A photovoltaic energy storage coordinated operation control method

Abstract

The present invention relates to a photovoltaic energy storage coordinated operation control method, which includes the following steps: Step 1: determine whether there is a reverse flow between the photovoltaic energy storage system and the power grid, and adjust the working state of each inverter according to the judgment result, and then execute step 2; Step 2: determine whether the current time is in the valley time period, if not, execute step 3, if yes, execute step 4; Step 3: determine whether there is a reverse flow between the photovoltaic energy storage system and the power grid, and adjust the charging power of the energy storage converter or the discharging power of the energy storage converter according to the judgment result under the constraint of the energy storage device charging and discharging constraint conditions; Step 4: determine whether the energy storage device meets the energy storage device charging and discharging constraint conditions and the transformer working constraint conditions, if satisfied, increase the charging power of the energy storage converter, if not satisfied, reduce the charging power of the energy storage converter. The present invention can adjust the power generation power and charging and discharging power of the photovoltaic energy storage system in real time to avoid reverse flow and transformer overload problems.

Description

Technical Field

[0001] The present invention belongs to the technical field of microgrid control, and in particular relates to a method for controlling coordinated operation in a photovoltaic energy storage system. Background Art

[0002] As an important support for "Internet +" smart energy and a technical means of friendly interaction with large power grids, microgrids can improve the safety and reliability of power systems, promote the access and local consumption of clean energy, improve energy utilization efficiency, play an important role in energy conservation and emission reduction, and are conducive to building a conservation-oriented society.

[0003] At present, deep-seated contradictions such as low overall efficiency of the power system, insufficient coordination between sources, networks and loads, and insufficient complementarity and mutual assistance among various power sources are becoming increasingly prominent, and they are in urgent need of overall optimization. We need to rely on new technologies such as modern information and communication technology, big data, artificial intelligence, and energy storage to fully mobilize the load-side regulation and response capabilities, study the comprehensive optimization configuration plan of sources, networks, loads, and storage, promote the integrated development with multi-energy complementary demonstration parks and smart integrated energy services, and, under economically feasible conditions, improve self-balancing capabilities and reduce the demand for peak regulation and capacity reserve on large power grids.

[0004] Photovoltaic storage is "photovoltaic + energy storage". Photovoltaic storage integrated microgrid is a typical microgrid networking form. During the low electricity price period, users give priority to photovoltaic power supply and charge energy storage at the same time. When photovoltaic power is insufficient, it is supplemented by the mains. During the peak electricity price period, energy storage and photovoltaic power are used together to supply power to users, and the insufficient part is supplemented by the mains. It not only achieves peak shaving and valley filling, but also realizes green substitution of electricity and reduces carbon emissions.

[0005] However, the photovoltaic and energy storage integrated microgrid may encounter the following problems during operation:

[0006] (1) When the energy storage device is shaving peak power (discharging), if the total power consumption of the user is less than the discharge power of the energy storage device + the power generation power of the photovoltaic power generation device, the power of the energy storage device or the photovoltaic power generation device will flow back to the upper-level power grid connected to the user, resulting in a decrease in the peak-shaving income of the energy storage device and an increase in the safety risk of the upper-level power grid;

[0007] (2) When the energy storage device is valley filling (charging), if the charging power of the energy storage device is too high, resulting in the user's total power consumption being too high, it may cause the user's transformer to overload or even trip, affecting the transformer's efficiency, life, and the user's power safety.

[0008] Therefore, during the operation of the integrated photovoltaic and energy storage microgrid, it is necessary to design a photovoltaic energy storage coordinated operation plan to adjust the power generation power of the photovoltaic power generation device and the charging and discharging power of the energy storage device according to the user's power consumption, so as to avoid the reverse grid connection of electricity or overload operation of the user's transformer.

[0009] At present, photovoltaic power generation devices are generally not controlled in the market. The mainstream energy storage devices generally achieve peak-shaving and valley-filling operation by pre-setting the charging and discharging power of the energy storage device in each period (such as setting the energy storage device to discharge from 8:00 to 12:00, with a discharge power of 200kW, and setting the energy storage device to charge from 0:00 to 8:00, with a charging power of 100kW). The photovoltaic energy storage coordinated operation scheme to prevent reverse flow and transformer overload is not designed in the microgrid. In this mode, the photovoltaic power generation device and the energy storage device will not adjust the power generation and charging and discharging power in real time according to the user's power consumption, so it is easy for power to go online in reverse (reverse flow) or the user's transformer to be overloaded (overloaded). Summary of the invention

[0010] The purpose of the present invention is to provide a photovoltaic energy storage coordinated operation control method that can adjust the power generation power and charging and discharging power of a photovoltaic energy storage system in real time to avoid reverse flow and transformer overload problems.

[0011] In order to achieve the above object, the technical solution adopted by the present invention is:

[0012] A photovoltaic energy storage coordinated operation control method is used to control the coordinated operation of a photovoltaic energy storage system connected to a power grid, wherein the photovoltaic energy storage system includes a photovoltaic device, an energy storage device and a transformer, wherein the photovoltaic device includes a plurality of photovoltaic panels, and a plurality of inverters connected to the photovoltaic panels in a one-to-one correspondence, and the energy storage device includes an energy storage battery and an energy storage converter connected to the energy storage battery, and the photovoltaic energy storage coordinated operation control method includes the following steps:

[0013] Step 1: Determine whether there is reverse flow between the photovoltaic energy storage system and the power grid, and adjust the working state of each inverter according to the determination result, so that when there is no reverse flow, the number of inverters in the power-on state reaches the maximum, and then execute step 2;

[0014] Step 2: Determine whether the current time is in the off-peak period, if not, go to step 3, if yes, go to step 4;

[0015] Step 3: Determine whether there is a reverse flow between the photovoltaic energy storage system and the power grid, and adjust the charging power of the energy storage inverter or the discharging power of the energy storage inverter according to the judgment result under the constraints of the charging and discharging constraints of the energy storage device. In the case of reverse flow, increase the charging power of the energy storage inverter or reduce the discharging power of the energy storage inverter; in the case of no reverse flow, increase the discharging power of the energy storage inverter or reduce the charging power of the energy storage inverter;

[0016] Step 4: Switch the energy storage inverter that is in the on state and discharge mode to the off state, or when the energy storage inverter is in the on state and charging mode or the energy storage inverter is in the off state, determine whether the energy storage device satisfies the charging and discharging constraints of the energy storage device and the working constraints of the transformer. If so, increase the charging power of the energy storage inverter; if not, reduce the charging power of the energy storage inverter.

[0017] A mains power anti-backflow threshold is preset, and the detected mains power and the mains power anti-backflow threshold are used to determine whether there is a backflow between the photovoltaic energy storage system and the power grid. When the detected mains power is greater than the mains power anti-backflow threshold, it is determined that there is no backflow.

