Multi-cluster parallel insulation detection circuit, insulation detection method and electronic equipment

Abstract

The invention discloses a multi-cluster parallel insulation detection circuit, an insulation detection method and electronic equipment. The multi-cluster parallel insulation detection circuit comprises N single-cluster insulation detection circuits connected to a load bus in parallel, and each single-cluster insulation detection circuit comprises a battery cluster, a first sampling unit, a load communication unit and a second sampling unit which are connected in parallel; the first sampling unit provides a first reference voltage, and the second sampling unit provides a second reference voltage; a lower bridge arm circuit in the second sampling unit is connected with the load communication unit; the lower bridge arm circuit and the load communication unit in each single-cluster insulation detection circuit form a parallel loop through a load bus and a grounding end; the first reference voltage, the second reference voltage and the parallel loop are used for calculating the resistance value of the resistance to ground of the battery cluster, and the resistance value is used for determining an insulation detection result. In the embodiment of the invention, the other parallel insulation detection circuits are regarded as the equivalent resistance of the current insulation detection circuit for calculation, and the accuracy of insulation detection is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of circuits, and particularly relates to a multi-cluster parallel insulation detection circuit, an insulation detection method and electronic equipment. BACKGROUND

[0002] With the rapid development of new energy technology, the scale of energy storage systems is continuously increasing, and as an important component of the energy storage system, the power demand of the battery system is also gradually increasing. Insulation detection is one of the core guarantee links for the safe operation of the battery system, and its purpose is to monitor the insulation resistance value of the positive and negative electrodes of the battery cluster to the shell or to the ground in real time, so as to prevent serious safety accidents such as electric leakage, short circuit, electric shock and fire caused by insulation failure.

[0003] The current mainstream insulation detection method is almost entirely designed and optimized based on a single cluster battery system. Its detection principle, circuit topology, parameter calculation model and fault diagnosis strategy are all established around a closed system composed of a single, independent battery cluster and a single insulation detection circuit corresponding thereto. For multi-cluster parallel application scenarios, the existing technical solutions lack targeted design considerations, which leads to the problem of insufficient adaptability when directly applying a single cluster detection scheme to a parallel system. SUMMARY

[0004] The purpose of the embodiments of the present application is to provide a multi-cluster parallel insulation detection circuit, an insulation detection method and electronic equipment, which can solve the problem of inadaptability of the existing single cluster insulation detection circuit in a multi-cluster parallel insulation detection circuit.

[0005] In a first aspect, the embodiments of the present application provide a multi-cluster parallel insulation detection circuit, which comprises N single cluster insulation detection circuits, N being an integer greater than 1, and the N single cluster insulation detection circuits are connected in parallel to a load bus, wherein each single cluster insulation detection circuit comprises a battery cluster, a first sampling unit, a load communication unit and a second sampling unit, and the battery cluster, the first sampling unit, the load communication unit and the second sampling unit are in parallel relationship.

[0006] The first sampling unit is configured to provide a first reference voltage, and the second sampling unit is configured to provide a second reference voltage.

[0007] The second sampling unit comprises a lower bridge arm circuit, and the lower bridge arm circuit is connected with the load communication unit; the lower bridge arm circuit and the load communication unit in each single cluster insulation detection circuit form a parallel loop through the load bus and a ground terminal, wherein the parallel loop comprises N-1 parallel equivalent resistances, and the resistance value of the parallel equivalent resistances is the sum of the resistance value of the load communication unit and the resistance value of the lower bridge arm circuit.

[0008] The first reference voltage, the second reference voltage and the parallel circuit are used to calculate the resistance of the ground resistance of the battery cluster, and the resistance is used to determine the insulation detection result.

[0009] Optionally, the single-cluster insulation detection circuit further comprises a positive contactor and a negative contactor.

[0010] The positive pole of the battery cluster is connected to the positive pole of the load bus through the positive contactor, and the negative pole of the battery cluster is connected to the negative pole of the load bus through the negative contactor; wherein, the positive contactor and the negative contactor are kept disconnected when the multi-cluster parallel insulation detection circuit performs insulation detection.

[0011] The first end of the load communication unit is connected to the positive pole of the load bus of the single-cluster insulation detection circuit, and the second end of the load communication unit is connected to the negative pole of the load bus of the single-cluster insulation detection circuit through the negative contactor; wherein, the load communication unit is used to keep the single-cluster insulation detection circuit in communication with the load bus when the positive contactor is disconnected.

[0012] Optionally, the second sampling unit comprises an upper bridge arm circuit, the lower bridge arm circuit, a ground switch and a switching switch.

[0013] The upper bridge arm circuit is used to calculate the ground voltage division of the positive pole of the battery cluster.

[0014] The first end of the upper bridge arm circuit is connected to the positive pole of the battery cluster, the second end of the upper bridge arm circuit and the first end of the lower bridge arm circuit are connected, and the second end of the upper bridge arm circuit and the first end of the lower bridge arm circuit are grounded through the ground switch.

[0015] The lower bridge arm circuit is used to provide a second reference voltage, and the second reference voltage is used to calculate the ground voltage division of the negative pole of the battery cluster.

[0016] The first end of the lower bridge arm circuit is grounded through the ground switch, and the second end of the lower bridge arm circuit is connected to the negative pole of the battery cluster; wherein, the ground switch is kept closed when the multi-cluster parallel insulation detection circuit performs insulation detection.

[0017] The upper bridge arm circuit is connected to the negative pole of the battery cluster through the switching switch, and the lower bridge arm circuit obtains the second reference voltage when the switching switch is disconnected.

[0018] Optionally, the upper bridge arm circuit comprises a fifth resistor, a sixth resistor, a seventh resistor and the switching switch.

[0019] The first end of the fifth resistor is connected with the positive pole of the battery cluster, the second end of the fifth resistor is connected with the first end of the sixth resistor, the second end of the sixth resistor is connected with the lower bridge arm circuit, and the second end of the sixth resistor is the second end of the upper bridge arm circuit;

[0020] The first end of the switching switch is connected with the second end of the fifth resistor, the second end of the switching switch is connected with the negative pole of the battery cluster, and the structure of the second sampling unit accessing the single-cluster insulation detection circuit is different in different states of the switching switch.

[0021] The first end of the ninth resistor is connected with the first end of the fifth resistor, and the second end of the ninth resistor is connected with the second end of the sixth resistor.

[0022] Optionally, the lower bridge arm circuit comprises a seventh resistor and an eighth resistor.

[0023] The first end of the seventh resistor is the first end of the lower bridge arm circuit, and the first end of the seventh resistor is connected with the upper bridge arm circuit.

[0024] The second end of the seventh resistor is connected with the first end of the eighth resistor, and the second end of the eighth resistor is connected with the negative pole of the battery cluster.

[0025] The second reference voltage is obtained at the second end of the seventh resistor.

[0026] Optionally, the first sampling unit comprises a first resistor and a second resistor.

[0027] The first end of the first resistor is connected with the positive pole of the battery cluster, the second end of the first resistor is connected with the first end of the second resistor, and the second end of the second resistor is connected with the negative pole of the battery cluster.

[0028] The first reference voltage is obtained at the second end of the first resistor.

[0029] Optionally, the load communication unit comprises a third resistor and a fourth resistor.

[0030] The first end of the third resistor is connected with the positive pole of the load bus, the second end of the third resistor is connected with the first end of the fourth resistor, and the second end of the fourth resistor is connected with the negative pole of the battery.

[0031] In a second aspect, the embodiments of the present application provide an insulation detection method, applied to a single-cluster insulation detection circuit, the single-cluster insulation detection circuit being any single-cluster insulation detection circuit in the multi-cluster parallel insulation detection circuit of any one of claims 1-7, and the insulation detection method comprising:

[0032] collecting a first reference voltage of the first sampling unit and a second reference voltage of the second sampling unit;

[0033] calculating the resistance value of the ground resistance of the battery cluster according to the first reference voltage, the second reference voltage and a preset voltage division formula; wherein the preset voltage division formula includes N-1 parallel equivalent resistances; the resistance value of a single parallel equivalent resistance is the sum of the resistance value of the load communication unit and the resistance value of the lower bridge arm circuit;

[0034] obtaining the insulation detection result according to the resistance value of the ground resistance.

[0035] Optionally, the calculating the resistance value of the ground resistance of the battery cluster according to the first reference voltage, the second reference voltage and a preset voltage division formula comprises:

[0036] calculating the positive electrode ground voltage division of the battery cluster and the negative electrode ground voltage division of the battery cluster according to the first reference voltage and the second reference voltage;

[0037] obtaining a first voltage division ratio according to the positive electrode ground voltage division and the negative electrode ground voltage division;

[0038] determining a target voltage division formula in the preset voltage division formula according to the first voltage division ratio; wherein in the case that the first voltage division ratio is less than or equal to a first threshold value, the target voltage division formula is a first voltage division formula, and the first voltage division formula is used to calculate the resistance value of the ground resistance of the positive electrode of the battery cluster; in the case that the first voltage division ratio is greater than or equal to a second threshold value, the target voltage division formula is a second voltage division formula, and the second voltage division formula is used to calculate the resistance value of the ground resistance of the negative electrode of the battery cluster;

[0039] inputting the positive electrode ground voltage division and the negative electrode ground voltage division into the target voltage division formula to calculate the resistance value of the ground resistance of the battery cluster.

