Control method of energy storage system

Abstract

The invention discloses a control method for an energy storage system, and the method comprises the steps: 1, system initialization and data collection, and when the energy storage system is started, 2, power grid state and load demand analysis, 3, energy storage unit state evaluation, 4, charging and discharging power distribution strategy making, and 5, bidirectional converter control. The method comprises the following steps of: 1, monitoring and adjusting a control effect, 7, diagnosing and processing faults, 8, managing and optimizing energy, 9, cooperatively controlling multiple energy storage systems, and 10, shutting down the systems and storing data. By collecting detailed parameters of a power grid and a load in real time, the method can accurately and accurately control the energy storage systems according to different operation states of the power grid and diversified requirements of the load; a targeted energy storage system control strategy is formulated, efficient and accurate control can be achieved whether the voltage fluctuation and frequency change of a power grid are dealt with or load requirements of different types and different powers are met, and the adaptability of the energy storage system under complex working conditions is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage systems, and in particular to a control method for an energy storage system. Background Art

[0002] As the global demand for renewable energy continues to increase, energy storage systems are increasingly used in the power sector. Energy storage systems can store electrical energy and release it when needed, playing an important role in shaving peaks and filling valleys, stabilizing grid voltage and frequency, and improving power quality. However, existing energy storage system control methods have some shortcomings. For example, in the process of charging and discharging control of the energy storage system, it is often not possible to accurately make dynamic adjustments according to the real-time state of the grid and load demand, resulting in low efficiency and low energy utilization of the energy storage system. Moreover, in the face of complex and changeable grid conditions and different types of loads, the energy storage system has poor adaptability and is prone to overcharging and over-discharging problems, affecting the service life and safety of the energy storage system. In addition, the existing control methods also lack an effective coordination mechanism for the collaborative work of multiple energy storage units, making it difficult to give full play to the overall performance of the energy storage system. Therefore, it is necessary to develop a new energy storage system control method to solve the above problems. Summary of the invention

[0003] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art and to provide a control method for an energy storage system. By real-time acquisition of detailed parameters of the power grid and the load and in-depth analysis, a targeted energy storage system control strategy can be accurately formulated according to the different operating states of the power grid and the diversified demands of the load. Whether it is to cope with voltage fluctuations and frequency changes in the power grid or to meet the demands of loads of different types and powers, efficient and accurate control can be achieved, greatly improving the adaptability of the energy storage system under complex working conditions.

[0004] Taking into account multiple key factors such as the remaining power, health status and temperature of the energy storage unit, comprehensive status assessment and intelligent management of the energy storage unit are carried out to avoid overcharging and over-discharging problems. Advanced optimization algorithms are used to solve the charging and discharging power distribution plan, with the goal of improving the overall efficiency of the energy storage system and the balance of the energy storage unit.

[0005] In the control of the bidirectional converter, the advanced pulse width modulation technology and efficiency optimization strategy are combined to accurately control the conversion process of electric energy, ensuring the quality of the output electric energy while minimizing the energy conversion loss. A comprehensive and complete fault diagnosis mechanism has been established to monitor the operating status of each component of the energy storage system in real time and promptly discover various potential faults. In terms of energy management, the difference in electricity prices, changes in grid loads, and the characteristics of the energy storage unit itself are fully considered, and an intelligent energy storage and release plan is formulated to achieve the goals of peak shaving and valley filling and improving energy utilization.

[0006] The present invention also provides a control method for the above energy storage system, comprising the following steps:

[0007] Step 1: System initialization and data collection. When the energy storage system is started, the controller and each energy storage unit are initialized, including setting the rated parameters of each energy storage unit, including the rated voltage, rated capacity parameters, and the initial working mode of the bidirectional converter. At the same time, the voltage, current, and frequency parameters of the power grid, as well as the power demand information of the load are collected in real time through sensors. The collected data will be transmitted to the controller as the basis for subsequent control decisions.

[0008] Step 2: Grid status and load demand analysis: After receiving the collected data, the controller analyzes and determines the current status of the grid to determine whether the grid is in normal operation;

[0009] Step 3: Energy storage unit status assessment, by assessing the current status of each energy storage unit, including the remaining power, health status, and temperature of the energy storage unit;

[0010] Step 4: Formulate a charging and discharging power allocation strategy. According to the grid status, load demand and energy storage unit status, formulate a reasonable charging and discharging power allocation strategy. Under the premise of meeting the load demand and grid support requirements, the charging and discharging power of each energy storage unit is allocated with the goal of improving the overall efficiency of the energy storage system and extending the service life of the energy storage unit.

