An insulation resistance detection system and method for a multi-cluster parallel system of energy storage batteries

Abstract

The application provides an insulation resistance detection system and method of a multi-cluster parallel system of energy storage batteries, and relates to the technical field of energy storage batteries, which comprises: a plurality of insulation resistance detection modules connected between the positive and negative poles of corresponding battery clusters; a plurality of battery cluster controllers used for collecting the parallel-in states of the corresponding battery clusters; and a total controller used for obtaining the parallel-in states of the battery clusters, and when the parallel-in states indicate that the battery clusters are currently connected to the multi-cluster parallel system of energy storage batteries, the corresponding battery cluster controllers are added to a control set, and detection start instructions are sequentially sent to the battery cluster controllers in the control set, so that only one battery cluster controller in the control set controls the corresponding insulation resistance detection module to detect the insulation resistance of the corresponding battery cluster at the same time according to the detection start instruction. The beneficial effect is that high-precision real-time insulation detection is realized, and the service life of the insulation resistance detection module is effectively prolonged.

Description

Technical Field

[0001] This invention relates to the field of energy storage battery technology, and in particular to an insulation resistance detection system and method for a multi-cluster parallel energy storage battery system. Background Technology

[0002] In the new energy industry, the development of energy storage technology provides strong support for the efficient use of new energy sources and is of great significance for achieving my country's energy transition and accelerating the growth of clean energy installed capacity. For energy storage technology, the safe management and effective control of energy storage batteries are fundamental.

[0003] To further increase battery capacity and meet greater energy requirements, in the application of batteries, after being connected in series to form battery clusters, multiple battery clusters are often connected in parallel. Each battery cluster has a main positive contactor and a main negative contactor installed on its positive and negative circuits, respectively, and is also connected to a circuit breaker to achieve electrical protection between battery clusters.

[0004] Insulation resistance testing is a crucial indicator of the quality of energy storage batteries and new energy vehicles. Its real-time automatic detection serves as a warning of internal system faults such as leakage, short circuits, and discharges, making it an essential component of system protection. In practical applications, the DC bus voltage of energy storage systems can reach over 500V. If a battery experiences leakage, a short circuit, or internal discharge, it can lead to serious system safety hazards. Therefore, insulation testing within the system is indispensable. A thorough study and analysis of battery system insulation testing technology is necessary.

[0005] Existing insulation detection technologies mainly focus on the detection and calculation within battery clusters, rarely considering the impact of coupling between battery clusters during parallel operation on the system insulation resistance. Therefore, there are shortcomings in insulation accuracy calculation, which may even lead to false alarms or missed alarms for insulation faults. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides an insulation resistance detection system for a multi-cluster parallel energy storage battery system, wherein the multi-cluster parallel energy storage battery system includes multiple battery clusters connected in parallel; the insulation resistance detection system includes:

[0007] Multiple insulation resistance detection modules are connected in parallel between the positive and negative terminals of the corresponding battery clusters;

[0008] Multiple battery cluster controllers are connected to the corresponding insulation resistance detection modules to collect the connection status of the corresponding battery clusters;

[0009] The main controller is connected to each of the battery cluster controllers and is used to obtain the connection status of each battery cluster. When the connection status indicates that the battery cluster is currently connected to the energy storage battery multi-cluster parallel system, the corresponding battery cluster controller is added to the control set, and a detection start command is sent to each battery cluster controller in the control set in sequence, so that at the same time only one battery cluster controller in the control set controls the corresponding insulation resistance detection module to detect the insulation resistance value of the corresponding battery cluster according to the detection start command.

[0010] Each of the battery cluster controllers is further configured to, when the parallel state indicates that the battery cluster is not currently connected to the energy storage battery multi-cluster parallel system, control the insulation resistance detection module to detect the insulation resistance value of the corresponding battery cluster and report it to the main controller.

[0011] Preferably, the positive electrode of each battery cluster is connected to the positive electrode of the energy storage battery multi-cluster parallel system through a main positive circuit, and the negative electrode of each battery cluster is connected to the negative electrode of the energy storage battery multi-cluster parallel system through a main negative circuit. A main positive contactor is provided on the main positive circuit, a main negative contactor is provided on the main negative circuit, and a cluster circuit breaker is also provided on the main positive circuit and the main negative circuit.