[0040] Optionally, the calculating the resistance value of the ground resistance of the battery cluster according to the first reference voltage, the second reference voltage and a preset voltage division formula comprises:

[0041] calculating the positive electrode ground voltage division of the battery cluster and the negative electrode ground voltage division of the battery cluster according to the first reference voltage and the second reference voltage, and obtaining a first voltage division ratio according to the positive electrode ground voltage division and the negative electrode ground voltage division; wherein the first reference voltage and the second reference voltage are collected in the case that the switching of the single-cluster insulation detection circuit is turned off;

[0042] Close the switch, obtain the third reference voltage and the fourth reference voltage; wherein the third reference voltage is consistent with the sampling point of the first reference voltage, and the fourth reference voltage is consistent with the sampling point of the second reference voltage;

[0043] According to the third reference voltage and the fourth reference voltage, calculate the second voltage division ratio;

[0044] According to the first voltage division ratio and the second voltage division ratio, calculate the resistance value of the ground resistance of the battery cluster.

[0045] In a third aspect, an embodiment of the present application discloses an electronic device, comprising: a processor and a memory, the memory is used to store at least one executable instruction, the executable instruction makes the processor execute the steps of the insulation detection method as described in any of the preceding.

[0046] In a fourth aspect, an embodiment of the present application discloses a readable storage medium, the readable storage medium stores programs or instructions, the programs or instructions can realize the insulation detection method as described in any of the preceding when executed by a processor.

[0047] The technical scheme provided by the embodiments of the present application can include the following beneficial effects:

[0048] When performing insulation detection, the load communication unit and the lower bridge arm circuit are connected, one side of the load communication unit accesses the load bus, one side of the lower bridge arm circuit is grounded, and the load communication unit and the lower bridge arm circuit can form a parallel loop with each single-cluster insulation detection circuit connected in parallel to the load bus. Due to the existence of the parallel loop, the part of the non-target insulation detection circuit connected to the parallel loop is regarded as a parallel equivalent resistance and is connected to the target insulation detection circuit. The target insulation detection circuit is any single-cluster insulation detection circuit in the multi-cluster parallel insulation detection circuit, and the non-target insulation detection circuit is any single-cluster insulation detection circuit in the multi-cluster parallel insulation detection circuit except the target insulation detection circuit. The other insulation detection circuits in the parallel system have been connected to the target insulation detection circuit as parallel equivalent resistances, that is, when performing insulation detection, the influence of other insulation detection circuits in the parallel system on the insulation detection result of the target insulation detection circuit has been considered, and the influence is quantified in the form of equivalent resistance, eliminating uncertain factors. Therefore, the insulation detection result of the target insulation detection circuit is more accurate, which can ensure the safety of the system and improve the user experience. BRIEF DESCRIPTION OF DRAWINGS

[0049] Figure 1 is a structural block diagram of a single-cluster insulation detection circuit provided by an exemplary embodiment;

[0050] Figure 2 is a structural block diagram of a multi-cluster parallel insulation detection circuit provided by an exemplary embodiment;

[0051] Figure 3 is a structural block diagram of another single cluster insulation detection circuit provided by an example embodiment;

[0052] Figure 4 is a structural block diagram of another single cluster insulation detection circuit provided by an example embodiment;

[0053] Figure 5 is a structural block diagram of another single cluster insulation detection circuit provided by an example embodiment;

[0054] Figure 6 is a structural block diagram of another single cluster insulation detection circuit provided by an example embodiment;

[0055] Figure 7 is a flowchart of an insulation detection method provided by an embodiment of the present application;

[0056] Figure 8 is a block diagram of an electronic device provided by an embodiment of the present application;

[0057] Figure 9 is a hardware structure schematic diagram of an electronic device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0058] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0059] The terms "first", "second", and the like in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally a category, not limited to the number of objects, for example, the first object can be one or more. In addition, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / ", generally indicates that the front and rear associated objects are in an "or" relationship.

[0060] Before introducing the multi-cluster parallel insulation detection circuit and insulation detection method provided by the present disclosure, first, the application scenarios involved in each embodiment of the present disclosure are introduced. The present disclosure can be applied to the battery system in the energy storage system, and is mainly used in the scene of insulation detection of the battery cluster in the battery system.

[0061] With the continuous development of energy storage technology, the safety and reliability of energy storage systems, as an important part of energy conversion and storage, become particularly important. The battery system is an important part of the energy storage system, and the battery cluster in the battery system is composed of multiple batteries in series and parallel connection. A good insulation environment needs to be maintained between the battery cluster and the external environment, which can ensure the safe and reliable operation of the energy storage system.

[0062] Currently, the battery system in the energy storage system usually adopts a three-layer architecture for management and control:

[0063] The third layer (the highest layer): the stack controller (Battery Stack Management Unit, BSMU) uniformly manages the collection and confirmation of multiple battery cluster data, the running state of the battery, system alarm, and real-time communication with the power conversion system (Power Conversion System, PCS), and sends out the state information of the battery, etc. functions, and all cluster controllers (Battery Cluster Management Unit, BCMU) are uniformly managed. When the battery needs to be protected, the BSMU will make appropriate judgments and issue instructions.

[0064] The second layer (the middle layer): the cluster controller BCMU is responsible for the information collection, arrangement and calculation, system insulation impedance detection, and high-voltage box contactor control of a battery cluster. The high-voltage box has functions such as battery loop current detection, pre-charging, DC contactor, and fuse control management. If the local protection of BCMU is triggered, BCMU will not wait for the instruction of BSMU and directly execute the local protection logic.

[0065] The first layer (the bottom layer), the battery management unit (Battery Management Unit, BMU) is a battery pack (Battery Pack, PACK) management control unit. The BMU is responsible for the voltage and temperature collection of the battery monomer, and the equalization control. Multiple battery monomers constitute a battery pack PACK, and multiple battery packs PACK constitute the above-mentioned battery cluster.

[0066] However, during the initial stage of system assembly, operation, and test, various abnormal problems are inevitable. The existing insulation detection technology is mainly applied in single cluster battery systems, and when calculating the insulation resistance, the parallel operation of multiple cluster systems is not considered. In a multiple cluster parallel operation system, if the clusters form a loop through the load side DC bus or the ground terminal PE in an uncontrollable manner, the calculation error will be caused by the loop when using traditional single-sided and double-sided algorithms for insulation detection, resulting in inaccurate insulation resistance calculation, which cannot reflect the true insulation state of a single battery cluster, especially in the case of single positive or negative ground leakage.

[0067] To solve the above problems, the disclosure provides a multi-cluster parallel insulation detection circuit and an insulation detection method. By regarding other non-target insulation detection circuits in the multi-cluster parallel insulation detection circuit as equivalent resistances when insulation detection is performed on a target insulation detection circuit, the current target insulation detection circuit is connected in parallel, and during the calculation process of the insulation detection performed by the target insulation detection circuit, the parallel equivalent resistances are brought into the calculation, so that the insulation detection result of the target insulation detection circuit is more accurate. Specifically, by quantifying the influence of other non-target insulation detection circuits on the target insulation detection circuit in the form of parallel equivalent resistances, the uncertain influencing factors of the non-target insulation detection circuits on the insulation detection process of the target insulation detection circuit are eliminated, and the accuracy of the insulation detection result in the target insulation detection circuit can be ensured.

[0068] The specific embodiments of the disclosure are described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the disclosure, and are not used to limit the disclosure.

[0069] Figure 1 is a structural block diagram of a single-cluster insulation detection circuit provided by an exemplary embodiment, the single-cluster insulation detection circuit is any single-cluster insulation detection circuit in N single-cluster insulation detection circuits in a multi-cluster parallel insulation detection circuit, N is an integer greater than 1, and the N single-cluster insulation detection circuits are connected in parallel to a load bus; wherein, the positive pole of the load bus is shown as P+, and the negative pole of the load bus is shown as P-; the positive pole of the battery cluster is shown as B+, and the negative pole of the battery cluster is shown as B-; the single-cluster insulation detection circuit comprises a battery cluster, a first sampling unit 101, a load communication unit 102 and a second sampling unit 103; the battery cluster, the first sampling unit 101, the load communication unit 102 and the second sampling unit 103 are in parallel relationship;

[0070] The first sampling unit 101 is configured to provide a first reference voltage V1, and the second sampling unit 103 is configured to provide a second reference voltage V2;

[0071] The second sampling unit 103 comprises a lower bridge arm circuit 1032, and the lower bridge arm circuit 1032 is connected with the load communication unit 102; the lower bridge arm circuit 1032 and the load communication unit 102 in each single-cluster insulation detection circuit form a parallel loop through the load bus and a ground terminal PE; wherein, the parallel loop comprises N-1 parallel equivalent resistances, and the resistance value of the parallel equivalent resistances is the sum of the resistance value of the load communication unit 102 and the resistance value of the lower bridge arm circuit 1032;

[0072] The first reference voltage, the second reference voltage and the parallel circuit are used to calculate the resistance of the ground resistance of the battery cluster, and the resistance is used to determine the insulation detection result.