[0018] The step 1 is: judging the working state of the currently selected inverter, and judging whether there is reverse flow between the photovoltaic energy storage system and the power grid; if there is no reverse flow and the currently selected inverter is in the on state, then continue to select the next inverter and execute the step 1; if there is no reverse flow and the currently selected inverter is in the on state, then switch the currently selected inverter to the on state and then continue to select the next inverter and execute the step 1; if there is reverse flow and the currently selected inverter is in the off state, then continue to select the next inverter and execute the step 1; if there is reverse flow and the currently selected inverter is in the on state, then switch the currently selected inverter to the off state and then continue to select the next inverter and execute the step 1.

[0019] In step 2, if the valley time start time ≤ current time ≤ valley time end time, it is determined that the current time is within the valley time period.

[0020] The charging and discharging constraints of the energy storage device include: the state of charge of the energy storage battery > the discharge depth of the energy storage battery; the state of charge of the energy storage battery < the charging depth of the energy storage battery; the discharge power of the energy storage inverter < the maximum discharge power of the energy storage battery; the charging power of the energy storage inverter < the maximum charging power of the energy storage battery; the working constraint of the transformer is: the detected mains power < the maximum load of the transformer.

[0021] In step 3, the method for increasing the charging power of the energy storage converter is as follows: determining the charging power increase amount based on the set battery charging power growth coefficient and the maximum charging power of the energy storage battery, and obtaining the charging power of the energy storage converter after the current charging power of the energy storage converter and the charging power increase amount, or switching the energy storage converter in the shutdown state to the power-on state and the charging mode, and determining the charging power of the energy storage converter based on the battery charging power growth coefficient and the maximum charging power of the energy storage battery;

[0022] The method for reducing the discharge power of the energy storage converter is as follows: determining the discharge power reduction amount based on the set battery discharge power growth coefficient and the maximum discharge power of the energy storage battery, and obtaining the discharge power of the energy storage converter after the reduction based on the current discharge power of the energy storage converter and the discharge power reduction amount, or switching the energy storage converter in the power-on state and the discharge mode to the power-off state;

[0023] The method for increasing the discharge power of the energy storage converter is as follows: switching the energy storage converter in the shutdown state to the startup state and the discharge mode, and determining the discharge power of the energy storage converter based on the set battery discharge power growth coefficient and the maximum discharge power of the energy storage battery, or determining the discharge power increase amount based on the set discharge power growth coefficient and the maximum discharge power of the energy storage battery, and obtaining the increased discharge power of the energy storage converter based on the current discharge power of the energy storage converter and the discharge power increase amount;

[0024] The method for reducing the charging power of the energy storage inverter is: determining the charging power reduction amount based on the set charging power growth coefficient and the maximum charging power of the energy storage battery, and reducing the charging power of the energy storage inverter based on the current charging power of the energy storage inverter and the charging power increase, or switching the energy storage inverter in the power-on state and charging mode to the power-off state.

[0025] The step 3 comprises the following steps:

[0026] Step 3-1: Determine the working state of the energy storage converter. If the energy storage converter is in the off state, execute step 3-2. If the energy storage converter is in the on state and the discharging mode, execute step 3-7. If the energy storage converter is in the on state and the charging mode, execute step 3-13.

[0027] Step 3-2: Determine whether there is reverse flow between the photovoltaic energy storage system and the power grid. If not, execute step 3-3; if so, execute step 3-5;

[0028] Step 3-3: Determine whether the state of charge of the energy storage battery > the depth of discharge of the energy storage battery is established, if so, execute step 3-4, if not, return to step 1;

[0029] Step 3-4: increasing the discharge power of the energy storage converter, switching the energy storage converter from the shutdown state to the startup state and the discharge mode, determining the discharge power of the energy storage converter based on the set battery discharge power growth coefficient and the maximum discharge power of the energy storage battery, and then returning to step 1;

[0030] Step 3-5: Determine whether the state of charge of the energy storage battery is less than the depth of charge of the energy storage battery. If so, execute step 3-6; if not, return to step 1;

[0031] Step 3-6: increasing the charging power of the energy storage converter, switching the energy storage converter from the shutdown state to the startup state and charging mode, and determining the charging power of the energy storage converter based on the battery charging power growth coefficient and the maximum charging power of the energy storage battery, and then returning to step 1;

[0032] Step 3-7: Determine whether the state of charge of the energy storage battery> the depth of discharge of the energy storage battery is established, if so, execute step 3-8, if not, execute step 3-12;

[0033] Step 3-8: Determine whether there is reverse flow between the photovoltaic energy storage system and the power grid. If not, execute step 3-9. If so, execute step 3-11.

[0034] Step 3-9: Determine whether the discharge power of the energy storage converter is less than the maximum discharge power of the energy storage battery. If so, execute step 3-10; otherwise, return to step 1;

[0035] Step 3-10: increasing the discharge power of the energy storage converter, determining the discharge power increase amount based on the set discharge power growth coefficient and the maximum discharge power of the energy storage battery, and obtaining the increased discharge power of the energy storage converter based on the current discharge power of the energy storage converter and the discharge power increase amount, and then returning to step 1;

[0036] Step 3-11: reducing the discharge power of the energy storage converter, determining the discharge power reduction amount based on the set battery discharge power growth coefficient and the maximum discharge power of the energy storage battery, and obtaining the reduced discharge power of the energy storage converter based on the current discharge power of the energy storage converter and the discharge power reduction amount, and then returning to step 1;

[0037] Step 3-12: reducing the discharge power of the energy storage converter, and switching the energy storage converter in the on state and the discharge mode to the off state;

[0038] Step 3-13: Determine whether the state of charge of the energy storage battery is less than the depth of charge of the energy storage battery. If so, execute step 3-14; if not, execute step 3-18;

[0039] Step 3-14: Determine whether there is reverse flow between the photovoltaic energy storage system and the power grid. If not, execute step 3-15. If so, execute step 3-16.

[0040] Step 3-15: reducing the charging power of the energy storage converter, determining the amount of reduction in charging power based on the set charging power growth coefficient and the maximum charging power of the energy storage battery, and obtaining the reduced charging power of the energy storage converter based on the current charging power of the energy storage converter and the charging power increase, and then returning to step 1;

[0041] Step 3-16: Determine whether the charging power of the energy storage converter is less than the maximum charging power of the energy storage battery. If so, execute step 3-17; otherwise, return to step 1;

[0042] Step 3-17: increasing the charging power of the energy storage converter, determining the charging power increase amount based on the set battery charging power growth coefficient and the maximum charging power of the energy storage battery, and obtaining the increased charging power of the energy storage converter based on the current charging power of the energy storage converter and the charging power increase amount, and then returning to step 1;

[0043] Step 3-18: Reduce the charging power of the energy storage inverter, switch the energy storage inverter in the power-on state and charging mode to the power-off state, and then return to step 1.

