Control method of energy storage system, energy storage control system and energy storage system

Abstract

The application discloses a control method of an energy storage system, an energy storage control system and the energy storage system. The control method of the energy storage system comprises the following steps: controlling a plurality of battery clusters to be connected to a bus unit in sequence, and controlling a first insulation detection unit to detect a first insulation state between the battery cluster and the bus unit while each battery cluster is connected to the bus unit; controlling a target energy storage module to be connected to a power conversion module, and controlling the first insulation detection unit to detect a second insulation state between the target energy storage module and the power conversion module; controlling the power conversion module in the energy storage system to be connected to a power grid, and controlling a second insulation detection unit to detect a third insulation state between the power conversion module in the energy storage system and the power grid; determining that the third insulation state has no insulation fault, and controlling the energy storage system to charge or discharge according to a charge-discharge control signal. The control method can realize the start of the energy storage system while completing the insulation detection function, and can improve the insulation detection efficiency.

Description

Technical Field

[0001] This invention relates to the field of energy storage technology, and in particular to a control method, an energy storage control system, and an energy storage system. Background Technology

[0002] In related technologies, insulation testing of energy storage systems is divided into three levels, so that battery clusters, BCP (Battery Collection Panel), and PCS (Power Conversion System) all have separate insulation testing functions. This allows for effective and accurate location of the insulation status of specific equipment, enabling online location of insulation faults in the energy storage system.

[0003] However, the above insulation testing method requires that the switch be disconnected after the battery cluster test is completed before the insulation test of the battery combiner cabinet and the energy storage converter can be performed. This makes the whole insulation testing process cumbersome, and the switch needs to be repeatedly opened and closed, which affects the mechanical life of the devices. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. Therefore, one object of the present invention is to propose a control method for an energy storage system, which can simultaneously perform insulation detection and start the energy storage system, and can improve the efficiency of insulation detection.

[0005] The second objective of this invention is to propose an energy storage control system.

[0006] The third objective of this invention is to propose an energy storage system.

[0007] To address the aforementioned problems, a first aspect of the present invention provides a control method for an energy storage system. The control method includes: receiving a start-up command and a charge / discharge control signal from an energy storage module comprising multiple battery clusters and a current collector; acquiring voltage information of each battery cluster in a target energy storage module; controlling the multiple battery clusters to sequentially connect to the current collector according to the order of the charge / discharge control signal and the voltage information of the multiple battery clusters in the target energy storage module; and simultaneously controlling a first insulation detection unit in the target energy storage module to detect a first insulation state between the battery cluster and the current collector, and controlling the connection relationship between the battery cluster and the current collector based on the first insulation state, wherein when the first insulation state is an insulation fault, the connection relationship between the battery cluster and the current collector is disconnected; when the first insulation state is no insulation fault, the connection relationship between the battery cluster and the current collector is open. The connection between the current units is continuous; when the first insulation state between all the battery clusters and the current collector in the target energy storage module is detected and it is determined that the connection between at least one battery cluster and the current collector is continuous, the target energy storage module is controlled to connect to the power conversion module and the first insulation detection unit is controlled to detect the second insulation state between the target energy storage module and the power conversion module; when the second insulation state between all the energy storage modules and the power conversion module in the energy storage system is detected and there is no insulation fault in the second insulation state, the power conversion module in the energy storage system is controlled to connect to the power grid and the second insulation detection unit in the power conversion module is controlled to detect the third insulation state between the power conversion module in the energy storage system and the power grid; when it is determined that there is no insulation fault in the third insulation state, the energy storage system is controlled to charge or discharge with the power grid according to the charge and discharge control signal.

[0008] According to the control method of the energy storage system of the present invention, after receiving the start command of the energy storage module, while controlling each battery cluster to connect to the combiner unit, the method controls the first insulation detection unit to detect the first insulation state between the battery cluster and the combiner unit; and when the detection of the first insulation state between all battery clusters and the combiner unit in the target energy storage module is completed and it is determined that the connection relationship between at least one battery cluster and the combiner unit is connected, the method controls the target energy storage module to connect to the power conversion module, and simultaneously controls the first insulation detection unit to detect the second insulation state between the target energy storage module and the power conversion module; and when the second insulation state between all energy storage modules and the power conversion module in the energy storage system is detected and the second insulation is achieved, the method controls the first insulation detection unit to detect the second insulation state between the target energy storage module and the power conversion module. After confirming that there are no insulation faults in the third insulation state, the power conversion module is connected to the power grid, and the second insulation detection unit is controlled to detect the third insulation state between the power conversion module and the power grid. Then, after confirming that there are no insulation faults in the third insulation state, the energy storage system can perform charging or discharging according to the charging and discharging control signal. In other words, this embodiment of the invention links the insulation detection process of the energy storage system with the system startup process. That is, while the components in the energy storage system are gradually connected, the insulation detection of the system is completed by controlling the first insulation detection unit or the second insulation detection unit. Thus, while realizing the insulation detection function of the energy storage system, the energy storage system also completes the startup process. Moreover, the insulation detection process is simpler and the efficiency of insulation detection is improved.

[0009] A third aspect of the present invention provides an energy storage system, comprising: at least one energy storage module, each energy storage module including a combiner unit and a plurality of battery clusters arranged in parallel, each battery cluster being connected to the combiner unit, and a battery cluster contactor being disposed between each battery cluster and the combiner unit; the combiner unit including a first insulation detection unit and a disconnecting switch; a power conversion module including a power device and a second insulation detection unit, the DC side of the power device being connected to each combiner unit, the disconnecting switch being disposed between the power device and the combiner unit, and an AC side circuit breaker being disposed on the AC side of the power device; and a control module connected to the energy storage module and the power conversion module, for executing the control method of the energy storage system described in the above embodiment.

[0010] According to the energy storage system of the present invention, based on the topology of the energy storage system, the control module executes the control method of the energy storage system provided in the above embodiments, which can realize the start-up of the energy storage system while completing the insulation detection function, and can improve the efficiency of insulation detection.

[0011] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0012] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0013] Figure 1 This is a structural topology diagram of an energy storage system according to an embodiment of the present invention;

[0014] Figure 2 This is a flowchart of a control method for an energy storage system according to an embodiment of the present invention;

[0015] Figure 3 This is a structural block diagram of an energy storage control system according to an embodiment of the present invention;

[0016] Figure 4 This is a flowchart of a control method for an energy storage system according to another embodiment of the present invention.

[0017] Figure label:

[0018] Energy storage system 100; Energy storage control system 50;

[0019] Energy storage module 10; power conversion module 20; control module 30; field control unit 31; energy management system 40;

[0020] Busbar unit 1; Battery cluster 2; Battery manager 3; Power device 4; Second insulation detection unit 5; Power control unit 6;

[0021] First insulation detection unit 11; Busbar control unit 12; Battery management control unit 13; DC-DC conversion unit 14;

[0022] Processor 51; Memory 52. Detailed Implementation

[0023] The embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. The embodiments of the present invention are described in detail below.

[0024] In related technologies, as the output power of power devices within energy storage systems continues to increase, multiple battery clusters are connected in parallel to match the demands of the power grid, thereby improving the system's output power. However, due to the inherent inconsistencies of the batteries themselves, parallel-connected battery clusters inevitably exhibit differences in internal resistance, voltage differentials, and other characteristics. Prolonged parallel operation of multiple battery clusters gradually amplifies these differences, specifically manifesting as increased deviations in SOC (State of Charge) or output current between clusters. Furthermore, as the number of battery clusters increases, the insulation testing methods for energy storage systems become more complex.

[0025] To address the aforementioned problems, a first aspect of this invention proposes a control method for an energy storage system. This control method enables the energy storage system to start up while performing insulation detection, and it also improves the efficiency of insulation detection.

