A management device of an energy storage system and a control method of an energy storage system

Abstract

The application discloses a kind of management device of energy storage system and a kind of control method of energy storage system, belong to energy storage system technical field, the device includes: N direct current control module, for respectively to the direct current loop of N battery cluster control;Power conversion module, for the output voltage of N direct current control module AC conversion and current control;Detection board with first control chip and second control chip, for by first control chip the operating parameter of each battery cluster is collected, and by first control chip each direct current control module is controlled;While by second control chip power conversion module is regulated and controlled, to N battery cluster is parallel off-grid control.The device can solve the technical problems of poor safety, strong coupling interference between battery clusters, long control response time and high line loss in the prior art when managing multiple battery clusters in the energy storage system.

Description

Technical Field

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

[0002] In existing energy storage systems, the output voltages of multiple battery clusters are typically connected in parallel on the DC side when fed into the grid. That is, in the existing energy storage architecture, each battery cluster is connected to a high-voltage box via cables. Then, multiple high-voltage boxes transmit the DC power output from each battery cluster to the PCS (Power Conversion System) through a combiner cabinet. Finally, a transformer feeds the AC power output from the PCS into the grid through the high-voltage cabinet.

[0003] However, in this energy storage architecture, the parallel connection of multiple battery clusters at the DC bus not only poses significant safety risks but also results in strong coupling interference between the clusters. Furthermore, in this architecture, the Battery Control Unit (BCU) in the high-voltage box monitors the operating parameters of the battery clusters, while the Power Conversion System (PCS) handles power conversion for each cluster. The communication time between the BCU and PCS is substantial, leading to lag and delay in the control response time of the energy storage system. Additionally, this architecture requires the laying of numerous power cables, resulting in high line losses and significant construction difficulties. Currently, there is no effective solution to this technical problem. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a management device for an energy storage system and a control method for an energy storage system, so as to solve the technical problems of poor security, strong coupling interference between battery clusters, long control response time, and high line loss in the prior art when managing multiple battery clusters in an energy storage system. The specific solution is as follows: To address the aforementioned technical problems, the present invention provides a management device for an energy storage system, comprising: N DC control modules are connected one-to-one with N battery clusters to control the DC circuits of the N battery clusters respectively. The power conversion module is connected to all N DC control modules and is used to perform AC conversion and current conversion control on the output voltage of the N DC control modules. A detection board equipped with a first control chip and a second control chip is connected to the power conversion module and the N DC control modules. It is used to collect the operating parameters of each battery cluster through the first control chip and to control each DC control module through the first control chip. At the same time, it uses the second control chip to regulate the power conversion module to control the N battery clusters for grid connection and disconnection.

[0005] Preferably, the DC control module includes: a first filter module, a DC fuse, a positive relay, and a negative relay; Wherein, the first end and the second end of the first filter module are connected to the positive and negative terminals of the battery cluster, respectively; the third end of the first filter module is connected to the first end of the DC fuse; the second end of the DC fuse is connected to the first end of the positive relay; and the fourth end of the first filter module is connected to the first end of the negative relay. Accordingly, the second terminal of the positive relay and the second terminal of the negative relay are respectively the first line connection terminal and the second line connection terminal of the DC control module.

[0006] Preferred options also include: The circulating current balancing module is used to balance and control the circulating current generated among the N battery clusters.

[0007] Preferably, the circulating equalization module includes: N-1 circulating current equalization units; each circulating current equalization unit includes a circulating current relay and a circulating current resistor, the second terminal of the circulating current relay and the first terminal of the circulating current resistor are connected, the first terminal of the circulating current relay is the first terminal of the circulating current equalization unit, and the second terminal of the circulating current resistor is the second terminal of the circulating current equalization unit; the first terminal and the second terminal of the circulating current equalization unit are respectively connected to the first terminal of the positive relay in two adjacent DC control modules; Alternatively, N DC / DC conversion units are used to perform DC conversion on the output voltages of the N DC control modules respectively.

[0008] Preferably, the power conversion module includes: a DC switch with pre-charge function, a power board, a second filter module, a first contactor, a second contactor, a third contactor, a first fuse, a second fuse, a third fuse, a surge protector, and an AC switch; The first terminal of the DC switch is connected to a common terminal formed by the first line connection terminals of the N DC control modules; the second terminal of the DC switch is connected to a common terminal formed by the second line connection terminals of the N DC control modules; the control terminal of the DC switch is connected to the first control chip; the third and fourth terminals of the DC switch are respectively connected to the first and second terminals of the power board; the third, fourth, and fifth terminals of the power board are respectively connected to the first, second, and third terminals of the second filter module; and the fourth, fifth, and sixth terminals of the second filter module are respectively connected to the first terminals of the first contactor, the first terminals of the second contactor, and the first terminals of the third contactor. The second terminals of the first contactor, the second contactor, and the third contactor are respectively connected to the first terminals of the first fuse, the second fuse, and the third fuse. The second terminals of the first fuse, the second fuse, and the third fuse are respectively connected to the first, second, and third terminals of the surge protector. The fourth terminal of the surge protector is grounded. The second terminals of the first fuse, the second fuse, and the third fuse are also respectively connected to the first, second, and third terminals of the AC switch. The fourth, fifth, and sixth terminals of the AC switch are respectively connected to the power grid.

[0009] Preferably, the DC switch includes: a first switch, a pre-charge relay, and a pre-charge resistor; Wherein, the first terminal and the second terminal of the first switch are respectively the first terminal and the second terminal of the DC switch, the control terminal of the first switch is connected to the first control chip, and the third terminal and the fourth terminal of the first switch are respectively the third terminal and the fourth terminal of the DC switch; the first terminal of the precharge relay is connected to the first terminal of the positive relay in the DC control module, the second terminal of the precharge relay is connected to the first terminal of the precharge resistor, and the second terminal of the precharge resistor is connected to the third terminal of the first switch.

