A power quality regulation method and system of a light storage coupling inverter

Abstract

The application provides a power quality regulation method and system of a light storage coupling inverter. The method acquires grid-connected point electrical parameters in real time, calculates power quality parameters, and determines whether the parameters exceed the standard. A cooperative control strategy is generated by comprehensively considering photovoltaic real-time output, energy storage state of charge, and problem types. Finally, the inverter is controlled to perform compensation operation. The power quality regulation system includes a monitoring module, a calculation and analysis module, a cooperative control decision module, and an inverter control module, and relates to the technical field of new energy power generation. Without additional special equipment, the existing hardware resources are reused, the comprehensive management of various power quality problems can be realized, the economy and grid friendliness of the system are improved, and the system is suitable for distributed light storage grid-connected systems.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of new energy power generation technology, in particular to a power quality regulation method and system of a light-storage coupled inverter. BACKGROUND

[0002] With the large-scale access of distributed power generation systems such as photovoltaic to the power grid, the randomness and intermittency of the distributed power generation systems bring many challenges to the power quality of the power grid, such as voltage fluctuation and sag, harmonic pollution, power factor reduction, frequency deviation and other problems. At the same time, the requirements of industrial production and resident life for power supply stability and reliability are continuously improved, and power quality has become a key factor affecting the safe and efficient operation of the power grid.

[0003] At present, the traditional scheme for improving power quality mainly relies on the installation of special compensation devices, such as active power filter (APF) for harmonic suppression and static var compensator (SVG) for regulating reactive power and voltage. However, such devices require additional hardware costs, which not only increase the system complexity and floor area, but also increase the overall cost of equipment procurement, installation and operation and maintenance, which is not conducive to the low-cost promotion of distributed photovoltaic systems.

[0004] The light-storage coupled system combines photovoltaic power generation units and energy storage units, and realizes grid-connected and off-grid operation switching through a bidirectional inverter, effectively improving energy utilization efficiency and power supply reliability. However, the control strategies of existing light-storage coupled inverters mainly focus on core energy conversion functions, such as maximum power point tracking (MPPT) of photovoltaic power generation, charge and discharge management of energy storage units, and smooth switching between grid-connected and off-grid modes. For the power quality problems introduced by the grid itself or photovoltaic grid connection, there is a lack of active and collaborative regulation capability. Even if some inverters have basic reactive power regulation functions, they do not fully exploit the collaborative potential of photovoltaic residual capacity and energy storage flexible charge and discharge, and cannot achieve comprehensive management of multiple power quality problems, resulting in that the additional value of the light-storage system is not fully released.

[0005] Therefore, how to exploit the control and capacity potential of the light-storage coupled system itself without significantly increasing the hardware cost, so that it has active and intelligent power quality regulation capability while completing the core function of energy conversion, has become a technical problem to be solved in the current new energy power generation field. SUMMARY

[0006] In order to overcome the existing problems, the present application provides a power quality regulation method and system of a light-storage coupled inverter, which aims to overcome the defects in the prior art that rely on special compensation devices to cause high cost, insufficient power quality regulation capability of the light-storage system, and inability to comprehensively manage multiple problems, and provides a power quality regulation method and system of a light-storage coupled inverter to realize collaborative management of multiple power quality problems without additional hardware, low cost and high efficiency.

[0007] The technical scheme adopted by the embodiment of the application to solve the technical problems is:

[0008] A power quality regulation method and system of a light-storage coupling inverter, comprising the following steps:

[0009] S1: Real-time acquisition of electrical parameters of a grid-connected point through a voltage sensor and a current sensor, the electrical parameters including three-phase voltage instantaneous values and three-phase current instantaneous values of the grid-connected point;

[0010] S2: Calculation of power quality parameters based on the acquired electrical parameters through a fast Fourier transform algorithm, the power quality parameters including at least three of total harmonic distortion, 3-25th harmonic current content, voltage effective value deviation, grid frequency deviation, and power factor;

[0011] The calculation formula of the total harmonic distortion is:

