Relay function integrity detection system and method for energy storage battery management system

Abstract

The invention provides a relay function integrity detection system and method for an energy storage battery management system, which ensures the function integrity of all relays under actual working conditions through comprehensive detection, improves the safety and reliability of the system, and comprises a battery module and a load module which are connected with each other, an anode relay, a cathode relay, a pre-charging relay and a pre-charging resistor are arranged between the battery module and the load module, and the control module is respectively connected with the anode relay, the cathode relay and the pre-charging relay. And the control module controls the switching of the positive relay, the negative relay and the pre-charging relay, and judges whether the positive relay, the negative relay and the pre-charging relay can be closed and disconnected by sampling the voltage of the output end of the battery module and the voltage of the input end of the load module when the relays are switched on and off.

Description

Technical Field

[0001] The present invention relates to the technical field of battery management systems, and in particular to a relay function integrity detection system and method for an energy storage battery management system. Background Art

[0002] With the development of energy storage technology, battery management systems (BMS) are increasingly used in energy storage systems. One of the main functions of a battery management system is to manage and protect battery packs to ensure their safe and efficient operation. Among them, the relay is a key component that connects the battery module and the load module, and is used to control the charging and discharging process of the battery pack of the battery module. The functional integrity of the relay directly affects the safety and reliability of the system, and its failure may lead to serious consequences. When the energy storage battery is connected to the load, if these relays do not work properly, it will bring serious safety hazards. For example, if the positive relay or the negative relay is stuck or has poor contact when closed, it may cause overcurrent or short circuit, which in turn causes overheating or even fire of the battery module.

[0003] In existing energy storage battery management systems, the functional integrity detection of relays usually relies on simple switch state detection or time-based timing detection, which cannot fully evaluate the functional integrity of the relays, that is, it cannot fully evaluate the closing and disconnecting capabilities of the relays under actual working conditions. Relays may have problems such as adhesion, poor contact, or incomplete disconnection during the closing or disconnection process, which are difficult to detect in simple switch state detection. In addition, existing detection methods usually lack the ability to fully evaluate the functional integrity of relays in different working stages, which may lead to safety hazards during actual use. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a relay function integrity detection system and method for an energy storage battery management system. Through comprehensive detection, the functional integrity of all relays under actual working conditions is ensured, thereby improving the safety and reliability of the system.

[0005] The technical solution is as follows: a relay function integrity detection system for an energy storage battery management system, comprising a battery module and a load module connected to each other, a positive electrode relay is arranged between the positive electrode of the battery module and the positive electrode of the load module, a negative electrode relay is arranged between the negative electrode of the battery module and the negative electrode of the load module, and a pre-charging relay and a pre-charging resistor are also connected between the positive electrode of the battery module and the positive electrode of the load module, characterized in that: it also includes:

[0006] A control module, wherein the control module is respectively connected to the positive relay, the negative relay and the pre-charging relay, and the control module controls the switching of the positive relay, the negative relay and the pre-charging relay, and determines whether the positive relay, the negative relay and the pre-charging relay can be closed and disconnected by sampling the voltage at the output end of the battery module and the voltage at the input end of the load module when the relay is switched.

[0007] A relay function integrity detection method for an energy storage battery management system is used to detect the relay function integrity between a battery module and a load module. The method comprises the following steps:

[0008] Step 1: Disconnect the positive relay, negative relay and pre-charge relay, and check whether the voltage at the input end of the load module is 0. If it is 0, execute step 2, otherwise it is determined that there is a fault;

[0009] Step 2: First close the negative relay, then close the pre-charge relay, and determine whether the voltage at the output end of the battery module is equal to the voltage at the input end of the load module. If so, it is considered that the negative relay can be closed, and step 3 is executed. Otherwise, it is determined that there is a fault.

[0010] Step 3: Disconnect the pre-charging relay and check whether the voltage at the input end of the load module is 0. If it is 0, it is considered that the positive relay can be disconnected without sticking, the pre-charging relay can be disconnected and closed, and continue to step 4. Otherwise, it is determined that there is a fault;

[0011] Step 4: Disconnect the negative relay, then close the pre-charge relay, and detect whether the voltage at the input end of the load module is 0. If it is 0, it is considered that the negative relay can be disconnected, and continue to step 5. Otherwise, it is determined that there is a fault;

[0012] Step 5: Close the negative pole relay for pre-charging until it is detected that the voltage at the output end of the battery module is equal to the voltage at the input end of the load module, then close the positive pole relay, and then disconnect the pre-charging relay to determine whether the voltage at the output end of the battery module is equal to the voltage at the input end of the load module. If so, it is considered that the positive pole relay can be closed, and it is confirmed that the positive pole relay, negative pole relay and pre-charging relay are all normal; otherwise, it is determined that a fault exists.