[0044] The increase in charging power is the product of the maximum charging power of the energy storage battery and the battery charging power growth coefficient, the reduction in discharge power is the product of the maximum discharge power of the energy storage battery and the battery discharge power growth coefficient, the increase in discharge power is the product of the maximum discharge power of the energy storage battery and the discharge power growth coefficient, and the reduction in charging power is the product of the maximum charging power of the energy storage battery and the charging power growth coefficient.

[0045] In step 4, the method for increasing the charging power of the energy storage converter is as follows: determining the charging power increase amount based on the set battery charging power growth coefficient and the maximum charging power of the energy storage battery, and obtaining the charging power of the energy storage converter after the current charging power of the energy storage converter and the charging power increase amount, or switching the energy storage converter in the shutdown state to the power-on state and the charging mode, and determining the charging power of the energy storage converter based on the battery charging power growth coefficient and the maximum charging power of the energy storage battery;

[0046] The method for reducing the charging power of the energy storage inverter is: determining the charging power reduction amount based on the set charging power growth coefficient and the maximum charging power of the energy storage battery, and reducing the charging power of the energy storage inverter based on the current charging power of the energy storage inverter and the charging power increase, or switching the energy storage inverter that is in the power-on state and charging mode to the power-off state.

[0047] The step 4 comprises the following steps:

[0048] Step 4-1: Determine the working state of the energy storage converter. If the energy storage converter is in the power-on state and the charging mode, execute step 4-2. If the energy storage converter is in the power-off state, execute step 4-8. If the energy storage converter is in the power-on state and the discharging mode, execute step 4-11.

[0049] Step 4-2: Determine whether the state of charge of the energy storage battery is less than the depth of charge of the energy storage battery. If so, execute step 4-3; otherwise, execute step 4-7;

[0050] Step 4-3: Determine whether the detected mains power is less than the maximum load of the transformer, if so, execute step 4-4, if not, execute step 4-6;

[0051] Step 4-4: Determine whether the charging power of the energy storage converter is less than the maximum charging power of the energy storage battery. If so, execute step 4-5; otherwise, return to step 1;

[0052] Step 4-5: increasing the charging power of the energy storage converter, determining the charging power increase amount based on the set battery charging power growth coefficient and the maximum charging power of the energy storage battery, and obtaining the increased charging power of the energy storage converter based on the current charging power of the energy storage converter and the charging power increase amount, and then returning to step 1;

[0053] Step 4-6: reducing the charging power of the energy storage converter, determining the amount of reduction in charging power based on the set charging power growth coefficient and the maximum charging power of the energy storage battery, and obtaining the reduced charging power of the energy storage converter based on the current charging power of the energy storage converter and the charging power increase, and then returning to step 1;

[0054] Step 4-7: reducing the charging power of the energy storage converter, switching the energy storage converter in the on state and charging mode to the off state, and then returning to step 1;

[0055] Step 4-8: Determine whether the state of charge of the energy storage battery is less than the depth of charge of the energy storage battery. If so, execute step 4-9; if not, return to step 1;

[0056] Step 4-9: Determine whether the detected mains power is less than the maximum load of the transformer. If so, execute step 4-10. If not, return to step 1.

[0057] Step 4-10: increasing the charging power of the energy storage converter, switching the energy storage converter from the shutdown state to the startup state and charging mode, and determining the charging power of the energy storage converter based on the battery charging power growth coefficient and the maximum charging power of the energy storage battery, and then returning to step 1;

[0058] Step 4-11: Switch the energy storage converter to the shutdown state, and then return to step 1.

[0059] The charging power increase is the product of the maximum charging power of the energy storage battery and the battery charging power growth coefficient, and the charging power reduction is the product of the maximum charging power of the energy storage battery and the charging power growth coefficient.

[0060] The value of the battery charging power growth coefficient and the battery discharging power growth coefficient is n%, where n is an integer divisible by 100.

[0061] The value of n is 1, 2, 4, 5, 10, 20 or 50.

[0062] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art: the present invention can operate automatically and adjust the power generation power and charging and discharging power of the photovoltaic energy storage system in real time, thereby controlling the coordinated operation of the photovoltaic energy storage and avoiding reverse current and transformer overload problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Attached Figure 1 Schematic diagram of photovoltaic energy storage system.

[0064] Attached Figure 2This is a flow chart of steps 1 and 2 in the photovoltaic energy storage coordinated operation control method of the present invention.

[0065] Attached Figure 3 This is a flow chart of step 3 in the photovoltaic energy storage coordinated operation control method of the present invention.

[0066] Attached Figure 4 This is a flow chart of step 4 in the photovoltaic energy storage coordinated operation control method of the present invention. DETAILED DESCRIPTION

[0067] The present invention will be further described below in conjunction with the embodiments shown in the accompanying drawings.

[0068] Embodiment 1: As shown in the attached Figure 1 As shown, the photovoltaic energy storage system connected to the power grid includes a photovoltaic device, an energy storage device, and a transformer. The mains power of the power grid is connected to the 400V bus through the transformer, and the photovoltaic device and the energy storage device are connected to the 400V bus. The user's electrical equipment can also be connected to the 400V bus. A smart meter can be set between the power grid and the 400V bus to detect power. The photovoltaic device includes a plurality of photovoltaic panels and a plurality of inverters connected to the photovoltaic panels one by one. In this embodiment, three photovoltaic panels and three inverters are taken as an example, and each inverter is connected to the 400V bus via a smart meter. The energy storage device includes an energy storage battery and an energy storage converter (PCS) connected to the energy storage battery. The energy storage converter is also connected to the 400V bus via a smart meter. The energy storage converter has an on state and an off state, and it can select a charging mode or a discharging mode.

[0069] In view of the above-mentioned photovoltaic energy storage system, the following photovoltaic energy storage coordinated operation control method is proposed.

[0070] In this method, the following parameters need to be preset:

[0071] 1. Battery charging power growth factor: The battery charging power growth factor is used to indicate the percentage of power increase when adjusting the charging power of the energy storage battery in the energy storage system;

[0072] 2. Battery discharge power growth coefficient: The battery discharge power growth coefficient is used to indicate the percentage of power increase when adjusting the discharge power of the energy storage battery in the energy storage system;

[0073] 3. Mains power reverse flow prevention threshold: The mains power reverse flow prevention threshold is used together with the detected mains power to determine whether there is reverse flow between the photovoltaic energy storage system and the power grid. When the detected mains power is greater than the mains power reverse flow prevention threshold, it is judged as no reverse flow, otherwise it is no reverse flow.

[0074] The above battery charging power growth coefficient and battery discharging power growth coefficient are set to n%, where n is an integer divisible by 100, for example, n is 1, 2, 4, 5, 10, 20 or 50. In the same solution, the battery charging power growth coefficient and the battery discharging power growth coefficient can be the same or different and can be set as needed. Usually, the mains power backflow prevention threshold is greater than the rated discharge power of the energy storage battery * the battery discharge power growth coefficient / 100.