[0073] It can be understood that the resistance includes the resistance Rp of the positive electrode of the battery cluster to the ground and the resistance Rn of the negative electrode to the ground. Wherein, Rp and Rn are virtual resistances of the positive electrode to the ground and the negative electrode to the ground respectively, and the positions can be referred to as Figure 5 .

[0074] It should be noted that the first reference voltage V1 is used to calculate the total voltage of the battery cluster, and the second reference voltage V2 is used to calculate the voltage of the negative electrode of the battery cluster to the ground; the difference between the total voltage of the battery cluster and the voltage of the negative electrode of the battery cluster to the ground is the voltage of the positive electrode of the battery cluster to the ground.

[0075] The ratio of the voltage of the positive electrode of the battery cluster to the ground and the voltage of the negative electrode of the battery cluster to the ground is equal to the ratio of the resistance of the positive electrode of the battery cluster to the ground and the resistance of the negative electrode of the battery cluster to the ground, so the resistance of the ground resistance of the battery cluster can be calculated by using the voltage of the positive electrode of the battery cluster to the ground and the voltage of the negative electrode of the battery cluster to the ground.

[0076] It can be understood that there are general leakage threshold and serious leakage threshold, and the insulation detection result between the two ends of the battery cluster is determined as insulation, general leakage or serious leakage by comparing the calculated resistance of the ground resistance of the battery cluster with the general leakage threshold and the serious leakage threshold.

[0077] For example, the general leakage threshold is 200Ω / V, and the serious leakage threshold is 100Ω / V. When the voltage between the two ends of the battery cluster (i.e. the voltage between B+ and B-) is 300V, if Rp>200Ω / V*300V, it is considered that Rp is infinite, i.e. the positive electrode of the battery cluster is insulated to the ground; if Rp≤200Ω / V*300V, it is considered that Rp is generally leaked, and the general leakage situation is reported for corresponding processing by the staff; if Rp≤100Ω / V*300V, it is considered that Rp is seriously leaked, and the serious leakage situation is reported for corresponding processing by the staff. The processing of Rn obtained after calculation is the same as that of Rp.

[0078] In this embodiment, the load communication unit 102 and the lower bridge arm circuit 1032 are connected, one end of the load communication unit 102 is connected to the load bus, and the other end of the lower bridge arm circuit 1032 is grounded. At this time, through the load bus and the ground terminal PE, each single cluster insulation detection circuit forms a parallel circuit. When one of the single cluster insulation detection circuits is running, the other single cluster insulation detection circuits connected in the parallel circuit can be regarded as equivalent resistances connected in parallel, and the resistance value is the sum of the resistance values of the load communication unit 102 and the lower bridge arm circuit 1032. When insulation detection is performed according to real-time parameters, the influence of each parallel equivalent resistance is considered, and an accurate insulation detection result can be obtained.

[0079] It can be understood that in the insulation detection of the present application, it is not necessary to separately control the connection state of a single cluster insulation detection circuit to the load bus or the ground terminal PE. Since all the parallel insulation detection circuits are connected in parallel, and the connected part is regarded as an equivalent resistance, multiple single cluster insulation detection circuits can be started at the same time for insulation detection, and the number of insulation detection circuits performing insulation detection at the same time is not limited.

[0080] In this embodiment, the target insulation detection circuit is any one of the single cluster insulation detection circuits in the multi-cluster parallel insulation detection circuit, and the non-target insulation detection circuit is the other single cluster insulation detection circuit in the multi-cluster parallel insulation detection circuit except the target insulation detection circuit. The non-target insulation detection circuit in the parallel system has been connected as a parallel equivalent resistance to the target insulation detection circuit, that is, when insulation detection is performed, the influence of the other non-target insulation detection circuit in the parallel system on the insulation detection result of the target insulation detection circuit has been considered. Specifically, the influence on the related resistance value is quantified in the form of an equivalent resistance, and the uncertain influence of the non-target insulation detection circuit on the target insulation detection circuit is eliminated. Therefore, the insulation detection result obtained by the target insulation detection circuit is more accurate, which can ensure the safety of the battery system and improve the user experience.

[0081] In some embodiments, the single cluster insulation detection circuit further comprises a positive contactor KM1 and a negative contactor KM2; the positive electrode of the battery cluster is connected to the positive electrode of the load bus through the positive contactor KM1, and the negative electrode of the battery cluster is connected to the negative electrode of the load bus through the negative contactor KM2; wherein the positive contactor KM1 and the negative contactor KM2 are kept disconnected when the multi-cluster parallel insulation detection circuit performs insulation detection.

[0082] The first end of the load communication unit 102 accesses the positive pole of the load bus of the single-cluster insulation detection circuit, and the second end of the load communication unit 102 accesses the negative pole of the load bus of the single-cluster insulation detection circuit through the negative pole contactor KM2; wherein the load communication unit 102 is configured to keep the single-cluster insulation detection circuit in communication with the load bus in the case that the positive pole contactor KM1 is disconnected.

[0083] It can be understood that, in the insulation detection process, in order to avoid the influence of the components on the load bus side on the detection result of the current insulation detection circuit, it is necessary to ensure that the load bus side is not electrified, and therefore, the positive pole contactor KM1 and the negative pole contactor KM2 are both disconnected during the insulation detection.

[0084] As shown in Figure 2 , in some embodiments, if the multi-cluster parallel insulation detection circuit includes two single-cluster insulation detection circuits, insulation detection is performed on battery cluster 1 and battery cluster 2 respectively, and the direction of the arrow shown in the figure forms the parallel circuit. That is, the load communication unit 102 and the lower bridge arm circuit 1032 in the two single-cluster insulation detection circuits, together with the positive pole P+ and the ground terminal PE of the load bus, form a parallel circuit. At this time, if insulation detection is performed on battery cluster 1, the insulation detection circuit of battery cluster 2 can be regarded as an equivalent resistance connected in parallel to the insulation detection circuit of battery cluster 1, and the resistance value of the equivalent resistance is the sum of the resistance values of the load communication unit 102 and the lower bridge arm circuit 1032.

[0085] Specifically, the insulation detection circuit of battery cluster 2 is regarded as an equivalent resistance connected in parallel to the insulation detection circuit of battery cluster 1, as shown in Figure 3 , where R is the state of the insulation detection circuit of battery cluster 2 regarded as an equivalent resistance connected in parallel to the insulation detection circuit of battery cluster 1, and the resistance value of R is the sum of the resistance values of the load communication unit 102 and the lower bridge arm circuit 1032.

[0086] It can be understood that, if the current multi-cluster parallel insulation detection circuit includes N single-cluster insulation detection circuits, the state of connecting the N single-cluster insulation detection circuits as equivalent resistances in parallel to the insulation detection circuit of battery cluster 1 is shown in Figure 4 . That is, there are N-1 equivalent resistances R connected in parallel to the insulation detection circuit of battery cluster 1.

[0087] In the embodiment, the load communication unit 102 directly accesses the positive pole P+ of the load bus without passing through the positive pole contactor KM1. In this way, in the insulation detection process, when the positive pole contactor KM1 and the negative pole contactor KM2 are both disconnected, the single-cluster insulation detection circuit can still access the load bus to form a loop. At the same time, the single-cluster insulation detection circuit only accesses the positive pole of the load bus, and the load bus is not electrified, so the structure in the load bus path does not affect the single-cluster insulation detection circuit, thereby ensuring the accuracy of the insulation detection result.

[0088] In a possible implementation, the second sampling unit 103 includes an upper bridge arm circuit 1031, a lower bridge arm circuit 1032, a grounding switch K1, and a switching switch K2.

[0089] The upper bridge arm circuit 1031 is configured to calculate the voltage of the positive pole of the battery cluster to ground.

[0090] The first end of the upper bridge arm circuit 1031 is connected to the positive pole of the battery cluster, the second end of the upper bridge arm circuit 1031 and the first end of the lower bridge arm circuit 1032 are connected, and the second end of the upper bridge arm circuit 1031 and the first end of the lower bridge arm circuit 1032 are grounded through the grounding switch K1.

[0091] The lower bridge arm circuit 1032 is configured to provide a second reference voltage V2, and the second reference voltage V2 is used to calculate the voltage of the negative pole of the battery cluster to ground.

[0092] The first end of the lower bridge arm circuit 1032 is grounded through the grounding switch K1, and the second end of the lower bridge arm circuit 1032 is connected to the negative pole of the battery cluster. When the multi-cluster parallel insulation detection circuit performs insulation detection, the grounding switch K1 remains closed.

[0093] The upper bridge arm circuit 1031 is connected to the negative pole of the battery cluster through the switching switch K2, and in the case where the switching switch K2 is disconnected, the lower bridge arm circuit 1032 obtains the second reference voltage V2.

