Coordination control method, device and equipment for optical storage converter of distributed power generation system

Abstract

The invention provides a distributed power generation system optical storage converter coordination control method, device and equipment, and relates to the technical field of converter control. The method comprises the following steps: acquiring a direct-current output voltage and a direct-current control voltage of a boost converter in the optical storage converter, a power grid voltage, a photovoltaic module output voltage and a photovoltaic module output current; calculating a difference value between the direct-current control voltage and the direct-current output voltage, and recording the difference value as a target difference value; if the target difference value is smaller than the set value, determining the maximum power point tracking control strategy as a target strategy; if the target difference value is greater than or equal to a set value, determining a sliding mode control strategy as a target strategy, and in the sliding mode control strategy, performing sliding mode regulation and control on a boost converter based on the photovoltaic module output voltage and the photovoltaic module output current, and performing sliding mode regulation and control on a three-phase voltage source type inverter in the optical storage converter based on the power grid voltage; and controlling the optical storage converter according to the target strategy. The DC bus voltage fluctuation can be improved, and the electric energy quality is improved.

Description

Technical Field

[0001] This invention relates to the field of converter control technology, and in particular to a method, apparatus and equipment for coordinated control of photovoltaic-storage converters in a distributed generation system. Background Technology

[0002] Increased energy demand and the scarcity of fossil fuels have forced the world to increase its use of renewable energy sources, such as wind and solar power, with solar power being more widely used.

[0003] To improve the conversion efficiency of photovoltaic (PV) power generation and increase electricity revenue, most PV generators employ maximum power point tracking (MPPT) control algorithms. However, PV power generation is closely related to solar irradiance and is highly susceptible to fluctuations due to variations in solar intensity, seasonal changes, and cloud cover. This fluctuating power input into the grid leads to instability in grid frequency and voltage, thus affecting grid operational stability. Furthermore, PV power generation exhibits a peak-off characteristic: during the day, when solar irradiance is high, PV power generation is significant while grid load is low, whereas at night, grid load is high, demanding more power generation, but PV power generation is not operational. This peak-off characteristic has led to "curtailment" of solar power in various regions, severely hindering the development of PV power generation.

[0004] A converter is an electrical device used to change the characteristics of current or voltage. It is an essential device for grid connection of renewable energy power generation, and the regulation of the converter directly affects the power quality and energy utilization efficiency of the power grid. However, existing converters usually adopt a single control strategy, such as maximum power point tracking control strategy, which makes it difficult to overcome the problem of DC bus voltage fluctuations caused by real-time fluctuations in solar irradiance and grid conditions during photovoltaic power generation, resulting in poor efficiency in improving power quality. Summary of the Invention

[0005] This invention provides a method, apparatus, and equipment for coordinated control of photovoltaic-storage converters in a distributed generation system, which addresses the problem that existing converter control strategies struggle to overcome the real-time fluctuations in solar irradiance and grid conditions during photovoltaic power generation, leading to DC bus voltage fluctuations and poor power quality improvement efficiency.

[0006] In a first aspect, embodiments of the present invention provide a coordinated control method for photovoltaic-storage converters in a distributed generation system, comprising: Obtain the DC output voltage and DC control voltage of the boost converter in the photovoltaic-storage converter, the grid voltage, the output voltage of the photovoltaic module, and the output current of the photovoltaic module; Calculate the difference between the DC control voltage and the DC output voltage, and record it as the target difference; If the target difference is less than the set value, the maximum power point tracking control strategy will be determined as the target strategy. If the target difference is greater than or equal to the set value, the sliding control strategy is determined as the target strategy. In the sliding control strategy, the boost converter is regulated by sliding control based on the output voltage and output current of the photovoltaic module, and the three-phase voltage source inverter in the photovoltaic-storage converter is regulated by sliding control based on the grid voltage. The photovoltaic-storage converter is controlled according to the target strategy.

[0007] Secondly, embodiments of the present invention provide a coordinated control device for a photovoltaic-storage converter in a distributed generation system, comprising: The acquisition module is used to acquire the DC output voltage and DC control voltage of the boost converter in the photovoltaic-storage converter, the grid voltage, the output voltage of the photovoltaic module, and the output current of the photovoltaic module; The calculation module is used to calculate the difference between the DC control voltage and the DC output voltage, and denoted as the target difference. The first processing module is used to determine the maximum power point tracking control strategy as the target strategy if the target difference is less than a set value. The second processing module is used to determine the sliding control strategy as the target strategy if the target difference is greater than or equal to the set value. In the sliding control strategy, the boost converter is regulated by sliding control based on the output voltage and output current of the photovoltaic module, and the three-phase voltage source inverter in the photovoltaic-storage converter is regulated by sliding control based on the grid voltage. The control module is used to control the photovoltaic-storage converter according to the target strategy.

