Insulation detection method, device and equipment of energy storage system, medium and program product

Abstract

The invention provides an insulation detection method, device and equipment of an energy storage system, a medium and a program product. The method comprises the step of performing insulation detection on the first battery cluster in the at least two battery clusters by adopting a balanced bridge method and an unbalanced bridge method. For any battery cluster except the first battery cluster in the at least two battery clusters, under the condition that the insulation detection of the previous battery cluster is passed, the resistance value of the positive electrode side insulation resistor and the resistance value of the negative electrode side insulation resistor obtained during the insulation detection of all the battery clusters before the battery cluster are utilized to obtain the resistance value of the positive electrode side insulation resistor and the resistance value of the negative electrode side insulation resistor. And carrying out insulation detection on the battery cluster through an unbalanced bridge method. According to the method, the time of insulation detection of the energy storage system is shortened, and the accuracy of insulation detection of the energy storage system is improved.

Description

Technical Field

[0001] The present application relates to the technical field of insulation detection, and in particular to an insulation detection method, device, equipment, medium and program product for an energy storage system. Background Art

[0002] Insulation detection is very important in energy storage systems. It can provide safety protection for the system and extend the service life of the battery in the energy storage system.

[0003] At present, the bridge method is often used to perform insulation testing on energy storage systems. Due to the existence of Y capacitors and parasitic capacitors in energy storage systems, it takes a long time to perform insulation testing using the conventional bridge method.

[0004] Therefore, how to shorten the insulation testing time of energy storage systems is an urgent problem to be solved. Summary of the invention

[0005] The present application provides an insulation detection method, device, equipment, medium and program product for an energy storage system, which are used to solve the problem that insulation detection of the energy storage system takes a long time.

[0006] In a first aspect, the present application provides an insulation detection method for an energy storage system, wherein the energy storage system comprises at least two battery clusters connected in parallel, and the method comprises:

[0007] Performing insulation detection on a first battery cluster of the at least two battery clusters by using a balanced bridge method and an unbalanced bridge method;

[0008] For any battery cluster other than the first battery cluster among the at least two battery clusters, if the insulation test of the battery cluster preceding it passes, the insulation test of the battery cluster is performed by an unbalanced bridge method using the positive electrode side insulation resistance values ​​and the negative electrode side insulation resistance values ​​obtained during the insulation test of all the battery clusters preceding the battery cluster.

[0009] In one possible manner, the insulation test of the battery cluster is performed by an unbalanced bridge method using the insulation resistance values ​​of the positive electrode side and the insulation resistance values ​​of the negative electrode side of all battery clusters before the battery cluster obtained during the insulation test, including:

[0010] When the balancing bridge of the insulating device is connected to all battery clusters before the battery cluster, the insulation resistance values ​​of the positive electrode side and the insulation resistance values ​​of the negative electrode side of the battery cluster are respectively obtained in the following manner:

[0011] Controlling the relay on the target pole side of the battery cluster to close; wherein the target pole is a positive pole or a negative pole;

[0012] Obtaining the positive side voltage and the negative side voltage of the battery cluster;

[0013] Calculate the resistance of the insulation resistance on the target electrode side of the battery cluster according to the positive electrode side voltage and the negative electrode side voltage of the battery cluster, the resistance values ​​of the insulation resistance on the positive electrode side and the insulation resistance values ​​on the negative electrode side of all battery clusters before the battery cluster, and the resistance value of the resistor in the balancing bridge;

[0014] Based on the insulation resistance value of the target pole side of the battery cluster, an insulation detection result of the battery cluster is determined.

[0015] In a possible manner, obtaining the voltage on the positive electrode side and the voltage on the negative electrode side of the battery cluster includes:

[0016] collecting an initial positive electrode side voltage and an initial negative electrode side voltage of the battery cluster;

[0017] Obtaining a positive electrode side voltage change rate and a negative electrode side voltage change rate according to the collected initial positive electrode side voltage and the initial negative electrode side voltage, and the last collected initial positive electrode side voltage and the initial negative electrode side voltage of the battery cluster;

[0018] When the voltage change rates are all less than or equal to the preset threshold, the initial positive side voltage collected this time is used as the positive side voltage of the battery cluster, and the initial negative side voltage collected this time is used as the negative side voltage of the battery cluster.

[0019] In one possible embodiment, the method further includes:

[0020] Recording the acquisition time of the initial positive side voltage and the initial negative side voltage when the voltage change rate is less than or equal to the preset threshold;

[0021] According to the collection time and the closing time of the relay on the target pole side of the battery cluster, the collection duration is obtained;

[0022] The mapping relationship among the acquisition duration, the target-side relay, and the battery cluster is stored.