[0012] The battery cluster controller is connected to the main positive contactor, the main negative contactor, and the cluster circuit breaker, and is used to collect the opening and closing states of the main positive contactor, the main negative contactor, and the cluster circuit breaker as the parallel connection state of the battery cluster.

[0013] Preferably, the insulation resistance detection module includes:

[0014] A first resistor, a second resistor, a third resistor, and a fourth resistor are connected in series between the positive terminal and the negative terminal of the corresponding battery cluster;

[0015] The first switch is connected in parallel across the two ends of the second resistor;

[0016] The second switch has one end connected between the second resistor and the third resistor, and the other end connected to the grounding terminal of the energy storage battery multi-cluster parallel system.

[0017] The third switch is connected between the fourth resistor and the negative terminal of the battery cluster;

[0018] A first insulation resistor, one end of which is connected to the positive terminal of the battery cluster, and the other end of which is connected to one end of the second switch;

[0019] The second insulation resistor has one end connected to one end of the second switch and the other end connected to the negative terminal of the battery cluster.

[0020] Preferably, the main controller includes;

[0021] The first control unit is used to obtain the connection status of each battery cluster. When the connection status indicates that the battery cluster is currently connected to the energy storage battery multi-cluster parallel system, the corresponding battery cluster controllers are sequentially numbered and added to the control set, and the smallest number in the control set is taken as the current number.

[0022] The second control unit, connected to the first control unit, is used to send a detection start command to the battery cluster controller corresponding to the current number, and to send a detection disable command to the battery cluster controllers corresponding to other numbers in the control set. At the same time, it starts a timer to control the battery cluster controller that receives the detection start command to control the corresponding insulation resistance detection module to detect the insulation resistance value of the corresponding battery cluster.

[0023] The third control unit, connected to the second control unit, is used to reset the timing result to zero when the timing result reaches a preset value, and to increment the current number by one to update the current number and send it to the second control unit, until all battery cluster controllers in the control set have received the detection start command.

[0024] Preferably, in the first control unit, each battery cluster controller is sequentially numbered according to its unique device code.

[0025] Preferably, the battery cluster controller includes:

[0026] The first cluster control unit is used to control the second switch and the third switch to close, and to control the first switch to open, so as to acquire the first voltage divider voltage at the sampling point set between the third resistor and the fourth resistor;

[0027] The second cluster control unit is used to control the closing of the second switch and the third switch, and to control the closing of the first switch, so as to acquire the second voltage divider voltage at the sampling point set between the third resistor and the fourth resistor;

[0028] The acquisition unit is used to acquire the main positive and main negative voltages between the positive and negative terminals of the battery cluster.

[0029] The resistance calculation unit is connected to the first cluster control unit, the second cluster control unit and the acquisition unit respectively, and is used to calculate the insulation resistance values ​​of the first insulation resistance and the second insulation resistance based on the first voltage divider voltage, the second voltage divider voltage and the main positive and main negative voltages respectively.

[0030] Preferably, the formula for calculating the insulation resistance is as follows:

[0031]

[0032] in,

[0033] Wherein, RA represents the insulation resistance value of the first insulation resistor, RB represents the insulation resistance value of the second insulation resistor, R1 represents the resistance value of the first resistor, R2 represents the resistance value of the second resistor, R3 represents the resistance value of the third resistor, R4 represents the resistance value of the fourth resistor, VPN represents the main positive and main negative voltages, Vi1 represents the first voltage divider voltage, and Vi2 represents the second voltage divider voltage.

[0034] This invention also provides a method for detecting the insulation resistance of a multi-cluster parallel energy storage battery system, applied to the aforementioned insulation resistance detection system. The insulation resistance detection method includes:

[0035] Step S1: The main controller acquires the connection status of each battery cluster and determines whether the corresponding battery cluster is currently connected to the energy storage battery multi-cluster parallel system based on the connection status.