[0010] To address the aforementioned technical problems, the present invention also provides a control method for an energy storage system, applied to a detection board in a management device for an energy storage system disclosed above, comprising: When N battery clusters in the energy storage system need to perform grid connection operations, the operating parameters of the N battery clusters are detected by the first control chip; the management device is installed in the energy storage system. When it is determined from the operating parameters of the N battery clusters that the line connections of the N DC control modules are all normal and the maximum inter-cluster voltage difference of the N battery clusters is less than the preset inter-cluster voltage difference, a pre-charge command is sent to the power conversion module. When the power conversion module has completed the pre-charge, the output voltage of the power conversion module is adjusted by the second control chip so that the N battery clusters can perform grid connection operation. When N battery clusters need to perform off-grid operation, the N battery clusters are controlled to stop performing charging and discharging operations, and the power conversion module is controlled by the second control chip to perform a power reduction operation. When the output power of the power conversion module is less than a preset power value, the line connection with the N battery clusters is disconnected, and the off-grid operation of the N battery clusters is completed synchronously.

[0011] Preferably, when it is determined from the operating parameters of the N battery clusters that the line connections of the N DC control modules are all normal and the maximum inter-cluster voltage difference of the N battery clusters is less than the preset inter-cluster voltage difference, a pre-charge command is issued to the power conversion module. When the power conversion module has completed pre-charging, the output voltage of the power conversion module is adjusted by the second control chip to enable the N battery clusters to perform grid connection operation, including: Determine whether the circuit connections of the N DC control modules are all normal based on the operating parameters of the N battery clusters; If so, determine whether the maximum inter-cluster pressure difference of the N battery clusters is less than the preset inter-cluster pressure difference; If not, the output voltages of the N battery clusters are subjected to current sharing processing until the maximum inter-cluster voltage difference of the N battery clusters is less than the preset inter-cluster voltage difference; If so, the power conversion module is determined to meet the conditions for applying high voltage. When a grid connection command is received from the BAU or EMS in the energy storage system, the power conversion module is pre-charged, and when the power conversion module is pre-charged, the output voltage of the power conversion module is regulated by the second control chip. When the output voltage of the power conversion module is consistent with the output voltage of the power grid, N battery clusters are connected to the power grid.

[0012] Preferably, controlling the N battery clusters to stop charging and discharging operations, and controlling the power conversion module to perform a power reduction operation through the second control chip, so as to disconnect the line connection with the N battery clusters when the output power of the power conversion module is less than a preset power value, and simultaneously complete the off-grid operation of the N battery clusters, including: Control N battery clusters to stop performing charging and discharging operations; The second control chip controls the power conversion module to perform a power reduction operation, and after a first preset time delay, it is determined whether the output power of the power conversion module is less than the preset power value. If not, the power conversion module is determined to be faulty, and the DC switch in the power conversion module is disconnected; If so, disconnect the line connection with each of the battery clusters and simultaneously complete the off-grid operation of N battery clusters.

[0013] Preferred options also include: Determine whether the energy storage system has triggered a preset alarm condition; If so, the power conversion module is controlled by the second control chip to perform a power reduction operation, and after a second preset time delay, it is determined whether the output power of the power conversion module is less than the preset power value; If not, disconnect the DC switch in the power conversion module and display the corresponding warning message.

[0014] Beneficial Effects: The energy storage system management device provided by this invention includes N DC control modules, one power conversion module, and one detection board. The N DC control modules are connected one-to-one with N battery clusters, the power conversion module is connected to all N DC modules, and the detection board is connected to both the power conversion module and the N DC control modules. The first control chip in the detection board can collect the operating parameters of each battery cluster and control each DC control module accordingly. Simultaneously, the second control chip in the detection board can regulate the power conversion module, thereby achieving the purpose of grid-connected and off-grid control of the N battery clusters.

[0015] In this configuration, because the battery clusters are completely isolated on the DC side, not only are coupling interference, inter-cluster circulating current, and fault transmission between battery clusters eliminated, but the safety and reliability of the energy storage system during operation are also further improved. Furthermore, since the first control chip in the detection board essentially takes over the control logic of the BCU in the high-voltage box of the original energy storage architecture, and the second control chip in the detection board essentially takes over the control logic of the PCS in the original energy storage architecture, when the first and second control chips are placed on the same detection board, they do not need to use long communication lines to communicate. Therefore, this configuration avoids the problem of control response time lag and delay in the energy storage system. In addition, compared with existing energy storage architectures, this energy storage architecture does not require a high-voltage box or PCS for each battery cluster, thus avoiding the laying of a large number of power cables in the energy storage system, thereby significantly reducing the line losses of the energy storage system.

[0016] Correspondingly, the control method for an energy storage system provided by the present invention also has the above-mentioned beneficial effects. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0018] Figure 1 This is a structural diagram of a management device for an energy storage system provided in an embodiment of the present invention; Figure 2 This is a structural diagram of a management device for another energy storage system provided in an embodiment of the present invention; Figure 3 A flowchart of a control method for an energy storage system provided in an embodiment of the present invention; Figure 4 This is a flowchart illustrating the grid connection operation of an energy storage system provided in an embodiment of the present invention. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Please see Figure 1 , Figure 1 This is a structural diagram of a management device for an energy storage system provided in an embodiment of the present invention. The device includes: N DC control modules 11 are connected one-to-one with N battery clusters to control the DC circuits of the N battery clusters respectively. The power conversion module 12 is connected to N DC control modules 11 and is used to perform AC conversion and current conversion control on the output voltage of the N DC control modules 11. The detection board 13, equipped with a first control chip and a second control chip, is connected to the power conversion module 12 and N DC control modules 11. It is used to collect the operating parameters of each battery cluster through the first control chip and control each DC control module 11 through the first control chip. At the same time, it uses the second control chip to regulate the power conversion module 12 to control the N battery clusters for grid connection and disconnection.

[0021] In this embodiment, a management device for an energy storage system is provided. This device can solve the technical problems of poor security, strong coupling interference between battery clusters, long control response time, and high line loss in the prior art when managing multiple battery clusters in an energy storage system.

[0022] The energy storage system management device provided in this embodiment includes N DC control modules 11, one power conversion module 12, and one detection board 13. The N DC control modules 11 are connected one-to-one with the N battery clusters, the power conversion module 12 is connected to all N DC control modules 11, and the detection board 13 is connected to both the power conversion module 12 and the N DC control modules 11. Functionally, the DC control modules 11 are equivalent to the high-voltage box in the energy storage system, while the power conversion module 12 is equivalent to the PCS (Power Control System) in the energy storage system.