[0026] The following is for reference. Figure 1 Describe the energy storage system provided in the embodiments of the present invention, such as Figure 1 As shown, the energy storage system 100 includes at least one energy storage module 10, a power conversion module 20, and a control module 30.

[0027] Each energy storage module 10 includes a combiner unit 1 and multiple battery clusters 2 connected in parallel. Each battery cluster 2 is connected to the combiner unit 1, and a battery manager 3 is provided between each battery cluster 2 and the combiner unit 1. Figure 1 As shown, each energy storage module 10 includes multiple battery clusters 2, namely: L1, L2, L3...Ln; each battery cluster 2 is composed of multiple cells connected in series, and each battery cluster 2 is equipped with a battery manager 3: BMS1, BMS2, BMS3...BMSn; all battery managers 3 in the energy storage module 10 are connected to the combiner unit 1.

[0028] The bus unit 1 includes a first insulation detection unit 11 and an isolating switch Q1 for connecting the energy storage module 10 and the power conversion module 20.

[0029] The power conversion module 20 includes a power device 4 and a second insulation detection unit 5. The DC side of the power device 4 is connected to each combiner unit 1. A disconnecting switch Q1 is set between the power device 4 and the combiner unit 1. An AC side circuit breaker QF1 is set on the AC side of the power device 4, and a DC side circuit breaker QF2 is set on the DC side of the power device 4.

[0030] As described above, the multiple battery clusters 2, combiner units 1, and power conversion modules 20 within each energy storage module 10 constitute the main circuit of the entire energy storage system. Under normal conditions, when the energy storage system 100 is started, the control module 30 controls at least one DC main circuit of the energy storage module 10 to be connected in parallel to the DC side of the power conversion module 20, and the AC side of the power conversion module 20 is connected to the power grid, thereby connecting the energy storage system 100 to the power grid.

[0031] In practical applications, the energy storage system 100 also includes a temperature control system, a fire protection system, and an EMS40 (Energy Management System), which will not be described in detail here.

[0032] The battery manager 3 includes a battery management control unit 13 and a battery cluster contactor KM that connects the battery cluster 2 and the combiner unit 1. Figure 1As shown, the battery management control unit 13 is communicatively connected to the combiner unit 1. Each battery cluster 2 is connected to a battery cluster contactor KM: KM1, KM2, KM3...KMn. Each battery cluster contactor KM is controlled by the corresponding connected battery management control unit 13, that is, the battery management control unit 13 controls the opening or closing of the corresponding battery cluster contactor KM.

[0033] based on Figure 1 The diagram shows the structural topology of the energy storage system. This embodiment of the invention proposes a control method for the energy storage system, which is applied to the control module 30. The basic idea of ​​the control method provided by this embodiment is to combine insulation detection logic with the energy storage system startup and operation control strategy. This allows the insulation status of the energy storage system to be detected simultaneously with the gradual connection of components within the system, by controlling either the first or second insulation detection unit. Thus, after completing the insulation detection of all components, the energy storage system completes its startup process and can directly output the target power to match the grid's demand. Furthermore, compared to independently detecting the insulation status by controlling the connection or disconnection of components within the energy storage system, this embodiment combines the insulation detection process with the system startup process. The insulation status of the system can be detected during the gradual connection of components without repeatedly controlling the connection relationships between components. This simplifies the entire insulation detection process and improves its efficiency.

[0034] The following is for reference. Figure 2 The control method of the energy storage system provided in the embodiments of the present invention is described in detail. The control method includes at least steps S1-S6.

[0035] Step S1: Receive the start command and charge / discharge control signal of the energy storage module, which includes multiple battery clusters and current collectors.

[0036] The start command or charge / discharge control signal of the energy storage module can be issued directly by the control module, or it can be issued by the upper-level controller of the control module, such as the energy management system. The upper-level controller sends the start command or charge / discharge control signal of the energy storage module to the control module to start multiple energy storage modules in the energy storage system.

[0037] Specifically, refer to Figure 1As shown, since the energy storage system includes multiple energy storage modules, each energy storage module can be started in a certain order when the energy storage system is started. For example, the start-up order of each energy storage module can be preset as needed, or the start-up order can be determined based on the characteristic state information of each energy storage module, such as the total voltage information. There are no restrictions on this. Thus, the control module can send start-up commands in sequence according to the start-up order of each energy storage module, so that each energy storage module starts up and is connected to the main circuit of the energy storage system.

[0038] Step S2: Obtain the voltage information of each battery cluster in the target energy storage module.

[0039] Here, the target energy storage module can be understood as an energy storage module that is in the startup state in response to the startup command of the energy storage module. For example, with Figure 1 For example, the energy storage system 100 includes two energy storage modules 10: a first energy storage module 101 and a second energy storage module 102. If the first energy storage module 101 receives a start command, the first energy storage module 101 will act as the target energy storage module to perform the start operation; if the second energy storage module 102 receives a start command, the second energy storage module 102 will act as the target energy storage module to perform the start operation.

[0040] Step S3: Based on the order of the charge / discharge control signal and the voltage information of multiple battery clusters in the target energy storage module, control the multiple battery clusters to connect to the current collector in sequence. At the same time as each battery cluster is connected to the current collector, control the first insulation detection unit in the target energy storage module to detect the first insulation state between the battery cluster and the current collector. Simultaneously, control the connection relationship between the battery cluster and the current collector based on the first insulation state. When the first insulation state is an insulation fault, the connection relationship between the battery cluster and the current collector is disconnected; when the first insulation state is no insulation fault, the connection relationship between the battery cluster and the current collector is connected.

[0041] Specifically, since each energy storage module includes multiple battery clusters connected in parallel, these clusters must be started sequentially in a specific order upon startup to improve the reliability of the control logic. This can be achieved by pre-setting the startup order of each battery cluster, or by determining the startup order based on characteristic state information such as voltage or SOC information. Therefore, based on the order of the battery clusters in the target energy storage module, the system controls the sequential connection of these clusters to the busbar unit, ensuring that each cluster is connected to the main circuit of the target energy storage module, thus enabling startup. It is understood that before startup, all battery clusters within the energy storage module are disconnected from the busbar unit, and both the first and second insulation detection units are in standby mode, meaning neither is operational.

[0042] Furthermore, during the process of connecting multiple battery clusters in the target energy storage module to the main circuit, the first insulation detection unit in the target energy storage module detects the first insulation state between the battery cluster and the combiner unit simultaneously with the connection of each battery cluster to the combiner unit. That is, before the target energy storage module is started, the battery cluster and the combiner unit are disconnected, and the first insulation detection unit within the combiner unit is not operational. After the target energy storage module receives the start command, the control module controls multiple battery clusters to connect to the combiner unit sequentially. After each battery cluster is connected to the combiner unit, the control module controls the first insulation detection unit to start and perform an insulation test to determine the first insulation state between the battery cluster connected to the combiner unit. Thus, during the start-up process of the battery clusters, both the operation of connecting the battery clusters to the main circuit of the target energy storage module and the detection of the insulation state between the battery clusters and the combiner unit are completed. It can be understood that after each battery cluster is connected to the combiner unit, a DC voltage exists within the combiner unit; therefore, the first insulation detection unit within the combiner unit can operate normally to detect the insulation state between the battery cluster and the combiner unit.

[0043] Furthermore, after each insulation test, the first insulation detection unit sends the first insulation status of the test to the control module. The control module then controls the connection between the tested battery cluster and the combiner unit based on the first insulation status. If the control module determines that the first insulation status is an insulation fault, it controls the tested battery cluster to disconnect from the combiner unit to avoid insulation risks in the entire circuit after the energy storage system is connected to the grid, thereby improving the safety of the energy storage system. Conversely, it controls the tested battery cluster to remain connected to the combiner unit.