[0012] = 100%;

[0013] Wherein, is the total harmonic distortion, is the 3th harmonic current effective value, is the 25th harmonic current effective value, and is the fundamental current effective value;

[0014] S3: Comparison of the calculated power quality parameters with preset threshold values to determine whether there is a power quality exceeding problem;

[0015] S4: If there is an exceeding problem, a collaborative control strategy is generated by comprehensively considering real-time output values of a photovoltaic power generation unit, state of charge of an energy storage unit, and specific types of power quality problems;

[0016] The collaborative control strategy is specifically:

[0017] When the power quality problem is voltage deviation or frequency deviation, the charge and discharge power of the energy storage unit is preferentially regulated, active power is injected or absorbed to the grid through the light-storage coupling inverter to realize voltage and frequency support, wherein the active power regulation amount satisfies the following formula:

[0018] ;

[0019] In the formula, is the active power regulation amount, is a voltage regulation coefficient, and the value range is 5-10kW / %, is a frequency regulation coefficient, and the value range is 100-200kW / Hz, is a voltage deviation percentage, is a frequency deviation value;

[0020] When the power quality problem is harmonic over-limit or low power factor, the light-storage coupling inverter is controlled to output compensation current with opposite phase and equal amplitude to the harmonic current, to realize harmonic suppression and power factor correction, wherein the target reactive power satisfies the following formula:

[0021] ;

[0022] In the formula, is a target reactive power, is a grid-connected point voltage effective value, is a grid-connected point current effective value, is a voltage phase angle;

[0023] S5: According to the cooperative control strategy, a PWM driving signal is generated to control the light-storage coupling inverter to perform corresponding power quality compensation operation.

[0024] Preferably, when the cooperative control strategy is formulated, the constraint logic for the state of charge of the energy storage unit is:

[0025] If the state of charge of the energy storage unit is lower than the preset lower limit value and the power quality problem needs to absorb active power, the active regulation depth is limited, or switched to a mode of only outputting reactive power / harmonic compensation current;

[0026] If the state of charge of the energy storage unit is higher than the preset upper limit value and the power quality problem needs to inject active power, the energy storage unit is preferentially controlled to absorb excess active power, to reduce the state of charge of the energy storage unit to a safe interval while completing power quality regulation.

[0027] Preferably, in step S4, when the real-time output of the photovoltaic power generation unit is lower than 90% of its rated power, the light-storage coupling inverter is controlled to operate at a reduced capacity, reserving at least 10% of the rated capacity for performing power quality regulation operation, and the reduction amplitude can be dynamically adjusted according to the degree of power quality over-limit, wherein the reserved capacity satisfies the following formula:

[0028] = (1- )+ ;

[0029] In the formula, is a reserved capacity, is an inverter rated power, is a ratio of real-time output of photovoltaic to rated power, is a capacity additionally reserved according to the degree of power quality over-limit.

[0030] The power quality regulation system of the light-storage coupled inverter comprises a monitoring module, a calculation and analysis module, a collaborative control decision module and an inverter control module.

[0031] The monitoring module is composed of high-precision voltage sensors and current sensors, and is used for real-time acquisition of grid-connected point electrical parameters.

[0032] The calculation and analysis module is equipped with a fast Fourier transform algorithm and a parameter calculation unit, and is used for converting the electrical parameters acquired by the monitoring module into power quality parameters, comparing the power quality parameters with preset national standard thresholds, and outputting an out-of-limit judgment result.

[0033] The collaborative control decision module is used for receiving the out-of-limit signal of the calculation and analysis module, reading real-time output of the photovoltaic and state of charge data of the energy storage unit, and generating a collaborative control strategy.

[0034] The collaborative control decision module comprises a load prediction unit, which predicts the load power change trend in the next quarter of an hour through an LSTM neural network, and adjusts the light-storage output power distribution in advance based on the prediction result, so that the response time of the power quality regulation is advanced.

