Multi-power full-time energy following energy storage system

Abstract

The invention relates to the technical field of energy. The invention relates to a multi-power full-time energy following energy storage system. The system comprises a data effective reservation unit, a PCS matching unit, a VSG control working unit, a parameter updating simulation unit and a simulation parameter reservation unit. The data validity retention unit is used for collecting load power data, performing validity analysis on the load power data and performing validity retention according to an analysis result; the PCS matching unit is used for establishing a PCS group and performing working parameter analysis on the multi-power PCS in the PCS group in combination with historical load power data; multi-power PCS efficiency value evaluation is carried out by combining the reserved real-time load power data and the PCS group, the prediction efficiency value of each multi-power PCS under the condition of the real-time load power data can be obtained, the multi-power PCS with the highest prediction efficiency value is selected as a working parameter to be input, working mode switching is carried out, and the overall efficiency of the system can be improved.

Description

Technical Field

[0001] The present invention relates to the field of energy technology, and in particular to a multi-power full-time energy following energy storage system. Background Art

[0002] In recent years, energy crises and environmental issues have promoted the rise of distributed power technology represented by clean energy power generation technology. Among them, industrial and commercial energy storage on the user side is the most widely used. Industrial and commercial energy storage systems refer to energy storage equipment installed in industrial or commercial facilities. These systems can store excess electricity and release it during peak demand, helping companies reduce electricity costs, optimize energy use, and improve the stability and security of energy supply. From industrial parks, commercial centers to data centers, to hospitals and schools, the application scenarios of energy storage systems are wide and diverse.

[0003] The design of existing user-side energy storage systems often uses multiple PCSs in parallel to form a circuit. In actual use, some PCSs are enabled according to demand to achieve the output of preset power; however, there are certain individual differences between each PCS, which is specifically reflected in the fact that different PCSs are often only most efficient in a specific power range. During the use of other power ranges, the system has a low overall efficiency when the power is reduced or exceeded. Therefore, in the existing technology, the method of fixing the output power of the PCS and starting and stopping some PCSs according to the preset total output is relatively simple and cannot effectively improve efficiency. Summary of the invention

[0004] The object of the present invention is to provide a multi-power full-time energy following energy storage system to solve the problems raised in the above background technology.

[0005] To achieve the above object, a multi-power full-time energy following energy storage system is provided, including a data valid retention unit, a PCS matching unit, a VSG control working unit, a parameter update simulation unit and a simulation parameter retention unit; The data validity retention unit is used to collect load power data, perform validity analysis on the load power data, and retain the validity according to the analysis result; The PCS matching unit is used to establish a PCS group, and simultaneously analyze the working parameters of the multi-power PCSs in the PCS group in combination with historical load power data, and then set the working parameters of the multi-power PCSs according to the analysis results, and simultaneously match the corresponding load power range for each multi-power PCS; The VSG control working unit is used to establish a VSG control end, and then perform load monitoring connection with the data effective retention unit through the VSG control end, combine the real-time load power data with the PCS group to evaluate the efficiency value of the multi-power PCS, and select the multi-power PCS with the highest efficiency value to switch the working mode; The parameter update simulation unit is used to establish a parameter simulation model at the VSG control end, and then input the real-time load power data into the parameter simulation model for simulation, and compare the simulation result with the efficiency value of the current multi-power PCS, and replace the current multi-power PCS with the simulation result according to the comparison result; The simulation parameter retention unit is used to monitor the energy storage quality during the simulation result replacement process, retain the simulation results in the PCS group according to the monitoring process, and update the range of multiple power PCSs with overlapping load power ranges.

[0006] As a further improvement of the technical solution, the data validity retention unit collects load power data through a smart meter, and immediately performs data validity judgment on the collected load power data, excludes abnormal and invalid data, and uses a data smoothing algorithm and the most recent valid data for replacement processing for abnormal and invalid data, and then retains the valid data and the replacement data; At the same time, the real-time working status and equipment parameters of the energy storage equipment are obtained.