[0023] It should be noted that in practical applications, once the management device of the energy storage system described in this application is connected to the back end of N battery clusters, it is no longer necessary to set up corresponding high-voltage boxes and PCS for each battery cluster in the energy storage system.

[0024] In this embodiment, a first control chip and a second control chip are installed in the detection board 13. The first control chip internally runs the BCU's algorithm logic; that is, it calculates the SOC (State of Charge), SOH (State of Health), overvoltage, and undervoltage of each battery cluster based on their operating parameters. The second control chip controls the power conversion module 12, which converts the high-voltage DC output from each battery cluster into AC power.

[0025] In this configuration, the first control chip essentially functions as an embedded BCU in the energy storage system. It can directly collect data such as the total voltage, cluster current, and insulation resistance of each battery cluster, eliminating the need for an external BCU. In practical applications, the first control chip can control each DC control module 11 based on the collected operating parameters of each battery cluster. If the first control chip detects a fault in a battery cluster, it can disconnect the faulty cluster from the energy storage system via the DC control module 11 connected to that cluster, further enhancing the safety and reliability of the energy storage system during operation.

[0026] It should be noted that in practical applications, the first control chip can be set as an MCU (Micro Controller Unit) with an ARM architecture, and the second control chip can be set as a DSP (Digital Signal Processor).

[0027] In this embodiment, since the first control chip and the second control chip are integrated on the same detection board 13, compared with the existing energy storage system architecture, when the first control chip and the second control chip need to interact with each other, there is no need to use an external low-speed communication link for data interaction. Data interaction can be carried out directly using the hardware connection lines inside the detection board 13. In this way, the control response time in the traditional energy storage architecture can be shortened from hundreds of milliseconds to microseconds.

[0028] Furthermore, in this embodiment, by eliminating the independent high-voltage box and DC combiner cabinet in the original energy storage architecture, the number of devices and cable connection points in the energy storage system can be reduced, thereby further improving the power density of the energy storage system. Simultaneously, since each battery cluster is completely isolated on the DC side, the inter-cluster voltage needs to be adjusted before each battery cluster can be connected to the grid, thus avoiding the "weakest link" effect in the energy storage system. Moreover, under this architecture, the capacity decay of a single battery cluster only affects the performance of that cluster, having a smaller impact on the entire energy storage system. This not only increases the lifespan of the entire energy storage system but also increases the total charge and discharge capacity throughout its lifespan.

[0029] Clearly, in the energy storage architecture provided in this embodiment, since the battery clusters are completely isolated on the DC side, this not only eliminates coupling interference, inter-cluster circulating current, and fault transmission between battery clusters, but also further improves the safety and reliability of the energy storage system during operation. Furthermore, because the first control chip in the detection board essentially takes over the control logic of the BCU in the high-voltage box of the original energy storage architecture, and the second control chip in the detection board essentially takes over the control logic of the PCS in the original energy storage architecture, when the first and second control chips are placed on the same detection board, they do not need to use long communication lines to communicate. Therefore, this arrangement avoids the problem of lag and delay in the control response time of the energy storage system. In addition, compared with existing energy storage architectures, this energy storage architecture does not require a high-voltage box or PCS for each battery cluster, thus avoiding the laying of a large number of power cables in the energy storage system, thereby significantly reducing the line losses of the energy storage system.

[0030] Based on the above embodiments, this embodiment further explains and optimizes the technical solution. Please refer to [link / reference]. Figure 2 , Figure 2 This is a structural diagram of a management device for another energy storage system provided in an embodiment of the present invention. To enable those skilled in the art to better understand the implementation principle of the present invention, in... Figure 2 The management device shown only has two battery clusters. Furthermore, the internal structure of the DC control module 11 is described as follows: Figure 2 The first DC control module 11 shown is used as an example for specific explanation. Additionally, it should be noted that... Figure 2 All the components shown are housed in the same enclosure. This arrangement not only reduces the number of cables required for on-site installation of the energy storage system, but also further reduces line losses in the energy storage system.

[0031] In a preferred embodiment, the DC control module 11 includes: a first filter module F11, a DC fuse FU10, a positive relay KM11, and a negative relay KM12; Among them, the first end and the second end of the first filter module F11 are connected to the positive terminal BAT+ and the negative terminal BAT- of the battery cluster, respectively; the third end of the first filter module F11 is connected to the first end of the DC fuse FU10; the second end of the DC fuse FU10 is connected to the first end of the positive relay KM11; and the fourth end of the first filter module F11 is connected to the first end of the negative relay KM12. Correspondingly, the second terminal of the positive relay KM11 and the second terminal of the negative relay KM12 are the first line connection terminal and the second line connection terminal of the DC control module 11, respectively.

[0032] This embodiment provides a detailed description of the internal structure of the DC control module 11. The first filter module F11 can be a DC filter inductor, primarily used to filter out low-frequency harmonics in the DC circuit and improve electromagnetic interference in the line. The DC fuse FU10 is installed on the main positive circuit, mainly used to protect electronic components in the circuit when a short circuit occurs. If design cost is not a concern, a DC fuse FU10 can also be added to the main negative circuit. The positive relay KM11 and negative relay KM12 are mainly used to control the closing and opening of the charging and discharging main circuit during grid-connected / off-grid switching, and to forcibly disconnect the lines in the DC main circuit in the event of an emergency fault in the energy storage system.

[0033] Furthermore, in practical applications, a current detection unit can be set in the DC control module 11 to sample the current in the DC main circuit. Specifically, the current detection unit can be set as a Hall current sensor and / or a shunt. Figure 2The circuit diagram shown shows that a Hall current sensor (HALL) is installed in the DC control module 11.

[0034] When the current detection unit detects current in the DC main circuit, it sends the current sampling result to the first control chip A. This allows the first control chip A to calculate the SOC of the battery cluster and provide overcurrent protection. If the first control chip A detects an overcurrent, short circuit, or low insulation fault in a battery cluster based on the collected operating parameters, it can disconnect the positive relay KM11 and negative relay KM12 connected to that battery cluster, thereby isolating the faulty battery cluster and ensuring the normal operation of other battery clusters. It should be noted that... Figure 2 In the diagram, B represents the second control chip in the detection board 13.

