Safety protection detection circuit of energy storage system, energy storage system and detection method

Abstract

The invention provides a safety protection detection circuit of an energy storage system, the energy storage system and a detection method. According to the safety protection detection circuit of the energy storage system, one end of a first resistor is connected with a bus anode, and the other end of the first resistor is connected with a bus cathode; the first input end of the operational amplifier is connected with one end of the first resistor, the second input end of the operational amplifier is connected with the other end of the first resistor, and the operational amplifier is used for collecting first voltage and outputting second voltage; a third input end of the comparator is connected with a first output end of the operational amplifier and is used for outputting a comparison result of the second voltage and a voltage threshold; the first control module is connected with the second output end of the comparator and is used for judging whether the battery pack has a reverse connection fault or not according to a comparison result when the main positive relay and the main negative relay are disconnected; or when the main negative relay is switched on and the main positive relay is switched off, whether the load has a short-circuit fault or not is judged according to the comparison result. According to the invention, detection of a reverse connection fault and a short circuit fault is realized.

Description

Technical Field

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

[0002] In current energy storage systems, when battery packs are connected in parallel, reverse connection detection is required before closing the relay to diagnose the risk of short circuit between battery packs. Some high-voltage battery products on the market do not have reverse connection detection (traditional reverse connection detection such as Figure 1 As shown in the figure, the circuit is not protected by the foolproof connection terminal, but by the foolproof connection terminal. Once the user uses a non-professional wiring harness to connect, there will be a risk of short circuit or damage to the FUSE (fuse). In addition, most high-voltage products do not have the function of load short circuit detection, and cannot detect short circuit at the load end, but rely on the burning of the FUSE to protect the circuit. Product failure will waste time and maintenance costs, etc., seriously affecting the customer experience. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0004] To this end, a first aspect of the present invention proposes a safety protection detection circuit for an energy storage system.

[0005] A second aspect of the present invention provides an energy storage system.

[0006] A third aspect of the present invention provides a reverse connection detection method for an energy storage system.

[0007] A fourth aspect of the present invention provides a load short-circuit detection method for an energy storage system.

[0008] In view of this, according to a first aspect of the present invention, a safety protection detection circuit of an energy storage system is proposed, wherein the energy storage system includes: a battery pack, a main positive relay, a main negative relay, a bus negative electrode and a bus positive electrode, wherein the two ends of the load are respectively connected to the bus negative electrode and the bus positive electrode; or the two ends of the battery pack are respectively connected to the bus negative electrode and the bus positive electrode; the safety protection detection circuit of the energy storage system includes: a first resistor, one end of the first resistor is connected to the bus positive electrode, and the other end of the first resistor is connected to the bus negative electrode; an operational amplifier, a first input end of the operational amplifier is connected to one end of the first resistor, and a second input end of the operational amplifier is connected to one end of the first resistor. The input end is connected to the other end of the first resistor, and is used to collect the first voltage across the first resistor and output the second voltage; the comparator, the third input end of the comparator is connected to the first output end of the operational amplifier, and is used to collect the second voltage and output the comparison result between the second voltage and the voltage threshold; the first control module, the first control module is connected to the fourth input end of the comparator, and is used to determine whether the battery pack has a reverse connection fault according to the comparison result when the main positive relay and the main negative relay are in the disconnected state; or, when the main negative relay is in the closed state and the main positive relay is in the disconnected state, determine whether the load has a short circuit fault according to the comparison result.

[0009] The present invention provides a safety protection detection circuit for an energy storage system, wherein the energy storage system includes: a battery pack, a main positive relay, a main negative relay, a bus positive pole and a bus negative pole, wherein the two ends of the load can be connected to the bus negative pole and the bus positive pole; or, the two ends of the battery pack can be connected to the bus negative pole and the bus positive pole; thereby realizing the connection of the load or battery pack to the energy storage system, wherein the energy storage system is a high-voltage battery system, which can be connected to an inverter, and the inverter can convert the direct current in the energy storage system into alternating current for use by household electrical loads. Therefore, the inverter connected to the high-voltage battery system can be regarded as the load described in the present invention. Furthermore, the safety protection detection circuit of the energy storage system mainly includes: a first resistor, an operational amplifier, a comparator and a first control module. wherein the first end of the first resistor is connected to the bus positive pole, and the second end of the first resistor is connected to the bus negative pole. The first input terminal of the operational amplifier is connected to one end of the first resistor, and the second input terminal of the operational amplifier is connected to the other end of the first resistor. When the two ends of the first resistor are connected to a high battery pack or a load, the operational amplifier can collect the first voltage at both ends of the first resistor, and then perform operational amplification on the first voltage, so as to finally input the second voltage. The third input terminal of the comparator is connected to the first output terminal of the operational amplifier, and can receive the second voltage output by the operational amplifier, and compare the second voltage with the voltage threshold inside the comparator, and output the comparison result through the second output terminal, wherein when the comparison result is that the second voltage is greater than the voltage threshold, the second output terminal outputs a high level, and when the comparison result is that the second voltage is less than the voltage threshold, the second output terminal outputs a low level. And the voltage threshold can be input to the comparator by the first control module after being connected to the fourth input terminal of the comparator. The first control module is also connected to the second output terminal of the comparator. When the main positive relay and the main negative relay are in a disconnected state, the first control module can judge whether the battery pack has a reverse connection fault according to the comparison result output by the second output terminal. When the main negative relay is in a closed state and the main positive relay is in an open state, the first control module can also determine whether a short circuit fault occurs in the load according to the comparison result output by the second output terminal. Specifically, when the second output terminal outputs a high level, the first control module determines that a reverse connection fault occurs in the battery pack or a short circuit fault occurs in the load, and when the second output terminal outputs a low level, the first control module determines that the current battery pack or load is in a normal state. The present invention forms a safety protection detection circuit of an energy storage system through a first resistor, an operational amplifier, a comparator and a first control module.In the case of parallel operation, that is, when the main positive relay and the main negative relay are in the disconnected state, and the two ends of the first resistor are connected to the two ends of the battery pack, the divided voltage of the first resistor, that is, the first voltage, is obtained, and then the first voltage is operationally amplified through the operational amplifier, and then the voltage after operational amplification, that is, the second voltage, is compared with the voltage threshold in the comparator, and finally the first control module determines whether there is a reverse connection fault according to the level of the comparator output; in the case of non-parallel operation, that is, when the main negative relay is in the closed state, the main positive relay is in the disconnected state, and the two ends of the first resistor are connected to the two ends of the load, the divided voltage of the first resistor, that is, the first voltage, is obtained, and then the first voltage is operationally amplified through the operational amplifier, and then the voltage after operational amplification, that is, the second voltage, is compared with the voltage threshold in the comparator, and finally the first control module determines whether there is a load short circuit fault according to the level of the comparator output, thereby realizing the detection of reverse connection and load short circuit without damaging the FUSE (fuse), thereby saving time and maintenance costs and improving customer experience.