[0008] Thirdly, embodiments of the present invention provide an electronic device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the method described in the first aspect or any possible implementation thereof.

[0009] In this embodiment of the invention, the DC output voltage and DC control voltage of the boost converter in the photovoltaic-storage converter, the grid voltage, the output voltage of the photovoltaic module, and the output current of the photovoltaic module are first obtained; then the difference between the DC control voltage and the DC output voltage is calculated and recorded as the target difference; if the target difference is less than a set value, the maximum power point tracking control strategy is determined as the target strategy; if the target difference is greater than or equal to the set value, the sliding control strategy is determined as the target strategy. In the sliding control strategy, the boost converter is regulated by sliding control based on the output voltage and output current of the photovoltaic module, and the three-phase voltage source inverter in the photovoltaic-storage converter is regulated by sliding control based on the grid voltage; and then the photovoltaic-storage converter is controlled according to the target strategy. Furthermore, during maximum power point tracking, the system effectively tracks the MPP when the voltage is below the maximum allowable voltage. If the voltage exceeds the set value, the system switches from the MPPT to the boost converter's SMC, which works in conjunction with the VSI controller to reduce the DC bus voltage. This significantly reduces the voltage fluctuation of the DC bus voltage under varying solar irradiance and grid conditions, and improves the transient response of the DC bus voltage. The system achieves better performance and reliability. Attached Figure Description

[0010] Figure 1 This is a flowchart illustrating the implementation of the photovoltaic-storage converter coordinated control method for distributed generation systems provided in this embodiment of the invention. Figure 2 This is a flowchart illustrating the implementation of a coordinated control method for a distributed generation system photovoltaic-storage converter provided in another embodiment of the present invention. Figure 3 This is a schematic diagram of the structure of the photovoltaic-storage converter coordination control device for a distributed generation system provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0011] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0012] See Figure 1 and Figure 2 The document illustrates a flowchart of the implementation of the photovoltaic-storage converter coordinated control method for a distributed generation system provided in an embodiment of the present invention, which is described in detail below: Step 101: Obtain the DC output voltage and DC control voltage of the boost converter in the photovoltaic-storage converter, the grid voltage, the output voltage of the photovoltaic module, and the output current of the photovoltaic module.

[0013] In this embodiment, the operating status parameters of the photovoltaic-storage converter, the grid operating status parameters, and the photovoltaic module operating status parameters are obtained. The photovoltaic-storage converter operating status parameters include the DC output voltage and DC control voltage of the boost converter in the photovoltaic-storage converter; the grid operating status parameters are the grid voltage; and the photovoltaic module operating status parameters are the photovoltaic module output voltage and photovoltaic module output current.

[0014] Step 102: Calculate the difference between the DC control voltage and the DC output voltage, and record it as the target difference.

[0015] In this embodiment, the DC output voltage of the boost converter in the photovoltaic-storage converter is obtained. and DC control voltage Then, calculate the difference between the DC control voltage and the DC output voltage. , denoted as the target difference.

[0016] Step 103: If the target difference is less than the set value, the maximum power point tracking control strategy is determined as the target strategy.

[0017] Optionally, the maximum power point tracking control strategy can be optimized using the spatial smoothing MUSIC algorithm.

[0018] For example, when using a maximum power point tracking control strategy, maximum power point tracking can also be performed based on a particle swarm optimization algorithm.

[0019] Step 104: If the target difference is greater than or equal to the set value, the sliding control strategy is determined as the target strategy. In the sliding control strategy, the boost converter is regulated by sliding control based on the output voltage and output current of the photovoltaic module, and the three-phase voltage source inverter in the photovoltaic-storage converter is regulated by sliding control based on the grid voltage.

[0020] In this embodiment, when the target difference is greater than or equal to the set value, a sliding control strategy is adopted. The sliding control strategy includes sliding control of boost converter and sliding control of three-phase voltage source inverter.