[0036] If so, proceed to step S2;

[0037] If not, proceed to step S3;

[0038] In step S2, the main controller adds the corresponding battery cluster controller to the control set and sends a detection start command to each battery cluster controller in the control set in sequence, so that at any given time only one battery cluster controller in the control set controls the corresponding insulation resistance detection module to detect the insulation resistance value of the corresponding battery cluster according to the detection start command, and then returns to step S1.

[0039] In step S3, the battery cluster controller controls the corresponding insulation resistance detection module to detect the insulation resistance value of the corresponding battery cluster and report it to the main controller.

[0040] Preferably, the positive electrode of each battery cluster is connected to the positive electrode of the energy storage battery multi-cluster parallel system through a main positive circuit, and the negative electrode of each battery cluster is connected to the negative electrode of the energy storage battery multi-cluster parallel system through a main negative circuit. A main positive contactor is provided on the main positive circuit, a main negative contactor is provided on the main negative circuit, and a cluster circuit breaker is also provided on the main positive circuit and the main negative circuit.

[0041] In step S1, the battery cluster controller is connected to the main positive contactor, the main negative contactor, and the cluster circuit breaker, and is used to collect the opening and closing states of the main positive contactor, the main negative contactor, and the cluster circuit breaker as the parallel connection state of the battery cluster and send them to the main controller.

[0042] Preferably, step S2 includes:

[0043] Step S21: The main controller obtains the connection status of each battery cluster. When the connection status indicates that the battery cluster is currently connected to the energy storage battery multi-cluster parallel system, the corresponding battery cluster controllers are sequentially numbered and added to the control set, and the smallest number in the control set is taken as the current number.

[0044] Step S22: The main controller sends a detection enable command to the battery cluster controller corresponding to the current number, and sends a detection disable command to the battery cluster controllers corresponding to other numbers in the control set. At the same time, a timer is started to control the battery cluster controller that receives the detection enable command to control the corresponding insulation resistance detection module to detect the insulation resistance value of the corresponding battery cluster.

[0045] Step S23: The main controller determines whether the timing result has reached a preset value.

[0046] If so, proceed to step S24;

[0047] If not, return to step S23;

[0048] Step S24, the main controller determines whether the current number is the largest number in the control set:

[0049] If so, output the corresponding insulation resistance value;

[0050] If not, the timing result is cleared to zero, and the current number is incremented by one to update the current number, then the process returns to step S22.

[0051] The above technical solution has the following advantages or beneficial effects: by using polling detection control between parallel battery clusters and hardware decoupling design between battery clusters, the problem of the influence of the impedance of the voltage acquisition circuit and other hardware on the insulation resistance value is effectively solved, achieving high-precision real-time insulation detection while effectively extending the service life of the insulation resistance detection module. Attached Figure Description

[0052] Figure 1 A schematic diagram of the structure of an insulation resistance detection system for a multi-cluster parallel energy storage battery system is shown in a preferred embodiment of the present invention.

[0053] Figure 2 In a preferred embodiment of the present invention, a control principle diagram of an insulation resistance detection system for a multi-cluster parallel energy storage battery system is provided.

[0054] Figure 3 This is a schematic diagram of the insulation resistance detection module in a preferred embodiment of the present invention.

[0055] Figure 4 A flowchart illustrating a method for detecting the insulation resistance of a multi-cluster parallel energy storage battery system is provided in a preferred embodiment of the present invention.

[0056] Figure 5 This is a schematic diagram of the sub-process of step S2 in a preferred embodiment of the present invention. Detailed Implementation

[0057] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The present invention is not limited to this embodiment; other embodiments that conform to the spirit of the present invention may also fall within the scope of the present invention.

[0058] In a preferred embodiment of the present invention, based on the above-mentioned problems existing in the prior art, an insulation resistance detection system for a multi-cluster parallel energy storage battery system is provided, such as... Figure 1 and Figure 2 As shown, the energy storage battery multi-cluster parallel system includes multiple battery clusters 1 connected in parallel; the insulation resistance detection system includes:

[0059] Multiple insulation resistance detection modules 2 are connected in parallel between the positive terminal B+ and the negative terminal B- of the corresponding battery cluster 1;

[0060] Multiple battery cluster controllers 3 are connected to corresponding insulation resistance detection modules 2 to collect the connection status of the corresponding battery cluster 1;

[0061] The main controller 4 is connected to each battery cluster controller 3 to obtain the connection status of each battery cluster 1. When the connection status indicates that the battery cluster 1 is currently connected to the energy storage battery multi-cluster parallel system, the corresponding battery cluster controller 3 is added to the control set, and detection start commands are sent to each battery cluster controller 3 in the control set in sequence, so that at the same time only one battery cluster controller 3 in the control set controls the corresponding insulation resistance detection module 2 to detect the insulation resistance value of the corresponding battery cluster 1 according to the detection start command.