[0010] The safety protection detection circuit of the energy storage system according to the present invention may also have the following technical features:

[0011] In some technical solutions, optionally, the safety protection detection circuit of the energy storage system also includes: a diode, the positive electrode of the diode is connected to the second end of the first resistor, and the negative electrode of the diode is connected to the negative electrode of the bus, for stabilizing the first voltage.

[0012] In this technical solution, the safety protection detection circuit of the energy storage system also includes: a diode. The positive electrode of the diode is connected to the second end of the first resistor, and the negative electrode of the diode is connected to the negative electrode of the busbar, that is, the second end of the first resistor is connected to the negative electrode of the busbar through the diode. By arranging a diode between the first resistor and the battery pack or the load, the first voltage at both ends of the first resistor is stabilized and the first resistor is protected.

[0013] In some technical solutions, optionally, the safety protection detection circuit of the energy storage system also includes: a voltage divider component, the voltage divider component includes at least one resistor, one end of the voltage divider component is connected to the positive pole of the bus, and the other end of the voltage divider component is connected to one end of the first resistor, wherein the voltage divider component is used for voltage division.

[0014] In this technical solution, the safety protection detection circuit of the energy storage system also includes: a voltage divider component. One end of the voltage divider component is connected to the positive electrode of the busbar, and the other end of the voltage divider component is connected to one end of the first resistor, and the voltage divider component can play a voltage dividing role. Further, the voltage divider component may include at least one resistor, and when there are multiple resistors in the voltage divider component, the multiple resistors are connected in series.

[0015] In some technical solutions, optionally, the safety protection detection circuit of the energy storage system also includes: a second resistor, a first end of the second resistor is connected to the first end of the first resistor, and the second end of the second resistor is connected to the first input end of the operational amplifier; a third resistor, a first end of the third resistor is connected to the second end of the first resistor, and the second end of the third resistor is connected to the second input end of the operational amplifier; wherein the second resistor and the third resistor are used to protect the operational amplifier.

[0016] In this technical solution, the safety protection detection circuit of the energy storage system also includes: a second resistor and a third resistor. Among them, the first end of the second resistor is connected to the first end of the first resistor, and the second end of the second resistor is connected to the first input end of the operational amplifier, that is, the first end of the first resistor is connected to the first input end of the operational amplifier through the second resistor, and the second resistor is set between the first resistor and the operational amplifier, thereby providing protection for the operational amplifier and protecting the operational amplifier from excessive voltage or current. The first end of the third resistor is connected to the second end of the first resistor, and the second end of the third resistor is connected to the second input end of the operational amplifier, that is, the second end of the first resistor is connected to the second input end of the operational amplifier through the third resistor, and the third resistor is set between the first resistor and the operational amplifier, thereby providing protection for the operational amplifier and protecting the operational amplifier from excessive voltage or current.

[0017] In some technical schemes, optionally, the safety protection detection circuit of the energy storage system also includes: a fourth resistor, a first end of the fourth resistor is connected to the power supply, and a second end of the fourth resistor is connected to the first input end of the operational amplifier, for protecting the operational amplifier; a fifth resistor, a first end of the fifth resistor is connected to the second input end of the operational amplifier, and a second end of the fifth resistor is connected to the third input end of the comparator, for protecting the comparator.

[0018] In this technical solution, the safety protection detection circuit of the energy storage system also includes: a fourth resistor and a fifth resistor. Among them, the first end of the fourth resistor is connected to the power supply, and the second end of the fourth resistor is connected to the first input terminal of the operational amplifier. The power supply can input the total voltage of the battery pack to the operational amplifier, and then determine the first voltage across the first resistor according to the total voltage. By setting the fourth resistor, protection is provided for the operational amplifier, protecting the operational amplifier from excessive voltage or current. The first end of the fifth resistor is connected to the second input terminal of the operational amplifier, and the second end of the fifth resistor is connected to the third input terminal of the comparator, thereby protecting the comparator from excessive voltage or current.

[0019] According to a second aspect of the present invention, an energy storage system is proposed, wherein the energy storage system includes: a main positive relay; a main negative relay; a battery pack, the battery pack includes a safety protection detection circuit of the energy storage system as in any of the above technical solutions, and the battery pack is respectively connected to the main positive relay and the main negative relay; a second control module, the second control module is connected to the first control module in the safety protection detection circuit of the energy storage system, and the second control module is connected to the main positive relay and the main negative relay.

[0020] The energy storage system provided by the present invention mainly includes: a main positive relay, a main negative relay, a battery pack and a second control module. Among them, the main positive relay is the main relay on the positive side of the energy storage system, and the main negative relay is the main relay on the negative side of the energy storage system. The positive pole of the battery pack is connected to the main positive relay, and the negative pole of the battery pack is connected to the main negative relay. At the same time, the battery pack includes a safety protection detection circuit of the energy storage system of any of the above technical solutions. When the energy storage system needs to be connected to a load or the battery pack needs to be operated in parallel, it is necessary to first use the safety protection detection circuit of the energy storage system to perform reverse connection detection or load short circuit detection. The second control module is connected to the first control module in the safety protection detection circuit of the energy storage system, and the second control module is also connected to the main positive relay and the main negative relay in communication. When the safety protection detection circuit of the energy storage system detects a reverse connection or a load short circuit, the first control module will send the current situation to the second controller, and then the second controller controls the main positive relay and the main negative relay to disconnect. The present invention realizes the detection of reverse connection and load short circuit by arranging a safety protection detection circuit of the energy storage system in the battery pack, thereby ensuring the safety of the energy storage system.