[0007] As a further improvement of the technical solution, the calculation formula of the data effective retention unit is as follows:

[0008] Among them, S t The power value of the tth data point after smoothing, P t is the power value of the current data point, S t-1 It is the power value of the previous data point after smoothing. α is the smoothing coefficient, which is between 0 and 1. By continuously adjusting the smoothing coefficient α, the abnormal and invalid data are smoothed.

[0009] As a further improvement of the technical solution, the PCS matching unit includes a PCS group establishment module and a PCS initialization module; The PCS group establishment module is used to establish a PCS group, thereby reserving the multi-power PCS, and at the same time establishing a blank multi-power PCS to be adjusted in the PCS group; The PCS initialization module is used to initialize the energy storage control working parameter analysis of the blank multi-power PCS to be adjusted in combination with the equipment parameters, adjust the working parameters of the blank multi-power PCS to be adjusted in the PCS group according to the analysis results, and match the corresponding load power range for each multi-power PCS in the PCS group according to the analysis results.

[0010] As a further improvement of the technical solution, the VSG control working unit includes a VSG establishment module and a VSG switching module; The VSG establishment module is used to establish a VSG control terminal. At the same time, the VSG control terminal receives the effective load power data retained by the data effective retention unit, and then controls the U output on the AC side through the VSG. vx and I vx Regression control of multiple PCS operations; The VSG switching module is used to combine the retained real-time load power data with the PCS group to evaluate the efficiency value of the multi-power PCS, obtain the predicted efficiency value of each multi-power PCS under the real-time load power data, and then select the multi-power PCS with the highest predicted efficiency value as the working parameter for input, thereby switching the working mode.

[0011] As a further improvement of the technical solution, the calculation formula of the VSG establishment module is as follows:

[0012] Where P is the active power, U is vx is the output AC side voltage, I vx is the output AC side current, cosβ is the power factor;

[0013] Where Q is reactive power, U is vx is the output AC side voltage, I vx is the output AC side current, sinδ is the sine value of the power factor;

[0014] Where w is the output frequency of the virtual synchronous generator, w0 is the rated frequency, D p is the active frequency droop coefficient, P ref is the reference active power, P is the actual active power;

[0015] Where E is the output voltage amplitude of the virtual synchronous generator, E0 is the rated voltage amplitude, C p is the reactive voltage droop coefficient, Q ref is the reference reactive power and Q is the reactive power.

[0016] As a further improvement of this technical solution, the calculation formula of the VSG switching module is as follows:

[0017] Among them, P out，i is the output power, U out，i (t) is the output voltage of the i-th PCS at time t, I out，i(t) is the output current at time t. Assume that the output voltage and current are functions that vary with time;

[0018] Among them, P in，i is the input power, U in，i (t) is the input voltage of the i-th PCS at time t, I in，i (t) is the input current at time t;

[0019] Among them, η i (t) is the efficiency value at each time t, and the time interval [t1, t2] is set, and the average efficiency value is calculated:

[0020] Among them, ηp i is the average efficiency value, dt is the integration of the variable t in the interval [t1, t2], and then find the multi-power PCS that maximizes the average efficiency value, and use its operating parameters as input to switch the operating mode.

[0021] As a further improvement of the technical solution, the parameter update simulation unit includes a parameter simulation module and an efficiency comparison module; The parameter simulation module is used to establish a parameter simulation model through the equipment parameters of the energy storage device at the VSG control end, and input the real-time load power data into the parameter simulation model for simulation, automatically adjust the working parameters of the multi-power PCS during the simulation process, and summarize and save the working parameters according to the simulation results; The efficiency comparison module is used to evaluate the efficiency value of the multi-power PCS obtained by the parameter simulation module, and then compare the efficiency value of the predicted efficiency value obtained by the simulation result with the efficiency value of the multi-power PCS corresponding to the current working mode. When the efficiency value of the simulation result is greater than the efficiency value of the multi-power PCS corresponding to the current working mode, the VSG control end uses the simulation result as a working parameter input to switch the working mode.