[0062] Each battery cluster controller 3 is also used to control the insulation resistance detection module 2 to detect the insulation resistance value of the corresponding battery cluster 1 and report it to the main controller 4 when the battery cluster 1 is not currently connected to the multi-cluster parallel energy storage system.

[0063] Specifically, in this embodiment, as Figure 1 As shown, the positive electrode B+ of each battery cluster 1 is connected to the positive electrode P+ of the energy storage battery multi-cluster parallel system through the main positive circuit, and the negative electrode B- of the battery cluster 1 is connected to the negative electrode P- of the energy storage battery multi-cluster parallel system through the main negative circuit. The main positive circuit is equipped with a main positive contactor SP, the main negative circuit is equipped with a main negative contactor SN, and the main positive circuit and the main negative circuit are also equipped with cluster circuit breakers BK.

[0064] The battery cluster controller 3 is connected to the main positive contactor SP, the main negative contactor SN, and the cluster circuit breaker BK. It is used to collect the opening and closing states of the main positive contactor SP, the main negative contactor SN, and the cluster circuit breaker BK as the parallel connection state of the battery cluster 1.

[0065] Specifically, in this embodiment, the battery cluster controller 3 sends the collected connection status to the main controller 4 in real time. The main controller 4 mainly functions as a control and display unit. It summarizes and judges the contactor and circuit breaker statuses fed back by each battery cluster, and sends the summarized information to each battery cluster as an instruction. After receiving the detection instruction, each battery cluster will start or stop the insulation resistance detection module from working. Preferably, the above-mentioned summarization and judgment includes:

[0066] When the main positive contactor SP, the main negative contactor SN, or the cluster circuit breaker BK is open, the battery cluster 1 is considered to be currently not connected to the energy storage battery multi-cluster parallel system. When the main positive contactor SP, the main negative contactor SN, and the cluster circuit breaker BK are all closed, the battery cluster 1 is considered to be currently connected to the energy storage battery multi-cluster parallel system.

[0067] In a preferred embodiment, the main controller 4 and the multiple battery cluster controllers 3 all serve as communication nodes, interacting with each other on the CAN communication bus to achieve mutual control and status reading.

[0068] During insulation testing, for each battery cluster 1 currently connected to the parallel multi-cluster energy storage system, the main controller 4 controls the insulation testing. Preferably, the main controller 4 controls only one battery cluster controller 3 in the control set at any given time to control the corresponding insulation resistance detection module 2 to detect the insulation resistance value of the corresponding battery cluster 1 according to the detection start command. Other battery cluster controllers 3 remain in an insulated state during this process. For each battery cluster 1 not currently connected to the parallel multi-cluster energy storage system, due to the circuit breaker or contactor being open, it will be decoupled from the parallel multi-cluster energy storage system. The insulation testing of the corresponding battery cluster controller 3 is not controlled by the main controller 4, and its insulation testing function is automatically activated.

[0069] In this embodiment, by controlling only one battery cluster in the parallel system of multiple energy storage battery clusters to receive the detection start command at any given time, while the other clusters receive the detection disable command; and by performing hardware decoupling control on battery clusters not connected to the parallel system of multiple energy storage battery clusters, the insulation resistance detection module of any cluster can be decoupled from other clusters during execution without affecting them. This not only solves the problem of the influence of the impedance of the voltage acquisition circuit and other hardware on the insulation resistance value, achieving the goal of high-precision real-time insulation detection, but also effectively extends the service life of the insulation module.

[0070] In a preferred embodiment of the present invention, such as Figure 3 As shown, the insulation resistance detection module 2 includes:

[0071] The first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4 are connected in series between the positive terminal B+ and the negative terminal B- of the corresponding battery cluster 1.