[0035] Clearly, the technical solution provided in this embodiment allows for independent filtering, short-circuit protection, and on / off control of each battery cluster.

[0036] In a preferred embodiment, the above-described apparatus further includes: The circulating current equalization module is used to equalize and control the circulating current generated among N battery clusters.

[0037] In this embodiment, in order to ensure that each battery cluster can be connected to the grid more safely and reliably, a circulating current balancing module is also set in the management device, and the circulating current balancing module is used to balance and control the circulating current generated between the N battery clusters.

[0038] Understandably, when the first control chip A detects that the maximum inter-cluster voltage difference exceeds the preset inter-cluster voltage difference, it indicates the presence of circulating current between the battery clusters. Performing grid connection under these conditions would pose a significant safety hazard. In this situation, a circulating current balancing module can be used to balance the circulating current generated between the N battery clusters. The magnitude of the balancing current is related to the energy storage system's settings.

[0039] Please continue reading Figure 2 As a specific implementation method, the circulating current equalization module includes: There are N-1 circulating current equalization units; each circulating current equalization unit includes a circulating current relay KM3 and a circulating current resistor R1. The second terminal of the circulating current relay KM3 is connected to the first terminal of the circulating current resistor R1. The first terminal of the circulating current relay KM3 is the first terminal of the circulating current equalization unit, and the second terminal of the circulating current resistor R1 is the second terminal of the circulating current equalization unit. The first and second terminals of the circulating current equalization unit are respectively connected to the first terminals of the positive relays in two adjacent DC control modules.

[0040] Alternatively, N DC / DC conversion units are used to perform DC conversion on the output voltages of N DC control modules respectively.

[0041] When the circulating current balancing module is configured with N-1 circulating current balancing units, the voltage difference between individual battery clusters can be eliminated using circulating current relays and circulating current resistors. When the circulating current balancing module is configured with N DC / DC conversion units, the output voltage of the corresponding connected DC control module can be DC-DC converted, thus eliminating the voltage difference between individual battery clusters. Furthermore, this method of adjusting the balancing current offers higher balancing accuracy and faster current sharing speed.

[0042] Obviously, the technical solution provided in this embodiment can not only eliminate the pressure difference between individual battery clusters, but also improve the charging and discharging efficiency of the energy storage system, extend the service life of the battery clusters, and enhance the safety of the energy storage system during operation.

[0043] In a preferred embodiment, the power conversion module 12 includes: a DC switch 201 with pre-charge function, a power board M1, a second filter module 202, a first contactor KMA, a second contactor KMB, a third contactor KMC, a first fuse FUA, a second fuse FUB, a third fuse FUC, a surge protector SPD, and an AC switch K2. Specifically, the first terminal of DC switch 201 is connected to a common terminal formed by the first line connection terminals of N DC control modules 11; the second terminal of DC switch 201 is connected to a common terminal formed by the second line connection terminals of N DC control modules 11; the control terminal of DC switch 201 is connected to the first control chip A; the third and fourth terminals of DC switch 201 are connected to the first and second terminals of power board M1, respectively; the third, fourth, and fifth terminals of power board M1 are connected to the first, second, and third terminals of second filter module 202, respectively; and the fourth, fifth, and sixth terminals of second filter module 202 are connected to the first terminals of first contactor KMA, second contactor KMB, and third contactor KMC, respectively. The second terminals of contactor KMA, KMB, and KMC are connected to the first terminals of fuses FUA, FUB, and FUC, respectively. The second terminals of fuses FUA, FUB, and FUC are connected to the first, second, and third terminals of surge protector SPD, respectively. The fourth terminal of surge protector SPD is grounded. The second terminals of fuses FUA, FUB, and FUC are also connected to the first, second, and third terminals of AC switch K2, respectively. The fourth, fifth, and sixth terminals of AC switch K2 are connected to the power grid.

[0044] In this embodiment, the main function of the power board M1 is to convert the direct current (DC) output from the N battery clusters into alternating current (AC). Specifically, in practical applications, power devices such as IGBTs (Insulated Gate Bipolar Transistors) or SiC (Silicon Carbide) can be used to build the power board M1. When the battery clusters in the energy storage system need to be charged, the power board M1 converts the AC power from the grid side into DC power and stores it in each battery cluster. When the battery clusters in the energy storage system need to be discharged, the power board M1 converts the DC power in each battery cluster into AC power and feeds it back into the grid.

[0045] The second filtering module 202 includes AC filter inductors L1, L2, and L3 and an AC filter board LF1. The AC filter inductors L1, L2, and L3 are primarily used to filter out low-frequency harmonics in the AC power output from the power board M1, while the AC filter board LF1 is primarily used to filter out high-frequency harmonics in the AC power output from the power board M1. Through the coordinated filtering of the AC filter inductors L1, L2, and L3 and the AC filter board LF1, the power quality of the AC power output from the power board M1 can be significantly improved.

[0046] Furthermore, in practical applications, bridge-side current sampling units (1TA, 1TB, and 1TC), inverter-side current sampling units (2TA, 2TB, and 2TC), and grid-side current sampling units (3TA, 3TB, and 3TC) can also be set in the power conversion module 12. Specifically, the bridge-side current sampling units (1TA, 1TB, and 1TC) can be used to sample the output current on the bridge side of the power board M1, the inverter-side current sampling units (2TA, 2TB, and 2TC) can be used to sample the output current on the inverter side of the power board M1, and the grid-side current sampling units (3TA, 3TB, and 3TC) can be used to sample the output current on the grid side of the power board M1.

[0047] The first contactor KMA, the second contactor KMB, and the third contactor KMC are mainly used to control the connection and disconnection of the AC main circuit when each battery cluster is connected to or disconnected from the grid. The first fuse FUA, the second fuse FUB, and the third fuse FUC are mainly used for protection disconnection when the AC side is short-circuited. The surge protector SPD is mainly used to suppress lightning strikes that occur in nature and to prevent damage to the energy storage system caused by overvoltage.