[0094] As Figure 5As shown, it is the connection mode of the upper bridge arm circuit 1031 and the lower bridge arm circuit 1032 in the second sampling unit 103 in the single-cluster insulation detection circuit. Specifically, the first end of the upper bridge arm circuit 1031 is connected with the positive electrode of the battery cluster, and the second end is grounded, so that the voltage between the positive electrode of the battery cluster and the ground can be calculated; the first end of the lower bridge arm circuit 1032 is grounded, and the second end is connected with the negative electrode of the battery cluster, so that the voltage between the negative electrode of the battery cluster and the ground can be calculated. Further, the ratio of the voltage between the positive electrode of the battery cluster and the ground to the voltage between the negative electrode of the battery cluster and the ground is the same as the ratio of the resistance value of the resistance between the positive electrode of the battery cluster and the ground to the resistance value of the resistance between the negative electrode of the battery cluster and the ground, so that the resistance value between the positive electrode of the battery cluster and the ground can be calculated by the ratio of the voltage between the positive electrode of the battery cluster and the ground to the voltage between the negative electrode of the battery cluster and the ground, and further, the insulation detection can be realized.

[0095] It can be understood that when calculating the voltage between the negative electrode of the battery cluster and the ground, the real-time voltage of a sampling point in the lower bridge arm circuit 1032 can be collected, and the voltage between the negative electrode of the battery cluster and the ground can be obtained by the ratio of the resistance value between the negative electrode of the battery cluster and the sampling point to the resistance value between the negative electrode of the battery cluster and the ground terminal PE.

[0096] As shown, it is a schematic diagram of the second sampling unit 103 containing the switching switch K2 and the ground switch K1. Figure 6

[0097] Here, the second reference voltage V2 is collected when the switching switch K2 is disconnected, so that when calculating the voltage between the negative electrode of the battery cluster and the ground by the collected V2, the calculation complexity is low, and only the resistance relationship in the lower bridge arm circuit 1032 needs to be considered. If the second reference voltage V2 is collected when the switching switch K2 is closed, when calculating the voltage between the negative electrode of the battery cluster and the ground by the second reference voltage V2, the influence of the devices in the upper bridge arm circuit 1031 on the resistance value or the voltage between the negative electrode of the battery cluster and the ground needs to be considered, the calculation complexity is high, and errors are easy to occur, which affects the user experience.

[0098] It should be noted that during the insulation detection process, the ground switch K1 remains closed, so that the current single-cluster insulation detection circuit is grounded, and the insulation detection of the battery cluster to the ground can be completed.

[0099] In the embodiment, the second sampling unit 103 is used to calculate the voltage between the positive electrode and the negative electrode of the battery cluster, and further calculate the resistance between the positive electrode and the negative electrode of the battery cluster, so as to realize the insulation detection. Specifically, the upper bridge arm circuit 1031 is used to calculate the voltage between the positive electrode of the battery cluster and the ground, and the lower bridge arm circuit 1032 is used to calculate the voltage between the negative electrode of the battery cluster and the ground, both of which are grounded through the ground switch K1; the ratio of the voltage between the positive electrode of the battery cluster and the ground to the voltage between the negative electrode of the battery cluster and the ground is the same as the ratio of the resistance value of the resistance between the positive electrode of the battery cluster and the ground to the resistance value of the resistance between the negative electrode of the battery cluster and the ground, so that the resistance value between the positive electrode of the battery cluster and the ground can be calculated by the ratio of the voltage between the positive electrode of the battery cluster and the ground to the voltage between the negative electrode of the battery cluster and the ground, so that the single-cluster insulation detection circuit can complete the insulation detection of the battery cluster to the ground. ​

[0100] In a possible implementation, the upper bridge arm circuit 1031 comprises a fifth resistor R5, a sixth resistor R6, a ninth resistor R9, and the switching switch K2;

[0101] The first end of the fifth resistor R5 is connected with the positive pole of the battery cluster, the second end of the fifth resistor R5 is connected with the first end of the sixth resistor R6, the second end of the sixth resistor R6 is connected with the lower bridge arm circuit 1032, and the second end of the sixth resistor R6 is the second end of the upper bridge arm circuit 1031;

[0102] The first end of the switching switch K2 is connected with the second end of the fifth resistor R5, the second end of the switching switch K2 is connected with the negative pole of the battery cluster, and the second sampling unit 103 accesses the single-cluster insulation detection circuit in different structures in different states of the switching switch K2;

[0103] The first end of the ninth resistor R9 is connected with the first end of the fifth resistor R5, and the second end of the ninth resistor R9 is connected with the second end of the sixth resistor R6.

[0104] Optionally, in some embodiments, according to actual use requirements, the resistance values of R6, R5, and R9 can be equal, and the resistance values are all located between 1 MΩ and 999 MΩ, so that the parameter acquisition device can accurately acquire parameters required for insulation detection.

[0105] In the embodiment, the upper bridge arm circuit 1031 comprises the fifth resistor R5, the sixth resistor R6, the ninth resistor R9, and the switching switch K2; R5 and R6 are connected in series and then are connected in parallel with R9, K2 is connected between R5 and R6, and is used for changing the structure of the upper bridge arm circuit 1031 accessing the single-cluster insulation detection circuit; R5 and R6 are present, avoiding that K2 is directly connected with the positive pole of the load bus or the ground, and ensuring that the closure of K2 cannot completely short-circuit and isolate the lower bridge arm circuit 1032; and R9 is used for being connected in parallel with R5 and R6, and controls the resistance value (the resistance value is reduced by being connected in parallel) of the upper bridge arm circuit 1031. When the upper bridge arm circuit 1031 and the lower bridge arm circuit 1032 are connected in series, more voltage is divided due to the reduced resistance of the upper bridge arm circuit 1031, and less voltage is divided by the lower bridge arm circuit 1032, so that the value of V2 can be controlled, and the parameter value at the sampling point of V2 is ensured to be not more than the range of the detection instrument.

[0106] In a possible implementation, the lower bridge arm circuit 1032 comprises a seventh resistor R7 and an eighth resistor R8;

[0107] The first end of the seventh resistor R7 is the first end of the lower bridge arm circuit 1032, and the first end of the seventh resistor R7 is connected with the upper bridge arm circuit 1031;

[0108] The second end of the seventh resistor R7 is connected with the first end of the eighth resistor R8, and the second end of the eighth resistor R8 is connected with the negative electrode of the battery cluster.

[0109] The second reference voltage V2 is obtained at the second end of the seventh resistor R7.

[0110] In the embodiment, the second reference voltage V2 is obtained between the seventh resistor R7 and the eighth resistor R8, the seventh resistor R7 is connected with the negative electrode of the battery cluster, and the eighth resistor R8 is grounded. The ratio of the voltage between the negative electrode of the battery cluster and the ground to the second reference voltage V2 is equal to the ratio of the resistance value of the seventh resistor R7 to the sum of the resistance values of the seventh resistor R7 and the eighth resistor R8. Therefore, the voltage between the negative electrode of the battery cluster and the ground can be calculated by V2.

[0111] In addition, because the voltage value is high in the actual use scene, the voltage is divided by using the seventh resistor R7 and the eighth resistor R8 to avoid that the to-be-measured value V2 exceeds the range of the detection instrument.

[0112] In a possible implementation, the first sampling unit 101 includes a first resistor R1 and a second resistor R2.

[0113] The first end of the first resistor R1 is connected with the positive electrode of the battery cluster, the second end of the first resistor R1 is connected with the first end of the second resistor R2, and the second end of the second resistor R2 is connected with the negative electrode of the battery cluster.

[0114] The first reference voltage is obtained at the second end of the first resistor R1.

[0115] It can be understood that the first reference voltage V1 is used to calculate the total voltage of the battery cluster. Specifically, the total voltage of the battery cluster can be obtained by V1 through the ratio of the resistance value between the positive electrode of the battery cluster or the negative electrode of the battery cluster and the first reference voltage V1 to the total resistance value.

[0116] For example, the first reference voltage V1 is obtained at the sampling point between the first resistor R1 and the second resistor R2, the first resistor R1 is connected with the positive electrode of the battery cluster, and the second resistor R2 is connected with the negative electrode of the battery cluster. The ratio of the total voltage of the battery cluster to V1 is equal to the ratio of the sum of R1 and R2 to R2.

[0117] In the embodiment, the total voltage of the battery cluster is calculated by the first sampling unit 101, and the voltage between the positive electrode of the battery cluster and the ground can be obtained by the total voltage and the voltage between the negative electrode of the battery cluster and the ground obtained by the lower bridge arm circuit 1032. The ratio of the voltage between the positive electrode of the battery cluster and the ground to the voltage between the negative electrode of the battery cluster is equal to the ratio of the ground resistance of the positive electrode of the battery cluster to the ground resistance of the negative electrode of the battery cluster. Therefore, after the above voltages are obtained, the resistance value of the ground resistance of the battery cluster can be further calculated, and the insulation detection is completed.

[0118] In addition, the first resistor R1 and the second resistor R2 are used to obtain the first reference voltage, and if only one resistor is arranged, the voltage value is high in an actual use scenario, so two resistors are used to realize voltage division, so as to avoid that the to-be-measured value exceeds the range of a detection instrument.

[0119] In a possible implementation, the load communication unit 102 includes a third resistor R3 and a fourth resistor R4.

[0120] The first end of the third resistor R3 is connected with the positive pole of the load bus, the second end of the third resistor R3 is connected with the first end of the fourth resistor R4, and the second end of the fourth resistor R4 is connected with the negative pole of the battery.