[0044] Step S4: When the first insulation state between all battery clusters and the current collector in the target energy storage module is detected and it is determined that the connection between at least one battery cluster and the current collector is connected, the target energy storage module is controlled to connect to the power conversion module and the first insulation detection unit is controlled to detect the second insulation state between the target energy storage module and the power conversion module.

[0045] Specifically, before the energy storage system starts up, each energy storage module within the system is disconnected from the power conversion module. When controlling the target energy storage module to start up, the control module first connects multiple battery clusters within the target energy storage module to the combiner unit and detects the insulation status between each battery cluster and the combiner unit. Then, after completing the detection of the first insulation status between all battery clusters and the combiner unit in the target energy storage module and determining that the connection between at least one battery cluster and the combiner unit is continuous, the control module controls the target energy storage module to connect to the power conversion module. Immediately after the target energy storage module is connected to the power conversion module, the control module controls the first insulation detection unit to perform an insulation test to determine the second insulation status between the target energy storage module and the power conversion module. Thus, in the process of controlling the connection between the target energy storage module and the power conversion module, both the operation of connecting the combiner unit to the main circuit of the target energy storage module, enabling the target energy storage module to start up, and the detection of the insulation status between the target energy storage module and the power conversion module are completed.

[0046] Understandably, after completing the first insulation test of all battery clusters and combiner units in the target energy storage module, if the connection between each battery cluster and combiner unit in the target energy storage module is disconnected, it indicates that the target energy storage module has an insulation fault. Therefore, the startup of the target energy storage module is stopped, and the next energy storage module is started according to the startup sequence of the energy storage modules in the energy storage system.

[0047] Step S5: After the second insulation status between all energy storage modules and power conversion modules in the energy storage system has been detected and there are no insulation faults in the second insulation status, the power conversion module in the energy storage system is connected to the power grid, and the second insulation detection unit in the power conversion module is controlled to detect the third insulation status between the power conversion module and the power grid in the energy storage system.

[0048] Specifically, during the startup process of the energy storage system, the control module first controls multiple energy storage modules of the energy storage system to start sequentially. When each energy storage module starts, the startup operation is completed by executing the above steps S2-S4 to connect all energy storage modules in the energy storage system to the DC side of the power conversion module in parallel. After the second insulation state between all energy storage modules and the power conversion module in the energy storage system has been detected and there are no insulation faults in the second insulation state, the control module will control the power conversion module to connect to the grid, realizing the connection between the energy storage system and the grid. At the same time, immediately after the power conversion module is connected to the grid, the second insulation detection unit is started and an insulation test is performed to determine the third insulation state between the power conversion module and the grid. Thus, in the process of controlling the connection between the power conversion module and the grid, the operation of connecting the power conversion module to the main circuit of the energy storage system is completed, enabling the entire energy storage system to start up, and the insulation state between the power conversion module and the grid is also detected.

[0049] Step S6: If it is determined that there is no insulation fault in the third insulation state, it means that the insulation of the entire energy storage system is normal. Then, according to the charging and discharging control signal, the energy storage system outputs the target power to complete the charging or discharging between the energy storage system and the grid.

[0050] Therefore, after steps S1-S6, the insulation status of the entire energy storage system can be confirmed. At the same time, while completing the insulation detection of all components, a loop is formed between the main circuit of the energy storage system and the power grid, and the energy storage system has completed the startup process. Therefore, the energy storage system is ready for operation. Thus, in response to the needs of the power grid, the energy storage system can directly output the target power through the power conversion module. In addition, the control method that combines the insulation detection process of the energy storage system with the system startup process is simpler and more efficient than the method of controlling the insulation detection process and the system startup process separately.

[0051] According to the control method of the energy storage system of the present invention, after receiving the start command of the energy storage module, while controlling each battery cluster to connect to the combiner unit, the method controls the first insulation detection unit to detect the first insulation state between the battery cluster and the combiner unit; and when the detection of the first insulation state between all battery clusters and the combiner unit in the target energy storage module is completed and it is determined that the connection relationship between at least one battery cluster and the combiner unit is connected, the method controls the target energy storage module to connect to the power conversion module, and simultaneously controls the first insulation detection unit to detect the second insulation state between the target energy storage module and the power conversion module; and when the second insulation state between all energy storage modules and the power conversion module in the energy storage system is detected and the second insulation is achieved, the method controls the first insulation detection unit to detect the second insulation state between the target energy storage module and the power conversion module. After confirming that there are no insulation faults in the third insulation state, the power conversion module is connected to the power grid, and the second insulation detection unit is controlled to detect the third insulation state between the power conversion module and the power grid. Then, after confirming that there are no insulation faults in the third insulation state, the energy storage system can perform charging or discharging according to the charging and discharging control signal. In other words, this embodiment of the invention links the insulation detection process of the energy storage system with the system startup process. That is, while the components in the energy storage system are gradually connected, the insulation detection of the system is completed by controlling the first insulation detection unit or the second insulation detection unit. Thus, while realizing the insulation detection function of the energy storage system, the energy storage system also completes the startup process. Moreover, the insulation detection process is simpler and the efficiency of insulation detection is improved.

[0052] In some embodiments, existing energy storage systems directly enter the system operation state after completing insulation detection, without considering the inrush current caused by voltage differences between battery clusters. Therefore, this embodiment of the invention considers the operating conditions of the energy storage system and controls the sequential startup of multiple parallel battery clusters by sorting the voltage information of multiple battery clusters in the target energy storage module, thus avoiding current surges. Specifically, a first sorting of the voltage information of multiple battery clusters in the target energy storage module is determined according to the charge / discharge control signal; the contactors of the battery clusters corresponding to the battery clusters in the target energy storage module are sequentially closed according to the first sorting, so that the battery clusters are connected to the current collector; in response to the closing of each battery cluster contactor, the first insulation detection unit is controlled to detect the first insulation state between the corresponding battery cluster and the current collector. Thus, by controlling multiple battery clusters to start sequentially in a first order through the control module, the voltage difference between battery clusters can be balanced during the sequential startup process, avoiding damage to devices caused by inrush current due to excessive voltage differences between battery clusters; and the insulation detection between the battery cluster and the current collector is completed by the first insulation detection unit while each battery cluster is gradually connected to the current collector.

[0053] Specifically, refer to Figure 1As shown, multiple battery clusters are connected in parallel. The control module collects or summarizes the voltage information of all battery clusters within each energy storage module. If the voltage difference between battery clusters is too large, a large inrush current will be generated instantaneously when multiple battery clusters are connected to the main circuit of the energy storage system. Battery clusters with lower voltage are easily damaged by the inrush current. Therefore, to avoid the inrush current problem caused by the voltage difference between battery clusters, each battery cluster is equipped with a data acquisition unit to collect battery voltage information in real time and transmit the collected data to the control module. The control module summarizes the received voltage information. Then, the control module sorts the multiple battery clusters according to the charge / discharge control signal and the electrical information of each battery cluster in the target energy storage module to obtain a first order. Thus, the control module sends battery cluster start commands sequentially according to the first order to control the corresponding battery cluster contactor to engage, thereby connecting the battery cluster corresponding to the contactor to the main circuit of the target energy storage module. Therefore, by controlling the multiple battery clusters to start in sequence according to the first order, the battery clusters with lower voltage can be started first or last in the first order, so as to achieve the purpose of charging first or discharging later. This effectively balances the voltage difference between battery clusters to a certain extent and reduces the risk of device damage caused by surge current.