[0022] As a further improvement of the technical solution, the simulation parameter retention unit includes a quality monitoring module and a range updating module; The quality monitoring module is used to monitor the energy storage quality of the real-time working state of the energy storage device when the simulation structure replaces the multi-power PCS corresponding to the current working mode. When the energy storage quality decreases, the replacement of the simulation result is stopped. On the contrary, when the energy storage quality does not decrease, the monitoring is continued until the simulation result is replaced. The range update module is used to save the simulation results as a multi-power PCS in the PCS group when the simulation results are replaced, and use the real-time load power data as the corresponding adaptive load range of the multi-power PCS, and then update the load range reduction of other multi-power PCSs with overlapping ranges.

[0023] Compared with the prior art, the present invention has the following beneficial effects: 1. In this multi-power full-time energy following energy storage system, by combining the retained real-time load power data and PCS group to evaluate the efficiency value of the multi-power PCS, the predicted efficiency value of each multi-power PCS under the real-time load power data can be obtained, and the multi-power PCS with the highest predicted efficiency value is selected as the working parameter for input, and the working mode is switched, which can improve the overall efficiency of the system. At the same time, at the VSG control end, a parameter simulation model is established through the equipment parameters of the energy storage device, and the real-time load power data is input into the model for simulation, and the working parameters of the multi-power PCS are automatically adjusted. Efficiency value evaluation and working mode switching are performed according to the simulation results, further optimizing the performance of the system.

[0024] 2. In this multi-power full-time energy following energy storage system, when the simulation results replace the multi-power PCS corresponding to the current working mode, the energy storage quality is monitored for the real-time working status of the energy storage equipment. When the energy storage quality decreases, the replacement of the simulation results is stopped to ensure the stability and reliability of the system. When the energy storage quality does not decrease, the monitoring is continued until the simulation results are replaced, and the simulation results are saved as multi-power PCS in the PCS group. At the same time, the real-time load power data is used as the corresponding adaptive load range of the multi-power PCS, and then the load range of other multi-power PCSs with overlapping ranges is reduced and updated, thereby realizing dynamic optimization of the energy storage system and reasonable allocation of resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is the overall structural principle diagram of the present invention; Figure 2 This is the VSG control principle diagram of the present invention.

[0026] The meaning of each number in the figure is: 10. Data valid retention unit; 20. PCS matching unit; 30. VSG control working unit; 40. Parameter update simulation unit; 50. Simulation parameter retention unit. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] See also Figure 1 - Figure 2 As shown, the purpose of this embodiment is to provide a multi-power full-time energy following energy storage system, including a data valid retention unit 10, a PCS matching unit 20, a VSG control working unit 30, a parameter update simulation unit 40 and a simulation parameter retention unit 50; The data validity retention unit 10 is used to collect load power data, perform validity analysis on the load power data, and retain the validity according to the analysis results; The data validity retention unit 10 collects load power data through the smart meter, and immediately judges the data validity of the collected load power data, excludes abnormal and invalid data, and uses a data smoothing algorithm and the latest valid data for replacement processing for abnormal and invalid data, and then retains the valid data and the replacement data. The specific steps are as follows: Install and configure smart meters: Select a suitable smart meter, ensure that its measurement accuracy and range meet the load power measurement requirements, correctly install the smart meter in the load circuit, and then the smart meter collects the load power in real time according to the set sampling frequency; Determine the validity judgment standard: set a reasonable power range. Data beyond this range is considered abnormal and invalid data. Set the upper and lower limit thresholds according to the normal working power range of the load. The formula is as follows:

[0029] Among them, S t The power value of the tth data point after smoothing, P t is the power value of the current data point, S t-1 It is the power value of the previous data point after smoothing. α is the smoothing coefficient, which is between 0 and 1. By continuously adjusting the smoothing coefficient α, the abnormal and invalid data are smoothed. Take the nearest valid data for replacement: determine the location of the abnormal invalid data point, find the valid data point closest to the data point, and replace the abnormal invalid data with the power value of the nearest valid data point found; At the same time, obtain the real-time working status and equipment parameters of the energy storage equipment. Establish a communication connection with the energy storage device, send instructions to the energy storage device, request to obtain real-time working status and device parameters, and then the energy storage device responds to the instructions and returns relevant data.