[0075] As attached Figure 2 To Attachment Figure 4 As shown, the photovoltaic energy storage coordinated operation control method includes the following steps:

[0076] Step 1: Determine whether there is reverse flow between the photovoltaic energy storage system and the power grid, and adjust the working state of each inverter according to the judgment result, so that when there is no reverse flow, the number of inverters in the power-on state reaches the maximum, and then execute step 2.

[0077] In step 1, it is necessary to judge whether there is reverse flow between the photovoltaic energy storage system and the power grid. After each judgment, an inverter is selected to determine whether the working state of the selected inverter needs to be adjusted. Then, the reverse flow judgment is performed again, and the next inverter is selected to determine whether its working state needs to be adjusted. This process is repeated until the states of all inverters are adjusted. At this time, there is no reverse flow between the photovoltaic energy storage system and the power grid, and the number of inverters in the power-on state reaches the maximum.

[0078] Therefore, step 1 is: judging the working state of the currently selected inverter, and judging whether there is reverse flow between the photovoltaic energy storage system and the power grid; if there is no reverse flow and the currently selected inverter is in the on state, then continue to select the next inverter and execute step 1; if there is no reverse flow and the currently selected inverter is in the on state, then switch the currently selected inverter to the on state and then continue to select the next inverter and execute step 1; if there is reverse flow and the currently selected inverter is in the off state, then continue to select the next inverter and execute step 1; if there is reverse flow and the currently selected inverter is in the on state, then switch the currently selected inverter to the off state and then continue to select the next inverter and execute step 1.

[0079] In this embodiment, since three inverters are provided, step 1 specifically includes the following steps:

[0080] Step 1-1: Determine whether the detected mains power > mains power reverse flow prevention threshold is met, thereby determining whether there is reverse flow between the photovoltaic energy storage system and the power grid. If so, execute step 1-2; otherwise, execute step 1-4;

[0081] Step 1-2: Select inverter No. 1 and determine whether inverter No. 1 is in the power-on state. If so, execute step 1-6; otherwise, execute step 1-3;

[0082] Step 1-3: Switch the currently selected inverter No. 1 to the power-on state, and then execute steps 1-6;

[0083] Step 1-4: Select inverter No. 1 and determine whether inverter No. 1 is in shutdown state. If yes, execute step 1-6; otherwise, execute step 1-5;

[0084] Step 1-5: Switch the currently selected inverter No. 1 to the shutdown state, and then execute steps 1-6;

[0085] Step 1-6: Determine whether the detected mains power > mains power reverse flow prevention threshold is met, thereby determining whether there is reverse flow between the photovoltaic energy storage system and the power grid. If so, execute step 1-7; otherwise, execute step 1-9;

[0086] Step 1-7: Select inverter No. 2 and determine whether inverter No. 2 is in the power-on state. If so, execute step 1-11; otherwise, execute step 1-8;

[0087] Step 1-8: Switch the currently selected inverter No. 2 to the power-on state, and then execute steps 1-11;

[0088] Step 1-9: Select inverter No. 2 and determine whether inverter No. 2 is in shutdown state. If yes, execute step 1-11; otherwise, execute step 1-10;

[0089] Step 1-10: Switch the currently selected inverter No. 2 to the shutdown state, and then execute steps 1-11;

[0090] Step 1-11: Determine whether the detected mains power > mains power reverse flow prevention threshold value is established, thereby determining whether there is reverse flow between the photovoltaic energy storage system and the power grid. If so, execute step 1-12; otherwise, execute step 1-14;

[0091] Step 1-12: Select inverter No. 3 and determine whether inverter No. 3 is in the power-on state. If so, execute step 1-13; otherwise, execute step 1-13;

[0092] Step 1-13: Switch the currently selected inverter No. 3 to the power-on state, and then proceed to step 2;

[0093] Step 1-14: Select inverter No. 3 and determine whether inverter No. 3 is in shutdown state. If yes, execute step 2; otherwise, execute step 1-15;

[0094] Step 1-15: Switch the currently selected inverter No. 3 to the shutdown state, and then perform step 2.

[0095] Step 2: Determine whether the current time is in the off-peak period, if not, execute step 3, if yes, execute step 4.

[0096] In step 2, if the valley time start time ≤ current time ≤ valley time end time, it is determined that the current time is within the valley time period. The valley time start time and valley time end time are obtained by the power grid.

[0097] Step 3: When the current time is in the non-off-peak period, determine whether there is reverse flow between the photovoltaic energy storage system and the power grid, and adjust the charging power or discharging power of the energy storage inverter according to the judgment result under the constraints of the charging and discharging constraints of the energy storage device. In the case of reverse flow, increase the charging power of the energy storage inverter or reduce the discharging power of the energy storage inverter. In the case of no reverse flow, increase the discharging power of the energy storage inverter or reduce the charging power of the energy storage inverter.

[0098] The charging and discharging constraints of the energy storage device include: the state of charge of the energy storage battery > the discharge depth of the energy storage battery; the state of charge of the energy storage battery < the charging depth of the energy storage battery; the discharge power of the energy storage inverter < the maximum discharge power of the energy storage battery; the charging power of the energy storage inverter < the maximum charging power of the energy storage battery.

[0099] In step 3:

[0100] (1) The method for increasing the charging power of the energy storage inverter is: determining the charging power increase based on the set battery charging power growth coefficient and the maximum charging power of the energy storage battery, and obtaining the increased charging power of the energy storage inverter based on the current charging power of the energy storage inverter and the charging power increase, or switching the energy storage inverter in the shutdown state to the power-on state and charging mode, and determining the charging power of the energy storage inverter based on the battery charging power growth coefficient and the maximum charging power of the energy storage battery. The charging power increase is the product of the maximum charging power of the energy storage battery and the battery charging power growth coefficient. For the solution of switching the energy storage inverter from the shutdown state to the power-on state and charging mode, it is equivalent to adding the above charging power increase to the original charging power of 0, thereby obtaining the charging power of the energy storage inverter;

[0101] (2) The method of reducing the discharge power of the energy storage inverter is: determining the discharge power reduction amount based on the set battery discharge power growth coefficient and the maximum discharge power of the energy storage battery, and obtaining the reduced discharge power of the energy storage inverter based on the current discharge power of the energy storage inverter and the discharge power reduction amount, or switching the energy storage inverter in the power-on state and discharge mode to the power-off state. The discharge power reduction amount is the product of the maximum discharge power of the energy storage battery and the battery discharge power growth coefficient. For the solution of switching the energy storage inverter from the power-on state and discharge mode to the power-off state, it is equivalent to reducing the original discharge power to 0;