[0121] It should be noted that the load communication unit 102 is used to enable the insulation detection circuit to access the load bus when insulation detection is performed. After the insulation detection process is completed, a sampling value of the load bus terminal voltage can be obtained, for example, a sampling point is between R3 and R4. Since the voltage value is high in an actual use scenario, two resistors R3 and R4 are used to realize voltage division, so as to avoid that the to-be-measured value exceeds the range of a detection instrument.

[0122] Specifically, in the energy storage multi-cluster parallel system, insulation detection is an important safety self-checking procedure after power-on. In addition, there are other main operating states, including standby, charging, discharging, balancing, fault protection and the like, and these states all need to measure the load bus voltage in real time and accurately. The multi-cluster parallel insulation detection circuit in the embodiment can be part of the energy storage multi-cluster parallel system. After the multi-cluster parallel insulation detection circuit completes the insulation detection, the energy storage multi-cluster parallel system continues other work of the energy storage system, and the load communication unit 102 can provide the real-time parameters of the load bus terminal required.

[0123] Optionally, considering other work (standby, charging, discharging and the like) of the energy storage system and the working interval of the acquisition device, corresponding resistance value ranges can be set for different resistors. For example, the resistance values of R1 and R3 are equal and are located between 1MΩ-999MΩ, the resistance values of R2 and R4 are equal and are located between 1kΩ-999kΩ, the resistance value of R8 is located between 1kΩ-10KΩ, the resistance values of R5, R6, R7 and R9 are equal and are located between 1MΩ-999MΩ. At the same time, R1>R5 and R2>R8. This can make the energy storage system run smoothly, and the parameters in the multi-cluster parallel insulation detection circuit do not exceed the working interval range of the acquisition device.

[0124] Figure 7 is a flowchart of an insulation detection method provided by the embodiment of the present application, as shown in Figure 7As shown, the method is applied to any single cluster insulation detection circuit in the above multi-cluster parallel insulation detection circuit.

[0125] The insulation detection method comprises the following steps:

[0126] In step 01, the first reference voltage V1 of the first sampling unit 101 and the second reference voltage V2 of the second sampling unit 103 are collected.

[0127] In step 02, the resistance value of the ground resistance of the battery cluster is calculated according to the first reference voltage V1, the second reference voltage V2 and a preset voltage division formula; wherein the preset voltage division formula includes N-1 parallel equivalent resistors; the resistance value of a single parallel equivalent resistor is the sum of the resistance value of the load communication unit 102 and the resistance value of the lower bridge arm circuit 1032.

[0128] In step 03, the insulation detection result is obtained according to the resistance value of the ground resistance.

[0129] It should be noted that the second reference voltage V2 needs to be collected when the switching switch K2 is disconnected, and the collection of the first reference voltage V1 is not affected by the switching switch K2.

[0130] By using the above technical scheme, in the multi-cluster parallel insulation detection scene, the part of the other non-target insulation circuit parallel to the target insulation detection circuit is regarded as a parallel equivalent resistor, which is connected to the target insulation detection circuit to calculate the resistance value of the ground resistance of the battery cluster in the target insulation detection circuit. Specifically, since the part connected to the parallel circuit in the non-target insulation detection circuit is the load communication unit 102 and the lower bridge arm circuit 1032, the resistance value of the equivalent resistor is the sum of the resistance value of the load communication unit 102 and the resistance value of the lower bridge arm circuit 1032. In this scheme, when the target insulation detection circuit performs insulation detection, the other non-target insulation detection circuit in parallel is connected as an equivalent resistor for calculation, that is, the influence of other single-cluster insulation detection circuits in the parallel system on the target insulation detection circuit is considered. Therefore, the target insulation detection circuit can obtain accurate insulation detection results, ensure the safety of the battery system, and improve the user experience.

[0131] In some embodiments, step 02 comprises:

[0132] S11, according to the first reference voltage V1 and the second reference voltage V2, the ground voltage division of the positive electrode of the battery cluster and the ground voltage division of the negative electrode of the battery cluster are calculated;

[0133] S12, according to the positive electrode ground voltage division and the negative electrode ground voltage division, a first voltage division ratio is obtained.

[0134] S13, determining a target voltage division formula in the preset voltage division formula according to the first voltage division ratio; wherein, in the case that the first voltage division ratio is less than or equal to a first threshold value, the target voltage division formula is a first voltage division formula, and the first voltage division formula is used to calculate the resistance value of the positive electrode-to-ground resistance of the battery cluster; in the case that the first voltage division ratio is greater than or equal to a second threshold value, the target voltage division formula is a second voltage division formula, and the second voltage division formula is used to calculate the resistance value of the negative electrode-to-ground resistance of the battery cluster;

[0135] S14, inputting the positive electrode-to-ground voltage division and the negative electrode-to-ground voltage division into the target voltage division formula to calculate the resistance value of the battery cluster-to-ground resistance.

[0136] That is, by sampling the reference voltage, the positive electrode-to-ground voltage division and the negative electrode-to-ground voltage division of the battery cluster are calculated, and according to the ratio of the electrode-to-ground voltage division and the known resistance parameter, the resistance value of the battery cluster-to-ground resistance is calculated. At the same time, the influence of the parallel equivalent resistance in the loop is considered in the calculation, and the resistance value of the battery cluster-to-ground resistance can be calculated more accurately.

[0137] For S11, the first reference voltage V1 and the second reference voltage V2 are obtained, the total voltage Vbat0 of the battery cluster is calculated according to V1, Vbat0 = V1*(1+R1 / R2), and the negative electrode-to-ground voltage division Vn0 of the battery cluster is obtained according to V2, Vn0 = V2*(1+R3 / R4).

[0138] Specifically, for Vbat0, the positive electrode of the battery cluster is connected with R1, and the negative electrode of the battery cluster is connected with R2, so that the voltage between R1 and R2 is V1 obtained by sampling, and then the voltage between R1 and R2 in series can be calculated according to the resistance values of R1 and R2, that is, the total voltage of the battery cluster. For Vn0, the negative electrode-to-ground path of the battery cluster is B- flowing through R4, R3 to PE, and V3 is the voltage of B- through R4, so that when the negative electrode-to-ground voltage division is calculated, the ratio of the negative electrode-to-ground voltage division to V3 is the same as the ratio of R3+R4 to R4, and the negative electrode-to-ground voltage division Vn0 can be obtained according to the ratio of V3 and the resistance.

[0139] For S12, after obtaining the total voltage Vbat0 of the battery cluster and the negative electrode-to-ground voltage division Vn0 of the battery cluster, the positive electrode-to-ground voltage division Vp0 of the battery cluster is Vp0 = Vbat0-Vn0. Further, the first voltage division ratio K0 is K0 = Vp0 / Vn0.

[0140] For S13, according to the first voltage division ratio, it can be determined whether the positive electrode or the negative electrode of the battery cluster is abnormal in terms of insulation to ground, and further detailed calculation is performed according to the abnormal condition. For example, the first threshold is set to 1 / 21, and the second threshold is set to 15. When K0≥15, i.e., Vp0 / Vn0≥15, it is considered that Rp is infinite, i.e., the positive electrode of the battery cluster is insulated to ground, and Rn is small (for example, Rn<200KΩ), and the specific Rn needs to be calculated to further determine the insulation detection result. When K0≤1 / 21, i.e., Vn0 / Vp0≥21, it is considered that Rn is infinite, i.e., the negative electrode of the battery cluster is insulated to ground, and Rp is small (for example, Rp<200KΩ), and the specific Rp needs to be calculated to further determine the insulation detection result. It can be understood that if the first voltage division ratio is not in the above interval, it is determined that the current battery cluster is in good insulation condition, and no further calculation is needed, and the insulation detection result output in step 03 is good.

[0141] Alternatively, when the first voltage division ratio is less than or equal to the first threshold, the voltage division formula can be:

[0142]

[0143] It can be understood that R9 / / Rp represents that R9 is connected in parallel with Rp. At this time, Rn is infinite, so Rn can be ignored in parallel calculation, and in actual use, R8 is usually a small resistance value, which can be ignored in calculation; further, considering the existence of parallel equivalent resistance, the result of connecting all equivalent resistances R in parallel to the current insulation detection circuit is regarded as R 总 , R 总 are connected in parallel to the current insulation detection circuit, and the above voltage division formula can be simplified as:

[0144]

[0145] The first voltage division formula is:

[0146]

[0147] The resistance values of each resistance and the calculated values of Vp0 and Vn0 are substituted into the formula, and Rp can be obtained.

[0148] It should be noted that the resistance value of R 总 is the result of connecting (N-1) equivalent resistances R in parallel with a load communication module 102 in series. Referring to Figure 4 , the parallel equivalent resistances in the parallel circuit finally pass through the load unit 102 and are connected between the negative electrode B- of the battery cluster and the ground terminal PE of the current insulation detection circuit, so the resistance value R 总 that affects the current insulation detection circuit in the parallel circuit includes a load communication unit 102 in addition to the multiple R connected as equivalent resistances. That is, there are N-1 Wherein, N is the number of single cluster insulation detection circuits in parallel in the multi-cluster parallel insulation detection circuit.