[0030] The PCS matching unit 20 is used to establish a PCS group, and analyze the operating parameters of the multi-power PCSs in the PCS group in combination with historical load power data, and then set the operating parameters of the multi-power PCSs according to the analysis results, and match the corresponding load power range for each multi-power PCS; The PCS matching unit 20 includes a PCS group establishment module and a PCS initialization module; The PCS group establishment module is used to establish a PCS group, thereby reserving the multi-power PCS, and at the same time establishing a blank multi-power PCS to be adjusted in the PCS group; The PCS initialization module is used to initialize the energy storage control working parameter analysis of the blank multi-power PCS to be adjusted in combination with the equipment parameters, and adjust the working parameters of the blank multi-power PCS to be adjusted in the PCS group according to the analysis results. At the same time, according to the analysis results, each multi-power PCS in the PCS group is matched with the corresponding load power range. The specific steps are as follows: Create data structure: select an array data structure to represent the PCS group, traverse the existing multi-power PCSs, add them to the PCS group one by one, and record the key attributes of each PCS; Establish a blank multi-power PCS to be adjusted: create multiple new PCS objects in the PCS group, the initial state is blank to be adjusted, and set a flag for this blank PCS object to indicate that it needs to be initialized and parameter adjusted; Initialization based on device parameters: Collect device parameters related to the energy storage system, analyze and initialize the energy storage control working parameters based on the device parameters and the working requirements of the energy storage system, and calculate the appropriate charging power, discharging power, power conversion efficiency, etc. Update parameter values: Update the corresponding attribute values ​​of the blank PCS objects to be adjusted according to the working parameters obtained by analysis, set parameters such as charging power, discharging power, and working mode, and verify the rationality of the adjusted parameters to ensure that they are within the allowable range of the equipment; Determine the load power range: Traverse each PCS object in the PCS group and match it with the corresponding load power range based on its rated power and performance characteristics.

[0031] The VSG control working unit 30 is used to establish a VSG control end, and then connect the load monitoring with the data valid retention unit 10 through the VSG control end, combine the real-time load power data with the PCS group to evaluate the efficiency value of the multi-power PCS, and select the multi-power PCS with the highest efficiency value to switch the working mode; The VSG control working unit 30 includes a VSG establishment module and a VSG switching module; like Figure 2 As shown, the VSG establishment module is used to establish the VSG control end. At the same time, the VSG control end receives the effective load power data retained by the data effective retention unit 10, and then controls the operation of multiple PCSs by returning Uvx and Ivx on the output AC side through VSG control. The specific steps are as follows: Establish the VSG control end: select a suitable controller, such as a digital signal processor (DSP) or a microcontroller (MCU), with sufficient computing power and input and output interfaces, connect sensors to measure the voltage and current on the output AC side, then develop the VSG control algorithm program to realize the function of the virtual synchronous generator, and set up the communication interface to receive the effective load power data; The VSG control end receives the retained effective load power data: determines the communication protocol and interface, connects to the data effective retention unit 10 storing the effective load power data, verifies and analyzes the received data to ensure the accuracy of the data; Measure the output AC side parameters: measure the output AC side voltage U in real time through the connected sensor vx and current I vx , filtering and amplifying the measured voltage and current signals to improve signal quality; Calculate the control parameters: Based on the measured U vx and I vx , combined with the VSG control algorithm, the parameters required to control the operation of multiple PCSs are calculated, and the formula is as follows:

[0032] Where P is the active power, U is vx is the output AC side voltage, I vx is the output AC side current, cosβ is the power factor;

[0033] Where Q is reactive power, U is vx is the output AC side voltage, I vx is the output AC side current, sinδ is the sine value of the power factor;

[0034] Where w is the output frequency of the virtual synchronous generator, w0 is the rated frequency, D p is the active frequency droop coefficient, P ref is the reference active power, P is the actual active power;

[0035] Where E is the output voltage amplitude of the virtual synchronous generator, E0 is the rated voltage amplitude, C p is the reactive voltage droop coefficient, Q ref is the reference reactive power, Q is the reactive power; Send control instructions: The calculated control parameters are converted into control instructions and sent to the multi-power PCS to control its output power, frequency, voltage and other parameters.