[0102] (3) The method of increasing the discharge power of the energy storage inverter is: switching the energy storage inverter in the shutdown state to the power-on state and the discharge mode, and determining the discharge power of the energy storage inverter based on the set battery discharge power growth coefficient and the maximum discharge power of the energy storage battery, or determining the discharge power increase based on the set discharge power growth coefficient and the maximum discharge power of the energy storage battery, and obtaining the increased discharge power of the energy storage inverter based on the current discharge power of the energy storage inverter and the discharge power increase. The discharge power increase is the product of the maximum discharge power of the energy storage battery and the discharge power growth coefficient. For the solution of switching the energy storage inverter from the shutdown state to the power-on state and the discharge mode, it is equivalent to adding the above discharge power increase to the original discharge power of 0, thereby obtaining the discharge power of the energy storage inverter;

[0103] (4) The method of reducing the charging power of the energy storage inverter is: determining the amount of charging power reduction based on the set charging power growth coefficient and the maximum charging power of the energy storage battery, and obtaining the reduced charging power of the energy storage inverter based on the current charging power and charging power increase of the energy storage inverter, or switching the energy storage inverter in the power-on state and charging mode to the power-off state. The amount of charging power reduction is the product of the maximum charging power of the energy storage battery and the charging power growth coefficient. For the solution of switching the energy storage inverter from the power-on state and charging mode to the power-off state, it is equivalent to reducing the original charging power to 0.

[0104] Based on this, step 3 specifically includes the following steps:

[0105] Step 3-1: Determine the working state of the energy storage converter. If the energy storage converter is in the off state, execute step 3-2. If the energy storage converter is in the on state and the discharging mode, execute step 3-7. If the energy storage converter is in the on state and the charging mode, execute step 3-13.

[0106] Step 3-2: Determine whether the detected mains power > mains power reverse flow prevention threshold is met, that is, determine whether there is reverse flow between the photovoltaic energy storage system and the power grid. If so, that is, there is no reverse flow, then execute step 3-3; if not, that is, there is reverse flow, then execute step 3-5;

[0107] Step 3-3: Determine whether the state of charge of the energy storage battery > the depth of discharge of the energy storage battery is established, if so, execute step 3-4, if not, return to step 1;

[0108] Step 3-4: Increase the discharge power of the energy storage converter, switch the energy storage converter in the shutdown state to the startup state and discharge mode, determine the discharge power of the energy storage converter based on the set battery discharge power growth coefficient and the maximum discharge power of the energy storage battery, the discharge power of the energy storage converter is the product of the maximum discharge power of the energy storage battery and the discharge power growth coefficient, that is, it is equivalent to increasing the discharge power increase amount on the basis of the discharge power of 0, and the discharge power increase amount is the product of the maximum discharge power of the energy storage battery and the discharge power growth coefficient, and then return to step 1;

[0109] Step 3-5: Determine whether the state of charge of the energy storage battery is less than the depth of charge of the energy storage battery. If so, execute step 3-6; if not, return to step 1;

[0110] Step 3-6: Increase the charging power of the energy storage inverter, switch the energy storage inverter in the shutdown state to the power-on state and charging mode, and determine the charging power of the energy storage inverter based on the battery charging power growth coefficient and the maximum charging power of the energy storage battery. The charging power of the energy storage inverter is the product of the maximum charging power of the energy storage battery and the battery charging power growth coefficient, which is equivalent to increasing the charging power increase amount on the basis of the charging power of 0, and the charging power increase amount is the product of the maximum charging power of the energy storage battery and the battery charging power growth coefficient, and then return to step 1;

[0111] Step 3-7: Determine whether the state of charge of the energy storage battery > the depth of discharge of the energy storage battery is established, if so, execute step 3-8, if not, execute step 3-12;

[0112] Step 3-8: Determine whether the detected mains power > mains power reverse flow prevention threshold value is established, that is, determine whether there is reverse flow between the photovoltaic energy storage system and the power grid. If so, that is, there is no reverse flow, then execute step 3-9; if not, that is, there is reverse flow, then execute step 3-11;

[0113] Step 3-9: Determine whether the discharge power of the energy storage converter is less than the maximum discharge power of the energy storage battery. If so, execute step 3-10. If not, return to step 1.

[0114] Step 3-10: Increase the discharge power of the energy storage converter, determine the discharge power increase based on the set discharge power growth coefficient and the maximum discharge power of the energy storage battery, the discharge power increase is the product of the maximum discharge power of the energy storage battery and the discharge power growth coefficient, and obtain the increased discharge power of the energy storage converter based on the current discharge power of the energy storage converter and the discharge power increase, the increased discharge power of the energy storage converter is the sum of the current discharge power of the energy storage converter and the discharge power increase, and then return to step 1;

[0115] Step 3-11: reducing the discharge power of the energy storage inverter, determining the discharge power reduction amount based on the set battery discharge power growth coefficient and the maximum discharge power of the energy storage battery, the discharge power reduction amount being the product of the maximum discharge power of the energy storage battery and the battery discharge power growth coefficient, and obtaining the reduced discharge power of the energy storage inverter based on the current discharge power of the energy storage inverter and the discharge power reduction amount, the reduced discharge power of the energy storage inverter being the difference between the current discharge power of the energy storage inverter and the discharge power reduction amount, and then returning to step 1;

[0116] Step 3-12: reducing the discharge power of the energy storage converter, and switching the energy storage converter in the on state and the discharge mode to the off state;

[0117] Step 3-13: Determine whether the state of charge of the energy storage battery is less than the depth of charge of the energy storage battery. If so, execute step 3-14; if not, execute step 3-18;

[0118] Step 3-14: Determine whether the detected mains power > mains power reverse flow prevention threshold value is established, that is, determine whether there is reverse flow between the photovoltaic energy storage system and the power grid. If so, that is, there is no reverse flow, then execute step 3-15; if not, that is, there is reverse flow, then execute step 3-16;

[0119] Step 3-15: reduce the charging power of the energy storage inverter, determine the charging power reduction amount based on the set charging power growth coefficient and the maximum charging power of the energy storage battery, the charging power reduction amount is the product of the maximum charging power of the energy storage battery and the charging power growth coefficient, and obtain the reduced charging power of the energy storage inverter based on the current charging power of the energy storage inverter and the charging power increase amount, the reduced charging power of the energy storage inverter is the difference between the current charging power of the energy storage inverter and the charging power increase amount, and then return to step 1;

[0120] Step 3-16: Determine whether the charging power of the energy storage converter is less than the maximum charging power of the energy storage battery. If so, execute step 3-17. If not, return to step 1.

[0121] Step 3-17: Increase the charging power of the energy storage inverter, determine the charging power increase based on the set battery charging power growth coefficient and the maximum charging power of the energy storage battery, the charging power increase is the product of the maximum charging power of the energy storage battery and the battery charging power growth coefficient, and obtain the increased charging power of the energy storage inverter based on the current charging power of the energy storage inverter and the charging power increase, the increased charging power of the energy storage inverter is the sum of the current charging power of the energy storage inverter and the charging power increase, and then return to step 1;

[0122] Step 3-18: Reduce the charging power of the energy storage inverter, switch the energy storage inverter in the on state and charging mode to the off state, and then return to step 1.