[0013] Further, in step 1, it is determined that the existing fault is: the negative pole relay cannot be disconnected, and at least one of the positive pole relay and the pre-charging relay cannot be disconnected.

[0014] Further, in step 2, it is determined that the existing fault is that at least one of the negative electrode relay and the pre-charging relay cannot be closed.

[0015] Further, in step 3, it is determined that the existing fault is that at least one of the positive relay and the pre-charging relay cannot be disconnected.

[0016] Further, in step 4, it is determined that the existing fault is: the negative pole relay cannot be disconnected.

[0017] Further, in step 5, it is determined that the existing fault is: the positive relay cannot be closed.

[0018] Furthermore, when judging whether the voltage at the output end of the battery module is equal to the voltage at the input end of the load module, a waiting time is set. If the ratio of the voltage at the output end of the battery module to the voltage at the input end of the load module during the waiting time meets the threshold, it is considered that the voltage at the output end of the battery module is equal to the voltage at the input end of the load module.

[0019] A control method for a relay used in an energy storage battery management system, used to connect a battery module and a load module, the method comprising the following steps:

[0020] Step 1: Disconnect the positive relay, negative relay and pre-charge relay, and check whether the voltage at the input end of the load module is 0. If it is 0, execute step 2, otherwise it is determined that there is a fault;

[0021] Step 2: First close the negative relay, then close the pre-charge relay, and determine whether the voltage at the output end of the battery module is equal to the voltage at the input end of the load module. If so, it is considered that the negative relay can be closed, and step 3 is executed. Otherwise, it is determined that there is a fault.

[0022] Step 3: Disconnect the pre-charging relay and check whether the voltage at the input end of the load module is 0. If it is 0, it is considered that the positive relay can be disconnected without sticking, the pre-charging relay can be disconnected and closed, and continue to step 4. Otherwise, it is determined that there is a fault;

[0023] Step 4: Disconnect the negative relay, then close the pre-charge relay, and detect whether the voltage at the input end of the load module is 0. If it is 0, it is considered that the negative relay can be disconnected, and continue to step 5. Otherwise, it is determined that there is a fault;

[0024] Step 5: Close the negative pole relay for pre-charging until the voltage at the output end of the battery module is detected to be equal to the voltage at the input end of the load module, then close the positive pole relay, and then disconnect the pre-charging relay to determine whether the voltage at the output end of the battery module is equal to the voltage at the input end of the load module. If so, it is considered that the positive pole relay can be closed. It is confirmed that the positive pole relay, negative pole relay and pre-charging relay are all normal, and step 6 is executed; otherwise, it is determined that there is a fault;

[0025] Step 6: Close the positive relay, negative relay and pre-charge relay, and then disconnect the pre-charge relay to complete the connection between the battery module and the load module.

[0026] The relay function integrity detection system and method for the energy storage battery management system of the present invention can comprehensively detect whether the positive relay, the negative relay and the pre-charging relay can be closed and opened, thereby ensuring the integrity of the relay function. The method of the present invention is used to perform multiple detections and verifications through the switching of the relay to ensure the accuracy of the detection results and avoid misjudgment.

[0027] Through comprehensive functional testing, the present invention can timely discover problems such as adhesion, poor contact or incomplete disconnection that may occur in the closing and disconnecting process of the relay, and can effectively prevent safety hazards such as overcurrent, overvoltage or short circuit; by controlling the switch of the relay in different steps, the specific fault type of the relay can be accurately identified, the efficiency of fault detection and repair can be improved, and it is convenient to take measures in time after detecting a relay fault, so as to avoid serious accidents such as battery overheating and short circuit, thereby improving the safety of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic diagram of a relay function integrity detection system for an energy storage battery management system in an embodiment;

[0029] Figure 2 A schematic diagram of the steps of a method for detecting the functional integrity of a relay used in an energy storage battery management system in an embodiment;