[0149] Similarly, when the first voltage division ratio is greater than or equal to the second threshold value, the voltage division formula can be:

[0150]

[0151] It can be understood that at this time Rp is infinite, so Rp can be ignored in parallel calculation. In actual use, R8 is usually a small resistance value, which can be ignored in calculation. At the same time, the result of connecting all equivalent resistances R in parallel to the current insulation detection circuit is regarded as R 总 , R 总 is connected in parallel to the current insulation detection circuit, and the above voltage division formula can be simplified as:

[0152]

[0153] The second voltage division formula is:

[0154]

[0155] Substituting the resistance values of each resistance and the calculated values of Vp0 and Vn0 into the formula, Rn can be obtained.

[0156] It can be understood that when K2 is disconnected, the impedance R of one parallel equivalent resistance is: R=R3+R4+R8+R7; when K2 is closed, the impedance R of one parallel equivalent resistance is: In the embodiments of the present application, K2 can be disconnected uniformly during insulation detection, and R=R3+R4+R8+R7 is kept unchanged to reduce the complexity of calculation or control.

[0157] In some examples, when the current insulation detection circuit is running, the opening and closing of K2 in other insulation detection circuits can be further detected to update the real-time R value, so that the insulation detection result is more accurate.

[0158] Optionally, after the multi-cluster parallel insulation detection circuit is powered on, the V2 voltage value is detected, and the detection is performed every 100 ms. When the difference of three consecutive times is less than 1 mV, it is considered that the voltage has been stabilized, and the V2 value can be used. In addition, when collecting the value of V1 or V2, 10 samples can be collected at the corresponding sampling points respectively, and the average value obtained by removing the highest and lowest values is the final value of V1 or V2.

[0159] In the embodiment, according to the ratio of the positive electrode-to-ground voltage division and the negative electrode-to-ground voltage division, whether the positive electrode or the negative electrode is insulated can be determined. When the first voltage division ratio is less than or equal to the first threshold value, it indicates that the negative electrode-to-ground voltage division of the battery cluster is infinite, that is, the negative electrode of the battery cluster is insulated to the ground, and only the positive electrode-to-ground voltage division of the battery cluster needs to be calculated. Therefore, the first voltage division formula needs to be used for calculation to obtain the positive electrode-to-ground resistance of the battery cluster. When the first voltage division ratio is greater than or equal to the second threshold value, it indicates that the positive electrode-to-ground voltage division of the battery cluster is infinite, that is, the positive electrode of the battery cluster is insulated to the ground, and only the negative electrode-to-ground voltage division of the battery cluster needs to be calculated. Therefore, the second voltage division formula needs to be used for calculation to obtain the negative electrode-to-ground resistance of the battery cluster. According to different cases of the voltage division ratio, the corresponding calculation is performed to obtain effective insulation detection results.

[0160] In some embodiments, different resistance values exist in different setting regions. When the resistance values of the resistors are different, the influence of the resistance values of the equivalent resistors on the equivalent resistance is different, and in some cases, the influence of the parallel equivalent resistance on the negative electrode-to-ground part of the battery cluster can be ignored. That is, when calculating the resistance value of the negative electrode-to-ground resistance of the battery cluster, the influence of the parallel equivalent resistance on the current insulation detection circuit does not need to be considered, and the calculation can be performed only through the internal device structure of the current insulation detection circuit.

[0161] For example, when the resistance values of R1 and R3 are equal and are between 1MΩ-999MΩ, the resistance values of R2 and R4 are equal and are between 1kΩ-999kΩ, the resistance value of R8 is between 1kΩ-10KΩ, and the resistance values of R5, R6, R7 and R9 are equal and are between 1MΩ-999MΩ. At the same time, R1>R5 and R2>R8.

[0162] At this time, since the loop resistance R 总 >1MΩ is connected in parallel between the negative electrode B- of the battery cluster and the ground PE, and the resistance value of the equivalent resistance Rn of the negative electrode B- of the battery cluster to the ground is between 1KΩ-999KΩ, the resistance value after parallel connection is still between 1KΩ-999KΩ, and therefore the influence of R 总 on Rn is small. Therefore, the equivalent resistance connected outside the ground of B- has little influence on the error of the insulation detection, and therefore the equivalent resistance does not need to be considered when calculating. Specifically, for example, the third voltage division formula

[0163] is used to calculate Rn instead of the second voltage division formula, and R 总 is not considered.

[0164] In some embodiments, step 01 includes:

[0165] In the case where the switching switch K2 is disconnected, the lower bridge arm circuit 1032 in the second sampling unit 103 obtains the second reference voltage V2.

[0166] That is, in the process of the insulation detection of the present application using unilateral detection (i.e., the above-mentioned steps 01-03), the sampling parameters for obtaining the relevant voltages, including the second reference voltage V2 and the first reference voltage V1, are acquired by breaking K2. The second reference voltage V2 needs to be acquired in the case of breaking K2 and closing K1, and the acquisition of the first reference voltage V1 does not limit the opening and closing of the switches.

[0167] In some embodiments, step 02 further comprises:

[0168] S21, according to the first reference voltage and the second reference voltage, calculating the positive electrode-to-ground voltage division ratio of the battery cluster and the negative electrode-to-ground voltage division ratio of the battery cluster, and obtaining a first voltage division ratio according to the positive electrode-to-ground voltage division ratio and the negative electrode-to-ground voltage division ratio; wherein the first reference voltage and the second reference voltage are acquired in the case of breaking the switching switch;

[0169] S22, closing the switching switch to acquire a third reference voltage and a fourth reference voltage; wherein the sampling point of the third reference voltage is consistent with that of the first reference voltage, and the sampling point of the fourth reference voltage is consistent with that of the second reference voltage;

[0170] S23, calculating a second voltage division ratio according to the third reference voltage and the fourth reference voltage;

[0171] S24, calculating the resistance value of the ground resistance of the battery cluster according to the first voltage division ratio and the second voltage division ratio.

[0172] Step S21 can refer to the preceding steps S11-S12. In the case of closing the grounding switch K1 and breaking the switching switch K2, V1 and V2 are acquired, and Vbat0, Vn0, and Vp0 are calculated according to V1 and V2.

[0173] In step S22, the switching switch K2 is closed to acquire the third reference voltage V1' value at the V1 sampling point and the fourth reference voltage V2' value at the V2 sampling point, and the positive electrode-to-ground voltage division ratio Vp0' of the battery cluster and the negative electrode-to-ground voltage division ratio Vn0' of the battery cluster in the current connection state are calculated according to V1' and V2'.

[0174] Specifically, the middle voltage Vbat0' of the battery cluster in the current connection state is V1'*(1+R1 / R2); the negative electrode-to-ground voltage division ratio Vn0' of the battery cluster in the current connection state is V2'*(1+R3 / R4); the positive electrode-to-ground voltage division ratio Vp0' of the battery cluster in the current connection state is Vbat0'–Vn0'; and the second voltage division ratio K0' is Vp0' / Vn0'. At this time, the result of connecting all equivalent resistances R in parallel to the current insulation detection circuit is regarded as R 总 R 总Parallel access to the current insulation detection circuit, K0 and K0' are:

[0175]

[0176] In step S24, the relationship of K0 and K0', the positive electrode of the battery cluster in the current connection state can be calculated Rp and the negative electrode of the battery cluster to ground insulation resistance Rn.

[0177] In the actual calculation process, the resistance range of R1-R8 can refer to the foregoing examples. In the calculation process, as described above, considering R 总 Parallel to the equivalent resistance Rn of B-ground, but R 总 The resistance value of the parallel resistance has little effect, so R 总 Can be ignored; at the same time, considering that the resistance of R8 is too small, it has little effect in the calculation process, in order to speed up the calculation result and reduce the complexity of the calculation, R8 can also be ignored. In addition, when the resistance values of R5, R6, R7 and R9 are equal, R5 is used to represent the resistance with the same value as described above, then:

[0178] Rp=2*R5*(K0'-K0) / (K0+2)

[0179] Rn=2*R5*(K0'-K0) / ((K0'+2)*K0)

[0180] It can be understood that the process of collecting V1' and V2' includes closing the switching switch K2 under the condition that the grounding switch K1 is closed, detecting the voltage at the V2 sampling point, detecting once every 200ms, and when the difference between the three consecutive times is less than 1mV, it is considered that the voltage has been stabilized, and the sampling value can be used. Alternately sample the value at the V2 sampling point or the value at the V1 sampling point, a total of 10 times, remove the highest and lowest values and take the average, which is V1' or V2'.

[0181] In the embodiment, two groups of reference voltages need to be obtained, and two groups of reference voltages in different circuit structures. For each group of reference voltages, the ground voltage division of the positive electrode of the battery cluster and the ground voltage division of the negative electrode of the battery cluster are calculated, and the voltage division ratio of the two voltage divisions corresponding to the group of reference voltages is obtained. The voltage division ratio is the same as the ratio of the ground resistance of the positive electrode of the battery cluster and the ground resistance of the negative electrode of the battery cluster corresponding to the current circuit structure. That is, according to the two voltage division ratios, the ratio of the ground resistance in the two cases is obtained, and the two calculation equations representing the ratio in the two cases are combined, that is, the resistance value of the ground resistance of the battery cluster can be calculated. At the same time, since the equivalent resistance in the parallel circuit is considered, more accurate resistance calculation results can be obtained, which is beneficial to timely feedback of the insulation condition according to the accurate resistance value, ensures the safety of the battery cluster, and improves the user experience.