[0123] Step 4: When the current time is in the off-peak period, the energy storage converter in the on state and the discharging mode is switched to the off state, or when the energy storage converter is in the on state and the charging mode or the energy storage converter is in the off state, it is determined whether the energy storage device meets the charging and discharging constraints of the energy storage device and the working constraints of the transformer. If so, the charging power of the energy storage converter is increased; if not, the charging power of the energy storage converter is reduced.

[0124] In step 4, the energy storage device charge and discharge constraint conditions are the same as those involved in step 3, and the transformer operation constraint condition is: the detected mains power < the maximum load of the transformer.

[0125] In step 4:

[0126] (1) The method for increasing the charging power of the energy storage inverter is: determining the charging power increase based on the set battery charging power growth coefficient and the maximum charging power of the energy storage battery, and obtaining the increased charging power of the energy storage inverter based on the current charging power of the energy storage inverter and the charging power increase, or switching the energy storage inverter from the shutdown state to the startup state and charging mode, and determining the charging power of the energy storage inverter based on the battery charging power growth coefficient and the maximum charging power of the energy storage battery; the charging power increase is the product of the maximum charging power of the energy storage battery and the battery charging power growth coefficient. For the solution of switching the energy storage inverter from the shutdown state to the startup state and charging mode, it is equivalent to adding the above charging power increase to the original charging power of 0, thereby obtaining the charging power of the energy storage inverter.

[0127] (2) The method of reducing the charging power of the energy storage inverter is: determining the amount of charging power reduction based on the set charging power growth coefficient and the maximum charging power of the energy storage battery, and obtaining the reduced charging power of the energy storage inverter based on the current charging power and charging power increase of the energy storage inverter, or switching the energy storage inverter in the power-on state and charging mode to the power-off state. The amount of charging power reduction is the product of the maximum charging power of the energy storage battery and the charging power growth coefficient. For the solution of switching the energy storage inverter from the power-on state and charging mode to the power-off state, it is equivalent to reducing the original charging power to 0.

[0128] Step 4 specifically includes the following steps:

[0129] Step 4-1: Determine the working state of the energy storage converter. If the energy storage converter is in the power-on state and the charging mode, execute step 4-2. If the energy storage converter is in the power-off state, execute step 4-8. If the energy storage converter is in the power-on state and the discharging mode, execute step 4-11.

[0130] Step 4-2: Determine whether the state of charge of the energy storage battery is less than the depth of charge of the energy storage battery. If so, execute step 4-3; if not, execute step 4-7;

[0131] Step 4-3: Determine whether the detected mains power is less than the maximum load of the transformer. If so, execute step 4-4; otherwise, execute step 4-6;

[0132] Step 4-4: Determine whether the charging power of the energy storage converter is less than the maximum charging power of the energy storage battery. If so, execute step 4-5; otherwise, return to step 1;

[0133] Step 4-5: Increase the charging power of the energy storage inverter, determine the charging power increase based on the set battery charging power growth coefficient and the maximum charging power of the energy storage battery, the charging power increase is the product of the maximum charging power of the energy storage battery and the battery charging power growth coefficient, and obtain the increased charging power of the energy storage inverter based on the current charging power of the energy storage inverter and the charging power increase, the increased charging power of the energy storage inverter is the sum of the current charging power of the energy storage inverter and the charging power increase, and then return to step 1;

[0134] Step 4-6: reduce the charging power of the energy storage inverter, determine the charging power reduction amount based on the set charging power growth coefficient and the maximum charging power of the energy storage battery, the charging power reduction amount is the product of the maximum charging power of the energy storage battery and the charging power growth coefficient, and obtain the reduced charging power of the energy storage inverter based on the current charging power of the energy storage inverter and the charging power increase amount, the reduced charging power of the energy storage inverter is the difference between the current charging power of the energy storage inverter and the charging power increase amount, and then return to step 1;

[0135] Step 4-7: Reduce the charging power of the energy storage converter, switch the energy storage converter in the power-on state and charging mode to the power-off state, and then return to step 1;

[0136] Step 4-8: Determine whether the state of charge of the energy storage battery is less than the depth of charge of the energy storage battery. If so, execute step 4-9; if not, return to step 1;

[0137] Step 4-9: Determine whether the detected mains power is less than the maximum load of the transformer. If so, execute step 4-10. If not, return to step 1.

[0138] Step 4-10: Increase the charging power of the energy storage inverter, switch the energy storage inverter in the shutdown state to the power-on state and charging mode, and determine the charging power of the energy storage inverter based on the battery charging power growth coefficient and the maximum charging power of the energy storage battery. The charging power of the energy storage inverter is the product of the maximum charging power of the energy storage battery and the battery charging power growth coefficient, which is equivalent to increasing the charging power increase amount on the basis of the charging power of 0, and the charging power increase amount is the product of the maximum charging power of the energy storage battery and the battery charging power growth coefficient, and then return to step 1;

[0139] Step 4-11: Switch the energy storage converter to the shutdown state, and then return to step 1.

[0140] The above scheme provides a photovoltaic storage coordinated operation control scheme for microgrids to prevent reverse flow and transformer overload, which can avoid the reverse grid access of power or overload of user transformers. It can be seen that the scheme includes the following processes and steps:

[0141] 1. Collect information on users’ electricity usage periods, energy storage devices and transformer rated parameters;

[0142] 2. Enter the collected information in the strategy configuration table as the judgment conditions for each process when the plan is running;

[0143] 3. In the strategy configuration table, enter the battery charging power growth coefficient and the battery discharging power growth coefficient. These two items are the key parameters for implementing this solution. They specify the specific values ​​that need to be adjusted for the charging and discharging power of the energy storage device in the scenarios where the user's power consumption is normal, the user's power consumption is too low but the photovoltaic power generation device is still generating power and the energy storage device is still discharging, and the user's power consumption is too high but the energy storage device is still charging. Through these two parameters, this solution realizes the charging and discharging power adjustment of the energy storage device without manual operation during the photovoltaic and storage coordinated operation;

[0144] 3. In the strategy configuration table, enter the transformer maximum load rate and the mains power reverse flow prevention threshold, which are also key parameters for implementing this strategy. They specify when the solution needs to adjust the charging and discharging power of the energy storage device and the direction of the adjustment (increase or decrease);

[0145] 4. The microgrid operates according to the scheme and adjusts the power generation of the photovoltaic power generation device and the charging and discharging power of the energy storage device according to the instructions output in the scheme.