[0030] Figure 3 Schematic diagram of the steps of a method for controlling a relay of an energy storage battery management system in an embodiment. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments, and people familiar with this technology can understand other advantages and effects of the present invention from the contents disclosed in this specification. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0032] See Figure 1, a relay function integrity detection system for an energy storage battery management system of the present invention includes a battery module 1 and a load module 2 connected to each other, and a positive relay 3 is provided between the positive electrode of the battery module 1 and the positive electrode of the load module 2, which is used to control the positive electrode connection between the battery module and the load module. The normal operation of the positive relay ensures the reliable connection and disconnection of the positive electrode of the battery module during the charging and discharging process. If the positive relay 3 cannot be closed, the battery module 1 cannot be normally connected to the load module, resulting in the system being unable to start. If the positive relay 3 cannot be disconnected, when the system needs to disconnect the battery module, the positive relay cannot be disconnected, which may cause the battery module to be over-discharged, over-charged or short-circuited, causing serious accidents such as fire;

[0033] A negative electrode relay 4 is provided between the negative electrode of the battery module 1 and the negative electrode of the load module 2, and is used to control the negative electrode connection between the battery module and the load module. The normal operation of the negative electrode relay ensures the reliable connection and disconnection of the negative electrode of the battery module during the charging and discharging process. If the negative electrode relay 4 cannot be closed, the battery module cannot be normally connected to the load module, resulting in the system being unable to start. If the negative electrode relay 4 cannot be disconnected, when the system needs to disconnect the battery module 1, the negative electrode relay 4 cannot be disconnected, which may cause problems such as over-discharging, over-charging or short circuit of the battery module.

[0034] A pre-charging relay 5 and a pre-charging resistor 6 are also connected between the positive pole of the battery module 1 and the positive pole of the load module 2. The function of the pre-charging relay 5 and the pre-charging resistor 6 is to gradually increase the voltage of the load module through the pre-charging resistor before the battery module 1 is connected to the load module, so as to prevent instantaneous large current shock and protect the load module and the battery pack. If the pre-charging relay 5 cannot be closed, the battery pack cannot be pre-charged, resulting in an instantaneous large current shock when the load module is connected. The shock current is very large and may cause the relay to stick. If the pre-charging relay 5 cannot be disconnected, after the pre-charging is completed, the pre-charging relay cannot be disconnected, which may cause the pre-charging resistor to work for a long time, generate serious heat, or even burn out.

[0035] The control module 7 is connected to the positive relay 3, the negative relay 4 and the pre-charging relay 5 respectively. The control module 7 controls the switching of the positive relay 3, the negative relay 4 and the pre-charging relay 5. By sampling the voltage at the output end of the battery module 1 and the voltage at the input end of the load module 2 when the positive relay 3, the negative relay 4 and the pre-charging relay 5 are switched, it is determined whether the positive relay 3, the negative relay 4 and the pre-charging relay 5 can be closed or opened.

[0036] See Figure 2 In the embodiment, the relay function integrity detection system may adopt the following steps when performing detection and judgment:

[0037] Step 1: The control module controls the disconnection of the positive relay, the negative relay and the pre-charging relay, and detects whether the voltage at the input end of the load module is 0. If it is 0, step 2 is executed, otherwise it is determined that there is a fault, and the fault is that the negative relay cannot be disconnected, and at least one of the positive relay and the pre-charging relay cannot be disconnected;

[0038] Step 2: The control module controls the negative electrode relay to be closed first, and then the pre-charging relay to be closed, to determine whether the voltage at the output end of the battery module is equal to the voltage at the input end of the load module. If so, it is considered that the negative electrode relay can be closed, and step 3 is executed. Otherwise, it is determined that there is a fault, and the fault is: at least one of the negative electrode relay and the pre-charging relay cannot be closed;

[0039] Step 3: The control module controls the disconnection of the pre-charging relay and detects whether the voltage at the input end of the load module is 0. If it is 0, it is considered that the positive relay can be disconnected without sticking, and the pre-charging relay can be disconnected and closed, and step 4 is continued. Otherwise, it is determined that there is a fault, and the fault is: at least one of the positive relay and the pre-charging relay cannot be disconnected;

[0040] Step 4: The control module controls to disconnect the negative relay, and then closes the pre-charge relay to detect whether the voltage at the input end of the load module is 0. If it is 0, it is considered that the negative relay can be disconnected, and step 5 is continued. Otherwise, it is determined that there is a fault, and the fault is: the negative relay cannot be disconnected;