[0072] The first switch S1 is connected to both ends of the second resistor R2;

[0073] The second switch S2 has one end connected between the second resistor R2 and the third resistor R3, and the other end connected to the grounding terminal PE of the energy storage battery multi-cluster parallel system.

[0074] The third switch S3 is connected between the fourth resistor R4 and the negative terminal B- of battery cluster 1;

[0075] The first insulation resistor RA has one end connected to the positive terminal B+ of the battery cluster and the other end connected to one end of the second switch S2.

[0076] The second insulation resistor RB is connected at one end to one end of the second switch S2 and at the other end to the negative terminal B- of the battery cluster 1.

[0077] Specifically, in this embodiment, the first resistor R1, the second resistor R2, the third resistor R3, and the fourth resistor R4 are the hardware impedances of the internal circuit of the insulation resistance detection module 2. Changes in these impedances directly affect the insulation voltage acquisition. The first switch S1 is a relay that controls the insulation voltage acquisition; the second switch S2 is a relay that controls the connection of the current cluster's grounding terminal PE to the parallel system's grounding terminal PE; and the third switch S3 is a relay that controls the connection of the current cluster's insulation circuit to the parallel cluster circuit.

[0078] In the actual operation of the energy storage battery system, each battery cluster 1 has sampling points for ground voltage sampling and main positive and main negative voltage sampling. Since voltage sampling uses a resistor divider method, the impedance of this voltage acquisition circuit itself will affect the acquisition of the insulation detection voltage, thus affecting the final insulation resistance value. Therefore, in this embodiment, the main controller 4 includes;

[0079] The first control unit 41 is used to obtain the connection status of each battery cluster. When the connection status indicates that the battery cluster is currently connected to the energy storage battery multi-cluster parallel system, the corresponding battery cluster controllers are sequentially numbered and added to the control set, and the smallest number in the control set is used as the current number.

[0080] The second control unit 42 is connected to the first control unit 41 and is used to send a detection start command to the battery cluster controller corresponding to the current number and a detection prohibition command to the battery cluster controllers corresponding to other numbers in the control set. At the same time, it starts timing so as to control the battery cluster controller that receives the detection start command to control the corresponding insulation resistance detection module to detect the insulation resistance value of the corresponding battery cluster.

[0081] The third control unit 43 is connected to the second control unit 42. When the timing result reaches the preset value, the timing result is cleared to zero, and the current number is incremented by one to update the current number and sent to the second control unit until all battery cluster controllers in the control set have received the detection start command.

[0082] Specifically, in this embodiment, the first control unit 41 sequentially numbers each battery cluster controller according to its unique device code. The main controller 4, for the N battery clusters 1 currently connected to the multi-cluster parallel energy storage system, sequentially numbers the device IDs of the battery cluster controllers 3 of the N online clusters from 1 to N, sends a detection start command to the battery cluster controller 3 with the smallest ID number 1, sends a detection disable command to the other clusters, and starts timing. Then, the following process continues:

[0083] After receiving the insulation control command from the main controller 4, each cluster's battery cluster controller 3, if the command is a detection enable command, controls the closing of the second switch S2 and the third switch S3 within the insulation resistance module 2, connecting the insulation resistance module 2 to the multi-cluster parallel system of energy storage batteries, and simultaneously calculates the insulation resistance value; if the command is a detection disable command, the battery cluster controller 3 controls the opening of the second switch S2 and the third switch S3 within the insulation resistance module 2, disconnecting the insulation resistance module 2 from the multi-cluster parallel system of energy storage batteries, and that cluster does not perform insulation resistance value calculation. If the current ID number is N, insulation fault determination and fault information reporting, insulation resistance value reporting, and this process ends. If the current ID number is not N, the following process continues:

[0084] Once the timer reaches the set time T, the timer is cleared, the ID number is incremented by 1, the main controller 4 sends a detection enable command to the battery cluster controller 3 corresponding to the ID number, and simultaneously sends a detection disable command to the battery cluster controller 3 of other clusters, and restarts the timing. Then the above process is repeated.