[0021] In some technical solutions, optionally, the battery pack includes: a battery, a positive electrode of the battery is connected to the main positive relay, and a negative electrode of the battery is connected to the main negative relay.

[0022] In this technical solution, the battery pack includes: a battery, wherein the positive electrode of the battery is connected to the main positive relay, and the negative electrode of the battery is connected to the main negative relay, and the battery can provide energy or store energy for the energy storage system.

[0023] In some technical solutions, optionally, the battery pack further includes: a fuse, one end of the fuse is connected to the positive electrode of the battery, and the other end of the fuse is connected to the main positive relay.

[0024] In this technical solution, the battery pack also includes: a fuse. One end of the fuse is connected to the positive electrode of the battery, and the other end of the fuse is connected to the main positive relay, that is, the fuse is located at the connection between the battery and the main positive relay. By setting the fuse between the battery and the main positive relay, when a failure occurs in the energy storage system, the connection between the battery and the main positive relay can be cut off in time, thereby protecting the battery and the main positive relay.

[0025] According to the third aspect of the present invention, a reverse connection detection method for an energy storage system is proposed, which is used for an energy storage system as in any of the above technical solutions. The reverse connection detection method for the energy storage system includes: based on the battery pack being in a parallel state and the main positive relay and the main negative relay being in a disconnected state, obtaining a first voltage across the first resistor; performing an operational amplification process on the first voltage to obtain a second voltage; based on the second voltage being greater than or equal to a voltage threshold, determining that a reverse connection fault occurs, and rejecting the closing request of the main positive relay and the main negative relay; based on the second voltage being less than the voltage threshold, controlling the main positive relay and the main negative relay to close.

[0026] The reverse connection detection method of the energy storage system provided by the present invention is mainly used for the energy storage system in any of the above technical solutions. Among them, the reverse connection detection method of the energy storage system mainly includes: when the battery pack is in a parallel state, and the main positive relay and the main negative relay are both in a disconnected state, that is, when the energy storage system needs to connect a new battery pack, first connect the positive electrode of the new battery pack to the negative electrode of the original battery pack, and connect the negative electrode of the new battery pack to the positive electrode of the original battery pack. At this time, the voltage across the new battery pack will be added to the safety protection detection circuit of the energy storage system, so that the first voltage across the first resistor in the safety protection detection circuit of the energy storage system can be obtained, and then the first voltage is given to the operational amplifier, and the operational amplifier performs operational amplification processing on the first voltage to obtain a second voltage. Further, the second voltage is compared with the voltage threshold in the comparator, wherein when the second voltage is greater than or equal to the voltage threshold, the comparator outputs a high level, so that it can be determined that a reverse connection fault has occurred at present, so the second controller can reject the closing request of the main positive relay and the main negative relay, and can also alarm to remind the user. If the second voltage is less than the voltage threshold, the comparator outputs a low level, so that it can be determined that there is no reverse connection fault at present, so the second controller can control the main positive relay and the main negative relay to close, thereby completing the parallel operation. The present invention collects the voltage across the first resistor when the battery pack is in parallel operation, then performs operational amplifier processing on the collected voltage, and finally determines whether a reverse connection fault currently occurs based on the magnitude relationship between the processed voltage and the voltage threshold, thereby achieving the technical effect of reverse connection detection when the battery pack is in parallel operation.

[0027] According to the fourth aspect of the present invention, a load short circuit detection method for an energy storage system is proposed, which is used for an energy storage system as in any of the above technical solutions. The load short circuit detection method for the energy storage system includes: based on the main negative relay being in a closed state, the main positive relay being in a disconnected state, and the battery pack being connected to the load, obtaining a first voltage across the first resistor; performing operational amplification processing on the first voltage to obtain a second voltage; based on the second voltage being greater than or equal to a voltage threshold, determining that a load short circuit fault occurs, rejecting the closing request of the main positive relay, and controlling the main negative relay to be disconnected; based on the second voltage being less than the voltage threshold, controlling the main positive relay to be closed.

[0028] The load short circuit detection method of the energy storage system provided by the present invention is mainly used for the energy storage system in any of the above technical solutions. Among them, the load short circuit detection method of the energy storage system mainly includes: when the main negative relay is in a closed state, the main positive relay is in a disconnected state, and the battery pack is connected to the load, firstly, the first voltage across the first resistor in the safety protection detection circuit of the energy storage system is collected, and then the first voltage is given to the operational amplifier, and the operational amplifier performs operational amplification processing on the first voltage to obtain a second voltage, and further, the second voltage is compared with the voltage threshold in the comparator, wherein, when the second voltage is greater than or equal to the voltage threshold, the comparator outputs a high level, so that it can be determined that a load short circuit fault has occurred at present, therefore, the second controller can reject the closing request of the main positive relay, and control the main negative relay to be disconnected, and can also alarm to remind the user. If the second voltage is less than the voltage threshold, the comparator outputs a low level, so that it can be determined that there is no load short circuit fault at present, so the second controller can control the main positive relay to close. The present invention collects the voltage across the first resistor when the battery pack is connected to the load, then performs operational amplifier processing on the collected voltage, and finally determines whether a load short circuit fault currently occurs based on the relationship between the processed voltage and the voltage threshold, thereby achieving the technical effect of performing load short circuit detection when the battery pack is connected to the load.

[0029] Additional aspects and advantages of the present invention will become apparent from the following description or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0031] Figure 1 A schematic diagram of the structure of an energy storage system in the related art is shown;

[0032] Figure 2 One of the structural schematic diagrams of the safety protection detection circuit of the energy storage system according to one embodiment of the present invention is shown;

[0033] Figure 3 A second structural schematic diagram of a safety protection detection circuit of an energy storage system according to an embodiment of the present invention is shown;

[0034] Figure 4 One of the structural schematic diagrams of an energy storage system according to an embodiment of the present invention is shown;

[0035] Figure 5 A second structural schematic diagram of an energy storage system according to an embodiment of the present invention is shown;

[0036] Figure 6 A third structural schematic diagram of an energy storage system according to an embodiment of the present invention is shown;

[0037] Figure 7 One of the flow charts of a reverse connection detection method for an energy storage system according to an embodiment of the present invention is shown;

[0038] Figure 8 One of the flow charts of a reverse connection detection method for an energy storage system according to an embodiment of the present invention is shown;

[0039] Fig. 9 One of the flow charts of a method for detecting a load short circuit of an energy storage system according to an embodiment of the present invention is shown;

[0040] Fig.10 A second flow chart of a method for detecting a load short circuit in an energy storage system according to an embodiment of the present invention is shown.