[0054] In some embodiments, when the charge / discharge control signal is a charging control signal, the voltages of multiple battery clusters in the target energy storage module are determined to be sorted from low to high as the first order. That is, when the energy storage system is charging, the control module will sort the voltages of each battery cluster in ascending order and send battery cluster start commands in ascending order so that the battery cluster contactors corresponding to each battery cluster will be engaged in sequence. Thus, compared with the battery clusters with higher voltage in the energy storage module, the battery clusters with lower voltage in the energy storage module can be connected to the main circuit of the energy storage system first for charging. Therefore, when the battery clusters with higher voltage in the energy storage module are connected to the main circuit of the energy storage system, the battery clusters with lower voltage in the energy storage module have already been charged with some energy, thereby reducing the voltage difference between the battery clusters with lower voltage and the battery clusters with higher voltage and reducing the risk of device damage caused by inrush current.

[0055] Alternatively, when the charge / discharge control signal is a discharge control signal, the voltages of multiple battery clusters in the target energy storage module are sorted from high to low as the first priority. That is, when the energy storage system discharges, the control module will sort the voltages of each battery cluster in descending order and send battery cluster start commands sequentially in descending order, so that the battery cluster contactors corresponding to each battery cluster will be engaged sequentially. Thus, compared to the battery clusters with lower voltages in the energy storage module, the battery clusters with higher voltages in the energy storage module can be connected to the main circuit of the energy storage system first to discharge. Therefore, when the battery clusters with lower voltages in the energy storage module are connected to the main circuit of the energy storage system, the battery clusters with higher voltages in the energy storage module have already released some energy, thereby reducing the voltage difference between the battery clusters with lower voltages and the battery clusters with higher voltages, and reducing the risk of device damage caused by inrush current.

[0056] In some embodiments, when it is determined that there is an insulation fault between the currently detected battery cluster and the combiner unit based on the first insulation state, the battery cluster contactor connected to the currently detected battery cluster is controlled to disconnect, so that the connection between the battery cluster and the combiner unit is disconnected. Then, the battery cluster contactor connected to the next battery cluster is controlled to close according to the first order, and the first insulation state between the next battery cluster and the combiner unit is detected.

[0057] Specifically, after each battery cluster contactor closes, the first insulation detection unit is activated to determine the insulation status between the closed battery cluster and the current collector. Therefore, when the insulation status detection is qualified, i.e., the first insulation status detected is no insulation fault, the control module continues to control the contactor of the next battery cluster to close according to the first sequence. Alternatively, when an insulation status abnormality is detected in a battery cluster, i.e., the first insulation status detected is an insulation fault, the first insulation detection unit can quickly locate the currently detected battery cluster according to the closing sequence of the battery clusters and upload the feedback information of the insulation fault of the currently detected battery cluster to the control module for fault alarm. The control module then sends a disconnect control signal to disconnect the contactor of the currently detected battery cluster, thereby disconnecting the battery cluster with insulation fault from the energy storage system. This ensures the normal operation of the energy storage system after startup. Subsequently, the control module continues to start the remaining battery clusters according to the first sequence until all battery clusters without insulation faults in the energy storage module are connected in parallel to the DC main circuit of the energy storage system, so as to realize the charging or discharging function of the energy storage system.

[0058] For example, see reference. Figure 1As shown, the first energy storage module 101 is taken as the target energy storage module. The first energy storage module 101 includes multiple battery clusters 2, which are: L1, L2, L3...Ln respectively. The battery cluster contactors corresponding to each battery cluster 2 are: KM1, KM2, KM3...KMn respectively. It can be understood that before the first energy storage module 101 is started, all battery cluster contactors are in the open state.Assuming the voltage information for each battery cluster 2 is U1, U2, U3…Un, the control module determines the first order of the voltage information of multiple battery clusters in the target energy storage module based on the charge / discharge control signal as U1, U2, U3…Un. Then, the control module controls the battery cluster contactor KM1 corresponding to battery cluster L1 to close according to the first order, connecting battery cluster L1 to the current collector 1. Simultaneously, after the battery cluster contactor KM1 closes, the control module immediately controls the first insulation detection unit 11 to start and perform insulation detection between battery cluster L1 and current collector 1 to obtain the first insulation state between the corresponding battery cluster L1 and current collector 1. This first insulation state is then sent to the control module, which then, based on the received first insulation state… The first insulation state determines whether there is an insulation fault between battery cluster L1 and current collector 1. If the first insulation state indicates no insulation fault, the control module controls the battery cluster contactor KM2 corresponding to battery cluster L2 to close according to the first sequence. Conversely, if the first insulation state indicates an insulation fault, the control module controls the battery cluster contactor KM1 to open, thereby cutting off the connection between battery cluster L1 and current collector 1. Then, it controls the battery cluster contactor KM2 corresponding to battery cluster L2 to close according to the first sequence. Further, the control module controls the battery cluster contactor KM2 corresponding to battery cluster L2 to close, so that battery cluster L2 is connected to current collector 1. At the same time, after the battery cluster contactor KM2 closes, the control module immediately controls the first insulation detection unit 11 to check the battery cluster L2. Insulation detection is performed between the battery cluster L2 and the current collector 1 to obtain the first insulation state between the corresponding battery cluster L2 and the current collector 1. This first insulation state is then sent to the control module. The control module determines whether there is an insulation fault between the battery cluster L2 and the current collector 1 based on the received first insulation state. If the first insulation state indicates no insulation fault, the control module controls the battery cluster contactor KM3 corresponding to battery cluster L3 to close according to the first sequence. Conversely, if the first insulation state indicates an insulation fault, the control module controls the battery cluster contactor KM2 to open, thus disconnecting the battery cluster L2 from the current collector 1. Then, it controls the battery cluster contactor KM3 corresponding to battery cluster L3 to close again according to the first sequence. This process continues until the control module controls the current collector L2 to close according to the first sequence. The battery cluster contactor KMn connected to the battery cluster Ln closes, connecting the battery cluster Ln to the combiner unit. Immediately after the battery cluster contactor Ln closes, the first insulation detection unit is controlled to perform insulation detection between the battery cluster Ln and the combiner unit 1 to obtain the first insulation state between the corresponding battery cluster Ln and the combiner unit 1. The first insulation state is then sent to the control module. The control module determines whether there is an insulation fault between the battery cluster Ln and the combiner unit 1 based on the received first insulation state. If the first insulation state indicates no insulation fault, the battery cluster contactor KMn remains closed. Conversely, if the first insulation state indicates an insulation fault, the control module controls the battery cluster contactor KMn to open, thereby disconnecting the battery cluster Ln from the combiner unit.At this point, the first energy storage module 101 has completed the startup operation, and during the startup process, it has also completed the detection between each battery cluster and the combiner unit.

[0059] Similarly, the startup and insulation testing of other energy storage modules within the energy storage system are also achieved through the above process, which will not be elaborated upon further.

[0060] In some embodiments, after the first insulation state between all battery clusters and the combiner unit in the target energy storage module is detected and it is determined that the first insulation state between at least one battery cluster and the combiner unit is without insulation fault, the isolating switch of the combiner unit in the target energy storage module is controlled to close, and the first insulation detection unit is controlled to detect the second insulation state between the target energy storage module and the power conversion module.

