The method according to claim 1, characterized in that: The switching of the overall mode is achieved by sequentially controlling the operation modes of the inverter module, the power conversion module and the DC conversion module, including: S1, determine whether the inverter module, the power conversion module and the DC conversion module are in standby mode, if so, enter the system standby mode; S2, obtain the battery status and determine whether the battery terminal can work normally. If so, the battery terminal is turned on; if not, the battery terminal is turned off; S21, obtaining the photovoltaic status, when the battery end is turned off, judging whether the photovoltaic power is working normally, if so, the photovoltaic end is turned on, if not, returning to the system standby mode; Get the inverter module status and determine whether the inverter module is working normally. If so, the grid end is turned on. If not, the system returns to standby mode. S22, obtaining the photovoltaic status, when the battery end is turned on, judging whether the photovoltaic power is working normally, if so, the photovoltaic end is turned on, if not, returning to the system standby mode; Get the inverter module status and determine whether the inverter module is working normally. If so, the grid end is turned on. If not, the system returns to standby mode.

10. A state machine control system under multiple working modes of a photovoltaic energy storage system, characterized in that: include: Mode conversion module, timing management module, inverter module, power conversion module and DC conversion module: The mode conversion module and the timing management module are electrically connected to the inverter module, the power conversion module and the DC conversion module respectively; The mode conversion module is used to obtain the collected signals to perform timing control on the inverter module, the power conversion module and the DC conversion module to enter different operation modes; The timing management module is used to sequentially control the operation modes of the inverter module, power conversion module and DC conversion module to achieve overall mode switching; The inverter module is connected to the grid end and the load end through the power distribution module, the power conversion module is connected to the photovoltaic end, and the DC conversion module is connected to the battery end.

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