[0085] In a preferred embodiment of the present invention, the battery cluster controller 3 includes:

[0086] The first cluster control unit 31 is used to control the second switch S2 and the third switch S3 to close, and to control the first switch S1 to open, so as to acquire the first voltage divider voltage of the sampling point Vi set between the third resistor R3 and the fourth resistor R4.

[0087] The second cluster control unit 32 is used to control the closing of the second switch S2 and the third switch S3, and to control the closing of the first switch S1, so as to acquire the second voltage divider voltage of the sampling point Vi set between the third resistor R3 and the fourth resistor R4.

[0088] The acquisition unit 33 is used to acquire the main positive and main negative voltages between the positive electrode B+ and the negative electrode B- of the battery cluster;

[0089] The resistance calculation unit 34 is connected to the first cluster control unit 31, the second cluster control unit 32 and the acquisition unit 33 respectively, and is used to calculate the insulation resistance values ​​of the first insulation resistance and the second insulation resistance based on the first voltage divider voltage, the second voltage divider voltage and the main positive and main negative voltages respectively.

[0090] In a preferred embodiment of the present invention, the formula for calculating the insulation resistance is as follows:

[0091]

[0092] in,

[0093] Wherein, RA represents the insulation resistance value of the first insulation resistor, RB represents the insulation resistance value of the second insulation resistor, R1 represents the resistance value of the first resistor, R2 represents the resistance value of the second resistor, R3 represents the resistance value of the third resistor, R4 represents the resistance value of the fourth resistor, VPN represents the main positive and main negative voltages, Vi1 represents the first voltage divider voltage, and Vi2 represents the second voltage divider voltage.

[0094] This invention also provides a method for detecting the insulation resistance of a multi-cluster parallel energy storage battery system, applicable to the aforementioned insulation resistance detection system, such as... Figure 4 As shown, the insulation resistance testing methods include:

[0095] Step S1: The main controller obtains the connection status of each battery cluster and determines whether the corresponding battery cluster is currently connected to the multi-cluster parallel energy storage system based on the connection status.

[0096] If so, proceed to step S2;

[0097] If not, proceed to step S3;

[0098] In step S2, the main controller adds the corresponding battery cluster controller to the control set and sends a detection start command to each battery cluster controller in the control set in sequence, so that at the same time only one battery cluster controller in the control set controls the corresponding insulation resistance detection module to detect the insulation resistance value of the corresponding battery cluster according to the detection start command, and then returns to step S1.

[0099] In step S3, the battery cluster controller controls the corresponding insulation resistance detection module to detect the insulation resistance value of the corresponding battery cluster and report it to the main controller.

[0100] In a preferred embodiment of the present invention, the positive electrode of each battery cluster is connected to the positive electrode of the energy storage battery multi-cluster parallel system through the main positive circuit, and the negative electrode of the battery cluster is connected to the negative electrode of the energy storage battery multi-cluster parallel system through the main negative circuit. A main positive contactor is provided on the main positive circuit, a main negative contactor is provided on the main negative circuit, and a cluster circuit breaker is also provided on the main positive circuit and the main negative circuit.

[0101] In step S1, the battery cluster controller is connected to the main positive contactor, the main negative contactor, and the cluster circuit breaker. It is used to collect the opening and closing status of the main positive contactor, the main negative contactor, and the cluster circuit breaker as the battery cluster's connection status and send it to the main controller.

[0102] In a preferred embodiment of the present invention, such as Figure 5 As shown, step S2 includes:

[0103] Step S21: The main controller obtains the connection status of each battery cluster. When the connection status indicates that the battery cluster is currently connected to the energy storage battery multi-cluster parallel system, the corresponding battery cluster controllers are sequentially numbered and added to the control set, and the smallest number in the control set is taken as the current number.

[0104] Step S22: The main controller sends a detection start command to the battery cluster controller corresponding to the current number, and sends a detection disable command to the battery cluster controllers corresponding to other numbers in the control set. At the same time, a timer is started so that the battery cluster controller that receives the detection start command controls the corresponding insulation resistance detection module to detect the insulation resistance value of the corresponding battery cluster.

[0105] Step S23: The main controller determines whether the timing result has reached the preset value.