[0146] Compared with the existing solutions, this patent solution focuses on improving the existing solutions, which do not design a photovoltaic and energy storage coordinated operation strategy to prevent reverse flow and transformer overload in the microgrid, resulting in the photovoltaic power generation device and the energy storage device not adjusting the power generation power and the charging and discharging power in real time according to the user's power consumption, so it is easy to cause the problem of reverse grid connection of electric energy or overload operation of the user's transformer. This solution designs a photovoltaic and energy storage coordinated operation strategy that can prevent reverse flow and transformer overload, and does not require frequent manual operation. It only needs to pre-set the strategy operation conditions, and the strategy can run automatically. After the strategy is run, it will not affect the peak shaving and valley filling operation of the energy storage device in the microgrid, and can effectively avoid the occurrence of reverse grid connection of electric energy or overload operation of the user's transformer.

[0147] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A photovoltaic energy storage coordinated operation control method, used to control the coordinated operation of a photovoltaic energy storage system connected to a power grid, wherein the photovoltaic energy storage system comprises a photovoltaic device, an energy storage device and a transformer, wherein the photovoltaic device comprises a plurality of photovoltaic panels, a plurality of inverters connected to the photovoltaic panels in a one-to-one correspondence, and the energy storage device comprises an energy storage battery, and an energy storage converter connected to the energy storage battery, characterized in that: The photovoltaic energy storage coordinated operation control method comprises the following steps: Step 1: Determine whether there is reverse flow between the photovoltaic energy storage system and the power grid, and adjust the working state of each inverter according to the determination result, so that when there is no reverse flow, the number of inverters in the power-on state reaches the maximum, and then execute step 2; Step 2: Determine whether the current time is in the off-peak period, if not, go to step 3, if yes, go to step 4; Step 3: Determine whether there is a reverse flow between the photovoltaic energy storage system and the power grid, and adjust the charging power of the energy storage inverter or the discharging power of the energy storage inverter according to the judgment result under the constraints of the charging and discharging constraints of the energy storage device. In the case of reverse flow, increase the charging power of the energy storage inverter or reduce the discharging power of the energy storage inverter; in the case of no reverse flow, increase the discharging power of the energy storage inverter or reduce the charging power of the energy storage inverter; Step 4: Switch the energy storage converter in the on state and the discharging mode to the off state, or under the condition that the energy storage converter is in the on state and the charging mode or the energy storage converter is in the off state, determine whether the energy storage device satisfies the energy storage device charging and discharging constraint conditions and the transformer working constraint conditions, if satisfied, increase the charging power of the energy storage converter, if not satisfied, reduce the charging power of the energy storage converter; The charging and discharging constraints of the energy storage device include: the state of charge of the energy storage battery > the discharge depth of the energy storage battery; the state of charge of the energy storage battery < the charging depth of the energy storage battery; the discharge power of the energy storage inverter < the maximum discharge power of the energy storage battery; the charging power of the energy storage inverter < the maximum charging power of the energy storage battery; the working constraint of the transformer is: the detected mains power < the maximum load of the transformer.

2. A photovoltaic energy storage coordinated operation control method according to claim 1, characterized in that: A mains power anti-backflow threshold is preset, and the detected mains power and the mains power anti-backflow threshold are used to determine whether there is a backflow between the photovoltaic energy storage system and the power grid. When the detected mains power is greater than the mains power anti-backflow threshold, it is determined that there is no backflow.

3. A photovoltaic energy storage coordinated operation control method according to claim 1, characterized in that: The step 1 is: judging the working state of the currently selected inverter, and judging whether there is reverse flow between the photovoltaic energy storage system and the power grid; if there is no reverse flow and the currently selected inverter is in the on state, then continue to select the next inverter and execute the step 1; if there is no reverse flow and the currently selected inverter is in the on state, then switch the currently selected inverter to the on state and then continue to select the next inverter and execute the step 1; if there is reverse flow and the currently selected inverter is in the off state, then continue to select the next inverter and execute the step 1; if there is reverse flow and the currently selected inverter is in the on state, then switch the currently selected inverter to the off state and then continue to select the next inverter and execute the step 1.

4. A photovoltaic energy storage coordinated operation control method according to claim 1, characterized in that: In step 2, if the valley time start time ≤ current time ≤ valley time end time, it is determined that the current time is within the valley time period.

5. A photovoltaic energy storage coordinated operation control method according to claim 1, characterized in that: In step 3, the method for increasing the charging power of the energy storage converter is as follows: determining the charging power increase amount based on the set battery charging power growth coefficient and the maximum charging power of the energy storage battery, and obtaining the charging power of the energy storage converter after the current charging power of the energy storage converter and the charging power increase amount, or switching the energy storage converter in the shutdown state to the power-on state and the charging mode, and determining the charging power of the energy storage converter based on the battery charging power growth coefficient and the maximum charging power of the energy storage battery; The method for reducing the discharge power of the energy storage converter is as follows: determining the discharge power reduction amount based on the set battery discharge power growth coefficient and the maximum discharge power of the energy storage battery, and obtaining the discharge power of the energy storage converter after the reduction based on the current discharge power of the energy storage converter and the discharge power reduction amount, or switching the energy storage converter in the power-on state and the discharge mode to the power-off state; The method for increasing the discharge power of the energy storage converter is as follows: switching the energy storage converter in the shutdown state to the startup state and the discharge mode, and determining the discharge power of the energy storage converter based on the set battery discharge power growth coefficient and the maximum discharge power of the energy storage battery, or determining the discharge power increase amount based on the set discharge power growth coefficient and the maximum discharge power of the energy storage battery, and obtaining the increased discharge power of the energy storage converter based on the current discharge power of the energy storage converter and the discharge power increase amount; The method for reducing the charging power of the energy storage inverter is: determining the charging power reduction amount based on the set charging power growth coefficient and the maximum charging power of the energy storage battery, and reducing the charging power of the energy storage inverter based on the current charging power of the energy storage inverter and the charging power increase, or switching the energy storage inverter in the power-on state and charging mode to the power-off state.