[0035] The inverter control module is used for receiving the strategy instruction of the collaborative control decision module, generating a PWM driving signal, controlling the action of an IGBT power switching device in the light-storage coupled inverter, and executing a power quality regulation operation.

[0036] Preferably, the collaborative control decision module is internally provided with a state of charge safety protection subprogram of the energy storage unit, which automatically triggers a constraint logic when it is detected that the state of charge of the energy storage unit exceeds the safety interval of 20%-80%, to preferentially ensure the safety of the energy storage unit. The state of charge safety protection subprogram of the energy storage unit further comprises an adaptive early warning function, which automatically triggers an early warning signal and reduces the regulation power in the corresponding direction when it is detected that the change rate of the state of charge of the energy storage unit within 5 minutes exceeds 10%, until the change rate of the state of charge of the energy storage unit is ≤5%, and the early warning is removed to gradually restore the regulation capability.

[0037] The advantages of the embodiments of the present application are as follows:

[0038] By real-time monitoring of the grid state and internal system parameters, the optimal control strategy is dynamically matched according to the type of power quality problem, the system can adapt to different grid conditions and system operating states, the limitations of fixed strategies are avoided, no additional special power quality compensation devices such as APF and SVG are needed, the existing hardware resources of the light-storage coupled inverter are directly reused, the function integration is realized, the hardware investment, installation and operation and maintenance costs are greatly reduced, and the low-cost large-scale application of distributed photovoltaic is facilitated.

[0039] The method can simultaneously treat multiple power quality problems such as harmonic over-standard, voltage deviation, frequency deviation and low power factor, without the need for multiple single-function adjusting devices, thereby improving the added value and grid friendliness of the optical storage system, embedding a storage state of charge safety threshold constraint in the control strategy to avoid excessive charging and discharging of the storage unit due to power quality regulation, effectively protecting the service life of the storage battery and ensuring long-term stable operation of the system.

[0040] The optical storage coupling inverter actively participates in power quality regulation of the power grid, supports active power to stabilize voltage and frequency, and optimizes reactive power / harmonic compensation to improve the stability and power supply quality of the local distribution network, thereby assisting in the construction of a new power system. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 The figure is a flowchart of the power quality regulation method of the optical storage coupling inverter of the present application.

[0042] Figure 2 The figure is a flowchart of the power quality regulation system of the optical storage coupling inverter of the present application. DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application. In addition, for the convenience of description, the "up", "down", "left", "right" and the like in the drawings are consistent with the up, down, left and right of the drawings, and the "first", "second" and the like in the following text are for distinguishing description, and have no other special meanings.

[0044] The embodiments of the present application provide a power quality regulation method and system of an optical storage coupling inverter, solve the problems in the prior art, dynamically match the type of power quality problems to generate an optimal control strategy by real-time monitoring of the state of the power grid and the internal parameters of the system, can adapt to different power grid conditions and system operating states, avoid the limitations of fixed strategies, do not need to additionally add special power quality compensation devices such as APF and SVG, directly reuse the existing hardware resources of the optical storage coupling inverter, realize function integration, greatly reduce the hardware investment, installation and operation and maintenance costs of the system, and assist in the low-cost large-scale application of distributed photovoltaic.

[0045] It can simultaneously address multiple power quality issues such as excessive harmonics, voltage deviation, frequency deviation, and low power factor, eliminating the need for multiple single-function regulation devices. This enhances the added value and grid-friendliness of the photovoltaic-storage system. The control strategy incorporates energy storage state-of-charge safety threshold constraints to prevent overcharging and discharging of energy storage units due to power quality regulation, effectively protecting the lifespan of energy storage batteries and ensuring long-term stable operation of the system.

[0046] Actively participate in power quality regulation of the power grid, stabilize voltage and frequency through active power support, optimize power waveform through reactive power / harmonic compensation, improve the stability and power supply quality of local distribution networks, and contribute to the construction of new power systems.