[0041] Step 5: The control module controls the closing of the negative pole relay for pre-charging until it detects that the voltage at the output end of the battery module is equal to the voltage at the input end of the load module, then closes the positive pole relay, and then disconnects the pre-charging relay to determine whether the voltage at the output end of the battery module is equal to the voltage at the input end of the load module. If so, it is considered that the positive pole relay can be closed, and it is confirmed that the positive pole relay, negative pole relay and pre-charging relay are all normal; otherwise, it is determined that there is a fault, and the fault is: the positive pole relay cannot be closed.

[0042] During implementation, the control module controls the switching of the relay and the voltage sampling, so as to realize the automation of the detection process and improve the detection efficiency. The detection is performed before starting to connect the load module, so as to ensure safety and control when encountering faults during actual use, and avoid safety accidents caused by relay failures. By controlling the switching of the positive relay, negative relay and pre-charging relay, and sampling the voltage of the battery module output and the power module input, the closing and opening functions of the three relays can be fully detected. By setting specific detection steps and judgment conditions, the state of the relay can be accurately judged, and potential faults can be discovered in time.

[0043] A specific implementation of the relay function integrity detection method is described below. There are positive relays, negative relays and pre-charging relays between the battery module and the load module, which are represented by positive relay HS, negative relay LS and pre-charging relay PC respectively. 0 and 1 are used to represent the states of the relays as open and closed respectively. The method is specifically performed as follows;

[0044] Step 1: The control module 7 controls the states of each relay to be HS=0, LS=0, and PC=0 respectively, samples the voltage at the input end of the load module, and detects whether the voltage Vout at the input end of the load module is 0. If it is 0, step 2 is executed. If it is not 0, it is determined that there is a fault, and the fault is that the negative relay LS cannot be disconnected, and at least one of the positive relay HS and the pre-charge relay PC cannot be disconnected;

[0045] Step 2: The control module 7 first controls the state of the negative relay to be closed, at this time HS=0, LS=1, PC=0, and then controls the pre-charge relay to be closed, at this time HS=0, LS=1, PC=1, and determines whether the voltage Vbat at the output end of the battery module is equal to the voltage Vout at the input end of the load module.

[0046] In the embodiment, a waiting time is set, and the ratio of the voltage at the output end of the battery module to the voltage at the input end of the load module during the waiting time meets the threshold. In the embodiment, it is set that when Vout reaches a specified voltage such as 97.5% of Vbat during the specified waiting time, it is considered that Vbat and Vout are equal. The ratio can range from 0.95 to 1;

[0047] If they are not equal, it is determined that there is a fault, and the fault is: at least one of the negative relay and the pre-charge relay cannot be closed;

[0048] Step 3: Disconnect the pre-charging relay. At this time, HS=0, LS=1, and PC=0. Check whether the voltage Vout at the input end of the load module is 0. If it is 0, it is considered that the positive relay can be disconnected without sticking, and the pre-charging relay can be disconnected and closed. Continue to step 4. When step 3 is executed and Vout=0 is satisfied, it is considered that the pre-charging relay PC is normal and can be disconnected and closed.

[0049] If Vout is not 0, it is determined that there is a fault, and the fault is: at least one of the positive relay and the pre-charge relay cannot be disconnected;

[0050] Step 4: disconnect the negative relay, so that HS = 0, LS = 0, PC = 0, and then close the pre-charge relay, so that HS = 0, LS = 0, PC = 1, and detect whether the voltage Vout at the input end of the load module is 0. If it is 0, it is considered that the negative relay can be disconnected. When step 4 is executed and Vout = 0 is satisfied, it is considered that the negative relay LS is normal at this time and can be disconnected or closed, and continue to step 5;

[0051] If Vout is not 0, it is determined that there is a fault, and the fault is: the negative relay cannot be disconnected;

[0052] Step 5: close the negative pole relay for pre-charging, at this time HS=0, LS=1, PC=1, until it is detected that the voltage at the output end of the battery module is equal to the voltage at the input end of the load module. In the embodiment, a waiting time is set, and the ratio of the voltage at the output end of the battery module to the voltage at the input end of the load module meets the threshold value during the waiting time. In the embodiment, it is set that when Vout reaches a specified voltage such as 97.5% of Vbat within the specified waiting time, it is considered that Vbat and Vout are equal, and the ratio can range from 0.95 to 1;

[0053] Close the positive relay again, and HS=1, LS=1, and PC=1 are obtained. Then disconnect the pre-charge relay, and HS=1, LS=1, and PC=1 are obtained. At this time, HS=1, LS=1, and PC=0 are obtained. Determine whether the voltage at the output of the battery module is equal to the voltage at the input of the load module.