[0021] In one embodiment, sliding mode control of the boost converter based on the output voltage and output current of the photovoltaic module may include: Based on the output voltage and output current of the photovoltaic module, a first state-space equation is established that includes the switching states of the boost converter.

[0022] The inductor current in the boost converter is used as the first state variable, the target difference is used as the second state variable, and the DC control current of the boost converter is used as the third state variable.

[0023] The sliding surface of the boost converter is determined based on the first state variable, the second state variable, and the third state variable.

[0024] Based on the value of the sliding surface, the switching state of the boost converter in the first state space equation is determined.

[0025] For example, determining the switching state of the boost converter in the first state space equation based on the value of the sliding surface may include: If the value of the sliding surface is less than or equal to 0, then the switching state of the boost converter in the first state space equation is determined to be on.

[0026] If the value of the sliding surface is greater than 0, then the switching state of the boost converter in the first state space equation is determined to be off.

[0027] For example, the specific process of sliding mode control of a boost converter is as follows: First, the state-space equations of the boost converter are constructed.

[0028] Secondly, the state variables of the boost converter are determined. Specifically, to control the DC bus voltage, the inductor current, target voltage difference, and DC control current of the boost converter can be used as the state variables of the boost converter. , , , This is the DC control current.

[0029] Then, determine the sliding surface of the boost converter. For example, the sliding surface of a boost converter as follows: ; in, is the conversion factor.

[0030] Finally, determine the control output of the boost converter. .

[0031] The state-space equations of the boost converter are as follows: ; ; ; in, and These are the output voltage and output current of the photovoltaic module, respectively. This refers to the inductor current in the boost converter. This refers to the inductance value in the boost converter. This refers to the capacitance value at the input of the boost converter. This indicates the switching state of the boost converter. This refers to the capacitance value of the DC bus of the boost converter. This refers to the output current of the DC bus capacitor in the boost converter.

[0032] Based on this, control the output. The determination method is as follows: when When less than 0, ,when When greater than 0, .

[0033] In addition, control output All must meet the following conditions when determining: , for The first derivative with respect to time, The stability coefficient can be determined according to actual needs. The larger the value, the faster the convergence and the stronger the system robustness.

[0034] In one embodiment, sliding mode control of the three-phase voltage source inverter in the photovoltaic-storage converter based on the grid voltage may include: Based on the output voltage, output current, resistance, inductance of the three-phase voltage source inverter, the first derivative of the output current of the three-phase voltage source inverter with respect to time, and the influence of the power grid on the output voltage of the three-phase voltage source inverter, the second state-space equation of the three-phase voltage source inverter is established.

[0035] Based on the grid voltage, the time-varying AC quantities in the second state-space equations are converted into DC quantities through the Park transformation.

[0036] The spatial state variables of the three-phase voltage source inverter are determined based on the d-axis current and q-axis current after the output current of the three-phase voltage source inverter in the DC-DC converter, as well as the DC control voltage.

[0037] The first sliding surface of the three-phase voltage source inverter is determined based on the q-axis current and the first derivative of the q-axis current with respect to time.

[0038] The second sliding surface of the three-phase voltage source inverter is determined based on the preset proportional coefficient, the target difference, and the first derivative of the target difference with respect to time.

[0039] The sliding control output of the three-phase voltage source inverter is determined based on the spatial state variables, the first sliding surface, and the second sliding surface.

[0040] For example, based on the output voltage, output current, resistance, inductance of the three-phase voltage source inverter, the first derivative of the output current of the three-phase voltage source inverter with respect to time, and the influence voltage value of the grid on the output voltage of the three-phase voltage source inverter, the second state-space equation of the three-phase voltage source inverter can be established, which may include: according to The second state-space equation of the three-phase voltage source inverter is established.

[0041] in, This is the output voltage of a three-phase voltage source inverter. The resistor is for a three-phase voltage source inverter. This refers to the output current of a three-phase voltage source inverter. The inductor is for a three-phase voltage source inverter. This is the first derivative of the output current of a three-phase voltage source inverter with respect to time. The voltage value representing the impact of the power grid on the output voltage of a three-phase voltage source inverter can be calculated based on the three-phase voltage of the power grid.

[0042] For example, determining the second sliding surface of a three-phase voltage source inverter based on a preset proportional coefficient, a target difference, and the first derivative of the target difference with respect to time may include: Calculate the product of the preset proportional coefficient and the target difference, and record it as the target product.