[0041] in, Figure 1 The corresponding relationship between the reference numerals and the component names is as follows:

[0042] 10' energy storage system, 102' main negative relay, 104' main positive relay, 106' fuse, 108' control module, 110' transistor, 112' anti-reverse circuit module, 114' voltage bias resistor, 116' negative electrode, 118' positive electrode, 120' load, 122' battery.

[0043] Figures 2 to 6 The corresponding relationship between the reference numerals and the component names is as follows:

[0044] 10 energy storage system, 102 main positive relay, 104 main negative relay, 106 battery pack, 100 safety protection detection circuit of energy storage system, 108 second control module, R1 first resistor, 114 operational amplifier, 116 comparator, 118 first control module, D1 diode, 122 voltage divider component, R2 sixth resistor, R3 seventh resistor, R4 second resistor, R5 third resistor, R6 fourth resistor, R7 fifth resistor, 110 load, 112 battery, 120 fuse, DC+ bus positive pole, DC- bus negative pole, 1062 first battery pack, 1064 second battery pack. DETAILED DESCRIPTION

[0045] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0046] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0047] like Figure 1 As shown, Figure 1 The energy storage system 10' in the related art mainly includes a battery 122', a main negative relay 102', a main positive relay 104' and a fuse 106'. The circuit for detecting the safety protection of the energy storage system is that the triode is connected to the negative electrode 116' in the energy storage system 10', and then the triode 110' is connected to the anti-reverse circuit module 112', the anti-reverse circuit module 112' is connected to the voltage bias resistor 114', the voltage bias resistor 114' is connected to the positive electrode 118', and the load 120' is respectively connected to the positive electrode 118' and the negative electrode 116', and the anti-reverse circuit module 112' is connected to the control module 108'. Therefore, the related art mainly relies on the anti-reverse connection terminal for reverse connection detection processing, but once the user uses a non-professional wiring harness connection, there will be a risk of short circuit or damage to the fuse.

[0048] like Figures 2 to 6As shown, the present invention proposes a safety protection detection circuit 100 for an energy storage system, comprising: a first resistor R1, one end of the first resistor R1 is connected to the positive electrode DC+ of the bus, and the other end of the first resistor R1 is connected to the negative electrode DC- of the bus; an operational amplifier 114, a first input end of the operational amplifier 114 is connected to one end of the first resistor R1, and a second input end of the operational amplifier 114 is connected to the other end of the first resistor R1, for collecting a first voltage across the first resistor R1 and outputting a second voltage; a comparator 116, a third input end of the comparator 116 is connected to the first input end of the comparator 116. The first control module 118 is connected to the first output terminal of the operational amplifier 114, and is used for collecting the second voltage and outputting the comparison result between the second voltage and the voltage threshold; the first control module 118 is connected to the fourth input terminal of the comparator 116, and is used for judging whether the battery pack 106 has a reverse connection fault according to the comparison result when the main positive relay 102 and the main negative relay 104 are in the disconnected state, or judging whether the load 110 has a short circuit according to the comparison result when the main negative relay 104 is in the closed state and the main positive relay 102 is in the disconnected state.

[0049] The present invention provides a safety protection detection circuit 100 for an energy storage system, wherein the energy storage system 10 includes: a battery pack 106, a main positive relay 102, a main negative relay 104, a bus positive pole DC+ and a bus negative pole DC-, wherein the two ends of the load 110 can be connected to the bus negative pole DC- and the bus positive pole DC+ respectively; or, the two ends of the battery pack 106 can be connected to the bus negative pole DC- and the bus positive pole DC+ respectively, so as to realize the connection of the load 110 or the battery pack 106 to the energy storage system 10, wherein the energy storage system 10 is a high-voltage battery system, which can be connected to an inverter, and the inverter can convert the direct current in the energy storage system 10 into alternating current for use by household electrical loads. Therefore, in some embodiments, the inverter connected to the high-voltage battery system can be regarded as the load 110 described in the present invention. Further, the safety protection detection circuit 100 of the energy storage system mainly includes: a first resistor R1, an operational amplifier 114, a comparator 116 and a first control module 118. The first end of the first resistor R1 is connected to the positive pole DC+ of the bus, and the second end of the first resistor R1 is connected to the negative pole DC- of the bus. The first input end of the operational amplifier 114 is connected to the first end of the first resistor R1, and the second input end of the operational amplifier 114 is connected to the second end of the first resistor R1. When the two ends of the first resistor R1 are connected to the high battery pack or the load 110, the operational amplifier 114 can collect the first voltage across the first resistor R1, and then perform operational amplification on the first voltage, so as to finally input the second voltage. The third input end of the comparator 116 is connected to the first output end of the operational amplifier 114, and can receive the second voltage output by the operational amplifier 114, and compare the second voltage with the voltage threshold inside the comparator 116, and output the comparison result through the second output end, wherein when the comparison result is that the second voltage is greater than the voltage threshold, the second output end outputs a high level, and when the comparison result is that the second voltage is less than the voltage threshold, the second output end outputs a low level. And the voltage threshold can be input to the comparator 116 by the first control module 118 after being connected to the fourth input terminal of the comparator 116. The first control module 118 is also connected to the second output terminal of the comparator 116. When the main positive relay 102 and the main negative relay 104 are in the disconnected state, the first control module 118 can determine whether the battery pack 106 has a reverse connection fault according to the comparison result output by the second output terminal. When the main negative relay 104 is in the closed state and the main positive relay 102 is in the disconnected state, the first control module 118 can also determine whether the load 110 has a short circuit fault according to the comparison result output by the second output terminal. Specifically, when the second output terminal outputs a high level, the first control module 118 determines that the battery pack 106 has a reverse connection fault or the load 110 has a short circuit fault. When the second output terminal outputs a low level, the first control module 118 determines that the current battery pack 106 or the load 110 is in a normal state.The present invention forms a safety protection detection circuit 100 of an energy storage system through a first resistor R1, an operational amplifier 114, a comparator 116 and a first control module 118. In the case of parallel operation, the parallel operation is as follows. Figure 6 As shown, the first battery group 1062 and the second battery group 1064 are connected to the same DC bus and participate in charging and discharging together. Then, when the main positive relay 102 and the main negative relay 104 are in the disconnected state, the divided voltage of the first resistor R1, that is, the first voltage, is obtained, and then the first voltage is amplified by the operational amplifier 114, and then the voltage after the operational amplification, that is, the second voltage, is compared with the voltage threshold in the comparator 116, and finally the first control module 118 determines whether there is a reverse connection fault according to the level of the output of the comparator 116; in the case of non-parallel operation, that is, when the main negative relay 104 is in the closed state and the main positive relay 102 is in the disconnected state, the divided voltage of the first resistor R1, that is, the first voltage, is obtained, and then the first voltage is amplified by the operational amplifier 114, and then the voltage after the operational amplification, that is, the second voltage, is compared with the voltage threshold in the comparator 116, and finally the first control module 118 determines whether there is a load 110 short-circuit fault according to the level of the output of the comparator 116, thereby realizing the detection of reverse connection and load 110 short-circuit without damaging the FUSE (fuse), thereby saving time and maintenance costs and improving customer experience.