[0047] The technical solution in this application is to solve the above problems, and the overall approach is as follows:

[0048] Example 1

[0049] This embodiment provides a power quality regulation method for a photovoltaic-storage coupled inverter, such as... Figure 1 As shown, it includes the following steps:

[0050] S1: Real-time acquisition of electrical parameters at the grid connection point via voltage and current sensors, including instantaneous values ​​of three-phase voltage and three-phase current at the grid connection point;

[0051] Furthermore, after the system starts up, the voltage and current sensors of the monitoring module collect the three-phase voltage and current signals at the grid connection point in real time. The sampled data is transmitted to the calculation and analysis module through high-speed AD conversion, and the data update frequency is 2kHz.

[0052] S2: Based on the collected electrical parameters, calculate the power quality parameters using the Fast Fourier Transform algorithm. The power quality parameters include at least three of the following: total harmonic distortion rate, current content of each harmonic from 3rd to 25th, voltage RMS deviation, grid frequency deviation, and power factor.

[0053] The formula for calculating the total harmonic distortion rate is as follows:

[0054] = 100%;

[0055] in, Total harmonic distortion (THD) for RMS value of subharmonic current This represents the effective value of the fundamental current.

[0056] S3: Compare the calculated power quality parameters with the preset threshold to determine whether there is a power quality exceeding the standard;

[0057] Further, the computing and analyzing module compares the above parameters with preset threshold values to determine three types of power quality problems, i.e., voltage deviation, frequency deviation and harmonic over-standard, and sends an over-standard trigger signal to the collaborative control decision module;

[0058] S4: If there is an over-standard problem, a collaborative control strategy is generated based on the real-time output value of the photovoltaic power generation unit, the state of charge of the energy storage unit and the specific type of the power quality problem;

[0059] When the collaborative control strategy is formulated, the constraint logic for the state of charge of the energy storage unit is as follows:

[0060] If the state of charge of the energy storage unit is lower than a preset lower limit value and the power quality problem needs to absorb active power, the active power regulation depth is limited, or the mode of outputting only reactive power / harmonic compensation current is switched to;

[0061] If the state of charge of the energy storage unit is higher than a preset upper limit value and the power quality problem needs to inject active power, the energy storage unit is preferentially controlled to absorb excess active power, so as to reduce the state of charge of the energy storage unit to the safe interval while completing the power quality regulation.

[0062] The collaborative control strategy is specifically as follows:

[0063] When the power quality problem is voltage deviation or frequency deviation, the charging and discharging power of the energy storage unit is preferentially regulated, active power is injected or absorbed to the grid through the light-storage coupled inverter, and voltage and frequency support is achieved, wherein the active power regulation amount satisfies the following formula:

[0064] ;

[0065] In the formula, is the active power regulation amount, is a voltage regulation coefficient, and the value range is 5-10 kW / %, is a frequency regulation coefficient, and the value range is 100-200 kW / Hz, is a voltage deviation percentage, is a frequency deviation value;

[0066] When the power quality problem is harmonic over-standard or low power factor, the light-storage coupled inverter is controlled to output a compensation current with the same amplitude and opposite phase as the harmonic current, so as to achieve harmonic suppression and power factor correction, wherein the target reactive power satisfies the following formula:

[0067] ;

[0068] In the formula, is the target reactive power, is the effective value of the grid grid-connected point voltage, is the effective value of the grid grid-connected point current, is the voltage phase angle;

[0069] When the real-time output of the photovoltaic power generation unit is less than 90% of its rated power, the control light storage coupling inverter is operated at a reduced capacity, at least 10% of the rated capacity is reserved for performing power quality regulation operation, and the reduction amplitude can be dynamically adjusted according to the degree of power quality exceeding the standard, wherein the reserved capacity satisfies the following formula:

[0070] = (1- )+ ;

[0071] In the formula, is the reserved capacity, is the rated power of the inverter, is the ratio of the real-time output of the photovoltaic unit to the rated power, is the capacity additionally reserved according to the degree of power quality exceeding the standard.

[0072] S5: According to the cooperative control strategy, the PWM driving signal is generated to control the light storage coupling inverter to perform the corresponding power quality compensation operation.