[0048] In practical applications, AC switch K2 can be configured as either a disconnector or an AC circuit breaker. When configured as a disconnector, AC switch K2 is primarily used to disconnect the main AC circuit during maintenance and repair of the energy storage system. When configured as an AC circuit breaker, it is primarily used for passive thermal protection against AC overload and passive magnetic protection against short circuits. Furthermore, in the event of an emergency stop in the energy storage system, the detection board can also trigger the shunt trip unit in the AC circuit breaker to disconnect the connection to the main circuit and prevent accidents.

[0049] Clearly, the technical solution provided in this embodiment can further improve the safety and reliability of the energy storage system during operation.

[0050] In a preferred embodiment, the DC switch 201 includes: a first switch K1, a precharge relay KM4, and a precharge resistor R2; Wherein, the first and second ends of the first switch K1 are the first and second ends of the DC switch 201, respectively; the control end of the first switch K1 is connected to the first control chip A; the third and fourth ends of the first switch K1 are the third and fourth ends of the DC switch 201, respectively; the first end of the precharge relay KM4 is connected to the first end of the positive relay MK11 in a DC control module 11; the second end of the precharge relay KM4 is connected to the first end of the precharge resistor R2; and the second end of the precharge resistor R2 is connected to the third end of the first switch K1.

[0051] It is understandable that the power conversion module 12 needs to be pre-charged before being connected to high voltage, in order to avoid damage to the device due to excessive inrush current when the power conversion module 12 is directly connected to high voltage.

[0052] In this embodiment, to reduce the cost of the DC switch 201, a first switch K1, a pre-charge relay KM4, and a pre-charge resistor R2 are incorporated into the DC switch 201. In practical applications, when the power conversion module 12 needs to be pre-charged, the pre-charge relay KM4 can be closed first, and the power board M1 can be pre-charged through the pre-charge resistor R2. Once the power board M1 is fully pre-charged, the first switch K1 is closed. This avoids damage to the components caused by excessive inrush current when applying high voltage directly to the power board M1.

[0053] Specifically, the first switch K1 can be configured as a DC circuit breaker or a disconnecting switch. When configured as a disconnecting switch, it is mainly used to disconnect the connecting lines in the main circuit during maintenance and repair of the lines in the energy storage system. When configured as a DC circuit breaker, it is mainly used for thermal passive protection on the DC side during overload and magnetic passive protection during short circuit. In addition, when an emergency stop fault occurs in the energy storage system, the detection board 13 can also disconnect the line connection with the main circuit by triggering the shunt trip unit in the DC circuit breaker to perform the shunt trip action, thus preventing safety accidents.

[0054] Obviously, the technical solution provided in this embodiment can avoid damage to the devices in the power conversion module caused by excessive inrush current.

[0055] Please see Figure 3 , Figure 3 This is a flowchart of a control method for an energy storage system provided in an embodiment of the present invention. The method is applied to a detection board in a management device of the aforementioned energy storage system. The method includes: Step S11: When N battery clusters in the energy storage system need to perform grid connection operation, the operating parameters of the N battery clusters are detected by the first control chip; the management device is set in the energy storage system. Step S12: When it is determined from the operating parameters of N battery clusters that the line connections of the N DC control modules are normal and the maximum inter-cluster voltage difference of the N battery clusters is less than the preset inter-cluster voltage difference, a pre-charge command is sent to the power conversion module. When the power conversion module has finished pre-charging, the output voltage of the power conversion module is adjusted by the second control chip so that the N battery clusters can perform grid connection operation. Step S13: When N battery clusters need to perform off-grid operation, control the N battery clusters to stop performing charging and discharging operations, and control the power conversion module to perform power reduction operation through the second control chip, so that when the output power of the power conversion module is less than the preset power value, disconnect the line connection with the N battery clusters, and simultaneously complete the off-grid operation of the N battery clusters.

[0056] In this embodiment, the control method for the energy storage system is specifically described using the detection board in the energy storage system management device as the executing entity. This method can control N battery clusters in the energy storage system to perform grid-connected operations and also control N battery clusters to perform off-grid operations. It should be noted that in this application, the logic for each battery cluster performing grid-connected and off-grid operations remains consistent.

[0057] When N battery clusters in an energy storage system perform grid-connected operation, the first control chip in the detection board will detect the operating parameters of the N battery clusters. These operating parameters include the total voltage, current, and insulation resistance of the battery clusters, etc.

[0058] After the first control chip acquires the operating parameters of each battery cluster, it can not only calculate the SOC and SOH of each battery cluster based on the operating parameters of each battery cluster, but also determine the line connection status of each DC control module and the inter-cluster voltage difference between each battery cluster based on the operating parameters of each battery cluster.

[0059] Only when the detection board determines, based on the operating parameters of each battery cluster, that the circuit connections of the N DC control modules are all normal, and the maximum inter-cluster voltage difference of the N battery clusters is less than the preset inter-cluster voltage difference, can the detection board issue a pre-charge command to the power conversion module. Once the power conversion module has completed pre-charging, the detection board can regulate the output voltage of the power conversion module through the second control chip and control the N battery clusters to perform grid-connected operation.

[0060] When N battery clusters need to perform off-grid operation, the detection board first needs to control each battery cluster to stop charging and discharging, and then control the power conversion module to reduce power. Only when the output power of the power conversion module drops below the preset power value can the line connection between the power conversion module and each battery cluster be disconnected. The main purpose of this operation is to avoid arcing caused by the relay breaking under load in the energy storage system.

[0061] Clearly, the technical solution provided in this embodiment enables N battery clusters to perform off-grid operations more safely and reliably.