[0106] If so, proceed to step S24;

[0107] If not, return to step S23;

[0108] Step S24: The main controller determines whether the current number is the largest number in the control set.

[0109] If so, output the corresponding insulation resistance value;

[0110] If not, the timing result is cleared to zero, and the current number is incremented by one to update the current number, then the process returns to step S22.

[0111] The above description is merely a preferred embodiment of the present invention and does not limit the implementation and protection scope of the present invention. Those skilled in the art should realize that any equivalent substitutions and obvious changes made using the content of this specification and illustrations should be included within the protection scope of the present invention.

Claims

1. An insulation resistance detection system for a multi-cluster parallel energy storage battery system, wherein the multi-cluster parallel energy storage battery system comprises multiple battery clusters connected in parallel; characterized in that, The insulation resistance detection system includes: Multiple insulation resistance detection modules are connected in parallel between the positive and negative terminals of the corresponding battery clusters; Multiple battery cluster controllers are connected to the corresponding insulation resistance detection modules to collect the connection status of the corresponding battery clusters; The main controller is connected to each of the battery cluster controllers and is used to obtain the connection status of each battery cluster. When the connection status indicates that the battery cluster is currently connected to the energy storage battery multi-cluster parallel system, the corresponding battery cluster controller is added to the control set, and a detection start command is sent to each battery cluster controller in the control set in sequence, so that at the same time only one battery cluster controller in the control set controls the corresponding insulation resistance detection module to detect the insulation resistance value of the corresponding battery cluster according to the detection start command. Each of the battery cluster controllers is further configured to, when the parallel state indicates that the battery cluster is not currently connected to the energy storage battery multi-cluster parallel system, control the insulation resistance detection module to detect the insulation resistance value of the corresponding battery cluster and report it to the main controller; The positive terminal of each battery cluster is connected to the positive terminal of the energy storage battery multi-cluster parallel system through the main positive circuit, and the negative terminal of each battery cluster is connected to the negative terminal of the energy storage battery multi-cluster parallel system through the main negative circuit. The main positive circuit is equipped with a main positive contactor, the main negative circuit is equipped with a main negative contactor, and the main positive circuit and the main negative circuit are also equipped with cluster circuit breakers. The battery cluster controller is connected to the main positive contactor, the main negative contactor, and the cluster circuit breaker, and is used to collect the opening and closing states of the main positive contactor, the main negative contactor, and the cluster circuit breaker as the parallel connection state of the battery cluster.

2. The insulation resistance detection system according to claim 1, characterized in that, The insulation resistance detection module includes: A first resistor, a second resistor, a third resistor, and a fourth resistor are connected in series between the positive terminal and the negative terminal of the corresponding battery cluster; The first switch is connected in parallel across the two ends of the second resistor; The second switch has one end connected between the second resistor and the third resistor, and the other end connected to the grounding terminal of the energy storage battery multi-cluster parallel system. The third switch is connected between the fourth resistor and the negative terminal of the battery cluster; A first insulation resistor, one end of which is connected to the positive terminal of the battery cluster, and the other end of which is connected to one end of the second switch; The second insulation resistor has one end connected to one end of the second switch and the other end connected to the negative terminal of the battery cluster.

3. The insulation resistance detection system according to claim 2, characterized in that, The main controller includes; The first control unit is used to obtain the connection status of each battery cluster. When the connection status indicates that the battery cluster is currently connected to the energy storage battery multi-cluster parallel system, the corresponding battery cluster controllers are sequentially numbered and added to the control set, and the smallest number in the control set is taken as the current number. The second control unit, connected to the first control unit, is used to send a detection start command to the battery cluster controller corresponding to the current number, and to send a detection disable command to the battery cluster controllers corresponding to other numbers in the control set. At the same time, it starts a timer to control the battery cluster controller that receives the detection start command to control the corresponding insulation resistance detection module to detect the insulation resistance value of the corresponding battery cluster. The third control unit, connected to the second control unit, is used to reset the timing result to zero when the timing result reaches a preset value, and to increment the current number by one to update the current number and send it to the second control unit, until all battery cluster controllers in the control set have received the detection start command.