[0073] Further, the inverter control module receives the strategy instruction to generate two-way PWM driving signals: one is used to control the active power regulation (15kW) of the energy storage discharge, and the other is used to generate harmonic compensation current (4kW) and reactive power (4kW). After the two signals are synthesized, the IGBT switching tube is driven to act, realizing the power quality regulation. The system continuously monitors the grid point parameters, and the cooperative control decision module determines that the power quality is restored to normal, instructs the inverter to exit the compensation mode, and restores to the normal grid-connected power generation state. The photovoltaic unit restores the MPPT tracking, and the energy storage unit operates according to the original charging and discharging plan.

[0074] Embodiment two

[0075] This embodiment gives a kind of power quality regulation system of light storage coupling inverter, as shown in Figure 2 The power quality regulation system of light storage coupling inverter includes monitoring module, calculation analysis module, cooperative control decision module and inverter control module;

[0076] The monitoring module is composed of high-precision voltage sensor and current sensor, which is used to collect the electrical parameters of grid point in real time;

[0077] Further, the voltage sensor with precision level 0.2S grade, model PT-10kV / 0.1kV, and the current sensor, model CT-0-1000A / 5A, are adopted, the sampling frequency is set to 20 kHz, the sampling period is 50 μs, the real-time acquisition of three-phase voltage instantaneous value (range: 0-12 kV) and three-phase current instantaneous value (range: 0-1200 A) of the grid point A, B and C is performed, the collected data is transmitted to the calculation and analysis module through the RS485 communication interface, the data transmission rate is 115200 bps, and the transmission delay is less than or equal to 10 ms.

[0078] The calculation and analysis module is provided with a fast Fourier transform algorithm and a parameter calculation unit, which is used to convert the electrical parameters collected by the monitoring module into power quality parameters, compare the power quality parameters with preset national standard thresholds, and output an out-of-standard judgment result.

[0079] Further, a hardware platform based on an ARM Cortex-A9 processor is built, which is provided with a fast Fourier transform (FFT) algorithm module and a power quality parameter calculation unit. The preset power quality national standard thresholds are set according to the standards, and specifically include: total harmonic distortion (THD) ≤5%, 3rd harmonic current content ≤2.4%, 5th harmonic current content ≤3.2%, voltage effective value deviation ±7%, power grid frequency deviation ±0.2 Hz, and power factor ≥0.95.

[0080] The collaborative control decision module is used to receive the out-of-standard signal of the calculation and analysis module, read the real-time output of the photovoltaic and the state of charge data of the energy storage unit, and generate a collaborative control strategy.

[0081] The collaborative control decision module includes a load prediction unit, which predicts the load power trend in the next quarter of an hour through an LSTM neural network, and adjusts the output power distribution of the light and storage in advance based on the prediction result, so that the response time of power quality regulation is advanced.

[0082] Further, the collaborative control strategy dynamically allocates the regulation weight of each energy source based on real-time working conditions:

[0083] When the photovoltaic output is sufficient and the state of charge of the energy storage unit is in a safe interval, the remaining capacity of the photovoltaic is preferentially used to perform reactive power compensation or harmonic suppression, thereby reducing the charging and discharging loss of the energy storage.

[0084] When the photovoltaic output fluctuates greatly, the energy storage quickly responds to transient regulation, and the photovoltaic undertakes the task of base load stability.

[0085] When the state of charge of the energy storage unit approaches the safety threshold, the strategy will automatically switch to the "photovoltaic dominant + power grid auxiliary" mode, and the power grid will be used for short-time support to avoid overcharging and overdischarging of the energy storage.

[0086] The collaborative control strategy is embedded with a machine learning module, which optimizes the decision by continuously learning historical data:

[0087] Sub-models are established for typical working conditions in different seasons, such as high photovoltaic output in summer and high load in winter, and the adjustment priority of photovoltaic / energy storage is automatically adjusted;

[0088] For similar problems that occur repeatedly, the optimal solution is memorized through reinforcement learning, the subsequent response time is shortened, and the strategy can dynamically adapt to diversified scenarios, solving the poor adaptability of traditional fixed strategies in complex power grid environments.