[0054] In the embodiment, a waiting time is set, and during the waiting time, the ratio of the voltage at the output end of the battery module to the voltage at the input end of the load module meets the threshold. In the embodiment, it is set that Vout reaches a specified voltage, such as 97.5% of Vbat, within the specified waiting time, then it is considered that Vbat and Vout are equal. The ratio can range from 0.95 to 1. If it is satisfied, it is considered that the positive relay can be closed, so that it is confirmed that the positive relay, the negative relay and the pre-charge relay are all normal;

[0055] If not satisfied, it is determined that there is a fault, the fault is: the positive relay cannot be closed.

[0056] The prior art usually only focuses on the detection of positive relays and negative relays. In the embodiment, the detection of pre-charge relays and pre-charge resistors is added to make the detection more comprehensive. In the embodiment, the positive relay, negative relay and pre-charge relay are respectively connected through the control module, and the closing and disconnecting capabilities of these relays are fully detected to ensure the functional integrity of the relays under actual working conditions. The prior art can usually only detect the closed state of the relay, while the present invention can simultaneously detect whether the relay can be closed and disconnected to ensure the integrity of the relay function. Through the detection and verification of multiple actions, the accuracy of the detection results is ensured to avoid misjudgment; through comprehensive functional detection, the present invention can promptly discover the problems that may occur in the relay, such as adhesion, poor contact or incomplete disconnection, and can effectively prevent safety hazards such as overcurrent, overvoltage or short circuit.

[0057] Furthermore, in the embodiment, the function of the relay is detected through the combination of relay switches in different steps, which can accurately identify the specific fault type that occurs during the closing and opening process of the relay, thereby improving the efficiency of fault detection and repair.

[0058] See Figure 3 In an embodiment of the present invention, a control method for a relay used in an energy storage battery management system is also provided, wherein a battery module and a load module are connected by starting a relay, and the method comprises the following steps:

[0059] Step 1: The control module 7 controls the states of each relay to be HS=0, LS=0, and PC=0 respectively, samples the voltage at the input end of the load module, and detects whether the voltage Vout at the input end of the load module is 0. If it is 0, step 2 is executed. If it is not 0, it is determined that there is a fault, and the fault is that the negative relay LS cannot be disconnected, and at least one of the positive relay HS and the pre-charge relay PC cannot be disconnected;

[0060] Step 2: The control module 7 first controls the state of the negative relay to be closed, at this time HS=0, LS=1, PC=0, and then controls the pre-charge relay to be closed, at this time HS=0, LS=1, PC=1, and determines whether the voltage Vbat at the output end of the battery module is equal to the voltage Vout at the input end of the load module.

[0061] In the embodiment, a waiting time is set, and the ratio of the voltage at the output end of the battery module to the voltage at the input end of the load module during the waiting time meets the threshold. In the embodiment, it is set that when Vout reaches a specified voltage such as 97.5% of Vbat during the specified waiting time, it is considered that Vbat and Vout are equal. The ratio can range from 0.95 to 1;

[0062] If they are not equal, it is determined that there is a fault, and the fault is: at least one of the negative relay and the pre-charge relay cannot be closed;

[0063] Step 3: Disconnect the pre-charging relay. At this time, HS=0, LS=1, and PC=0. Check whether the voltage Vout at the input end of the load module is 0. If it is 0, it is considered that the positive relay can be disconnected without sticking, and the pre-charging relay can be disconnected and closed. Continue to step 4. When step 3 is executed and Vout=0 is satisfied, it is considered that the pre-charging relay PC is normal and can be disconnected and closed.