[0182] For step 03, the insulation detection result is obtained according to the resistance value of the ground resistance.

[0183] It can be understood that there are a general leakage threshold and a serious leakage threshold, and the insulation detection result between the battery cluster is determined as insulation, general leakage or serious leakage according to the resistance value of the ground resistance of the battery cluster calculated and compared with the general leakage threshold and the serious leakage threshold.

[0184] For example, the general leakage threshold is 200Ω / V, and the serious leakage threshold is 100Ω / V. When the voltage between the battery cluster (i.e. the voltage between B+ and B-) is 300V, if Rp>200Ω / V*300V, it is considered that Rp is infinite, i.e. the positive electrode of the battery cluster is insulated from the ground; if Rp≤200Ω / V*300V, it is considered that Rp is generally leaked, and the general leakage condition is reported for corresponding processing by the staff; if Rp≤100Ω / V*300V, it is considered that Rp is seriously leaked, and the serious leakage condition is reported for corresponding processing by the staff. The processing of Rn after calculation is the same as that of Rp.

[0185] It can be understood that when Rn and Rp are calculated by using unilateral insulation detection (i.e. steps S11-S14), whether the positive electrode or the ground of the battery cluster is insulated has been determined according to the relationship between the first voltage division value K0 and the first threshold and the second threshold, and the ground resistance of the other side which is uncertain needs to be calculated. Specifically, when K0≥15 (second threshold), it is considered that Rp is infinite, i.e. the positive electrode of the battery cluster is insulated from the ground, and the ground voltage Rn of the negative electrode of the battery cluster is further calculated; when K0≤1 / 21 (first threshold), it is considered that Rn is infinite, i.e. the negative electrode of the battery cluster is insulated from the ground, and the ground voltage Rp of the negative electrode of the battery cluster is further calculated. At this time, the value of the uncertain Rp or Rn is further calculated, and the insulation condition of the end is determined according to the general leakage threshold and the serious leakage threshold.

[0186] In summary, more accurate insulation detection can be achieved by the accurate ground resistance of the battery cluster calculated by the above-mentioned parallel equivalent resistance. When the current battery cluster is determined to be non-insulated, the accurate ground resistance can be provided for subsequent adjustment or improvement.

[0187] Optionally, as shown in Figure 8 The embodiment of the application further provides an electronic device 300, which comprises a processor 301 and a memory 302, and the memory 302 stores programs or instructions which can be run on the processor 301. The programs or instructions are executed by the processor 301 to realize each step of the above-mentioned insulation detection method embodiment, and achieve the same technical effect. To avoid repetition, details are not described here.

[0188] It should be noted that the electronic device in the embodiments of the present application includes the mobile electronic device and the non-mobile electronic device described above

[0189] Figure 9 A hardware structure schematic diagram of an electronic device according to an embodiment of the present application.

[0190] The electronic device 400 includes, but is not limited to, a radio frequency unit 401, a network module 402, an audio output unit 403, an input unit 404, a sensor 405, a display unit 406, a user input unit 407, an interface unit 408, a memory 409, and a processor 410, etc.

[0191] Those skilled in the art can understand that the electronic device 400 can also include a power supply (such as a battery) for powering each component, and the power supply can be logically connected to the processor 410 through a power management system, so as to realize the functions of managing charging, discharging, and power consumption management through the power management system. Figure 9 The electronic device structure shown in the figure does not constitute a limitation on the electronic device, and the electronic device can include more or fewer components than the figure, or combine certain components, or different component arrangements, which are not described here.

[0192] The processor 410 is configured to collect a first reference voltage V1 of the first sampling unit 101 and a second reference voltage V2 of the second sampling unit 103; calculate the resistance value of the ground resistance of the battery cluster according to the first reference voltage V1, the second reference voltage V2, and a preset voltage division formula; the preset voltage division formula includes N-1 parallel equivalent resistors; the resistance value of a single parallel equivalent resistor is the sum of the resistance value of the load connection unit 102 and the resistance value of the lower bridge arm circuit 1032; and obtain the insulation detection result according to the resistance value of the ground resistance.

[0193] In the embodiment of the present application, through the above technical solution, the multi-cluster parallel insulation detection circuit includes N single-cluster insulation detection circuits, N is an integer greater than 1, the N single-cluster insulation detection circuits are connected in parallel to the load bus, and the single-cluster insulation detection circuit includes a battery cluster, a first sampling unit 101, a load communication unit 102, and a second sampling unit 103. The battery cluster, the first sampling unit 101, the load communication unit 102, and the second sampling unit 103 are in parallel relationship. The first sampling unit 101 is configured to provide a first reference voltage V1, and the second sampling unit 103 is configured to provide a second reference voltage V2. The second sampling unit 103 includes a lower bridge arm circuit 1032 connected with the load communication unit 102. The lower bridge arm circuit 1032 and the load communication unit 102 in each single-cluster insulation detection circuit form a parallel loop through the load bus and the ground terminal PE. The parallel loop includes N-1 parallel equivalent resistors, and the resistance of the parallel equivalent resistor is the sum of the resistance of the load communication unit 102 and the resistance of the lower bridge arm circuit 1032. The first reference voltage, the second reference voltage, and the parallel loop are used to calculate the resistance of the ground resistance of the battery cluster, and the resistance is used to determine the insulation detection result. In this way, when performing insulation detection, the influence of other insulation detection circuits in the parallel system on the insulation detection result of the target insulation detection circuit has been considered, so that the insulation detection result obtained by the target insulation detection circuit is more accurate, which can ensure the safety of the battery system and improve the user experience.

[0194] It should be understood that in the embodiment of the present application, the input unit 404 can include a graphics processing unit (GPU) 4041 and a microphone 4042. The graphics processing unit 4041 processes image data of a still picture or a video obtained by an image capture device (such as a camera) in a video capture mode or an image capture mode. The display unit 406 can include a display panel 4061, which can be configured in the form of a liquid crystal display, an organic light-emitting diode, etc. The user input unit 407 includes at least one of a touch panel 4071 and other input devices 4072. The touch panel 4071 is also called a touch screen. The touch panel 4071 can include a touch detection device and a touch controller. The other input devices 4072 can include, but are not limited to, a physical keyboard, function keys (such as volume control keys, on-off keys, etc.), trackballs, mice, joysticks, and the like, which will not be described here.

[0195] The memory 409 can be used to store software programs and various data, and can mainly include a first storage area storing programs or instructions and a second storage area storing data, wherein the first storage area can store an operating system, application programs or instructions required by at least one function (such as a sound playing function, an image playing function, etc.), and the like. In addition, the memory 409 can include a volatile memory or a non-volatile memory, or the memory 409 can include both a volatile memory and a non-volatile memory. The non-volatile memory can be a Read-Only Memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an Electrically EPROM (EEPROM), or a flash memory. The volatile memory can be a Random Access Memory (RAM), a Static RAM (SRAM), a Dynamic RAM (DRAM), a Synchronous DRAM (SDRAM), a Double Data Rate SDRAM (DDR SDRAM), an Enhanced SDRAM (ESDRAM), a Synch link DRAM (SLDRAM), and a Direct Rambus RAM (DRRAM). The memory 409 in the embodiments of the present application includes but is not limited to these and any other suitable types of memory.

[0196] The processor 410 can include one or more processing units; optionally, the processor 410 integrates an application processor and a modem processor, wherein the application processor mainly processes operations related to an operating system, a user interface, and an application program, and the modem processor mainly processes wireless communication signals, such as a baseband processor. It can be understood that the above-mentioned modem processor can also not be integrated into the processor 410.

[0197] The embodiments of the present application also provide a readable storage medium, and the readable storage medium stores programs or instructions, which are executed by a processor to realize each process of the above-mentioned insulation detection method embodiments and achieve the same technical effects. To avoid repetition, details are not described herein.

[0198] The processor is the processor in the electronic device described in the above embodiments. The readable storage medium includes a computer readable storage medium, such as a computer read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0199] The embodiment of the present application further provides a chip, which comprises a processor and a communication interface, the communication interface is coupled with the processor, the processor is used for running programs or instructions to realize the processes of the above insulation detection method embodiments and achieve the same technical effects. To avoid repetition, details are not described here.

[0200] It should be understood that the chip mentioned in the embodiment of the present application can also be referred to as a system-level chip, a system chip, a chip system or a system-on-chip chip, etc.

[0201] The embodiment of the present application provides a computer program product, which is stored in a storage medium, and the program product is executed by at least one processor to realize the processes of the above insulation detection method embodiments and achieve the same technical effects. To avoid repetition, details are not described here.

[0202] It should be noted that in this document, the term "comprising" or "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of additional identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the method and device in the embodiment of the present application is not limited to the order of performing the functions as shown or discussed, but can also include performing the functions in a substantially simultaneous manner or in the opposite order, for example, the described method can be performed in an order different from that described, and various steps can also be added, omitted or combined. In addition, the features described with reference to some examples can be combined in other examples.