[0011] Step 5: bidirectional converter control: according to the established charging and discharging power allocation strategy, the controller sends a control signal to the bidirectional converter to control the working state and power conversion of the bidirectional converter;

[0012] Step 6: Control effect monitoring and adjustment: During the operation of the energy storage system, the control effect is monitored in real time, and the grid parameters, load parameters and energy storage unit parameters are continuously collected through sensors and compared with the set target values;

[0013] Step 7: Fault diagnosis and processing: Establish a complete fault diagnosis mechanism to monitor in real time whether there are faults in each component of the energy storage system;

[0014] Step 8: Energy management and optimization: During the long-term operation of the energy storage system, energy management and optimization are carried out. According to the differences in electricity prices in different time periods, the grid load conditions and the characteristics of the energy storage unit, a reasonable energy storage and release plan is formulated;

[0015] Step 9: Coordinated control of multiple energy storage systems. When multiple energy storage systems work together, a coordinated control mechanism is established. The energy storage systems exchange information through the communication network, share the grid status, load demand, and the status of their own energy storage units. Based on this information, a global charging and discharging power allocation strategy is formulated to achieve coordinated power allocation among multiple energy storage systems.

[0016] Step 10: System shutdown and data storage. When the energy storage system needs to be shut down, first gradually reduce the charging and discharging power of the energy storage unit until it stops working. During the shutdown process, the operating data of the energy storage system is stored, including the grid parameters, load parameters, energy storage unit parameters, and control strategy execution data during the entire operation process. These data will be stored in the local storage device or uploaded to the remote server for subsequent data analysis, performance evaluation, and fault tracing. After the storage is completed, the various components of the energy storage system are safely shut down to complete the shutdown operation.

[0017] According to a control method for an energy storage system provided by the present invention, the grid state and load demand analysis is performed by checking whether the grid voltage is within the allowable fluctuation range of ±5% of the rated voltage, and whether the grid frequency is stable at the rated 50Hz±0.2Hz. If the grid is in an abnormal state, when a voltage drop or excessive frequency fluctuation occurs, the corresponding grid support strategy is activated. At the same time, the load demand is analyzed to determine the load power, power factor and load type. Different energy storage system output strategies are formulated according to the different characteristics of the load demand. For high-power, low-power-factor inductive loads, the energy storage system needs to provide more reactive power compensation.

[0018] According to a control method for an energy storage system provided by the present invention, the energy storage unit status evaluation can understand the working capacity and reliability of each energy storage unit by monitoring these parameters. For energy storage units with too low a temperature, their discharge power should be appropriately reduced or charging should be given priority. For energy storage units with too high a temperature, corresponding heat dissipation measures should be taken and their working power should be adjusted to prevent overheating damage. At the same time, it can be judged whether the energy storage unit has performance degradation based on the SOH value. For energy storage units with serious performance degradation, their weight can be appropriately reduced or isolated for maintenance in subsequent collaborative control.

[0019] According to a control method for an energy storage system provided by the present invention, the charge and discharge power allocation strategy is formulated, and a particle swarm optimization algorithm and a genetic algorithm are used to solve the optimal charge and discharge power allocation scheme. During the allocation process, the SOC balance of the energy storage units is considered to avoid the situation where some energy storage units are overcharged and discharged while other energy storage units are idle. For energy storage units with higher SOCs, discharge is given priority, and for energy storage units with lower SOCs, charging is given priority, so that the SOCs of each energy storage unit gradually tend to be consistent.

[0020] According to a control method for an energy storage system provided by the present invention, the bidirectional converter controls the direct current of the energy storage unit to be converted into alternating current suitable for use by a power grid or a load according to a control signal, and the alternating current of the power grid is converted into direct current and stored in the energy storage unit. During the conversion process, pulse width modulation technology PWM control technology is used to accurately control the output voltage, current amplitude, frequency and phase to ensure the quality of electric energy. At the same time, the efficiency of the bidirectional converter is optimized to reduce the loss in the energy conversion process. By adjusting the duty cycle of the PWM signal, the bidirectional converter operates near the optimal efficiency point.