[0043] Summing the first derivative of the target product and the target difference with respect to time, the second sliding surface of the three-phase voltage source inverter is determined based on the summation result.

[0044] For example, determining the sliding control output of a three-phase voltage source inverter based on spatial state variables, a first sliding surface, and a second sliding surface may include: according to Determine the sliding diaphragm control output of the three-phase voltage source inverter; in, and These are the first and second control variables in the sliding diaphragm control output of the voltage source inverter, respectively. The coefficient matrix, Let be the target vector, where To control the first derivative of the q-axis current with respect to time after the output current of a three-phase voltage source inverter is transformed. This is the second derivative of the DC control voltage with respect to time. For correction factor, For the target difference, and They represent about The first nonlinear function and the second nonlinear function, A matrix consisting of spatial state variables The transpose of the matrix, and These are the first control gain parameter and the second control gain parameter, respectively. For the first synovial surface, This is the second synovial surface. and These are the first control parameter and the second control parameter, respectively. The switching function in the sliding diaphragm control causes the state of the three-phase voltage source inverter to approach and maintain on the first and second sliding diaphragm surfaces.

[0045] For example, the specific process of sliding mode control in a three-phase voltage source inverter can be as follows: First, the state-space equations of the three-phase voltage source inverter are constructed.

[0046] Then, the time-varying AC quantity is converted into DC quantity through the Park transformation.

[0047] Then, determine the space state variables of the three-phase voltage source inverter. For example, the space state variables can be... .

[0048] Then, the two sliding surfaces of the three-phase voltage source inverter are determined, wherein: The first sliding surface of a three-phase voltage source inverter .

[0049] The second sliding surface of a three-phase voltage source inverter ,in This is a preset proportional coefficient. It is the first derivative of the difference between the DC output voltage and the DC control voltage (i.e., the target difference) with respect to time.

[0050] Then, the sliding mode control output of the three-phase voltage source inverter is determined so as to control the voltage output of the three-phase voltage source inverter through the sliding mode control output.

[0051] The state-space equation of the three-phase voltage source inverter is as described above. .

[0052] The Parker transformation formula is as follows: ; in, and These represent the d-axis and q-axis voltages after three-phase voltage transformation by the inverter, respectively. and These are the d-axis current and q-axis current after the three-phase current transformation of the inverter, respectively. The phase angle is obtained through the phase-locked loop in the inverter. and These are the d-axis voltage and q-axis voltage after the grid voltage has been transformed, respectively.

[0053] Sliding mode control output is The calculation formula is

[0054] Step 105: Control the photovoltaic-storage converter according to the target strategy.

[0055] To verify the superiority of this embodiment, the following simulation experiment was conducted: Light intensity settings are as follows: 0-0.4 seconds: 1000 0.4-0.8 seconds: from 1000 Gradually decrease to 200 0.8-1.2 seconds: 200 1.2-1.6 seconds: 1000 1.6-2.0 seconds: 900 .

[0056] This demonstrates the impact of high, low, gradual, and sudden changes in solar irradiance on the performance of photovoltaic power generation systems. The simulation results are shown in Table 1. Table 1

[0057] Depend on Figure 1 It can be seen that the technical solution of this embodiment has a better effect on reducing overshoot than the existing control strategy. The DC bus voltage is the lowest at 1.2 seconds, and the standard deviation of the DC bus voltage is also the smallest, indicating that the DC bus voltage fluctuation is small and the stability is good. For the average power difference, the difference is not large. The embodiment has a better effect on reducing the total harmonic distortion (THD) value.

[0058] This invention acquires operating status parameters of the photovoltaic-storage converter, the power grid, and the photovoltaic modules, and determines a control strategy based on these parameters. The photovoltaic-storage converter is then controlled according to this strategy. Furthermore, Maximum Power Point Tracking (MPPT) and Sliding Mode Control (SMC) are used for coordinated control of the boost converter and the three-phase voltage source inverter (VSI) within the converter. This effectively improves the stability of the DC bus voltage and enhances the overall power quality of the photovoltaic power generation system. During MPPT, the converter effectively tracks the MPP when the voltage is below the maximum allowable voltage. If the voltage exceeds a set value, the SMC switches from MPPT to the boost converter, working in conjunction with the VSI controller to reduce the DC bus voltage. This significantly reduces voltage fluctuations on the DC bus under varying solar irradiance and grid conditions, and improves the transient response of the DC bus voltage, resulting in better system performance and reliability.