[0036] The VSG switching module is used to evaluate the efficiency value of the multi-power PCS by combining the retained real-time load power data with the PCS group, obtain the predicted efficiency value of each multi-power PCS under the real-time load power data, and then select the multi-power PCS with the highest predicted efficiency value as the working parameter for input, so as to switch the working mode. There are n multi-power PCSs. For the i-th PCS, the formula is as follows:

[0037] Among them, P out，i is the output power, U out，i (t) is the output voltage of the i-th PCS at time t, I out，i (t) is the output current at time t. Assume that the output voltage and current are functions that vary with time;

[0038] Among them, P in，i is the input power, U in，i (t) is the input voltage of the i-th PCS at time t, I in，i (t) is the input current at time t;

[0039] Among them, η i (t) is the efficiency value at each time t, and the time interval [t1, t2] is set, and the average efficiency value is calculated:

[0040] Among them, ηp i is the average efficiency value, dt is the integration of the variable t in the interval [t1, t2], and then find the multi-power PCS that maximizes the average efficiency value, and use its operating parameters as input to switch the operating mode.

[0041] The parameter update simulation unit 40 is used to establish a parameter simulation model at the VSG control end, and then input the real-time load power data into the parameter simulation model for simulation, and compare the simulation result with the efficiency value of the current multi-power PCS, and replace the current multi-power PCS with the simulation result according to the comparison result; The parameter updating simulation unit 40 includes a parameter simulation module and an efficiency comparison module; The parameter simulation module is used to establish a parameter simulation model through the equipment parameters of the energy storage device at the VSG control end, and input the real-time load power data into the parameter simulation model for simulation. During the simulation process, the working parameters of the multi-power PCS are automatically adjusted, and the working parameters are summarized and saved according to the simulation results. The specific steps are as follows: Model building: For modeling based on physical principles, the mathematical models of energy storage systems and PCS can be established using circuit theory, the law of conservation of energy, etc. For example, the overall model can be constructed based on the equivalent circuit model of the battery and the power conversion equation of the PCS. At the same time, the established model can be verified using a portion of known data to check the accuracy and reliability of the model. Input real-time load power data for simulation: Input real-time load power data into the parameter simulation model, simulate the operation process of the energy storage system and PCS according to the calculation logic of the model, and record key parameters in the simulation process, such as PCS output power, input power, efficiency, etc.; Automatically adjust the operating parameters of multi-power PCS: Rule-based adjustment can adjust the operating parameters according to preset conditions and rules. For example, when the load power increases, the output power of the PCS is increased. Optimization algorithm adjustment can use optimization algorithms, such as genetic algorithms and particle swarm optimization algorithms, to search for the optimal operating parameter combination through continuous iterations. According to the determined adjustment strategy, the operating parameters of the multi-power PCS are automatically adjusted; Summarize and save the working parameters according to the simulation results: Analyze the simulation results, extract key information, such as efficiency values ​​and stability under different working parameters, and summarize the analyzed working parameters and corresponding simulation results.

[0042] The efficiency comparison module is used to evaluate the efficiency value of the simulation results obtained by the parameter simulation module, and then compare the predicted efficiency value obtained by the simulation result with the efficiency value of the multi-power PCS corresponding to the current working mode. When the efficiency value of the simulation result is greater than the efficiency value of the multi-power PCS corresponding to the current working mode, the VSG control end uses the simulation result as the working parameter input to switch the working mode.

[0043] The simulation parameter retaining unit 50 is used to monitor the energy storage quality during the simulation result replacement process, retain the simulation results in the PCS group according to the monitoring process, and update the range of multiple power PCSs with overlapping load power ranges.

[0044] The simulation parameter retention unit 50 includes a quality monitoring module and a range updating module; The quality monitoring module is used to monitor the energy storage quality of the real-time working state of the energy storage device when the simulation structure replaces the multi-power PCS corresponding to the current working mode. When the energy storage quality decreases, the replacement of the simulation result is stopped. On the contrary, when the energy storage quality does not decrease, the monitoring is continued until the simulation result is replaced. If it is determined that the energy storage quality has deteriorated, immediately stop replacing the simulation results, perform fault diagnosis on the system, and find out the cause of the deterioration in the energy storage quality. It may be that the simulation results are not suitable for the current state of the energy storage equipment, equipment failure, etc. Take appropriate repair measures, such as adjusting simulation parameters, repairing or replacing faulty equipment, etc.