[0050] For example, assuming that the total voltage of the battery pack 106 is U0, the voltage of the first resistor R1 is u1, and the output voltage of the operational amplifier is U1, when performing reverse connection detection, Figure 2 As shown, when the energy storage system 10 is normally connected, there is no voltage at both ends of the first resistor R1, U1 is also a default system voltage, and the voltage threshold Uref of the comparator 116 is greater than U1, the comparator 116 outputs a low level, and the first control module 118 determines that there is no reverse connection fault. When the energy storage system 10 is reversely connected, the safety protection detection circuit 100 of the energy storage system collects the voltage u1 of the first resistor R1 = R1×(U0-U D1 ) / (R1+R2+R3), where U Di is the voltage across the diode D1, the voltage threshold Uref of the comparator 116 is less than U1, the comparator 116 outputs a high level, the first control module 118 determines a reverse connection fault, and sends a reverse connection fault signal to the second control module 108. The system fault will not close the relay of the main circuit.

[0051] Furthermore, if Figure 3 As shown, before the load 110 is short-circuited, the main negative relay 104 needs to be closed, and then the voltage of the first resistor R1 for short-circuit detection is u1=R1×(1.6-U D1) / (R6+R4+R1+RL), where U Di is the voltage across the diode D1, and RL is the resistance of the load 110. The op amp outputs a voltage U1, and U1>Uref, the comparator 116 outputs a high level, the first control module 118 determines that the load 110 is short-circuited, and sends a short-circuit fault signal to the second control module 108. In case of system failure, the main positive relay 102 will not be closed, and the main negative relay 104 will be disconnected to ensure system safety.

[0052] In some technical solutions, optionally, as Figure 2 and Figure 3 As shown, the safety protection detection circuit 100 of the energy storage system also includes: a diode D1, the positive electrode of the diode D1 is connected to the second end of the first resistor R1, and the negative electrode of the diode D1 is connected to the negative electrode DC- of the bus, for stabilizing the first voltage.

[0053] In this technical solution, the safety protection detection circuit 100 of the energy storage system further includes: a diode D1. The positive electrode of the diode D1 is connected to the second end of the first resistor R1, and the negative electrode of the diode D1 is connected to the negative electrode DC- of the busbar, that is, the first end of the first resistor R1 is connected to the negative electrode DC- of the power supply through the diode D1. By arranging the diode D1 between the first resistor R1 and the battery pack 106 or the load 110, the first voltage at both ends of the first resistor R1 is stabilized, and the first resistor R1 is also protected.

[0054] In some embodiments, optionally, the safety protection detection circuit 100 of the energy storage system also includes: a voltage divider component 122, the voltage divider component 122 includes at least one resistor, one end of the voltage divider component 122 is connected to the bus positive pole DC+, and the other end of the voltage divider component 122 is connected to one end of the first resistor R1, wherein the voltage divider component 122 is used for voltage division.

[0055] In this embodiment, the safety protection detection circuit 100 of the energy storage system also includes: a voltage divider component 122. Among them, one end of the voltage divider component 122 is connected to one end of the bus positive electrode DC+, and the other end of the voltage divider component 122 is connected to one end of the first resistor R1, and the voltage divider component 122 can play a voltage dividing role. Further, the voltage divider component 122 may include at least one resistor, and when there are multiple resistors in the voltage divider component 122, the multiple resistors are in series. Among them, the voltage divider component 122 may include a sixth resistor R2 and a seventh resistor R3. Among them, the sixth resistor R2 is connected in series with the seventh resistor R3, and at the same time, the first end of the sixth resistor R2 is connected to the positive electrode of the load 110 or the battery pack 106, the second end of the sixth resistor R2 is connected to the first end of the seventh resistor R3, and the second end of the seventh resistor R3 is connected to the first end of the first resistor R1, that is, the first resistor R1 is connected to the positive electrode of the load 110 or the battery pack 106 through the sixth resistor R2 and the seventh resistor R3 connected in series. By disposing the sixth resistor R2 and the seventh resistor R3 between the first resistor R1 and the load 110 or the battery pack 106 , the voltage of the first resistor R1 is divided by the sixth resistor R2 and the seventh resistor R3 .

[0056] In some technical solutions, optionally, as Figure 3 As shown, the safety protection detection circuit 100 of the energy storage system also includes: a second resistor R4, a first end of the second resistor R4 is connected to the first end of the first resistor R1, and a second end of the second resistor R4 is connected to the first input end of the operational amplifier 114; a third resistor R5, a first end of the third resistor R5 is connected to the second end of the first resistor R1, and a second end of the third resistor R5 is connected to the second input end of the operational amplifier 114; wherein the second resistor R4 and the third resistor R5 are used to protect the operational amplifier 114.