[0203] Through the above description of the embodiments, those skilled in the art can clearly understand that the above-mentioned example methods can be realized by means of software and a necessary general hardware platform, and of course, can also be realized by hardware, but in many cases, the former is a better embodiment. Based on such understanding, the technical solutions of the present application can be embodied in the form of a computer software product in essence or in the form of a part that contributes to the prior art, which is stored in a storage medium (such as a ROM / RAM, a magnetic disk, or an optical disk) and includes a plurality of instructions for causing a terminal (which can be a mobile phone, a computer, a server, or a network device, etc.) to execute the methods described in the various embodiments of the present application.

[0204] The embodiments of the present application are described above in combination with the drawings, but the present application is not limited to the above-mentioned specific embodiments, and the above-mentioned specific embodiments are only illustrative and not restrictive. Those skilled in the art can make many forms under the inspiration of the present application without departing from the scope of the present application and the scope protected by the claims.

Claims

1. A multi-cluster parallel insulation detection circuit, characterized in that, The multi-cluster parallel insulation detection circuit includes N single-cluster insulation detection circuits, where N is an integer greater than 1. The N single-cluster insulation detection circuits are connected in parallel to the load bus. Each single-cluster insulation detection circuit includes: a battery cluster, a first sampling unit, a load connection unit, and a second sampling unit. The battery cluster, the first sampling unit, the load connection unit, and the second sampling unit are all connected in parallel. The first sampling unit is used to provide a first reference voltage, and the second sampling unit is used to provide a second reference voltage; The second sampling unit includes a lower bridge arm circuit, which is connected to the load connection unit; the lower bridge arm circuit and the load connection unit in each of the single-cluster insulation detection circuits form a parallel loop through the load bus and the grounding terminal; wherein, the parallel loop includes N-1 parallel equivalent resistors, and the resistance value of the parallel equivalent resistor is the sum of the resistance value of the load connection unit and the resistance value of the lower bridge arm circuit; The first reference voltage, the second reference voltage, and the parallel circuit are used to calculate the resistance value of the battery cluster to ground, and the resistance value is used to determine the insulation test result.

2. The multi-cluster parallel insulation detection circuit according to claim 1, characterized in that, The single-cluster insulation detection circuit also includes a positive contactor and a negative contactor; The positive terminal of the battery cluster is connected to the positive terminal of the load bus via the positive terminal contactor, and the negative terminal of the battery cluster is connected to the negative terminal of the load bus via the negative terminal contactor; wherein, when the multi-cluster parallel insulation detection circuit performs insulation detection, the positive terminal contactor and the negative terminal contactor remain disconnected; The first end of the load connection unit is connected to the positive terminal of the load bus of the single-cluster insulation detection circuit, and the second end of the load connection unit is connected to the negative terminal of the load bus of the single-cluster insulation detection circuit through the negative contactor; wherein, the load connection unit is used to maintain the connection between the single-cluster insulation detection circuit and the load bus when the positive contactor is disconnected.

3. The multi-cluster parallel insulation detection circuit according to claim 1, characterized in that, The second sampling unit includes: an upper bridge arm circuit, a lower bridge arm circuit, a grounding switch, and a switching switch; The upper bridge arm circuit is used to calculate the voltage drop to ground at the positive terminal of the battery cluster; The first end of the upper bridge arm circuit is connected to the positive terminal of the battery cluster, the second end of the upper bridge arm circuit is connected to the first end of the lower bridge arm circuit, and the second end of the upper bridge arm circuit and the first end of the lower bridge arm circuit are grounded through the grounding switch. The lower bridge arm circuit is used to provide a second reference voltage, which is used to calculate the voltage drop to ground at the negative terminal of the battery cluster. The first end of the lower bridge arm circuit is grounded through the grounding switch, and the second end of the lower bridge arm circuit is connected to the negative terminal of the battery cluster; wherein, when the multi-cluster parallel insulation detection circuit performs insulation detection, the grounding switch remains closed; The upper bridge arm circuit is connected to the negative terminal of the battery cluster through the switching switch. When the switching switch is off, the lower bridge arm circuit obtains the second reference voltage.

4. The multi-cluster parallel insulation detection circuit according to claim 3, characterized in that, The upper bridge arm circuit includes a fifth resistor, a sixth resistor, a ninth resistor, and the switching switch; The first end of the fifth resistor is connected to the positive terminal of the battery cluster, the second end of the fifth resistor is connected to the first end of the sixth resistor, the second end of the sixth resistor is connected to the lower bridge arm circuit, and the second end of the sixth resistor is the second end of the upper bridge arm circuit. The first terminal of the switching switch is connected to the second terminal of the fifth resistor, and the second terminal of the switching switch is connected to the negative terminal of the battery cluster. The structure of the second sampling unit connected to the single cluster insulation detection circuit is different when the switching switch is in different states. The first end of the ninth resistor is connected to the first end of the fifth resistor, and the second end of the ninth resistor is connected to the second end of the sixth resistor.

5. The multi-cluster parallel insulation detection circuit according to claim 3, characterized in that, The lower bridge arm circuit includes a seventh resistor and an eighth resistor; The first end of the seventh resistor is the first end of the lower bridge arm circuit, and the first end of the seventh resistor is connected to the upper bridge arm circuit. The second end of the seventh resistor is connected to the first end of the eighth resistor, and the second end of the eighth resistor is connected to the negative terminal of the battery cluster. The second reference voltage is obtained at the second terminal of the seventh resistor.

6. The multi-cluster parallel insulation detection circuit according to claim 1, characterized in that, The first sampling unit includes a first resistor and a second resistor; The first end of the first resistor is connected to the positive terminal of the battery cluster, the second end of the first resistor is connected to the first end of the second resistor, and the second end of the second resistor is connected to the negative terminal of the battery cluster. The first reference voltage is obtained at the second end of the first resistor.

7. The multi-cluster parallel insulation detection circuit according to claim 1, characterized in that, The load connection unit includes a third resistor and a fourth resistor; The first end of the third resistor is connected to the positive terminal of the load bus, the second end of the third resistor is connected to the first end of the fourth resistor, and the second segment of the fourth resistor is connected to the negative terminal of the battery.

8. An insulation testing method, characterized in that, The insulation detection method is applied to a single-cluster insulation detection circuit, wherein the single-cluster insulation detection circuit is any single-cluster insulation detection circuit in the multi-cluster parallel insulation detection circuit according to any one of claims 1-7, and the insulation detection method includes: The first reference voltage of the first sampling unit and the second reference voltage of the second sampling unit are collected; The resistance value of the battery cluster to ground is calculated based on the first reference voltage, the second reference voltage, and a preset voltage divider formula; wherein, the preset voltage divider formula includes N-1 parallel equivalent resistors; the resistance value of a single parallel equivalent resistor is the sum of the resistance value of the load connection unit and the resistance value of the lower bridge arm circuit; The insulation test result is obtained based on the resistance value to ground.

9. The insulation testing method according to claim 8, characterized in that, The step of calculating the resistance value of the battery cluster to ground based on the first reference voltage, the second reference voltage, and a preset voltage divider formula includes: Based on the first reference voltage and the second reference voltage, calculate the voltage drop between the positive terminal and ground of the battery cluster and the voltage drop between the negative terminal and ground of the battery cluster; The first voltage division ratio is obtained based on the voltage division between the positive electrode and the ground and the voltage division between the negative electrode and the ground. The target voltage division formula in the preset voltage division formula is determined based on the first voltage division ratio; wherein, when the first voltage division ratio is less than or equal to a first threshold, the target voltage division formula is a first voltage division formula, which is used to calculate the resistance value of the positive electrode of the battery cluster to ground; when the first voltage division ratio is greater than or equal to a second threshold, the target voltage division formula is a second voltage division formula, which is used to calculate the resistance value of the negative electrode of the battery cluster to ground; The voltage divider between the positive electrode and ground and the voltage divider between the negative electrode and ground are input into the target voltage divider formula to calculate the resistance value of the battery cluster to ground.

10. The insulation testing method according to claim 8, characterized in that, The step of calculating the resistance value of the battery cluster to ground based on the first reference voltage, the second reference voltage, and a preset voltage divider formula includes: Based on the first reference voltage and the second reference voltage, the voltage division to ground of the positive electrode and the voltage division to ground of the negative electrode of the battery cluster are calculated, and the first voltage division ratio is obtained based on the voltage division to ground of the positive electrode and the voltage division to ground of the negative electrode; wherein, the first reference voltage and the second reference voltage are collected when the switching switch in the single cluster insulation detection circuit is open; Close the switching switch to obtain a third reference voltage and a fourth reference voltage; wherein the sampling point of the third reference voltage is the same as that of the first reference voltage, and the sampling point of the fourth reference voltage is the same as that of the second reference voltage. Calculate the second voltage division ratio based on the third reference voltage and the fourth reference voltage; The resistance value of the battery cluster to ground is calculated based on the first voltage division ratio and the second voltage division ratio.

11. An electronic device, characterized in that, include: A processor and a memory, the memory being used to store at least one executable instruction that causes the processor to perform the steps of the insulation detection method as described in any one of claims 8 to 10.

12. A readable storage medium, characterized in that, The readable storage medium stores a program or instructions that, when executed by a processor, implement the steps of the insulation detection method as described in any one of claims 8 to 10.

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