[0059] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0060] The following are device embodiments of the present invention. For details not described in detail, please refer to the corresponding method embodiments described above.

[0061] Figure 3 A schematic diagram of the structure of the photovoltaic-storage converter coordination control device for a distributed generation system provided in an embodiment of the present invention is shown. For ease of explanation, only the parts related to the embodiment of the present invention are shown, and are described in detail below: like Figure 3 As shown, the distributed generation system photovoltaic-storage converter coordination control device includes: an acquisition module 31, a calculation module 32, a first processing module 33, a second processing module 34, and a control module 35.

[0062] The acquisition module 31 is used to acquire the DC output voltage and DC control voltage of the boost converter in the photovoltaic-storage converter, the grid voltage, the output voltage of the photovoltaic module, and the output current of the photovoltaic module; The calculation module 32 is used to calculate the difference between the DC control voltage and the DC output voltage, which is denoted as the target difference. The first processing module 33 is used to determine the maximum power point tracking control strategy as the target strategy if the target difference is less than the set value. The second processing module 34 is used to determine the sliding control strategy as the target strategy if the target difference is greater than or equal to the set value. In the sliding control strategy, the boost converter is regulated by sliding based on the output voltage and output current of the photovoltaic module, and the three-phase voltage source inverter in the photovoltaic-storage converter is regulated by sliding based on the grid voltage. The control module 35 is used to control the photovoltaic-storage converter according to the target strategy.

[0063] In one possible implementation, the maximum power point tracking control strategy is optimized using the Musician algorithm.

[0064] In one possible implementation, the second processing module 34 can be used to establish a first state space equation containing the switching states of the boost converter based on the output voltage and output current of the photovoltaic module; use the inductor current in the boost converter as the first state variable, the target difference as the second state variable, and the DC control current of the boost converter as the third state variable; determine the sliding surface of the boost converter according to the first state variable, the second state variable, and the third state variable; and determine the switching states of the boost converter in the first state space equation according to the value of the sliding surface.

[0065] In one possible implementation, the second processing module 34 can be used to determine the switching state of the boost converter in the first state space equation as "on" if the value of the sliding surface is less than or equal to 0, and to determine the switching state of the boost converter in the first state space equation as "off" if the value of the sliding surface is greater than 0.

[0066] In one possible implementation, the second processing module 34 can be used to establish a second state-space equation for the three-phase voltage source inverter based on the output voltage, output current, resistance, inductance, first derivative of the output current of the three-phase voltage source inverter with respect to time, and the influence voltage value of the grid on the output voltage of the three-phase voltage source inverter; based on the grid voltage, convert the time-varying AC quantities in the second state-space equation into DC quantities through Park transformation; determine the spatial state variables of the three-phase voltage source inverter based on the d-axis current and q-axis current after the DC current is transformed, and the DC control voltage; determine the first sliding surface of the three-phase voltage source inverter based on the q-axis current and the first derivative of the q-axis current with respect to time; determine the second sliding surface of the three-phase voltage source inverter based on the preset proportional coefficient, target difference, and the first derivative of the target difference with respect to time; and determine the sliding control output of the three-phase voltage source inverter based on the spatial state variables, the first sliding surface, and the second sliding surface.

[0067] In one possible implementation, the second processing module 34 can be used to... Establish the second state-space equations for a three-phase voltage source inverter; in, This is the output voltage of a three-phase voltage source inverter. The resistor is for a three-phase voltage source inverter. This refers to the output current of a three-phase voltage source inverter. The inductor is for a three-phase voltage source inverter. This is the first derivative of the output current of a three-phase voltage source inverter with respect to time. The voltage value represents the effect of the power grid on the output voltage of a three-phase voltage source inverter.

[0068] In one possible implementation, the second processing module 34 can be used to calculate the product of the preset proportional coefficient and the target difference, denoted as the target product; sum the first derivative of the target product and the target difference with respect to time, and determine the second sliding surface of the three-phase voltage source inverter based on the summation result.