[0021] According to a control method for an energy storage system provided by the present invention, the control effect monitoring and adjustment is performed by monitoring whether the grid voltage has returned to a normal range, whether the load power is stably supplied, and whether the SOC of the energy storage unit is adjusted as expected. If it is found that the control effect does not reach the expected goal, the control strategy is adjusted according to the actual situation, the grid status and load demand are re-evaluated, the charging and discharging power allocation strategy is adjusted, and the control parameters of the bidirectional converter are optimized until a satisfactory control effect is achieved.

[0022] According to a control method for an energy storage system provided by the present invention, the fault diagnosis and processing determines whether a fault occurs by monitoring abnormal changes in circuit current and voltage, abnormal increase in temperature of the energy storage unit, and interruption of communication signals. Once a fault is detected, the fault handling procedure is immediately started. For minor faults, including sensor failure, redundant sensors or data estimation methods can be used for temporary processing, and a fault alarm signal is issued to notify maintenance personnel to perform repairs. For serious faults, including short circuit of the energy storage unit and damage of the bidirectional converter, the connection between the faulty component and the system is quickly cut off to prevent the fault from expanding, and the backup system is started or emergency shutdown measures are taken to ensure the safe and stable operation of the energy storage system.

[0023] According to a control method of an energy storage system provided by the present invention, the energy management and optimization controls the energy storage system to charge in large quantities when the electricity price is low at night, and releases electric energy when the electricity consumption is peak during the day, so as to achieve peak shaving and valley filling and reduce electricity costs. At the same time, the self-discharge characteristics and energy conversion efficiency of the energy storage system are considered to optimize the energy storage and release process, thereby improving the energy utilization rate of the entire energy storage system. When combined with a renewable energy power generation system, the working state of the energy storage system is reasonably adjusted according to the power generation power fluctuation of the renewable energy, the power generation power output is smoothed, and the grid connection stability of the renewable energy is improved.

[0024] According to a control method for an energy storage system provided by the present invention, the coordinated control of multiple energy storage systems adopts a distributed coordinated control algorithm, and each energy storage system autonomously adjusts the charging and discharging power according to its own local information and the received global information to achieve the optimal operating state of the entire multi-energy storage system cluster. In the coordinated control process, the geographical distribution differences and transmission line loss factors between the energy storage systems are taken into consideration to ensure efficient transmission and reasonable distribution of energy between the energy storage systems.

[0025] Compared with the prior art, the control method of the energy storage system of the present invention can accurately formulate targeted energy storage system control strategies according to the different operating states of the power grid and the diversified demands of the load by collecting detailed parameters of the power grid and the load in real time and conducting in-depth analysis. Whether it is to cope with voltage fluctuations and frequency changes in the power grid or to meet the demands of loads of different types and powers, efficient and accurate control can be achieved, greatly improving the adaptability of the energy storage system under complex working conditions.

[0026] Compared with the prior art, a control method for an energy storage system of the present invention comprehensively considers multiple key factors such as the remaining power, health status and temperature of the energy storage unit, performs comprehensive status evaluation and intelligent management of the energy storage unit, avoids overcharging and over-discharging problems, and adopts advanced optimization algorithms to solve the charging and discharging power distribution plan, with the goal of improving the overall efficiency of the energy storage system and the balance of the energy storage unit.

[0027] Compared with the prior art, the control method of the energy storage system of the present invention combines advanced pulse width modulation technology and efficiency optimization strategy in the control of the bidirectional converter, which can accurately control the conversion process of electric energy, ensure the quality of output electric energy, and minimize energy conversion loss. A comprehensive and complete fault diagnosis mechanism has been established, which can monitor the operating status of each component of the energy storage system in real time and discover various potential faults in time. In terms of energy management, the difference in electricity prices, changes in grid load, and the characteristics of the energy storage unit itself are fully considered, and an intelligent energy storage and release plan is formulated to achieve the goals of peak shaving and valley filling and improving energy utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention is further described below in conjunction with the accompanying drawings and embodiments;

[0029] Figure 1 The present invention is a flow chart of a control method for an energy storage system. DETAILED DESCRIPTION

[0030] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0031] Reference Figure 1 , an embodiment of the present invention provides a control method for an energy storage system, which comprises the following steps:

[0032] Step 1: System initialization and data collection. When the energy storage system is started, the controller and each energy storage unit are initialized, including setting the rated parameters of each energy storage unit, including the rated voltage, rated capacity parameters, and the initial working mode of the bidirectional converter. At the same time, the voltage, current, and frequency parameters of the power grid, as well as the power demand information of the load are collected in real time through sensors. The collected data will be transmitted to the controller as the basis for subsequent control decisions.