[0045] The range update module is used to save the simulation results as a multi-power PCS in the PCS group when the simulation results are replaced, and use the real-time load power data as the corresponding adaptive load range of the multi-power PCS, and then reduce and update the load range of other multi-power PCSs with overlapping ranges. The specific steps are as follows: Save simulation results to PCS group: confirm the key parameters of multi-power PCS in the simulation results, such as output power, input power, efficiency, etc., and add the multi-power PCS information in the simulation results to the PCS group for saving; Analyze real-time load power data: Analyze the real-time load power data to determine its characteristics, such as power range, fluctuation, etc., and record the real-time load power data range obtained by analysis as the corresponding adaptive load range of the multi-power PCS just saved; Find PCS with overlapping ranges: traverse all multi-power PCSs in the PCS group and find other PCSs that overlap with the newly saved multi-power PCS load range; Perform load range reduction and update: For the PCS with overlapping ranges found, reduce and update its load range according to the actual situation. If the newly saved PCS load range completely includes part of the load range of another PCS, then the load range of the other PCS can be adjusted to the part that does not overlap with the new PCS.

[0046] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the present invention and are not intended to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A multi-power full-time energy following energy storage system, characterized in that: It includes a data validity retention unit (10), a PCS matching unit (20), a VSG control working unit (30), a parameter update simulation unit (40) and a simulation parameter retention unit (50); The data validity retention unit (10) is used to collect load power data, perform validity analysis on the load power data, and retain the validity according to the analysis result; The PCS matching unit (20) is used to establish a PCS group, and simultaneously analyze the working parameters of the multi-power PCSs in the PCS group in combination with historical load power data, and then set the working parameters of the multi-power PCSs according to the analysis results, and simultaneously match the corresponding load power range for each multi-power PCS; The VSG control working unit (30) is used to establish a VSG control end, and then connect the load monitoring to the data valid retention unit (10) through the VSG control end, combine the real-time load power data with the PCS group to evaluate the efficiency value of the multi-power PCS, and select the multi-power PCS with the highest efficiency value to switch the working mode; The parameter updating simulation unit (40) is used to establish a parameter simulation model at the VSG control end, then input the real-time load power data into the parameter simulation model for simulation, and compare the simulation result with the efficiency value of the current multi-power PCS, and replace the current multi-power PCS with the simulation result according to the comparison result; The simulation parameter retention unit (50) is used to monitor the energy storage quality during the simulation result replacement process, retain the simulation results in the PCS group according to the monitoring process, and update the range of multiple power PCSs with overlapping load power ranges.

2. A multi-power full-time energy following energy storage system according to claim 1, characterized in that: The data validity retention unit (10) collects load power data through a smart meter, and immediately performs data validity judgment on the collected load power data, excludes abnormal and invalid data, and uses a data smoothing algorithm and the most recent valid data for replacement processing for the abnormal and invalid data, and then retains the valid data and the replacement data; At the same time, the real-time working status and equipment parameters of the energy storage equipment are obtained.

3. A multi-power full-time energy following energy storage system according to claim 1, characterized in that: The calculation formula of the data valid retention unit (10) is as follows: ； Among them, S t The power value of the tth data point after smoothing, P t is the power value of the current data point, S t-1 It is the power value of the previous data point after smoothing. α is the smoothing coefficient, which is between 0 and 1. By continuously adjusting the smoothing coefficient α, the abnormal and invalid data are smoothed.

4. A multi-power full-time energy following energy storage system according to claim 1, characterized in that: The PCS matching unit (20) comprises a PCS group establishment module and a PCS initialization module; The PCS group establishment module is used to establish a PCS group, thereby reserving the multi-power PCS, and at the same time establishing a blank multi-power PCS to be adjusted in the PCS group; The PCS initialization module is used to initialize the energy storage control working parameter analysis of the blank multi-power PCS to be adjusted in combination with the equipment parameters, adjust the working parameters of the blank multi-power PCS to be adjusted in the PCS group according to the analysis results, and match the corresponding load power range for each multi-power PCS in the PCS group according to the analysis results.