[0062] Based on the above embodiments, this embodiment further explains and optimizes the technical solution. Please refer to [link / reference]. Figure 4 , Figure 4 This is a flowchart illustrating the grid connection operation of an energy storage system provided in an embodiment of the present invention. In a preferred embodiment, step S12 involves: when it is determined, based on the operating parameters of the N battery clusters, that the line connections of the N DC control modules are all normal and the maximum inter-cluster voltage difference of the N battery clusters is less than a preset inter-cluster voltage difference, a pre-charge command is issued to the power conversion module. When the power conversion module has completed pre-charging, the output voltage of the power conversion module is adjusted through the second control chip to enable the N battery clusters to perform grid connection operation, including: Step S201: Determine whether the wiring connections of the N DC control modules are all normal based on the operating parameters of the N battery clusters; Step S202: If yes, then determine whether the maximum inter-cluster voltage difference of the N battery clusters is less than the preset inter-cluster voltage difference; Step S203: If not, perform current sharing processing on the output voltage of the N battery clusters until the maximum inter-cluster voltage difference of the N battery clusters is less than the preset inter-cluster voltage difference; Step S204: If yes, then the power conversion module is determined to meet the conditions for applying high voltage. Step S205: When a grid connection command is received from the BAU or EMS in the energy storage system, the power conversion module is pre-charged, and when the power conversion module is pre-charged, the output voltage of the power conversion module is regulated by the second control chip. Step S206: When the output voltage of the power conversion module is consistent with the output voltage of the power grid, the N battery clusters are connected to the power grid.

[0063] In this embodiment, the grid connection process of N battery clusters is described in detail. Before the N battery clusters are connected to the grid, the operation parameters of the N battery clusters are used to determine whether the line connections of the N DC control modules are normal.

[0064] If the wiring connections of the N DC control modules are all normal, it is necessary to determine whether the maximum inter-cluster voltage difference of the N battery clusters is less than the preset inter-cluster voltage difference. If the maximum inter-cluster voltage difference of the N battery clusters is less than the preset inter-cluster voltage difference, it means that the power conversion module meets the high-voltage condition. If the maximum inter-cluster voltage difference of the N battery clusters is greater than or equal to the preset inter-cluster voltage difference, it is necessary to perform current sharing processing on the output voltage of the N battery clusters until the maximum inter-cluster voltage difference of the N battery clusters is less than the preset inter-cluster voltage difference.

[0065] This place is Figure 2 Taking this example, the process of determining whether the circuit connection of the DC control module 11 is normal will be explained in detail. Specifically, when determining whether the circuit connection of the DC control module 11 is normal, it is first necessary to determine whether the insulation resistance between the positive terminal of the battery cluster and ground is normal, and whether the insulation resistance between the negative terminal of the battery cluster and ground is normal. When checking whether the insulation resistance between the positive terminal of the battery cluster and ground is normal, it means checking... Figure 2 Is the insulation resistance between point 1BAT+ and ground greater than or equal to the preset resistance value? If so... Figure 2 If the insulation resistance between the 1BAT+ terminal and ground is greater than or equal to the preset resistance, it indicates that there is no grounding fault at the positive terminal of the battery cluster. Figure 2 If the insulation resistance between the 1BAT+ terminal and ground is less than the preset value, it indicates a grounding fault at the positive terminal of the battery cluster. Similarly, when checking whether the insulation resistance between the negative terminal and ground of the battery cluster is normal, it refers to checking... Figure 2 Is the insulation resistance between 1BAT and ground greater than or equal to the preset resistance value? If so... Figure 2 If the insulation resistance between the 1BAT terminal and ground is greater than or equal to the preset resistance, it indicates that there is no grounding fault at the negative terminal of the battery cluster. Figure 2If the insulation resistance between the 1BAT- terminal and ground is less than the preset resistance, it indicates a grounding fault at the negative terminal of the battery cluster. If a grounding fault occurs at either the negative or positive terminal of the battery cluster, a corresponding fault message should be displayed, and high voltage should be prohibited from being applied to the power conversion module.

[0066] When the insulation resistance between the positive terminal and ground of the battery cluster and the insulation resistance between the negative terminal and ground of the battery cluster are both normal, it is still necessary to continue to check whether the difference between the total voltage detection value of the N battery clusters and the cumulative voltage value of the N battery clusters reported by the BMU (Battery Management Unit) is within a preset difference range. If the difference between the total voltage detection value of the N battery clusters and the cumulative voltage value of the N battery clusters reported by the BMU is within the preset difference range, it indicates that the DC side connection line is normal; if the difference between the total voltage detection value of the N battery clusters and the cumulative voltage value of the N battery clusters reported by the BMU is not within the preset difference range, it indicates that there is an abnormality in the DC side connection line. At this time, the corresponding fault information should be displayed, and the power conversion module should be prohibited from applying high voltage. When checking the total voltage detection value of the N battery clusters, by... Figure 2 Voltage detection can be performed on the wire connected to the second terminal of positive relay KM11, the second terminal of negative relay KM12, the second terminal of positive relay KM21, and the second terminal of negative relay KM22.

[0067] When the difference between the total voltage detected value of the N battery clusters and the cumulative voltage value of the N battery clusters reported by the BMU is within a preset difference range, and if the maximum inter-cluster voltage difference of the N battery clusters is less than the preset inter-cluster voltage difference, it indicates that the power conversion module has met the high-voltage judgment condition. At this time, the subsequent grid connection process can continue. During this process, if the N battery clusters can be powered on locally, the detection board can wait for the grid connection command issued by the BAU (Battery Array Unit). If the N battery clusters need to be powered on remotely, the detection board can wait for the grid connection command issued by the EMS. When the detection board receives the grid connection command, if the energy storage system is in local mode or a combination of remote mode and local mode, the detection board 13 needs to determine whether the DC switch 201 in the power conversion module 12 is in the closed state.

[0068] If the DC switch 201 is in the closed state, the detection board 13 can send a pre-charge command to the power conversion module. If the DC switch 201 is in the open state, it needs to be closed. When the DC switch 201 is in the closed state, the detection board 13 can send a pre-charge command to the power conversion module 12, that is, through... Figure 2The power conversion module 12 is charged using a pre-charge resistor R2 and a pre-charge relay KM4. Once the power conversion module 12 is fully pre-charged, the positive relay KM11 and negative relay KM12 in each battery cluster are closed. After a delay of several seconds, the pre-charge relay KM4 is then turned off. The output voltage of the power conversion module 12 is then regulated by the second control chip B. When the output voltage of the power conversion module 12 matches the output voltage of the power grid, N battery clusters can be connected to the grid.