[0069] In one possible implementation, the second processing module 34 can be used to... Determine the sliding diaphragm control output of the three-phase voltage source inverter; in, and These are the first and second control variables in the sliding diaphragm control output of the voltage source inverter, respectively. The coefficient matrix, Let be the target vector, where To control the first derivative of the q-axis current with respect to time after the output current of a three-phase voltage source inverter is transformed. This is the second derivative of the DC control voltage with respect to time. For correction factor, For the target difference, and They represent about The first nonlinear function and the second nonlinear function, A matrix consisting of spatial state variables The transpose of the matrix, and These are the first control gain parameter and the second control gain parameter, respectively. For the first synovial surface, This is the second synovial surface. and These are the first control parameter and the second control parameter, respectively. The switching function in the sliding diaphragm control causes the state of the three-phase voltage source inverter to approach and maintain on the first and second sliding diaphragm surfaces.

[0070] Figure 4 This is a schematic diagram of an electronic device provided in an embodiment of the present invention. For example... Figure 4As shown, the electronic device 4 in this embodiment includes a processor 40 and a memory 41. The memory 41 stores a computer program 42. When the processor 40 executes the computer program 42, it implements the steps in the various method embodiments described above. Alternatively, when the processor 40 executes the computer program 42, it implements the functions of each module / unit in the various device embodiments described above.

[0071] For example, computer program 42 may be divided into one or more modules / units, which are stored in memory 41 and executed by processor 40 to complete the present invention. The one or more modules / units may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of computer program 42 in electronic device 4.

[0072] Electronic device 4 may include, but is not limited to, processor 40 and memory 41. Those skilled in the art will understand that... Figure 4 This is merely an example of electronic device 4 and does not constitute a limitation on electronic device 4. It may include more or fewer components than shown, or combine certain components, or different components. For example, electronic device 4 may also include input / output devices, network access devices, buses, etc.

[0073] For the sake of simplicity and clarity, only the above-described functional modules / units are used as examples. In practical applications, the functions described above can be assigned to different functional modules / units as needed. These modules / units can be implemented in hardware, software, or a combination of both.

[0074] In the above embodiments, the descriptions of each embodiment have their own emphasis. Parts not detailed or described in a particular embodiment can be referred to in the relevant descriptions of other embodiments. Unless otherwise specified or in conflict with logic, the terminology and / or descriptions between different embodiments are consistent and can be referenced interchangeably. Technical features in different embodiments can be combined to form new embodiments based on their inherent logical relationships.

[0075] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A method for coordinated control of photovoltaic-storage converters in a distributed generation system, characterized in that, include: Obtain the DC output voltage and DC control voltage of the boost converter in the photovoltaic-storage converter, the grid voltage, the output voltage of the photovoltaic module, and the output current of the photovoltaic module; Calculate the difference between the DC control voltage and the DC output voltage, and record it as the target difference; If the target difference is less than the set value, the maximum power point tracking control strategy will be determined as the target strategy. If the target difference is greater than or equal to the set value, the sliding control strategy is determined as the target strategy. In the sliding control strategy, the boost converter is regulated by sliding control based on the output voltage and output current of the photovoltaic module, and the three-phase voltage source inverter in the photovoltaic-storage converter is regulated by sliding control based on the grid voltage. The photovoltaic-storage converter is controlled according to the target strategy.

2. The method for coordinated control of photovoltaic-storage converters in a distributed generation system according to claim 1, characterized in that, The maximum power point tracking control strategy is optimized using the spatial smoothing MUSIC algorithm.

3. The method for coordinated control of photovoltaic-storage converters in a distributed generation system according to claim 1, characterized in that, Sliding control of the boost converter based on the output voltage and output current of the photovoltaic module includes: Based on the output voltage and output current of the photovoltaic module, a first state space equation including the switching state of the boost converter is established; The inductor current in the boost converter is used as the first state variable, the target difference is used as the second state variable, and the DC control current of the boost converter is used as the third state variable. The sliding surface of the boost converter is determined based on the first state variable, the second state variable, and the third state variable; Based on the value of the sliding surface, the switching state of the boost converter in the first state space equation is determined.

4. The method for coordinated control of photovoltaic-storage converters in a distributed generation system according to claim 3, characterized in that, Based on the value of the sliding surface, the switching state of the boost converter in the first state space equation is determined, including: If the value of the sliding surface is less than or equal to 0, then the switching state of the boost converter in the first state space equation is determined to be on. If the value of the sliding surface is greater than 0, then the switching state of the boost converter in the first state space equation is determined to be off.