[0057] In this technical solution, the safety protection detection circuit 100 of the energy storage system also includes: a second resistor R4 and a third resistor R5. Among them, the first end of the second resistor R4 is connected to the first end of the first resistor R1, and the second end of the second resistor R4 is connected to the first input end of the operational amplifier 114, that is, the first end of the first resistor R1 is connected to the first input end of the operational amplifier 114 through the second resistor R4, and the second resistor R4 is set between the first resistor R1 and the operational amplifier 114, thereby providing protection for the operational amplifier 114, and protecting the operational amplifier 114 from excessive voltage or current. The first end of the third resistor R5 is connected to the second end of the first resistor R1, and the second end of the third resistor R5 is connected to the second input end of the operational amplifier 114, that is, the second end of the first resistor R1 is connected to the second input end of the operational amplifier 114 through the third resistor R5, and the third resistor R5 is set between the first resistor R1 and the operational amplifier 114, thereby providing protection for the operational amplifier 114, and protecting the operational amplifier 114 from excessive voltage or current.

[0058] In some technical solutions, optionally, as Figure 3 As shown, the safety protection detection circuit 100 of the energy storage system also includes: a fourth resistor R6, a first end of the fourth resistor R6 is connected to the power supply, and a second end of the fourth resistor R6 is connected to the first input end of the operational amplifier 114, for protecting the operational amplifier 114; a fifth resistor R7, a first end of the fifth resistor R7 is connected to the second input end of the operational amplifier 114, and a second end of the fifth resistor R7 is connected to the third input end of the comparator 116, for protecting the comparator 116.

[0059] In this technical solution, the safety protection detection circuit 100 of the energy storage system also includes: a fourth resistor R6 and a fifth resistor R7. Among them, the first end of the fourth resistor R6 is connected to the power supply, and the second end of the fourth resistor R6 is connected to the first input end of the operational amplifier 114. The power supply can input the total voltage of the battery pack 106 to the operational amplifier 114, and then determine the first voltage across the first resistor R1 according to the total voltage. By setting the fourth resistor R6, protection is provided for the operational amplifier 114, and the operational amplifier 114 is protected from excessive voltage or current. The first end of the fifth resistor R7 is connected to the second input end of the operational amplifier 114, and the second end of the fifth resistor R7 is connected to the third input end of the comparator 116, thereby protecting the comparator 116 and protecting the comparator 116 from excessive voltage or current.

[0060] like Figure 4As shown, according to the present invention, an energy storage system 10 is proposed, wherein the energy storage system 10 includes: a main positive relay 102; a main negative relay 104; a battery pack 106, the battery pack 106 includes a safety protection detection circuit 100 of the energy storage system as in any of the above embodiments, and the battery pack 106 is respectively connected to the main positive relay 102 and the main negative relay 104; a second control module 108, the second control module 108 is connected to the first control module 118 in the safety protection detection circuit 100 of the energy storage system, and the second control module 108 is connected to the main positive relay 102 and the main negative relay 104.

[0061] The energy storage system 10 provided by the present invention is as follows: Figure 4 As shown, it mainly includes: a main positive relay 102, a main negative relay 104, a battery pack 106 and a second control module 108. Among them, the main positive relay 102 is the main relay on the positive side of the energy storage system 10, and the main negative relay 104 is the main relay on the negative side of the energy storage system 10. The positive pole of the battery pack 106 is connected to the main positive relay 102, and the negative pole of the battery pack 106 is connected to the main negative relay 104. At the same time, the battery pack 106 includes the safety protection detection circuit 100 of the energy storage system of any of the above technical solutions. When the energy storage system 10 needs to be connected to the load 110 or the battery pack 106 needs to be operated in parallel, it is necessary to first use the safety protection detection circuit 100 of the energy storage system to perform reverse connection detection or load 110 short circuit detection. The second control module 108 is connected to the first control module 118 in the safety protection detection circuit 100 of the energy storage system through RS485 communication, and the second control module 108 is also connected to the main positive relay 102 and the main negative relay 104. When the safety protection detection circuit 100 of the energy storage system detects a reverse connection or a short circuit of the load 110, the first control module 118 will send the current situation to the second controller, and then the second controller controls the main positive relay 102 and the main negative relay 104 to disconnect. Furthermore, the energy storage system 10 also includes a battery 112 and a fuse 120. The present invention realizes the detection of reverse connection and short circuit of the load 110 by setting the safety protection detection circuit 100 of the energy storage system in the battery pack 106, thereby ensuring the safety of the energy storage system 10.

[0062] In some embodiments, optionally, the battery pack 106 includes: a battery 112 , a positive electrode of the battery 112 is connected to the main positive relay 102 , and a negative electrode of the battery 112 is connected to the main negative relay 104 .

[0063] In this embodiment, the battery pack 106 includes a battery 112 , wherein the positive electrode of the battery 112 is connected to the main positive relay 102 , and the negative electrode of the battery 112 is connected to the main negative relay 104 . The battery 112 can provide energy or store energy for the energy storage system 10 .

[0064] In some embodiments, optionally, the battery pack 106 further includes: a fuse 120 , one end of the fuse 120 is connected to the positive electrode of the battery 112 , and the other end of the fuse 120 is connected to the main positive relay 102 .

[0065] In this embodiment, the battery pack 106 further includes: a fuse 120. One end of the fuse 120 is connected to the positive electrode of the battery 112, and the other end of the fuse 120 is connected to the main positive relay 102, that is, the fuse 120 is located at the connection between the battery 112 and the main positive relay 102. By setting the fuse 120 between the battery 112 and the main positive relay 102, when a fault occurs in the energy storage system 10, the connection between the battery 112 and the main positive relay 102 can be cut off in time, thereby protecting the battery 112 and the main positive relay 102.

[0066] Figure 7 One of the flow diagrams of a reverse connection detection method for an energy storage system according to an embodiment of the present invention is shown; wherein the reverse connection detection method for an energy storage system comprises:

[0067] Step 702: Based on the battery pack being in a parallel state, and the main positive relay and the main negative relay being in a disconnected state, obtaining a first voltage across the first resistor;

[0068] Step 704: performing operational amplification processing on the first voltage to obtain a second voltage;

[0069] Step 706: When the second voltage is greater than or equal to the voltage threshold, it is determined that a reverse connection fault occurs, and a closing request of the main positive relay and the main negative relay is rejected;

[0070] Step 708: When the second voltage is less than the voltage threshold, control the main positive relay and the main negative relay to close.