[0061] Specifically, refer to Figure 1 As shown, one side of the current collector unit 1 in each energy storage module is connected to the battery cluster via a battery cluster contactor, and the other side of the current collector unit 1 is connected to the power conversion module 20 via an isolating switch Q1. Before the energy storage module starts, the isolating switch in each energy storage module is in the open state. After detecting the first insulation state between all battery clusters and current collector units in the target energy storage module and determining that at least one battery cluster has no insulation fault (i.e., all battery clusters without insulation faults in the target energy storage module are connected in parallel to the main circuit of the energy storage system), the isolating switch Q1 is closed. Simultaneously, the first insulation detection unit is controlled to detect the second insulation state between the target energy storage module and the power conversion module, for example... Figure 1 The diagram shows the insulation status between the disconnector Q1 and the DC-side circuit breaker QF2. Therefore, when the disconnector Q1 is closed, the operation of connecting the combiner unit to the main circuit of the target energy storage module is completed, allowing the target energy storage module to connect to the main circuit of the energy storage system to the power grid. Simultaneously, the insulation status between the combiner unit 1 and the power conversion module 20 is also detected. Similarly, the above operation is performed when each energy storage module starts up, so that all energy storage modules in the energy storage system are connected in parallel to the DC side of the power conversion module.

[0062] In some embodiments, after the second insulation state between all energy storage modules and the power conversion module in the energy storage system has been detected and there are no insulation faults in the second insulation state, the AC side circuit breaker of the power conversion module connected to the power grid is closed, and the second insulation detection unit is controlled to detect the third insulation state between the AC side of the power conversion module and the power grid.

[0063] Specifically, refer to Figure 1As shown, the side of the power conversion module 20 connected to the grid has an AC side circuit breaker QF1, which is open before the power conversion module 20 is connected to the grid. When the second insulation state between all energy storage modules and the power conversion module in the energy storage system has been detected—that is, for all energy storage modules in the energy storage system, except for those with insulation faults between all battery clusters and combiner units—and all second insulation states are free of insulation faults, the control module controls the AC side circuit breaker QF1 to close and controls the second insulation detection unit 5 to detect the third insulation state between the AC side of the power conversion module and the grid. Figure 1 The insulation status of the AC side circuit breaker QF1 to the grid is shown in the figure. Thus, after the AC side circuit breaker QF1 is closed, the insulation status of the AC side of the power conversion module is detected at the same time as the power conversion module 20 is connected to the grid. This avoids the risk of insulation reduction in the local distribution network, or even breakdown or short circuit, caused by introducing insulation faults into the grid during the connection of the energy storage system and the grid.

[0064] In some embodiments, before the AC side circuit breaker connected to the power grid in the control power conversion module is closed, the control module controls the DC side circuit breaker in the power conversion module used to connect all energy storage modules to close, and controls the second insulation detection unit to detect the fourth insulation state between the DC side of the power conversion module and all energy storage modules, and determines that the fourth insulation state is no insulation fault.

[0065] Specifically, refer to Figure 1 As shown, the side of the power conversion module 20 connected to the energy storage module 10 has a DC-side circuit breaker QF2. Before the power conversion module 20 is started, the DC-side circuit breaker QF2 is open. When the second insulation state between all energy storage modules and the power conversion module in the energy storage system has been detected, that is, for all energy storage modules in the energy storage system, except for those energy storage modules with insulation faults between all battery clusters and combiner units, the second insulation state has been detected and there are no insulation faults, the control module considers all energy storage modules except those energy storage modules with insulation faults between all battery clusters and combiner units to be normal, and sends a power conversion start command to control the power conversion module 20 to start. After the power conversion module 20 starts, the control module first controls the DC-side circuit breaker QF2 to close, and then controls the fourth insulation state between the DC side and all energy storage modules detected by the second insulation detection unit 5, that is... Figure 1The insulation status between the DC-side circuit breaker QF2 and the AC-side circuit breaker QF1 shown in the figure means that, after controlling the DC-side circuit breaker QF2 to close and before controlling the AC circuit breaker QF1 to close, the insulation status of the DC side of the power conversion module 20 can be detected at the same time as the main circuit of the energy storage system is connected to the DC side of the power conversion module 20.

[0066] In some embodiments, when the fourth insulation state is determined to be an insulation fault, it indicates that there is an insulation abnormality in the power devices or other protection devices on the DC side of the power conversion module. Therefore, the control module controls the DC side circuit breaker to open and sends feedback information indicating that there is an insulation fault on the DC side of the power conversion module. The control module also controls all switching devices in the entire energy storage system to open based on the feedback information, thereby cutting off the DC voltage of the energy storage system. When the third insulation state is determined to be an insulation fault, the control module controls the AC side circuit breaker to open and sends feedback information indicating that there is an insulation fault on the AC side of the power conversion module. The control module also controls all switching devices in the entire energy storage system to open based on the feedback information, thereby cutting off the DC voltage of the energy storage system.

[0067] In some embodiments, when a portion of the energy storage modules in a plurality of energy storage modules are in a second insulation state of insulation fault, the plurality of energy storage modules are disconnected from the power conversion module, and an insulation fault is reported in the energy storage modules. That is, when a portion of the energy storage modules in a plurality of energy storage modules are in an insulation state, it indicates that the energy storage modules that report insulation faults have insulation abnormalities or that the energy storage modules that do not report insulation faults have insulation abnormalities. For example, a fault in the first insulation detection unit in the energy storage module that reports insulation faults causes the second insulation state to be in an insulation fault state, while the first insulation detection unit in the energy storage module that does not report insulation faults is normal, or a fault in the first insulation detection unit in the energy storage module that does not report insulation faults causes the second insulation state to be in an insulation fault state, while the first insulation detection unit in the energy storage module that reports insulation faults is normal. Therefore, to avoid the risk of abnormality after the energy storage system is started, the isolating switch in each energy storage module is disconnected or all switching devices in each energy storage module are disconnected, thereby cutting off the connection of all energy storage modules to the main circuit of the energy storage system.

[0068] Alternatively, if multiple energy storage modules exhibit insulation faults in their second insulation state, the system disconnects these modules from the power conversion module and reports an insulation fault on the DC side of the power conversion module. In other words, if multiple energy storage modules exhibit insulation faults, it indicates an insulation fault in the line between the combiner unit and the DC side of the power conversion module. Therefore, the isolating switch in each energy storage module is disconnected, or all switching devices in each energy storage module are disconnected, thereby severing the connection of all energy storage modules to the main circuit of the energy storage system.

[0069] In some embodiments, a start command and a charge / discharge control signal for starting the energy storage system are received; the total voltage information of each energy storage module in the energy storage system is obtained; a second order is determined based on the charge / discharge control signal and the total voltage information of each energy storage module; and start commands for starting the energy storage modules are issued sequentially according to the second order.

[0070] Specifically, refer to Figure 1 As shown, multiple energy storage modules are connected in parallel. To avoid inrush current issues caused by voltage differences between the energy storage modules, the control module summarizes the total voltage of each energy storage module 10 and sorts the modules according to the charge / discharge control signal and the total voltage information of each module to obtain a second order. The control module then sends start-up commands to the energy storage modules sequentially according to this second order, controlling the corresponding modules to connect to the DC main circuit of the energy storage system. Therefore, by starting the energy storage modules sequentially according to the second order, the module with the lower total voltage can be started first or last, achieving the purpose of charging first or discharging later. This effectively balances the voltage difference between the energy storage modules to a certain extent, reducing the risk of device damage caused by inrush current.

[0071] For example, see reference. Figure 2 As shown, the energy storage system 100 includes a first energy storage module 101 and a second energy storage module 102. Assuming that the second order determined by the control module based on the charge and discharge control signal and the total voltage information of each energy storage module is: first energy storage module 101, second energy storage module 102, then the control module first sends a start command to the first energy storage module 101 to control the first energy storage module 101 to start. After the first energy storage module 101 starts, the control module then sends a start command to the first energy storage module 102 to control the first energy storage module 102 to start.