[0069] It should be noted that when determining whether the power conversion module 12 has completed pre-charging, the main method is to check whether the total DC voltage is greater than or equal to 95% of the total load voltage. If the total DC voltage is greater than or equal to 95% of the total load voltage, the power conversion module 12 is considered pre-charged. If the total DC voltage is less than 95% of the total load voltage, the power conversion module 12 is considered not yet pre-charged and requires further pre-charging. The total DC voltage refers to the voltage at the front ends of the positive relay KM11 and the negative relay KM12, while the total load voltage refers to the voltage at the rear ends of the positive relay KM11 and the negative relay KM12.

[0070] Clearly, the technical solution provided in this embodiment can further ensure the safety and reliability of the energy storage system during grid connection.

[0071] Based on the above embodiments, this embodiment further explains and optimizes the technical solution. As a preferred implementation, step S13 above: controlling the N battery clusters to stop performing charging and discharging operations, and controlling the power conversion module to perform a power reduction operation through the second control chip, so that when the output power of the power conversion module is less than a preset power value, the line connection with the N battery clusters is disconnected, and the off-grid operation of the N battery clusters is completed simultaneously, including: Control N battery clusters to stop performing charging and discharging operations; The second control chip controls the power conversion module to perform a power reduction operation, and after a first preset time delay, it is determined whether the output power of the power conversion module is less than the preset power value. If not, the power conversion module is determined to be faulty, and the DC switch in the power conversion module is disconnected; If so, disconnect the line connection with each battery cluster and simultaneously complete the off-grid operation of N battery clusters.

[0072] In this embodiment, when N battery clusters need to perform off-grid operation, it is first necessary to control the N battery clusters to stop charging and discharging operations, and then control the power conversion module to perform a power reduction operation through the second control chip. After the power conversion module has performed the power reduction operation for a first preset time, it is necessary to determine whether the output power of the power conversion module is less than a preset power value.

[0073] If the output power of the power conversion module is greater than or equal to the preset power value, it indicates that the power conversion module has malfunctioned. In this case, it is necessary to disconnect the shunt trip unit in the DC switch of the power conversion module to avoid safety accidents.

[0074] If the output power of the power conversion module is less than the preset power value, it indicates that the energy storage system has met the off-grid criteria. At this point, the line connection with each battery cluster can be disconnected, and the off-grid operation of N battery clusters can be completed simultaneously. Disconnecting the line connection with each battery cluster refers to disconnecting the positive and negative relays in each DC control module.

[0075] It should be noted that in practical applications, the first preset duration and preset power value can be flexibly set according to the power reduction execution rate of the power conversion module and the specific application scenario and setting parameters of the energy storage system.

[0076] Clearly, the technical solution provided in this embodiment can ensure the safety and reliability of each battery cluster during the off-grid process.

[0077] Based on the above embodiments, this embodiment further explains and optimizes the technical solution. As a preferred implementation, the above control method further includes: Determine whether the energy storage system has triggered preset alarm conditions; If so, the power conversion module is controlled by the second control chip to perform a power reduction operation, and after a second preset time delay, it is determined whether the output power of the power conversion module is less than the preset power value. If not, disconnect the DC switch in the power conversion module and display the corresponding warning message.

[0078] In this embodiment, to further ensure the safety and reliability of the energy storage system during operation, preset alarm conditions can be set for the energy storage system in advance. These preset alarm conditions can be fault alarm conditions such as low SOC alarm, over-temperature alarm, and insulation abnormality alarm.

[0079] If the energy storage system triggers a preset alarm condition, it indicates a safety hazard, and the power supply to the energy storage system needs to be disconnected. In this case, the second control chip needs to control the power conversion module to perform a power reduction operation, and after a second preset delay, determine whether the output power of the power conversion module is less than the preset power value.

[0080] If the output power of the power conversion module is greater than or equal to the preset power value, it indicates that the energy storage system cannot execute the normal power-down logic. In this case, to prevent the fault from escalating further, the DC switch in the power conversion module needs to be disconnected, and a corresponding warning message should be displayed. If the output power of the power conversion module is less than the preset power value, it indicates that the energy storage system can execute the power-down operation according to the normal logic. At this time, the detection board can control the positive and negative relays in the DC control module to disconnect from the circuit connection of the battery cluster.

[0081] When disconnecting the positive and negative relays from the battery pack, it is also necessary to check whether the positive and negative relays are actually disconnected. If the positive relay is not disconnected and / or the negative relay is not disconnected, it indicates that the positive relay has a sticking fault and / or the negative relay has a sticking fault. In this case, it is necessary to disconnect the shunt trip unit in the DC circuit breaker and display the corresponding fault information.

[0082] Obviously, the technical solution provided in this embodiment can handle the alarm faults triggered by the energy storage system and prevent the faults from escalating further, thereby ensuring the overall reliability of the energy storage system during operation.

[0083] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0084] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0085] The above provides a detailed description of a management device for an energy storage system and a control method for an energy storage system provided by the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A management device for an energy storage system, characterized in that, include: N DC control modules are connected one-to-one with N battery clusters to control the DC circuits of the N battery clusters respectively. The power conversion module is connected to all N DC control modules and is used to perform AC conversion and current conversion control on the output voltage of the N DC control modules. A detection board equipped with a first control chip and a second control chip is connected to the power conversion module and the N DC control modules. It is used to collect the operating parameters of each battery cluster through the first control chip and to control each DC control module through the first control chip. At the same time, it uses the second control chip to regulate the power conversion module to control the N battery clusters for grid connection and disconnection.

2. The management device for an energy storage system according to claim 1, characterized in that, The DC control module includes: a first filter module, a DC fuse, a positive relay, and a negative relay; Wherein, the first end and the second end of the first filter module are connected to the positive and negative terminals of the battery cluster, respectively; the third end of the first filter module is connected to the first end of the DC fuse; the second end of the DC fuse is connected to the first end of the positive relay; and the fourth end of the first filter module is connected to the first end of the negative relay. Accordingly, the second terminal of the positive relay and the second terminal of the negative relay are respectively the first line connection terminal and the second line connection terminal of the DC control module.