[0089] A double-layer constraint mechanism is fused with device state and power quality demand;

[0090] Inner constraint: The state of charge of the energy storage unit, the maximum derating amplitude of the photovoltaic, the overload capacity of the inverter, and other device parameters are hard limits to ensure that the adjustment process does not damage the hardware.

[0091] Outer constraint: The power quality national standard is the target, and the optimization algorithm is used to make the power quality index optimal under the premise of meeting the inner constraint.

[0092] When it is detected that the harmonics exceed the standard and the state of charge of the energy storage unit has reached 90%, the strategy will preferentially call the remaining capacity of the photovoltaic, and jointly compensate with the grid side, avoiding overcharging of the energy storage, and achieving the standard through multi-path cooperation, which is an important improvement over traditional strategies.

[0093] The inverter control module is used to receive the strategy instructions of the collaborative control decision module, generate PWM drive signals, control the IGBT power switch devices in the photovoltaic and energy storage coupled inverter, and execute power quality adjustment operations.

[0094] The energy storage unit state of charge safety protection subprogram is built in the collaborative control decision module. When it is detected that the state of charge of the energy storage unit exceeds the 20%-80% safe interval, the constraint logic is automatically triggered to preferentially protect the safety of the energy storage unit. The energy storage unit state of charge safety protection subprogram also includes an adaptive warning function. When it is detected that the change rate of the state of charge of the energy storage unit within 5 minutes exceeds 10%, an early warning signal is automatically triggered and the adjustment power in the corresponding direction is reduced until the change rate of the state of charge of the energy storage unit is ≤5%, and the warning is lifted and the adjustment capability is gradually restored.

[0095] Finally, it should be noted that: obviously, the above embodiments are only examples for clearly illustrating the present application, and are not limitations on the embodiments. For ordinary skilled persons in the art, other different forms of changes or variations can be made on the basis of the above description. Here, it is not necessary and impossible to exhaust all the embodiments. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A method for power quality regulation of a photovoltaic-storage coupled inverter, characterized in that, The method comprises the following steps: S1: collecting electrical parameters of a grid-connected point in real time through a voltage sensor and a current sensor; S2: calculating power quality parameters based on the collected electrical parameters through a fast Fourier transform algorithm; S3: comparing the calculated power quality parameters with preset threshold values to determine whether there is a power quality exceeding problem; S4: if there is an exceeding problem, generating a collaborative control strategy by comprehensively considering real-time output values of a photovoltaic power generation unit, a state of charge of an energy storage unit, and a specific type of the power quality problem; The collaborative control strategy is specifically as follows: When the power quality problem is voltage deviation or frequency deviation, the charging and discharging power of the energy storage unit is preferentially adjusted, active power is injected or absorbed to the grid through a light-storage coupling inverter to realize voltage and frequency support, wherein the active power adjustment amount satisfies the following formula: ； In the formula, is the active power adjustment amount, is the voltage adjustment coefficient, the value range is 5-10 kW / %, is the frequency adjustment coefficient, the value range is 100-200 kW / Hz, is the voltage deviation percentage, is the frequency deviation value; When the power quality problem is harmonic exceeding or low power factor, the light-storage coupling inverter outputs compensation current with a phase opposite to that of the harmonic current and an amplitude equal to that of the harmonic current to realize harmonic suppression and power factor correction, wherein the target reactive power satisfies the following formula: ； In the formula, is the target reactive power, is the effective value of the grid point voltage, is the effective value of the grid point current, is the voltage phase angle; S5: generating a PWM driving signal according to the collaborative control strategy to control the light-storage coupling inverter to perform corresponding power quality compensation operations.

2. The power quality conditioning method of a light storage coupled inverter according to claim 1, wherein, The electrical parameters in the step S1 include three-phase voltage instantaneous values and three-phase current instantaneous values of the grid-connected point.