[0033] Step 2: Grid status and load demand analysis: After receiving the collected data, the controller analyzes and determines the current status of the grid to determine whether the grid is in normal operation;

[0034] Step 3: Energy storage unit status assessment, by assessing the current status of each energy storage unit, including the remaining power, health status, and temperature of the energy storage unit;

[0035] Step 4: Formulate a charging and discharging power allocation strategy. According to the grid status, load demand and energy storage unit status, formulate a reasonable charging and discharging power allocation strategy. Under the premise of meeting the load demand and grid support requirements, the charging and discharging power of each energy storage unit is allocated with the goal of improving the overall efficiency of the energy storage system and extending the service life of the energy storage unit.

[0036] Step 5: bidirectional converter control: according to the established charging and discharging power allocation strategy, the controller sends a control signal to the bidirectional converter to control the working state and power conversion of the bidirectional converter;

[0037] Step 6: Control effect monitoring and adjustment: During the operation of the energy storage system, the control effect is monitored in real time, and the grid parameters, load parameters and energy storage unit parameters are continuously collected through sensors and compared with the set target values;

[0038] Step 7: Fault diagnosis and processing: Establish a complete fault diagnosis mechanism to monitor in real time whether there are faults in each component of the energy storage system;

[0039] Step 8: Energy management and optimization: During the long-term operation of the energy storage system, energy management and optimization are carried out. According to the differences in electricity prices in different time periods, the grid load conditions and the characteristics of the energy storage unit, a reasonable energy storage and release plan is formulated;

[0040] Step 9: Coordinated control of multiple energy storage systems. When multiple energy storage systems work together, a coordinated control mechanism is established. The energy storage systems exchange information through the communication network, share the grid status, load demand, and the status of their own energy storage units. Based on this information, a global charging and discharging power allocation strategy is formulated to achieve coordinated power allocation among multiple energy storage systems.

[0041] Step 10: System shutdown and data storage. When the energy storage system needs to be shut down, first gradually reduce the charging and discharging power of the energy storage unit until it stops working. During the shutdown process, the operating data of the energy storage system is stored, including the grid parameters, load parameters, energy storage unit parameters, and control strategy execution data during the entire operation process. These data will be stored in the local storage device or uploaded to the remote server for subsequent data analysis, performance evaluation, and fault tracing. After the storage is completed, the various components of the energy storage system are safely shut down to complete the shutdown operation.

[0042] Working principle: First, when the energy storage system is started, the system is initialized and data is collected according to step 1. The rated voltage of energy storage unit A is set to 480V, the rated capacity is set to 100kWh, and the initial working mode of the bidirectional converter is the standby mode. At the same time, the voltage transformer and current transformer sensors collect the data of the grid voltage of 220V, current of 50A, frequency of 50Hz, and load power demand of 30kW, and transmit them to the controller.

[0043] Next, the controller analyzes the grid status and load demand according to step 2. It determines that the grid is in normal operation, the load is a resistive load and the power demand is 30kW. Then, the energy storage unit status is evaluated according to step 3, assuming that the SOC of energy storage unit A is 60%, the SOH is 90%, and the temperature is 30°C.

[0044] According to step 4, the particle swarm optimization algorithm is used to formulate the charging and discharging power allocation strategy. For example, it is calculated that the energy storage unit A should discharge 20kW to meet the load demand and maintain SOC balance. In step 5, the controller sends a control signal to the bidirectional converter. The bidirectional converter converts the DC power of the energy storage unit A into 220V, 50Hz AC power to supply the load according to the signal. By adjusting the PWM signal duty cycle, the bidirectional converter works at the optimal efficiency point, assuming that the conversion efficiency reaches 95%.

[0045] During the operation of the energy storage system, the control effect is continuously monitored according to step 6. If the load power demand is found to suddenly increase to 40kW, the analysis and adjustment are performed again according to steps 2 to 5. For example, if the grid state is re-evaluated to be normal, the load demand becomes 40kW, and the SOC of energy storage unit A becomes 55%, the discharge power of energy storage unit A is adjusted to 30kW through the optimization algorithm again, and the control parameters of the bidirectional converter are adjusted accordingly.