6. A photovoltaic energy storage coordinated operation control method according to claim 5, characterized in that: The step 3 comprises the following steps: Step 3-1: Determine the working state of the energy storage converter. If the energy storage converter is in the off state, execute step 3-2. If the energy storage converter is in the on state and the discharging mode, execute step 3-7. If the energy storage converter is in the on state and the charging mode, execute step 3-13. Step 3-2: Determine whether there is reverse flow between the photovoltaic energy storage system and the power grid. If not, execute step 3-3; if so, execute step 3-5; Step 3-3: Determine whether the state of charge of the energy storage battery > the depth of discharge of the energy storage battery is established, if so, execute step 3-4, if not, return to step 1; Step 3-4: increasing the discharge power of the energy storage converter, switching the energy storage converter from the shutdown state to the startup state and the discharge mode, determining the discharge power of the energy storage converter based on the set battery discharge power growth coefficient and the maximum discharge power of the energy storage battery, and then returning to step 1; Step 3-5: Determine whether the state of charge of the energy storage battery is less than the depth of charge of the energy storage battery. If so, execute step 3-6; if not, return to step 1; Step 3-6: increasing the charging power of the energy storage converter, switching the energy storage converter from the shutdown state to the startup state and charging mode, and determining the charging power of the energy storage converter based on the battery charging power growth coefficient and the maximum charging power of the energy storage battery, and then returning to step 1; Step 3-7: Determine whether the state of charge of the energy storage battery> the depth of discharge of the energy storage battery is established, if so, execute step 3-8, if not, execute step 3-12; Step 3-8: Determine whether there is reverse flow between the photovoltaic energy storage system and the power grid. If not, execute step 3-9. If so, execute step 3-11. Step 3-9: Determine whether the discharge power of the energy storage converter is less than the maximum discharge power of the energy storage battery. If so, execute step 3-10; otherwise, return to step 1; Step 3-10: increasing the discharge power of the energy storage converter, determining the discharge power increase amount based on the set discharge power growth coefficient and the maximum discharge power of the energy storage battery, and obtaining the increased discharge power of the energy storage converter based on the current discharge power of the energy storage converter and the discharge power increase amount, and then returning to step 1; Step 3-11: reducing the discharge power of the energy storage converter, determining the discharge power reduction amount based on the set battery discharge power growth coefficient and the maximum discharge power of the energy storage battery, and obtaining the reduced discharge power of the energy storage converter based on the current discharge power of the energy storage converter and the discharge power reduction amount, and then returning to step 1; Step 3-12: reducing the discharge power of the energy storage converter, and switching the energy storage converter in the on state and the discharge mode to the off state; Step 3-13: Determine whether the state of charge of the energy storage battery is less than the depth of charge of the energy storage battery. If so, execute step 3-14; otherwise, execute step 3-18; Step 3-14: Determine whether there is reverse flow between the photovoltaic energy storage system and the power grid. If not, execute step 3-15. If so, execute step 3-16. Step 3-15: reducing the charging power of the energy storage converter, determining the amount of reduction in charging power based on the set charging power growth coefficient and the maximum charging power of the energy storage battery, and obtaining the reduced charging power of the energy storage converter based on the current charging power of the energy storage converter and the charging power increase, and then returning to step 1; Step 3-16: Determine whether the charging power of the energy storage converter is less than the maximum charging power of the energy storage battery. If so, execute step 3-17; otherwise, return to step 1; Step 3-17: increasing the charging power of the energy storage converter, determining the charging power increase amount based on the set battery charging power growth coefficient and the maximum charging power of the energy storage battery, and obtaining the increased charging power of the energy storage converter based on the current charging power of the energy storage converter and the charging power increase amount, and then returning to step 1; Step 3-18: Reduce the charging power of the energy storage inverter, switch the energy storage inverter in the power-on state and charging mode to the power-off state, and then return to step 1.

7. A photovoltaic energy storage coordinated operation control method according to claim 6, characterized in that: The increase in charging power is the product of the maximum charging power of the energy storage battery and the battery charging power growth coefficient, the reduction in discharge power is the product of the maximum discharge power of the energy storage battery and the battery discharge power growth coefficient, the increase in discharge power is the product of the maximum discharge power of the energy storage battery and the discharge power growth coefficient, and the reduction in charging power is the product of the maximum charging power of the energy storage battery and the charging power growth coefficient.

8. A photovoltaic energy storage coordinated operation control method according to claim 1, characterized in that: In step 4, the method for increasing the charging power of the energy storage converter is as follows: determining the charging power increase amount based on the set battery charging power growth coefficient and the maximum charging power of the energy storage battery, and obtaining the charging power of the energy storage converter after the current charging power of the energy storage converter and the charging power increase amount, or switching the energy storage converter in the shutdown state to the power-on state and the charging mode, and determining the charging power of the energy storage converter based on the battery charging power growth coefficient and the maximum charging power of the energy storage battery; The method for reducing the charging power of the energy storage inverter is: determining the charging power reduction amount based on the set charging power growth coefficient and the maximum charging power of the energy storage battery, and reducing the charging power of the energy storage inverter based on the current charging power of the energy storage inverter and the charging power increase, or switching the energy storage inverter that is in the power-on state and charging mode to the power-off state.

9. A photovoltaic energy storage coordinated operation control method according to claim 8, characterized in that: The step 4 comprises the following steps: Step 4-1: Determine the working state of the energy storage converter. If the energy storage converter is in the power-on state and the charging mode, execute step 4-2. If the energy storage converter is in the power-off state, execute step 4-8. If the energy storage converter is in the power-on state and the discharging mode, execute step 4-11. Step 4-2: Determine whether the state of charge of the energy storage battery is less than the depth of charge of the energy storage battery. If so, execute step 4-3; otherwise, execute step 4-7; Step 4-3: Determine whether the detected mains power is less than the maximum load of the transformer, if so, execute step 4-4, if not, execute step 4-6; Step 4-4: Determine whether the charging power of the energy storage converter is less than the maximum charging power of the energy storage battery. If so, execute step 4-5; otherwise, return to step 1; Step 4-5: increasing the charging power of the energy storage converter, determining the charging power increase amount based on the set battery charging power growth coefficient and the maximum charging power of the energy storage battery, and obtaining the increased charging power of the energy storage converter based on the current charging power of the energy storage converter and the charging power increase amount, and then returning to step 1; Step 4-6: reducing the charging power of the energy storage converter, determining the amount of reduction in charging power based on the set charging power growth coefficient and the maximum charging power of the energy storage battery, and obtaining the reduced charging power of the energy storage converter based on the current charging power of the energy storage converter and the charging power increase, and then returning to step 1; Step 4-7: reducing the charging power of the energy storage converter, switching the energy storage converter in the power-on state and the charging mode to the power-off state, and then returning to step 1; Step 4-8: Determine whether the state of charge of the energy storage battery is less than the depth of charge of the energy storage battery. If so, execute step 4-9; if not, return to step 1; Step 4-9: Determine whether the detected mains power is less than the maximum load of the transformer. If so, execute step 4-10. If not, return to step 1. Step 4-10: increasing the charging power of the energy storage converter, switching the energy storage converter from the shutdown state to the startup state and charging mode, and determining the charging power of the energy storage converter based on the battery charging power growth coefficient and the maximum charging power of the energy storage battery, and then returning to step 1; Step 4-11: Switch the energy storage converter to the shutdown state, and then return to step 1.

10. A photovoltaic energy storage coordinated operation control method according to claim 9, characterized in that: The charging power increase is the product of the maximum charging power of the energy storage battery and the battery charging power growth coefficient, and the charging power reduction is the product of the maximum charging power of the energy storage battery and the charging power growth coefficient.

11. A photovoltaic energy storage coordinated operation control method according to any one of claims 6 to 10, characterized in that: The value of the battery charging power growth coefficient and the battery discharging power growth coefficient is n%, where n is an integer divisible by 100.

12. A photovoltaic energy storage coordinated operation control method according to claim 11, characterized in that: The value of n is 1, 2, 4, 5, 10, 20 or 50.

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