[0064] If Vout is not 0, it is determined that there is a fault, and the fault is: at least one of the positive relay and the pre-charge relay cannot be disconnected;

[0065] Step 4: disconnect the negative relay, so that HS = 0, LS = 0, PC = 0, and then close the pre-charge relay, so that HS = 0, LS = 0, PC = 1, and detect whether the voltage Vout at the input end of the load module is 0. If it is 0, it is considered that the negative relay can be disconnected. When step 4 is executed and Vout = 0 is satisfied, it is considered that the negative relay LS is normal at this time and can be disconnected or closed, and continue to step 5;

[0066] If Vout is not 0, it is determined that there is a fault, and the fault is: the negative relay cannot be disconnected;

[0067] Step 5: close the negative pole relay for pre-charging, at this time HS=0, LS=1, PC=1, until it is detected that the voltage at the output end of the battery module is equal to the voltage at the input end of the load module. In the embodiment, a waiting time is set, and the ratio of the voltage at the output end of the battery module to the voltage at the input end of the load module meets the threshold value during the waiting time. In the embodiment, it is set that when Vout reaches a specified voltage such as 97.5% of Vbat within the specified waiting time, it is considered that Vbat and Vout are equal, and the ratio can range from 0.95 to 1;

[0068] Close the positive relay again, and HS=1, LS=1, and PC=1 are obtained. Then disconnect the pre-charge relay, and HS=1, LS=1, and PC=1 are obtained. At this time, HS=1, LS=1, and PC=0 are obtained. Determine whether the voltage at the output of the battery module is equal to the voltage at the input of the load module.

[0069] In the embodiment, a waiting time is set. During the waiting time, the ratio of the voltage at the output end of the battery module to the voltage at the input end of the load module meets the threshold. In the embodiment, it is set that Vout reaches a specified voltage, such as 97.5% of Vbat, within the specified waiting time. Then it is considered that Vbat and Vout are equal. The ratio can range from 0.95 to 1. If it is satisfied, it is considered that the positive relay can be closed. At this point, it is confirmed that the positive relay, the negative relay and the pre-charge relay are all normal, and step 6 is executed;

[0070] If not satisfied, it is determined that there is a fault, the fault is: the positive relay cannot be closed.

[0071] Step 6: After confirming that the positive relay, negative relay and pre-charge relay are all normal, close the positive relay, negative relay and pre-charge relay, control the relay status to HS=1, LS=1, PC=1, then disconnect the pre-charge relay, control the relay status to HS=1, LS=1, PC=0, and complete the connection between the negative pole of the battery module and the load module.

[0072] The control method of the relays for the energy storage battery management system in the embodiment not only detects the functional integrity of the three relays, but also can effectively avoid large current shocks. First, all three relays are closed. When the LS and PC pre-charges reach the target, the HS can be safely closed, and then the PC is disconnected. The ultimate goal is to have only the LS and HS closed at the same time; if the LS and PC are disconnected after the pre-charge is successful, and then the HS is closed, the port voltage may drop, which will still cause a large voltage difference, resulting in a large current shock at the moment the HS is closed.

[0073] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0074] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A relay function integrity detection system for an energy storage battery management system, comprising a battery module and a load module connected to each other, a positive electrode relay is arranged between the positive electrode of the battery module and the positive electrode of the load module, a negative electrode relay is arranged between the negative electrode of the battery module and the negative electrode of the load module, and a pre-charging relay and a pre-charging resistor are also connected between the positive electrode of the battery module and the positive electrode of the load module, characterized in that: Also includes: A control module, wherein the control module is respectively connected to the positive relay, the negative relay and the pre-charging relay, and the control module controls the switching of the positive relay, the negative relay and the pre-charging relay, and determines whether the positive relay, the negative relay and the pre-charging relay can be closed and disconnected by sampling the voltage at the output end of the battery module and the voltage at the input end of the load module when the relay is switched.