[0046] If a fault is detected during operation, such as a temperature sensor failure of energy storage unit A, the redundant temperature sensor will continue to monitor and issue a fault alarm signal according to the fault diagnosis and handling mechanism in step 7. If a serious fault occurs, such as an internal short circuit in energy storage unit A, the connection between energy storage unit A and the system will be immediately cut off, and the backup energy storage unit will be started or emergency shutdown measures will be taken.

[0047] During long-term operation, energy management and optimization are performed according to step eight. When the electricity price is low at night, control the energy storage unit A to charge at a power of 50kW; during the peak power consumption during the day, release electricity according to the load demand and the state of the grid. When there are multiple energy storage systems, perform coordinated control according to step nine. For example, energy storage system A and energy storage system B share information through the communication network, and adopt a distributed collaborative control algorithm to coordinate the allocation of charging and discharging power according to the overall load of the grid and its own state. For example, energy storage system A discharges 20kW and energy storage system B discharges 15kW to meet the total load demand.

[0048] Finally, when the energy storage system needs to be shut down, the charging and discharging power of the energy storage unit is gradually reduced according to step 10, and the system is shut down safely after storing the operating data.

[0049] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in the technical field without departing from the purpose of the present invention.

Claims

1. A control method for an energy storage system, characterized in that: The following steps are involved: Step 1: System initialization and data collection. When the energy storage system is started, the controller and each energy storage unit are initialized, including setting the rated parameters of each energy storage unit, including the rated voltage, rated capacity parameters, and the initial working mode of the bidirectional converter. At the same time, the voltage, current, and frequency parameters of the power grid, as well as the power demand information of the load are collected in real time through sensors. The collected data will be transmitted to the controller as the basis for subsequent control decisions. Step 2: Grid status and load demand analysis: After receiving the collected data, the controller analyzes and determines the current status of the grid to determine whether the grid is in normal operation; Step 3: Energy storage unit status assessment, by assessing the current status of each energy storage unit, including the remaining power, health status, and temperature of the energy storage unit; Step 4: Formulate a charging and discharging power allocation strategy. According to the grid status, load demand and energy storage unit status, formulate a reasonable charging and discharging power allocation strategy. Under the premise of meeting the load demand and grid support requirements, the charging and discharging power of each energy storage unit is allocated with the goal of improving the overall efficiency of the energy storage system and extending the service life of the energy storage unit. Step 5: bidirectional converter control: according to the established charging and discharging power allocation strategy, the controller sends a control signal to the bidirectional converter to control the working state and power conversion of the bidirectional converter; Step 6: Control effect monitoring and adjustment: During the operation of the energy storage system, the control effect is monitored in real time, and the grid parameters, load parameters and energy storage unit parameters are continuously collected through sensors and compared with the set target values; Step 7: Fault diagnosis and processing: Establish a complete fault diagnosis mechanism to monitor in real time whether there are faults in each component of the energy storage system; Step 8: Energy management and optimization: During the long-term operation of the energy storage system, energy management and optimization are carried out. According to the differences in electricity prices in different time periods, the grid load conditions and the characteristics of the energy storage unit, a reasonable energy storage and release plan is formulated; Step 9: Coordinated control of multiple energy storage systems. When multiple energy storage systems work together, a coordinated control mechanism is established. The energy storage systems exchange information through the communication network, share the grid status, load demand, and the status of their own energy storage units. Based on this information, a global charging and discharging power allocation strategy is formulated to achieve coordinated power allocation among multiple energy storage systems. Step 10: System shutdown and data storage. When the energy storage system needs to be shut down, first gradually reduce the charging and discharging power of the energy storage unit until it stops working. During the shutdown process, the operating data of the energy storage system is stored, including the grid parameters, load parameters, energy storage unit parameters, and control strategy execution data during the entire operation process. These data will be stored in the local storage device or uploaded to the remote server for subsequent data analysis, performance evaluation, and fault tracing. After the storage is completed, the various components of the energy storage system are safely shut down to complete the shutdown operation.

2. A control method for an energy storage system according to claim 1, characterized in that: The grid status and load demand analysis is performed by checking whether the grid voltage is within the allowable fluctuation range of ±5% of the rated voltage, and whether the grid frequency is stable at the rated 50Hz±0.2Hz. If the grid is in an abnormal state, there is a voltage drop or excessive frequency fluctuation, the corresponding grid support strategy is activated. At the same time, the load demand is analyzed to determine the load power, power factor and type. Different energy storage system output strategies are formulated according to the different characteristics of the load demand. For high-power, low-power-factor inductive loads, the energy storage system needs to provide more reactive power compensation.