[0072] In some embodiments, when the charge / discharge control signal is a charging control signal, the order of the total voltage of multiple energy storage modules in the energy storage system from low to high is determined as the second order. That is, when the energy storage system is charging, the control module will sort the total voltage of each energy storage module in ascending order and send the start command of the energy storage module in ascending order so that the corresponding energy storage module can be connected to the DC main circuit of the energy storage system. Thus, compared with the energy storage module with a higher total voltage in the energy storage system, the energy storage module with a lower total voltage in the energy storage system can be connected to the main circuit of the energy storage system first to be charged. Thus, when the energy storage module with a higher total voltage in the energy storage system is connected to the main circuit of the energy storage system, the energy storage module with a lower total voltage in the energy storage system has already been charged with some energy, thereby reducing the voltage difference between the energy storage modules and reducing the risk of device damage caused by inrush current.

[0073] Alternatively, when the charge / discharge control signal is a discharge control signal, the second order is determined by ranking the total voltage of multiple energy storage modules in the energy storage system from high to low. That is, when the energy storage system discharges, the control module will sort the total voltage of each energy storage module in descending order and send start commands to the energy storage modules in descending order so that the corresponding energy storage modules can be connected to the DC main circuit of the energy storage system. Thus, compared with the energy storage modules with lower total voltage in the energy storage system, the energy storage modules with higher total voltage in the energy storage system can be connected to the main circuit of the energy storage system first to discharge. Thus, when the energy storage modules with lower total voltage in the energy storage system are connected to the main circuit of the energy storage system, the energy storage modules with higher total voltage in the energy storage system have already released some electrical energy, thereby reducing the voltage difference between the energy storage modules and reducing the risk of device damage caused by inrush current.

[0074] In some embodiments, after the second insulation state between all energy storage modules and power conversion modules has been detected and there are no insulation faults in the second insulation state, the first insulation detection unit is controlled to shut down.

[0075] Specifically, after each battery cluster contactor closes, the disconnect switch in the combiner unit remains open, so the energy storage module is not yet connected to the power conversion module. Therefore, only the first insulation detection unit performs insulation detection within the energy storage system. Furthermore, after insulation detection is completed in a certain energy storage module, the first insulation detection unit in that module is first disconnected from the DC main circuit of the energy storage system. At this point, there are no insulation detection units in the energy storage system. Then, the control module controls the next energy storage module to start according to the module startup sequence, and the first insulation detection unit in the next energy storage module performs the detection. This cycle repeats, ensuring that during the startup of each energy storage module, only one insulation detection unit is always active within the energy storage system, performing tests to check the insulation status of the battery clusters and combiner units within the corresponding energy storage module. Furthermore, since the corresponding first insulation detection unit is shut down after each energy storage module completes its insulation test, there are no insulation detection units in the energy storage system when all energy storage modules are connected in parallel to the DC side of the power conversion module. Therefore, after confirming that all energy storage modules are free of insulation faults, the power conversion module is started, and the second insulation detection unit is controlled to perform insulation tests to check the insulation status within the power conversion module. Thus, during the startup process of the energy storage system, only one insulation detection unit is always operational within the system at any given time, thereby avoiding inaccurate insulation detection caused by mutual interference between multiple insulation detection circuits.

[0076] Understandably, the second insulation detection unit remains operational during the operation of the energy storage system to detect the insulation status of the system and ensure insulation testing during operation.

[0077] A second aspect of the present invention provides an energy storage control system, such as... Figure 3 As shown, the energy storage control system 50 includes at least one processor 51 and a memory 52 communicatively connected to the at least one processor 51.

[0078] The memory 52 stores a computer program that can be executed by at least one processor 51. When the at least one processor 51 executes the computer program, it implements the control method of the energy storage system provided in the above embodiments.

[0079] According to the energy storage control system 50 of the present invention, the processor 52 executes the control method of the energy storage system provided in the above embodiment, which can realize the start-up of the energy storage system while completing the insulation detection function, and can improve the efficiency of insulation detection.

[0080] In some embodiments, such as Figure 1 As shown, the control module 30 includes a battery manager 3, a bus control unit 12, a power control unit 6, and a field control unit 31.

[0081] The battery manager 3 is located between each battery cluster 2 and the corresponding busbar unit 1. The battery manager 3 is used to acquire the voltage information of each battery cluster 2, control the closing of the battery cluster contactor corresponding to each battery cluster 2, and control the connection relationship between the battery cluster 2 and the busbar unit 1 based on the first insulation state. When the first insulation state is faulty, the connection relationship between the battery cluster 2 and the busbar unit 1 is disconnected; when the first insulation state is fault-free, the connection relationship between the battery cluster 2 and the busbar unit 1 is connected.

[0082] The combiner control unit 12 is disposed within the combiner unit 1. The combiner control unit 12 is communicatively connected to the first insulation detection unit 11, the disconnect switch Q1, and each battery manager 3 in the combiner unit 1. The combiner control unit 12 is used to receive the start command and charge / discharge control signal of the corresponding energy storage module 10, and according to the order of the charge / discharge control signal and the voltage information of the multiple battery clusters 2 in the corresponding energy storage module 10, it controls the multiple battery clusters 2 to connect to the combiner unit 1 in sequence. At the same time as each battery cluster 2 connects to the combiner unit 1, it controls the first insulation detection unit 11 to detect the first insulation state between the battery cluster 2 and the combiner unit 1. When the detection of the first insulation state between all battery clusters 2 in the corresponding energy storage module 10 and the combiner unit 1 is completed and it is determined that the connection relationship between at least one battery cluster 2 and the combiner unit 1 is connected, it controls the disconnect switch Q1 to close and controls the first insulation detection unit 11 to detect the second insulation state between the corresponding energy storage module 10 and the power conversion module 20.

[0083] The power control unit 6 is installed in the power conversion module 20. The power control unit 6 is connected to the power device 4 and the second insulation detection unit 5. The power control unit 6 is used to control the power conversion module 20 in the energy storage system 100 to connect to the power grid after the second insulation state between all energy storage modules 10 and the power conversion module 20 has been detected and there is no insulation fault in the second insulation state. The power control unit 6 also controls the second insulation detection unit 5 in the power conversion module 20 to detect the third insulation state between the power conversion module 20 in the energy storage system 100 and the power grid.

[0084] The field control unit 31 is communicatively connected to each bus control unit 12 and power control unit 6. The field control unit 31 is used to receive the start command and charge / discharge control signal of the energy storage module 10, and after determining that there is no insulation fault in the third insulation state, it controls the energy storage system 100 to charge or discharge with the grid according to the charge / discharge control signal.

[0085] In some embodiments, the battery manager 3 includes a battery management control unit 13 and a DC-DC conversion unit 14 (not shown in the figure).

[0086] The battery management control unit 13 is communicatively connected to the corresponding combiner control unit 12; and the DC-DC conversion unit 14 is connected to the battery management control unit 13 and the corresponding battery cluster 2, and is used to perform DC voltage conversion on the corresponding battery cluster 2 to reduce the grid voltage difference.

[0087] In this embodiment, the battery manager 3 also includes protective devices such as a manual disconnect switch, a fuse, and a maintenance switch.

[0088] In this embodiment, the energy storage system 100 further includes a DC-DC conversion module. One end of the DC-DC conversion module is connected to multiple energy storage modules 10, another end of the DC-DC conversion module is connected to a power conversion module 20, and another end of the DC-DC conversion module is connected to a field control unit 31, for realizing the function of DC-DC conversion. If there is isolation between the DC-DC conversion module and the power conversion module 20, an insulation detection unit needs to be added to the DC-DC conversion module to perform insulation detection when the DC-DC conversion module starts up; or, if there is no isolation between the DC-DC conversion module and the power conversion module 20, the DC-DC conversion module can share a second insulation detection unit with the power conversion module 20 to perform insulation detection when the DC-DC conversion module starts up.