4. The insulation resistance detection system according to claim 3, characterized in that, In the first control unit, each battery cluster controller is sequentially numbered according to its unique device code.

5. The insulation resistance detection system according to claim 2, characterized in that, The battery cluster controller includes: The first cluster control unit is used to control the second switch and the third switch to close, and to control the first switch to open, so as to acquire the first voltage divider voltage at the sampling point set between the third resistor and the fourth resistor; The second cluster control unit is used to control the closing of the second switch and the third switch, and to control the closing of the first switch, so as to acquire the second voltage divider voltage at the sampling point set between the third resistor and the fourth resistor; The acquisition unit is used to acquire the main positive and main negative voltages between the positive and negative terminals of the battery cluster. The resistance calculation unit is connected to the first cluster control unit, the second cluster control unit and the acquisition unit respectively, and is used to calculate the insulation resistance values ​​of the first insulation resistance and the second insulation resistance based on the first voltage divider voltage, the second voltage divider voltage and the main positive and main negative voltages respectively.

6. The insulation resistance detection system according to claim 5, characterized in that, The formula for calculating the insulation resistance is as follows: ； in, ; in, The insulation resistance value used to represent the first insulation resistance. The insulation resistance value used to represent the second insulation resistance. Used to represent the resistance value of the first resistor. Used to indicate the resistance value of the second resistor. Used to indicate the resistance value of the third resistor. Used to indicate the resistance value of the fourth resistor, Used to represent the main positive and main negative voltages. Used to represent the first voltage divider voltage. Used to represent the second voltage divider.

7. A method for detecting the insulation resistance of a multi-cluster parallel energy storage battery system, characterized in that, The insulation resistance detection method, applied to the insulation resistance detection system as described in any one of claims 1-6, comprises: Step S1: The main controller acquires the connection status of each battery cluster and determines whether the corresponding battery cluster is currently connected to the energy storage battery multi-cluster parallel system based on the connection status. If so, proceed to step S2; If not, proceed to step S3; In step S2, the main controller adds the corresponding battery cluster controller to the control set and sends a detection start command to each battery cluster controller in the control set in sequence, so that at any given time only one battery cluster controller in the control set controls the corresponding insulation resistance detection module to detect the insulation resistance value of the corresponding battery cluster according to the detection start command, and then returns to step S1. Step S3: The battery cluster controller controls the corresponding insulation resistance detection module to detect the insulation resistance value of the corresponding battery cluster and report it to the main controller. The positive terminal of each battery cluster is connected to the positive terminal of the energy storage battery multi-cluster parallel system through the main positive circuit, and the negative terminal of each battery cluster is connected to the negative terminal of the energy storage battery multi-cluster parallel system through the main negative circuit. The main positive circuit is equipped with a main positive contactor, the main negative circuit is equipped with a main negative contactor, and the main positive circuit and the main negative circuit are also equipped with cluster circuit breakers. In step S1, the battery cluster controller is connected to the main positive contactor, the main negative contactor, and the cluster circuit breaker, and is used to collect the opening and closing states of the main positive contactor, the main negative contactor, and the cluster circuit breaker as the parallel connection state of the battery cluster and send them to the main controller.

8. The insulation resistance detection method according to claim 6, characterized in that, Step S2 includes: Step S21: The main controller obtains the connection status of each battery cluster. When the connection status indicates that the battery cluster is currently connected to the energy storage battery multi-cluster parallel system, the corresponding battery cluster controllers are sequentially numbered and added to the control set, and the smallest number in the control set is taken as the current number. Step S22: The main controller sends a detection enable command to the battery cluster controller corresponding to the current number, and sends a detection disable command to the battery cluster controllers corresponding to other numbers in the control set. At the same time, a timer is started to control the battery cluster controller that receives the detection enable command to control the corresponding insulation resistance detection module to detect the insulation resistance value of the corresponding battery cluster. Step S23: The main controller determines whether the timing result has reached a preset value. If so, proceed to step S24; If not, return to step S23; Step S24, the main controller determines whether the current number is the largest number in the control set: If so, output the corresponding insulation resistance value; If not, the timing result is cleared to zero, and the current number is incremented by one to update the current number, then the process returns to step S22.

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