2. A relay function integrity detection method for an energy storage battery management system, used to detect the relay function integrity between a battery module and a load module, characterized in that: The method comprises the following steps: Step 1: Disconnect the positive relay, negative relay and pre-charge relay, and check whether the voltage at the input end of the load module is 0. If it is 0, execute step 2, otherwise it is determined that there is a fault; Step 2: First close the negative relay, then close the pre-charge relay, and determine whether the voltage at the output end of the battery module is equal to the voltage at the input end of the load module. If so, it is considered that the negative relay can be closed, and step 3 is executed. Otherwise, it is determined that there is a fault. Step 3: Disconnect the pre-charging relay and check whether the voltage at the input end of the load module is 0. If it is 0, it is considered that the positive relay can be disconnected without sticking, the pre-charging relay can be disconnected and closed, and continue to step 4. Otherwise, it is determined that there is a fault; Step 4: Disconnect the negative relay, then close the pre-charge relay, and detect whether the voltage at the input end of the load module is 0. If it is 0, it is considered that the negative relay can be disconnected, and continue to step 5. Otherwise, it is determined that there is a fault; Step 5: Close the negative pole relay for pre-charging until it is detected that the voltage at the output end of the battery module is equal to the voltage at the input end of the load module, then close the positive pole relay, and then disconnect the pre-charging relay to determine whether the voltage at the output end of the battery module is equal to the voltage at the input end of the load module. If so, it is considered that the positive pole relay can be closed, and it is confirmed that the positive pole relay, negative pole relay and pre-charging relay are all normal; otherwise, it is determined that a fault exists.

3. A relay function integrity detection method for an energy storage battery management system according to claim 2, characterized in that: In step 1, it is determined that the existing fault is: the negative relay cannot be disconnected, and at least one of the positive relay and the pre-charge relay cannot be disconnected.

4. A relay function integrity detection method for an energy storage battery management system according to claim 2, characterized in that: In step 2, it is determined that the existing fault is that at least one of the negative relay and the pre-charge relay cannot be closed.

5. The method for detecting the functional integrity of a relay for an energy storage battery management system according to claim 2, characterized in that: In step 3, it is determined that the existing fault is that at least one of the positive relay and the pre-charge relay cannot be disconnected.

6. A relay function integrity detection method for an energy storage battery management system according to claim 2, characterized in that: In step 4, it is determined that the existing fault is: the negative pole relay cannot be disconnected.

7. A relay function integrity detection method for an energy storage battery management system according to claim 2, characterized in that: In step 5, it is determined that the existing fault is: the positive relay cannot be closed.

8. A relay function integrity detection method for an energy storage battery management system according to claim 2, characterized in that: When judging whether the voltage at the output end of the battery module is equal to the voltage at the input end of the load module, a waiting time is set. If the ratio of the voltage at the output end of the battery module to the voltage at the input end of the load module meets the threshold during the waiting time, it is considered that the voltage at the output end of the battery module is equal to the voltage at the input end of the load module.

9. A control method for a relay in an energy storage battery management system, used to connect a battery module and a load module, characterized in that: The method comprises the following steps: Step 1: Disconnect the positive relay, negative relay and pre-charge relay, and check whether the voltage at the input end of the load module is 0. If it is 0, execute step 2, otherwise it is determined that there is a fault; Step 2: First close the negative relay, then close the pre-charge relay, and determine whether the voltage at the output end of the battery module is equal to the voltage at the input end of the load module. If so, it is considered that the negative relay can be closed, and step 3 is executed. Otherwise, it is determined that there is a fault. Step 3: Disconnect the pre-charging relay and check whether the voltage at the input end of the load module is 0. If it is 0, it is considered that the positive relay can be disconnected without sticking, the pre-charging relay can be disconnected and closed, and continue to step 4. Otherwise, it is determined that there is a fault; Step 4: Disconnect the negative relay, then close the pre-charge relay, and detect whether the voltage at the input end of the load module is 0. If it is 0, it is considered that the negative relay can be disconnected, and continue to step 5. Otherwise, it is determined that there is a fault; Step 5: Close the negative pole relay for pre-charging until the voltage at the output end of the battery module is detected to be equal to the voltage at the input end of the load module, then close the positive pole relay, and then disconnect the pre-charging relay to determine whether the voltage at the output end of the battery module is equal to the voltage at the input end of the load module. If so, it is considered that the positive pole relay can be closed. It is confirmed that the positive pole relay, negative pole relay and pre-charging relay are all normal, and step 6 is executed; otherwise, it is determined that there is a fault; Step 6: Close the positive relay, negative relay and pre-charge relay, and then disconnect the pre-charge relay to complete the connection between the battery module and the load module.

10. The control method of a relay for an energy storage battery management system according to claim 9, characterized in that: When judging whether the voltage at the output end of the battery module is equal to the voltage at the input end of the load module, a waiting time is set. If the ratio of the voltage at the output end of the battery module to the voltage at the input end of the load module meets the threshold during the waiting time, it is considered that the voltage at the output end of the battery module is equal to the voltage at the input end of the load module.

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