[0089] The following is for reference. Figure 1 and Figure 3 The control process of the energy storage system according to an embodiment of the present invention is described below, with specific steps as follows.

[0090] In step S3, the field control unit receives the start command for the energy storage system from the energy management system.

[0091] In step S4, the field control unit receives the charging and discharging control signal from the energy management system.

[0092] Step S5: Determine the charge / discharge control signal as a charging control signal. In response to the charging control signal, the field total control unit determines the total voltage of each energy storage module.

[0093] In step S6, the field control unit sends start commands to the energy storage modules in order of increasing total voltage to start each energy storage module. After receiving the start command, the bus control unit in each energy storage module sends start commands to the battery management control unit in order of increasing voltage for each battery cluster in the energy storage module. The battery management control unit then controls the corresponding battery cluster contactor to close.

[0094] Step S7: Determine that the charge / discharge control signal is a discharge control signal. In response to the discharge control signal, the field total control unit determines the total voltage of each energy storage module.

[0095] In step S8, the field control unit sends start commands to the energy storage modules in descending order of total voltage to start each energy storage module. After receiving the start command, the bus control unit in each energy storage module sends start commands to the battery management control unit in descending order of voltage of each battery cluster in the energy storage module. The battery management control unit then controls the corresponding battery cluster contactor to close.

[0096] In step S9, after each battery cluster contactor is closed, the bus control unit controls the corresponding first insulation detection unit to perform insulation detection. The first insulation detection unit sends the first insulation status of each detection to the bus control unit.

[0097] Step S10: The combiner control unit determines whether there is an insulation fault between each battery cluster and the combiner unit based on the first insulation state. Specifically, for battery clusters with insulation faults, step S11 is executed; for all battery clusters in the energy storage module, after the first insulation state between all battery clusters and the combiner unit in the target energy storage module has been detected and it has been determined that the first insulation state between at least one battery cluster and the combiner unit is free of insulation faults, step S12 is executed.

[0098] In step S11, the busbar control unit sends insulation fault feedback information to the battery management control unit and the field control unit corresponding to the currently detected battery cluster. After receiving the insulation fault feedback information, the battery management control unit controls the corresponding battery cluster contactor to disconnect and reports that there is an insulation fault in the currently detected battery cluster.

[0099] In step S12, the bus control unit controls the closing of the disconnect switch within the bus unit.

[0100] In step S13, the bus control unit controls the first insulation detection unit to perform insulation detection, and the first insulation detection unit sends the second insulation status of each detection to the bus control unit.

[0101] In step S14, the bus control unit in each energy storage module determines whether there is an insulation fault in each energy storage module based on the second insulation status.

[0102] Step S15: When the second insulation status between all energy storage modules and the power conversion module in the energy storage system has been detected and there are no insulation faults in the second insulation status, that is, after all energy storage modules are free of insulation faults, the field control unit sends a power conversion start command to the power control unit. The power control unit controls the DC side circuit breaker to close. At the same time, after the DC side circuit breaker closes, it controls the second insulation detection unit to perform insulation detection. The second insulation detection unit sends the detected fourth insulation status to the power control unit. After the power control unit determines that the fourth insulation status is free of insulation faults, it controls the AC side circuit breaker to close. At the same time, after the DC side circuit breaker closes, it controls the second insulation detection unit to perform insulation detection. The second insulation detection unit sends the detected third insulation status to the power control unit. After the power control unit determines that the third insulation status is free of insulation faults, it executes step S18.

[0103] Step S16: When there is an insulation fault in the second insulation state between some energy storage modules and the power conversion module in the energy storage system, each bus control unit controls all the switching devices in the corresponding energy storage module to disconnect and reports that there is a fault in the energy storage module.

[0104] Step S17: When there is an insulation fault in the second insulation state between all energy storage modules and the power conversion module in the energy storage system, each bus control unit controls all the switching devices in the corresponding energy storage module to disconnect and reports that there is an insulation fault on the DC side of the power conversion module.

[0105] Step S18: All insulation in the energy storage system passes the test, and the power conversion module responds to the target operating power.

[0106] In summary, the control method, control system, and energy storage system of the energy storage system according to embodiments of the present invention are based on... Figure 1The topology of the energy storage system 100 shown associates the insulation detection process with the system startup process. The insulation state of the system is detected during the closing sequence of the switching devices of each component. This achieves the insulation detection function while simultaneously completing the startup process. Compared to independently detecting the insulation state by controlling the connection or disconnection between components within the energy storage system, this embodiment combines the insulation detection process with the startup process. This eliminates the need for repeated control of the connection relationships between components, simplifying the insulation detection process and effectively improving efficiency. Furthermore, it eliminates the need for repeated opening and closing of switching devices, extending device lifespan. Considering the operating conditions of the energy storage system, it starts up sequentially from low to high battery voltage during charging and from high to low battery voltage during discharging. This balances the voltage between battery clusters, preventing excessive voltage differences between parallel battery clusters that could cause large instantaneous surge currents and damage devices.

[0107] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0108] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A control method for an energy storage system, characterized in that, The control method includes: It receives start-up commands and charge / discharge control signals from an energy storage module that includes multiple battery clusters and combiner units; Obtain the voltage information of each battery cluster in the target energy storage module; Based on the charging / discharging control signal and the order of voltage information of multiple battery clusters in the target energy storage module, the multiple battery clusters are sequentially connected to the combiner unit. Simultaneously, when each battery cluster is connected to the combiner unit, the first insulation detection unit in the target energy storage module detects the first insulation state between the battery cluster and the combiner unit. Based on the first insulation state, the connection between the battery cluster and the combiner unit is controlled. Wherein, if the first insulation state is an insulation fault, the connection between the battery cluster and the combiner unit is disconnected; if the first insulation state is no insulation fault, the connection between the battery cluster and the combiner unit is connected. When the first insulation state between all the battery clusters and the combiner unit in the target energy storage module is detected and it is determined that the connection between at least one battery cluster and the combiner unit is connected, the target energy storage module is controlled to connect to the power conversion module and the first insulation detection unit is controlled to detect the second insulation state between the target energy storage module and the power conversion module. After the second insulation state between all energy storage modules and the power conversion module in the energy storage system has been detected and there are no insulation faults in the second insulation state, the power conversion module in the energy storage system is connected to the power grid, and the second insulation detection unit in the power conversion module is controlled to detect the third insulation state between the power conversion module and the power grid in the energy storage system. Once it is determined that there is no insulation fault in the third insulation state, the energy storage system is controlled to charge or discharge with the power grid according to the charge / discharge control signal.

2. The control method for the energy storage system according to claim 1, characterized in that, Based on the order of the charge / discharge control signal and the voltage information of the multiple battery clusters in the target energy storage module, the multiple battery clusters are controlled to be connected to the current collector in sequence. Simultaneously, at the same time each battery cluster is connected to the current collector, the first insulation detection unit in the target energy storage module is controlled to detect the first insulation state between the battery cluster and the current collector, including: Based on the charge and discharge control signal, a first order of voltage information of multiple battery clusters in the target energy storage module is determined; The contactors of the battery clusters in the target energy storage module that are connected to the battery clusters are closed sequentially according to the first order, so that the battery clusters are connected to the combiner unit. In response to the closure of each of the battery cluster contactors, the first insulation detection unit is controlled to detect the first insulation state between the corresponding battery cluster and the busbar unit.

3. The control method for the energy storage system according to claim 2, characterized in that, Based on the charge / discharge control signal, a first order of voltage information of multiple battery clusters in the target energy storage module is determined, including: When the charge / discharge control signal is a charging control signal, the voltages of the multiple battery clusters in the target energy storage module are determined to be sorted from low to high as the first sorting. Alternatively, when the charge / discharge control signal is a discharge control signal, the voltages of the multiple battery clusters in the target energy storage module are determined to be sorted from high to low as the first sorting.