[0071] The reverse connection detection method of the energy storage system provided by the present invention is mainly used for the energy storage system 10 in any of the above-mentioned technical solutions. Among them, the reverse connection detection method of the energy storage system mainly includes: when the battery pack 106 is in a parallel state, and the main positive relay 102 and the main negative relay 104 are both in a disconnected state, that is, when the energy storage system 10 needs to connect a new battery pack 106, first connect the positive pole of the new battery pack 106 with the negative pole of the original battery pack 106, and connect the negative pole of the new battery pack 106 with the positive pole of the original battery pack 106. At this time, the voltage across the new battery pack 106 will be added to the safety protection detection circuit 100 of the energy storage system, so the safety of the energy storage system can be obtained. The first voltage across the first resistor R1 in the protection detection circuit 100 is then given to the operational amplifier 114, and the operational amplifier 114 performs operational amplification processing on the first voltage to obtain a second voltage. Further, the second voltage is compared with the voltage threshold in the comparator 116, wherein when the second voltage is greater than the voltage threshold, the comparator 116 outputs a high level, so that it can be determined that a reverse connection fault has occurred at present, and therefore, the second controller can reject the closing request of the main positive relay 102 and the main negative relay 104, and can also alarm to remind the user. If the second voltage is less than the voltage threshold, the comparator 116 outputs a low level, so that it can be determined that there is no reverse connection fault at present, so the second controller can control the main positive relay 102 and the main negative relay 104 to close, thereby completing the parallel operation. The present invention collects the voltage across the first resistor R1 when the battery pack 106 is in parallel operation, then performs operational amplifier processing on the collected voltage, and finally determines whether a reverse connection fault currently occurs based on the relationship between the processed voltage and the voltage threshold, thereby achieving the technical effect of reverse connection detection when the battery pack 106 is in parallel operation.

[0072] Figure 8 A second flow chart of a reverse connection detection method for an energy storage system according to an embodiment of the present invention is shown; wherein the reverse connection detection method for an energy storage system comprises:

[0073] Step 802: reverse connection detection starts;

[0074] Step 804: the module collects the reverse voltage value;

[0075] Step 806: the operational amplifier outputs a reverse voltage Uo;

[0076] Step 808: Determine whether the reverse voltage Uo is greater than the voltage threshold Uref; if the result is yes, execute step 810; if the result is no, execute step 814;

[0077] Step 810: A reverse connection fault is detected;

[0078] Step 812: The fault reporting BCU module rejects the relay closing request;

[0079] Step 814: The BCU module controls the relay to close.

[0080] like Figure 5 As shown, when two battery packs 106 are connected in parallel, the positive electrode of the original battery pack 106 is connected to the negative electrode of the newly added battery pack 106, and the negative electrode of the original battery pack 106 is connected to the positive electrode of the newly added battery pack 106. At this time, the safety protection detection circuit 100 of the energy storage system is turned on, and the reverse connection module detects the voltage of the sampling resistor and the first resistor R1, and outputs the voltage Uo, i.e., the second voltage, through the operational amplifier 114, and compares the Uo voltage with the voltage threshold Uref in the comparator 116 to determine the size. When the comparator 116 outputs a high level, it means that the reverse connection fault of the parallel connection is detected. The fault is reported to the BCU control module through communication with the BCU (Battery Control Unit, battery control unit) module, i.e., the second control module 108. The BCU module cannot close the main positive relay 102 and the main negative relay 104; if the comparator 116 outputs a low level, it is detected that the system is connected normally, and the MCU (Microcontroller The micro control unit (MCU) module, namely the first control module 118 , has no fault output, and the BCU module closes the main positive relay 102 and the main negative relay 104 .

[0081] Fig. 9 One of the flow diagrams of a method for detecting a load short circuit of an energy storage system according to an embodiment of the present invention is shown; wherein the method for detecting a load short circuit of an energy storage system comprises:

[0082] Step 902: based on the main negative relay being in a closed state, the main positive relay being in an open state, and the battery pack being connected to the load, obtaining a first voltage across the first resistor;

[0083] Step 904: performing operational amplification processing on the first voltage to obtain a second voltage;

[0084] Step 906: when the second voltage is greater than or equal to the voltage threshold, it is determined that a load short circuit fault occurs, the closing request of the main positive relay is rejected, and the main negative relay is controlled to be opened;

[0085] Step 908: When the second voltage is less than the voltage threshold, control the main positive relay to close.

[0086] The load short-circuit detection method of the energy storage system provided by the present invention is mainly used for the energy storage system 10 in any of the above technical solutions. Among them, the load 110 short-circuit detection method of the energy storage system 10 mainly includes: when the main negative relay 104 is in a closed state, the main positive relay 102 is in a disconnected state, and the battery pack 106 is connected to the load 110, firstly collect the first voltage across the first resistor R1 in the safety protection detection circuit 100 of the energy storage system, and then give the first voltage to the operational amplifier 114, the operational amplifier 114 performs operational amplification processing on the first voltage to obtain a second voltage, and further, the second voltage is compared with the voltage threshold in the comparator 116, wherein when the second voltage is greater than the voltage threshold, the comparator 116 outputs a high level, so that it can be determined that the load 110 short-circuit fault currently occurs, therefore, the second controller can reject the closing request of the main positive relay 102, and control the main negative relay 104 to be disconnected, and can also alarm to remind the user. If the second voltage is less than the voltage threshold, the comparator 116 outputs a low level, so that it can be determined that there is no short-circuit fault in the load 110 at present, and the second controller can control the main positive relay 102 to close. The present invention collects the voltage across the first resistor R1 when the battery pack 106 is connected to the load 110, then performs operational amplifier processing on the collected voltage, and finally determines whether there is a short-circuit fault in the load 110 at present according to the magnitude relationship between the processed voltage and the voltage threshold, thereby achieving the technical effect of performing short-circuit detection of the load 110 when the battery pack 106 is connected to the load 110.