3. The method of claim 1, wherein the method further comprises: The power quality parameters in the step S2 include at least three of total harmonic distortion, 3-25th harmonic current content, voltage effective value deviation, grid frequency deviation, and power factor.

4. The power quality conditioning method of claim 3, wherein, When the collaborative control strategy is formulated, the constraint logic for the state of charge of the energy storage unit is as follows: If the state of charge of the energy storage unit is lower than a preset lower limit value and active power needs to be absorbed due to the power quality problem, the active power adjustment depth is limited, or the mode of only outputting reactive power / harmonic compensation current is switched to; If the state of charge of the energy storage unit is higher than a preset upper limit value and active power needs to be injected due to the power quality problem, the energy storage unit preferentially absorbs excess active power, and the state of charge of the energy storage unit is reduced to a safe interval while the power quality adjustment is completed.

5. The method of power quality conditioning of a light storage inverter of claim 1, wherein, In the step S4, when the real-time output of the photovoltaic power generation unit is lower than 90% of its rated power, the light-storage coupling inverter is controlled to operate at a reduced capacity, at least 10% of the rated capacity is reserved for performing power quality adjustment operations, and the reduction amplitude can be dynamically adjusted according to the degree of power quality exceeding, wherein the reserved capacity satisfies the following formula: = (1- )+ ； wherein, is the reserve capacity, is the inverter rated power, is the ratio of the photovoltaic real-time output to the rated power, is the capacity reserved according to the degree of power quality exceeding.

6. The method of power quality conditioning of a light storage inverter of claim 3, wherein, The calculation formula of the total harmonic distortion in the step S2 is as follows: = 100%； wherein is the total harmonic distortion, is the is the second harmonic current effective value, is the fundamental current effective value.

7. A power quality conditioning system for implementing the method of any one of claims 1-6, characterized by a light storage coupled inverter, wherein The system comprises a monitoring module, a calculation and analysis module, a collaborative control decision module, and an inverter control module; The monitoring module is composed of high-precision voltage sensors and current sensors and is used for collecting electrical parameters of the grid-connected point in real time; The calculation and analysis module is equipped with a fast Fourier transform algorithm and a parameter calculation unit, is used for converting the electrical parameters collected by the monitoring module into power quality parameters, comparing the power quality parameters with preset national standard threshold values, and outputting an exceeding judgment result; The collaborative control decision module is used for receiving an exceeding signal of the calculation and analysis module, reading real-time output of the photovoltaic power generation unit and state of charge data of the energy storage unit to generate a collaborative control strategy; and The inverter control module is configured to receive the strategy instruction of the cooperative control decision module, generate a PWM driving signal, control the IGBT power switch device in the optical storage coupling inverter to act, and perform power quality regulation operation.

8. A power quality conditioning system for a light storage inverter according to claim 7, characterized in that, The cooperative control decision module comprises a load prediction unit, which predicts the load power change trend in the next quarter of an hour through an LSTM neural network, and adjusts the output power distribution of the optical storage in advance based on the prediction result, so that the response time of the power quality regulation is advanced.

9. A power quality conditioning system for an optical storage-coupled inverter as recited in claim 7, wherein, The cooperative control decision module is internally provided with a state of charge safety protection subprogram of the energy storage unit, which automatically triggers a constraint logic when it is detected that the state of charge of the energy storage unit exceeds the safety interval of 20%-80%, and preferentially guarantees the safety of the energy storage unit.

10. A power quality conditioning system for a light storage inverter according to claim 9, characterized in that, The state of charge safety protection subprogram of the energy storage unit further comprises an adaptive early warning function, which automatically triggers a warning signal and reduces the regulation power in the corresponding direction when it is detected that the change rate of the state of charge of the energy storage unit within 5 minutes exceeds 10%, until the change rate of the state of charge of the energy storage unit is less than or equal to 5%, and the regulation ability is gradually restored after the warning is removed.

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