5. A multi-power full-time energy following energy storage system according to claim 1, characterized in that: The VSG control working unit (30) comprises a VSG establishment module and a VSG switching module; The VSG establishment module is used to establish a VSG control terminal. At the same time, the VSG control terminal receives the effective load power data retained by the data effective retention unit (10), and then controls the U output on the AC side through the VSG. vx and I vx Regression control of multiple PCS operations; The VSG switching module is used to combine the retained real-time load power data with the PCS group to evaluate the efficiency value of the multi-power PCS, obtain the predicted efficiency value of each multi-power PCS under the real-time load power data, and then select the multi-power PCS with the highest predicted efficiency value as the working parameter for input, thereby switching the working mode.

6. A multi-power full-time energy following energy storage system according to claim 5, characterized in that: The calculation formula of the VSG establishment module is as follows: ； Where P is the active power, U is vx is the output AC side voltage, I vx is the output AC side current, cosβ is the power factor; ； Where Q is reactive power, U is vx is the output AC side voltage, I vx is the output AC side current, sinδ is the sine value of the power factor; ； Where w is the output frequency of the virtual synchronous generator, w0 is the rated frequency, D p is the active frequency droop coefficient, P ref is the reference active power, P is the actual active power; ； Where E is the output voltage amplitude of the virtual synchronous generator, E0 is the rated voltage amplitude, C p is the reactive voltage droop coefficient, Q ref is the reference reactive power and Q is the reactive power.

7. A multi-power full-time energy following energy storage system according to claim 5, characterized in that: The calculation formula of the VSG switching module is as follows: ； Among them, P out，i is the output power, U out，i (t) is the output voltage of the i-th PCS at time t, I out，i (t) is the output current at time t. Assume that the output voltage and current are functions that vary with time; ； Among them, P in，i is the input power, U in，i (t) is the input voltage of the i-th PCS at time t, I in，i (t) is the input current at time t; ； Among them, η i (t) is the efficiency value at each time t, and the time interval [t1, t2] is set, and the average efficiency value is calculated: ； Among them, ηp i is the average efficiency value, dt is the integration of the variable t in the interval [t1, t2], and then find the multi-power PCS that maximizes the average efficiency value, and use its operating parameters as input to switch the operating mode.

8. A multi-power full-time energy following energy storage system according to claim 1, characterized in that: The parameter updating simulation unit (40) comprises a parameter simulation module and an efficiency comparison module; The parameter simulation module is used to establish a parameter simulation model through the equipment parameters of the energy storage device at the VSG control end, and input the real-time load power data into the parameter simulation model for simulation, automatically adjust the working parameters of the multi-power PCS during the simulation process, and summarize and save the working parameters according to the simulation results; The efficiency comparison module is used to evaluate the efficiency value of the multi-power PCS obtained by the parameter simulation module, and then compare the efficiency value of the predicted efficiency value obtained by the simulation result with the efficiency value of the multi-power PCS corresponding to the current working mode. When the efficiency value of the simulation result is greater than the efficiency value of the multi-power PCS corresponding to the current working mode, the VSG control end uses the simulation result as a working parameter input to switch the working mode.

9. A multi-power full-time energy following energy storage system according to claim 1, characterized in that: The simulation parameter retaining unit (50) comprises a quality monitoring module and a range updating module; The quality monitoring module is used to monitor the energy storage quality of the real-time working state of the energy storage device when the simulation structure replaces the multi-power PCS corresponding to the current working mode. When the energy storage quality decreases, the replacement of the simulation result is stopped. On the contrary, when the energy storage quality does not decrease, the monitoring is continued until the simulation result is replaced. The range update module is used to save the simulation results as a multi-power PCS in the PCS group when the simulation results are replaced, and use the real-time load power data as the corresponding adaptive load range of the multi-power PCS, and then update the load range reduction of other multi-power PCSs with overlapping ranges.

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