3. The control method of an energy storage system according to claim 1, characterized in that: The energy storage unit status assessment can understand the working capacity and reliability of each energy storage unit by monitoring these parameters. For energy storage units with too low a temperature, their discharge power should be appropriately reduced or charging should be given priority. For energy storage units with too high a temperature, corresponding heat dissipation measures should be taken and their working power should be adjusted to prevent overheating damage. At the same time, it can be judged whether the energy storage unit has performance degradation based on the SOH value. For energy storage units with serious performance degradation, their weight can be appropriately reduced or isolated for maintenance in subsequent collaborative control.

4. The control method of an energy storage system according to claim 1, characterized in that: The charge and discharge power allocation strategy is formulated by using a particle swarm optimization algorithm and a genetic algorithm to solve the optimal charge and discharge power allocation scheme. During the allocation process, the SOC balance of the energy storage units is considered to avoid the situation where some energy storage units are overcharged and discharged while other energy storage units are idle. For energy storage units with higher SOCs, discharging is given priority, and for energy storage units with lower SOCs, charging is given priority, so that the SOCs of each energy storage unit gradually tend to be consistent.

5. The control method of an energy storage system according to claim 1, characterized in that: The bidirectional converter control converts the direct current of the energy storage unit into alternating current suitable for use by the power grid or load according to the control signal, and converts the alternating current of the power grid into direct current and stores it in the energy storage unit. During the conversion process, pulse width modulation technology PWM control technology is used to accurately control the output voltage and current amplitude, frequency and phase to ensure the quality of electric energy. At the same time, the efficiency of the bidirectional converter is optimized to reduce the loss in the energy conversion process. By adjusting the duty cycle of the PWM signal, the bidirectional converter operates near the optimal efficiency point.

6. The control method of an energy storage system according to claim 1, characterized in that: The control effect monitoring and adjustment is performed by monitoring whether the grid voltage has returned to a normal range, whether the load power is stably supplied, and whether the SOC of the energy storage unit is adjusted as expected. If it is found that the control effect does not meet the expected goal, the control strategy is adjusted according to the actual situation, the grid status and load demand are re-evaluated, the charging and discharging power allocation strategy is adjusted, and the control parameters of the bidirectional converter are optimized until a satisfactory control effect is achieved.

7. The control method of an energy storage system according to claim 1, characterized in that: The fault diagnosis and processing determines whether a fault occurs by monitoring abnormal changes in circuit current and voltage, abnormal increase in energy storage unit temperature, and interruption of communication signals. Once a fault is detected, the fault handling procedure is immediately started. For minor faults, including sensor failure, redundant sensors or data estimation methods can be used for temporary processing, and a fault alarm signal is issued to notify maintenance personnel to perform repairs. For serious faults, including short circuit of the energy storage unit and damage of the bidirectional converter, the connection between the faulty component and the system is quickly cut off to prevent the fault from expanding, and the backup system is started or emergency shutdown measures are taken to ensure the safe and stable operation of the energy storage system.

8. The control method of an energy storage system according to claim 1, characterized in that: The energy management and optimization controls the energy storage system to charge in large quantities at night when electricity prices are low, and releases electricity during the peak hours of electricity consumption during the day, thereby achieving peak shaving and valley filling and reducing electricity costs. At the same time, the self-discharge characteristics and energy conversion efficiency of the energy storage system are considered to optimize the energy storage and release processes to improve the energy utilization rate of the entire energy storage system. When combined with a renewable energy power generation system, the working state of the energy storage system is reasonably adjusted according to the fluctuation of the power generation power of renewable energy, the power generation output is smoothed, and the grid connection stability of renewable energy is improved.

9. The control method of an energy storage system according to claim 1, characterized in that: The collaborative control of the multiple energy storage systems adopts a distributed collaborative control algorithm. Each energy storage system autonomously adjusts the charging and discharging power according to its own local information and the received global information to achieve the optimal operating state of the entire multi-energy storage system cluster. In the collaborative control process, the geographical distribution differences and transmission line loss factors between the energy storage systems are taken into consideration to ensure efficient transmission and reasonable distribution of energy between the energy storage systems.

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