5. The method for coordinated control of photovoltaic-storage converters in a distributed generation system according to claim 1, characterized in that, Sliding control of the three-phase voltage source inverter in the photovoltaic-storage converter based on the grid voltage includes: Based on the output voltage, output current, resistance, inductance of the three-phase voltage source inverter, the first derivative of the output current of the three-phase voltage source inverter with respect to time, and the influence voltage value of the grid on the output voltage of the three-phase voltage source inverter, the second state space equation of the three-phase voltage source inverter is established. Based on the grid voltage, the time-varying AC quantities in the second state-space equation are converted into DC quantities through the Park transformation; The spatial state variables of the three-phase voltage source inverter are determined based on the d-axis current and q-axis current after the output current of the three-phase voltage source inverter in the DC flow, and the DC control voltage. The first sliding surface of the three-phase voltage source inverter is determined based on the q-axis current and the first derivative of the q-axis current with respect to time. The second sliding surface of the three-phase voltage source inverter is determined based on the preset proportional coefficient, the target difference, and the first derivative of the target difference with respect to time. The sliding control output of the three-phase voltage source inverter is determined based on the spatial state variables, the first sliding surface, and the second sliding surface.

6. The method for coordinated control of photovoltaic-storage converters in a distributed generation system according to claim 5, characterized in that, Based on the output voltage, output current, resistance, inductance of the three-phase voltage source inverter, the first derivative of the output current with respect to time, and the influence of the grid on the output voltage of the three-phase voltage source inverter, the second state-space equation of the three-phase voltage source inverter is established, including: according to Establish the second state-space equation of the three-phase voltage source inverter; in, The output voltage of the three-phase voltage source inverter is [the voltage attribution]. The resistor is the resistor of the three-phase voltage source inverter. The output current of the three-phase voltage source inverter is [current name]. The inductance of the three-phase voltage source inverter is given. Let be the first derivative of the output current of the three-phase voltage source inverter with respect to time. The voltage value represents the effect of the power grid on the output voltage of the three-phase voltage source inverter.

7. The method for coordinated control of photovoltaic-storage converters in a distributed generation system according to claim 5, characterized in that, The second sliding surface of the three-phase voltage source inverter is determined based on a preset proportional coefficient, the target difference, and the first derivative of the target difference with respect to time, including: Calculate the product of the preset proportional coefficient and the target difference, and record it as the target product; The second sliding surface of the three-phase voltage source inverter is determined by summing the first derivative of the target product and the target difference with respect to time.

8. The method for coordinated control of photovoltaic-storage converters in a distributed generation system according to claim 5, characterized in that, Based on the spatial state variables, the first sliding surface, and the second sliding surface, the sliding control output of the three-phase voltage source inverter is determined, including: according to Determine the sliding diaphragm control output of the three-phase voltage source inverter; in, and These are the first and second control variables in the sliding diaphragm control output of the voltage source inverter, respectively. The coefficient matrix, Let be the target vector, where To control the first derivative of the q-axis current with respect to time after the output current of the three-phase voltage source inverter is transformed. Let be the second derivative of the DC control voltage with respect to time. For correction factor, The target difference, and They represent about The first nonlinear function and the second nonlinear function, The matrix formed by the spatial state variables The transpose of the matrix, and These are the first control gain parameter and the second control gain parameter, respectively. The first synovial surface, This is the second synovial surface. and These are the first control parameter and the second control parameter, respectively. The switching function in the sliding diaphragm control causes the state of the three-phase voltage source inverter to approach and maintain on the first and second sliding diaphragm surfaces.

9. A coordinated control device for photovoltaic-storage converters in a distributed generation system, characterized in that, include: The acquisition module is used to acquire the DC output voltage and DC control voltage of the boost converter in the photovoltaic-storage converter, the grid voltage, the output voltage of the photovoltaic module, and the output current of the photovoltaic module; The calculation module is used to calculate the difference between the DC control voltage and the DC output voltage, and denoted as the target difference. The first processing module is used to determine the maximum power point tracking control strategy as the target strategy if the target difference is less than a set value. The second processing module is used to determine the sliding control strategy as the target strategy if the target difference is greater than or equal to the set value. In the sliding control strategy, the boost converter is regulated by sliding control based on the output voltage and output current of the photovoltaic module, and the three-phase voltage source inverter in the photovoltaic-storage converter is regulated by sliding control based on the grid voltage. The control module is used to control the photovoltaic-storage converter according to the target strategy.

10. An electronic device, characterized in that, It includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the method as described in any one of claims 1 to 8.

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