4. The control method for the energy storage system according to claim 2, characterized in that, The control method further includes: When it is determined that there is an insulation fault between the currently detected battery cluster and the current collector unit based on the first insulation state, the battery cluster contactor connected to the currently detected battery cluster is disconnected, so that the connection between the battery cluster and the current collector unit is disconnected. According to the first sorting, the contactor of the next battery cluster connected to it is closed, and the first insulation state between the next battery cluster and the bus unit is detected.

5. The control method for the energy storage system according to claim 1, characterized in that, When the first insulation state between all battery clusters and the combiner unit in the target energy storage module is detected and it is determined that the connection between at least one battery cluster and the combiner unit is continuous, the target energy storage module is controlled to connect to the power conversion module, and the first insulation detection unit is controlled to detect the second insulation state between the target energy storage module and the power conversion module, including: After completing the detection of the first insulation state between all the battery clusters and the combiner unit in the target energy storage module and determining that the first insulation state between at least one battery cluster and the combiner unit is without insulation fault, the isolation switch of the combiner unit in the target energy storage module is controlled to close, and the first insulation detection unit is controlled to detect the second insulation state between the target energy storage module and the power conversion module.

6. The control method for the energy storage system according to claim 1, characterized in that, After the second insulation state between all energy storage modules and the power conversion module in the energy storage system has been detected and no insulation faults are found in the second insulation state, the power conversion module in the energy storage system is connected to the power grid, and the second insulation detection unit within the power conversion module is controlled to detect the third insulation state between the power conversion module and the power grid in the energy storage system, including: After the second insulation state between all energy storage modules in the energy storage system and the power conversion module has been detected and there are no insulation faults in the second insulation state, the AC side circuit breaker in the power conversion module connected to the power grid is closed, and the second insulation detection unit is controlled to detect the third insulation state between the AC side of the power conversion module and the power grid.

7. The control method for the energy storage system according to claim 6, characterized in that, Before the AC side circuit breaker connected to the power grid in the power conversion module is closed, the control method further includes: The DC-side circuit breaker in the power conversion module used to connect all energy storage modules is closed, and the second insulation detection unit is controlled to detect the fourth insulation state between the DC side of the power conversion module and all energy storage modules, and the fourth insulation state is determined to be no insulation fault.

8. The control method for the energy storage system according to claim 7, characterized in that, The control method further includes: When the fourth insulation state is determined to be an insulation fault, the DC-side circuit breaker is controlled to open, and feedback information indicating an insulation fault on the DC side of the power conversion module is sent. When the third insulation state is determined to be an insulation fault, the AC side circuit breaker is controlled to open, and feedback information indicating an insulation fault on the AC side of the power conversion module is sent.

9. The control method for the energy storage system according to claim 1, characterized in that, The control method further includes: When a portion of the energy storage modules are in a second insulation state with an insulation fault, the system controls the multiple energy storage modules to disconnect from the power conversion module and reports that the energy storage modules have an insulation fault. Alternatively, if an insulation fault exists in the second insulation state of multiple energy storage modules, the multiple energy storage modules are disconnected from the power conversion module, and an insulation fault is reported on the DC side of the power conversion module.

10. The control method for the energy storage system according to claim 1, characterized in that, The control method further includes: Receives the start command and charge / discharge control signal to activate the energy storage system; Obtain the total voltage information of each energy storage module in the energy storage system; The second sorting is determined based on the charge / discharge control signal and the total voltage information of each energy storage module; Start-up commands to activate the energy storage modules are issued sequentially according to the second order.

11. The control method for an energy storage system according to claim 10, characterized in that, The second sorting is determined based on the charge / discharge control signal and the total voltage information of each energy storage module, including: When the charge / discharge control signal is a charge control signal, the order of the total voltage of the multiple energy storage modules in the energy storage system from low to high is determined as the second order. Alternatively, when the charge / discharge control signal is a discharge control signal, the order of the total voltage of the multiple energy storage modules in the energy storage system from high to low is determined as the second order.

12. The control method for the energy storage system according to any one of claims 1-11, characterized in that, After the second insulation state between all the energy storage modules and the power conversion module has been detected and there are no insulation faults in the second insulation state, the control method further includes: controlling the first insulation detection unit to shut down.

13. An energy storage control system, characterized in that, include: At least one processor; A memory that is communicatively connected to at least one of the processors; The memory stores a computer program that can be executed by at least one of the processors, and when the at least one processor executes the computer program, it implements the control method of the energy storage system according to any one of claims 1-12.

14. An energy storage system, characterized in that, include: At least one energy storage module, each energy storage module including a combiner unit and a plurality of battery clusters arranged in parallel, each battery cluster being connected to the combiner unit, and a battery cluster contactor being provided between each battery cluster and the combiner unit, the combiner unit including a first insulation detection unit and a disconnecting switch; A power conversion module, comprising a power device and a second insulation detection unit, wherein the DC side of the power device is connected to each of the current collectors, a disconnecting switch is disposed between the power device and the current collectors, and an AC side circuit breaker is disposed on the AC side of the power device; A control module, connected to the energy storage module and the power conversion module, is used to execute the control method of the energy storage system according to any one of claims 1-12.

15. The energy storage system according to claim 14, characterized in that, The power device is equipped with a DC-side circuit breaker on its DC side.

16. The energy storage system according to claim 14 or 15, characterized in that, The control module includes: A battery manager is configured between each battery cluster and its corresponding combiner unit. The battery manager is used to acquire voltage information of each battery cluster, control the closing of the battery cluster contactor corresponding to each battery cluster, and control the connection relationship between the battery cluster and the combiner unit based on the first insulation state. When the first insulation state is faulty, the connection relationship between the battery cluster and the combiner unit is disconnected; when the first insulation state is fault-free, the connection relationship between the battery cluster and the combiner unit is connected. A current control unit is disposed in the current combiner unit. The current control unit is communicatively connected to the first insulation detection unit, the disconnect switch and each battery manager in the current combiner unit. The current control unit is used to receive the start command and charge / discharge control signal of the corresponding energy storage module, and according to the order of the charge / discharge control signal and the voltage information of multiple battery clusters in the corresponding energy storage module, control multiple battery clusters to connect to the current combiner unit in sequence. While each battery cluster is connected to the current combiner unit, the current control unit controls the first insulation detection unit to detect the first insulation state between the battery cluster and the current combiner unit. When the detection of the first insulation state between all battery clusters in the corresponding energy storage module and the current combiner unit is completed and it is determined that the connection relationship between at least one battery cluster and the current combiner unit is connected, the current control unit controls the disconnect switch to close and controls the first insulation detection unit to detect the second insulation state between the corresponding energy storage module and the power conversion module. A power control unit is disposed in the power conversion module and connected to the power device and the second insulation detection unit. The power control unit is used to control the power conversion module in the energy storage system to connect to the power grid after the second insulation status between all energy storage modules and the power conversion module has been detected and there is no insulation fault in the second insulation status. The power control unit also controls the second insulation detection unit in the power conversion module to detect the third insulation status between the power conversion module in the energy storage system and the power grid. The field control unit is communicatively connected to each of the bus control units and the power control units. The field control unit is used to receive the start command and charge / discharge control signal of the energy storage module, and after determining that there is no insulation fault in the third insulation state, it controls the energy storage system to charge or discharge with the power grid according to the charge / discharge control signal.

17. The energy storage system according to claim 16, characterized in that, The battery manager includes: A battery management control unit, which is communicatively connected to a corresponding bus control unit; A DC-DC converter unit is connected to the battery management control unit and the corresponding battery cluster.

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