3. The management device for an energy storage system according to claim 2, characterized in that, Also includes: The circulating current balancing module is used to balance and control the circulating current generated among the N battery clusters.

4. The management device for an energy storage system according to claim 3, characterized in that, The circulating equalization module includes: N-1 circulating current equalization units; each circulating current equalization unit includes a circulating current relay and a circulating current resistor, the second terminal of the circulating current relay and the first terminal of the circulating current resistor are connected, the first terminal of the circulating current relay is the first terminal of the circulating current equalization unit, and the second terminal of the circulating current resistor is the second terminal of the circulating current equalization unit; the first terminal and the second terminal of the circulating current equalization unit are respectively connected to the first terminal of the positive relay in two adjacent DC control modules; Alternatively, N DC / DC conversion units are used to perform DC conversion on the output voltages of the N DC control modules respectively.

5. A management device for an energy storage system according to claim 2, characterized in that, The power conversion module includes: a DC switch with pre-charge function, a power board, a second filter module, a first contactor, a second contactor, a third contactor, a first fuse, a second fuse, a third fuse, a surge protector, and an AC switch; The first terminal of the DC switch is connected to a common terminal formed by the first line connection terminals of the N DC control modules; the second terminal of the DC switch is connected to a common terminal formed by the second line connection terminals of the N DC control modules; the control terminal of the DC switch is connected to the first control chip; the third and fourth terminals of the DC switch are respectively connected to the first and second terminals of the power board; the third, fourth, and fifth terminals of the power board are respectively connected to the first, second, and third terminals of the second filter module; and the fourth, fifth, and sixth terminals of the second filter module are respectively connected to the first terminals of the first contactor, the first terminals of the second contactor, and the first terminals of the third contactor. The second terminals of the first contactor, the second contactor, and the third contactor are respectively connected to the first terminals of the first fuse, the second fuse, and the third fuse. The second terminals of the first fuse, the second fuse, and the third fuse are respectively connected to the first, second, and third terminals of the surge protector. The fourth terminal of the surge protector is grounded. The second terminals of the first fuse, the second fuse, and the third fuse are also respectively connected to the first, second, and third terminals of the AC switch. The fourth, fifth, and sixth terminals of the AC switch are respectively connected to the power grid.

6. A management device for an energy storage system according to claim 5, characterized in that, The DC switch includes: a first switch, a pre-charge relay, and a pre-charge resistor; Wherein, the first terminal and the second terminal of the first switch are respectively the first terminal and the second terminal of the DC switch, the control terminal of the first switch is connected to the first control chip, and the third terminal and the fourth terminal of the first switch are respectively the third terminal and the fourth terminal of the DC switch; the first terminal of the precharge relay is connected to the first terminal of the positive relay in the DC control module, the second terminal of the precharge relay is connected to the first terminal of the precharge resistor, and the second terminal of the precharge resistor is connected to the third terminal of the first switch.

7. A control method for an energy storage system, characterized in that, A detection board applied in a management device for an energy storage system according to any one of claims 1 to 6, comprising: When N battery clusters in the energy storage system need to perform grid connection operations, the operating parameters of the N battery clusters are detected by the first control chip; the management device is installed in the energy storage system. When it is determined from the operating parameters of the N battery clusters that the line connections of the N DC control modules are all normal and the maximum inter-cluster voltage difference of the N battery clusters is less than the preset inter-cluster voltage difference, a pre-charge command is sent to the power conversion module. When the power conversion module has completed the pre-charge, the output voltage of the power conversion module is adjusted by the second control chip so that the N battery clusters can perform grid connection operation. When N battery clusters need to perform off-grid operation, the N battery clusters are controlled to stop performing charging and discharging operations, and the power conversion module is controlled by the second control chip to perform a power reduction operation. When the output power of the power conversion module is less than a preset power value, the line connection with the N battery clusters is disconnected, and the off-grid operation of the N battery clusters is completed synchronously.

8. The control method for an energy storage system according to claim 7, characterized in that, When it is determined from the operating parameters of the N battery clusters that the line connections of the N DC control modules are all normal and the maximum inter-cluster voltage difference of the N battery clusters is less than the preset inter-cluster voltage difference, a pre-charge command is issued to the power conversion module. When the power conversion module has completed pre-charging, the output voltage of the power conversion module is adjusted through the second control chip to enable the N battery clusters to perform grid connection operation, including: Determine whether the circuit connections of the N DC control modules are all normal based on the operating parameters of the N battery clusters; If so, determine whether the maximum inter-cluster pressure difference of the N battery clusters is less than the preset inter-cluster pressure difference; If not, the output voltages of the N battery clusters are shared until the maximum inter-cluster voltage difference of the N battery clusters is less than the preset inter-cluster voltage difference. If so, the power conversion module is determined to meet the conditions for applying high voltage. When a grid connection command is received from the BAU or EMS in the energy storage system, the power conversion module is pre-charged, and when the power conversion module is pre-charged, the output voltage of the power conversion module is regulated by the second control chip. When the output voltage of the power conversion module is consistent with the output voltage of the power grid, the N battery clusters are connected to the power grid.

9. The control method for an energy storage system according to claim 7, characterized in that, The control of N battery clusters to stop charging and discharging operations, and the control of the power conversion module to perform a power reduction operation via the second control chip, so as to disconnect the line connection with the N battery clusters when the output power of the power conversion module is less than a preset power value, and simultaneously complete the off-grid operation of the N battery clusters, including: Control N battery clusters to stop performing charging and discharging operations; The second control chip controls the power conversion module to perform a power reduction operation, and after a first preset time delay, it is determined whether the output power of the power conversion module is less than the preset power value. If not, the power conversion module is determined to be faulty, and the DC switch in the power conversion module is disconnected; If so, disconnect the line connection with each of the battery clusters and simultaneously complete the off-grid operation of N battery clusters.

10. The control method for an energy storage system according to claim 7, characterized in that, Also includes: Determine whether the energy storage system has triggered a preset alarm condition; If so, the power conversion module is controlled by the second control chip to perform a power reduction operation, and after a second preset time delay, it is determined whether the output power of the power conversion module is less than the preset power value; If not, disconnect the DC switch in the power conversion module and display the corresponding warning message.

Images