[0087] Fig.10 A second flow chart of a method for detecting a load short circuit of an energy storage system according to an embodiment of the present invention is shown; wherein the method for detecting a load short circuit of an energy storage system comprises:

[0088] Step 1002: Load short circuit detection starts;

[0089] Step 1004: the main negative relay is closed first;

[0090] Step 1006: Obtain the sampling resistor voltage;

[0091] Step 1008: Determine whether the reverse voltage Uo is greater than the voltage threshold Uref; if the result is yes, execute step 1010; if the result is no, execute step 1016;

[0092] Step 1010: MCU detects a load short circuit fault;

[0093] Step 1012: The fault is reported to the BCU module to reject the main positive relay closing request;

[0094] Step 1014: the main negative relay is disconnected;

[0095] Step 1016: The BCU control module controls the main positive relay to close.

[0096] like Figure 6 As shown, when the load 110 is short-circuited, the main negative relay 104 is in a closed state, and the load 110 is connected to the positive and negative electrodes of the energy storage system 10, wherein R1 is a sampling resistor, i.e., the first resistor R1, and the resistance of the load 110 is 100 ohms. The short-circuit detection circuit of the load 110 collects the voltage of the sampling resistor, and the voltage output by the operational amplifier is greater than the voltage threshold Uref of the comparator 116. The comparator 116 outputs a high level, and the MCU determines that the load 110 is short-circuited and reports the fault to the BCU module. The BCU controller will not close the main positive relay 102, and will disconnect the main negative relay 104. If the comparator 116 outputs a low level, it is detected that the load 110 is normal, the MCU has no fault, and the BCU control module closes the main positive relay 102.

[0097] In the description of this specification, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance unless otherwise clearly specified and limited; the terms "connection", "installation", "fixation" and the like should be understood in a broad sense, for example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0098] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0099] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A safety protection detection circuit for an energy storage system, the energy storage system comprising: A battery pack, a main positive relay, a main negative relay, a bus negative electrode and a bus positive electrode, wherein the two ends of the load are respectively connected to the bus negative electrode and the bus positive electrode; or, the two ends of the battery pack are respectively connected to the bus negative electrode and the bus positive electrode; characterized in that, The safety protection detection circuit of the energy storage system comprises: a first resistor, one end of the first resistor being connected to the positive electrode of the busbar, and the other end of the first resistor being connected to the negative electrode of the busbar; an operational amplifier, wherein a first input terminal of the operational amplifier is connected to one end of the first resistor, and a second input terminal of the operational amplifier is connected to the other end of the first resistor, and is used to collect a first voltage across the first resistor and output a second voltage; a comparator, wherein a third input terminal of the comparator is connected to the first output terminal of the operational amplifier, and is used to collect the second voltage and output a comparison result between the second voltage and a voltage threshold; A first control module, the first control module is connected to the second output terminal of the comparator, and is used for: When the main positive relay and the main negative relay are in the disconnected state, judging whether the battery pack has a reverse connection fault according to the comparison result; or, When the main negative relay is in a closed state and the main positive relay is in an open state, it is determined whether a short circuit fault occurs in the load according to the comparison result.

2. The safety protection detection circuit of the energy storage system according to claim 1, characterized in that: Also includes: A diode, wherein the anode of the diode is connected to the second end of the first resistor, and the cathode of the diode is connected to the cathode of the bus, for stabilizing the first voltage.

3. The safety protection detection circuit of the energy storage system according to claim 2, characterized in that: Also includes: A voltage divider component, wherein the voltage divider component includes at least one resistor, one end of the voltage divider component is connected to the positive electrode of the busbar, and the other end of the voltage divider component is connected to one end of the first resistor, wherein the voltage divider component is used for voltage division.

4. The safety protection detection circuit of the energy storage system according to claim 1, characterized in that: Also includes: a second resistor, wherein a first end of the second resistor is connected to a first end of the first resistor, and a second end of the second resistor is connected to the first input end of the operational amplifier; a third resistor, wherein a first end of the third resistor is connected to a second end of the first resistor, and a second end of the third resistor is connected to the second input end of the operational amplifier; Wherein, the second resistor and the third resistor are used to protect the operational amplifier.

5. The safety protection detection circuit of the energy storage system according to claim 4, characterized in that: Also includes: a fourth resistor, wherein a first end of the fourth resistor is connected to a power supply, and a second end of the fourth resistor is connected to the first input end of the operational amplifier, and is used to protect the operational amplifier; A fifth resistor, wherein a first end of the fifth resistor is connected to the second input end of the operational amplifier, and a second end of the fifth resistor is connected to the third input end of the comparator, for protecting the comparator.

6. An energy storage system, characterized in that: include: Main positive relay; Main negative relay; A battery pack, the battery pack comprising a safety protection detection circuit of the energy storage system according to any one of claims 1 to 5, the battery pack being connected to the main positive relay and the main negative relay respectively; A second control module, wherein the second control module is connected to the first control module in the safety protection detection circuit of the energy storage system, and the second control module is also connected to the main positive relay and the main negative relay.

7. The energy storage system according to claim 6, characterized in that: The battery pack comprises: A battery, wherein the positive electrode of the battery is connected to the main positive relay, and the negative electrode of the battery is connected to the main negative relay.

8. The energy storage system according to claim 7, characterized in that: The battery pack further comprises: A fuse, one end of the fuse is connected to the positive electrode of the battery, and the other end of the fuse is connected to the main positive relay.

9. A reverse connection detection method for an energy storage system, used for the energy storage system as claimed in any one of claims 6 to 8, characterized in that: include: Based on the battery pack being in a parallel state and the main positive relay and the main negative relay being in a disconnected state, obtaining a first voltage across the first resistor; Performing operational amplification processing on the first voltage to obtain a second voltage; When the second voltage is greater than or equal to a voltage threshold, it is determined that a reverse connection fault occurs, and a closing request of the main positive relay and the main negative relay is rejected; When the second voltage is less than a voltage threshold, the main positive relay and the main negative relay are controlled to be closed.

10. A load short circuit detection method for an energy storage system, used in the energy storage system according to any one of claims 6 to 8, characterized in that: include: Based on the main negative relay being in a closed state, the main positive relay being in an open state, and the battery pack being connected to a load, obtaining a first voltage across the first resistor; Performing operational amplification processing on the first voltage to obtain a second voltage; When the second voltage is greater than or equal to a voltage threshold, it is determined that a load short circuit fault occurs, a closing request of the main positive relay is rejected, and the main negative relay is controlled to be opened; When the second voltage is less than a voltage threshold, the main positive relay is controlled to be closed.

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