[0023] In a possible manner, after performing insulation detection on the battery cluster by using an unbalanced bridge method, the method further includes:

[0024] If the battery cluster insulation test fails, a test result indicating that the energy storage system insulation test fails is output.

[0025] In a possible manner, the detecting the insulation resistance value of the positive electrode side and the insulation resistance value of the negative electrode side of the first battery cluster of the at least two battery clusters by using the balanced bridge method and the unbalanced bridge method includes:

[0026] Connecting a balancing bridge of the insulating device to the first battery cluster to obtain a positive side voltage and a negative side voltage of the first battery cluster;

[0027] Controlling the unbalanced bridge of the insulation device to be connected to the first battery cluster, and obtaining the positive side voltage and the negative side voltage of the first battery cluster again;

[0028] The positive and negative electrode insulation resistances of the first battery cluster are calculated based on the positive and negative electrode voltages of the first battery cluster obtained twice, the resistances of the resistors in the balanced bridge, and the resistances of the resistors in the unbalanced bridge.

[0029] The unbalanced bridge controlling the isolating device is disconnected from the first battery cluster.

[0030] In a second aspect, the present application provides an insulation detection device for an energy storage system, the energy storage system comprising at least two battery clusters connected in parallel, the device comprising:

[0031] A first detection module, configured to perform insulation detection on a first battery cluster of the at least two battery clusters by using a balanced bridge method and an unbalanced bridge method;

[0032] The second detection module is used to perform insulation detection on any battery cluster other than the first battery cluster among the at least two battery clusters by an unbalanced bridge method using the resistance values ​​of the positive electrode side insulation resistance and the negative electrode side insulation resistance of all battery clusters before the battery cluster obtained during the insulation detection, if the insulation detection of the previous battery cluster passes.

[0033] In a third aspect, the present application provides an electronic device, comprising: a processor, and a memory communicatively connected to the processor;

[0034] The memory stores computer-executable instructions;

[0035] The processor executes the computer-executable instructions stored in the memory to implement the method described in any one of the first aspect or the second aspect.

[0036] In a fourth aspect, the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, and when the computer-executable instructions are executed by a processor, they are used to implement any one of the methods described in the first aspect or the second aspect.

[0037] In a fifth aspect, the present application provides a computer program product, including a computer program, which, when executed by a processor, implements any one of the first aspect or the method described in the second aspect.

[0038] The insulation detection method, device, equipment, medium and program product of the energy storage system provided in the embodiments of the present application, when performing insulation detection on the energy storage system, except for the first battery cluster, when subsequent battery clusters are connected in parallel, the unbalanced bridge of the insulation device itself no longer operates, and relies on the resistance values ​​of the insulation resistance on the positive side and the insulation resistance on the negative side of all battery clusters before the battery cluster and the battery cluster itself to act as a bridge, thereby reducing the time for insulation voltage collection and shortening the time for insulation detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0040] Figure 1 A schematic diagram of insulation detection of an energy storage system;

[0041] Figure 2 A curve diagram of voltage boost of a battery cluster provided in an embodiment of the present application;

[0042] Figure 3 A curve diagram of voltage drop of a battery cluster is provided for an embodiment of the present application;

[0043] Figure 4 A schematic diagram of a flow chart of an insulation detection method for an energy storage system provided in an embodiment of the present application;

[0044] Figure 5 A schematic diagram of a process for detecting the insulation resistance value of a first battery cluster provided in an embodiment of the present application;

[0045] Figure 6 A schematic flow chart of a method for obtaining the positive electrode side voltage and the negative electrode side voltage of a battery cluster provided in an embodiment of the present application;

[0046] Figure 7 A schematic flow chart of a method for performing insulation detection on a battery cluster by an unbalanced bridge method provided in an embodiment of the present application;

[0047] Figure 8 A schematic diagram of the structure of an insulation detection device for an energy storage system provided in an embodiment of the present application;

[0048] Fig. 9 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application.

[0049] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0050] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0051] It should be noted that the brief description of the terms in this application is only for the convenience of understanding the embodiments described below, and is not intended to limit the embodiments of the present application. Unless otherwise specified, these terms should be understood according to their common and usual meanings. The terms "including" and "having" in the specification and claims and the above-mentioned drawings in this application and any variation thereof are intended to cover but not exclude inclusion. For example, a product or device containing a series of components is not necessarily limited to those components clearly listed, but may include other components that are not clearly listed or inherent to these products or devices. The term "module" used in this application refers to any known or later developed hardware, software, firmware, artificial intelligence, fuzzy logic or a combination of hardware and / or software code that can perform functions related to the element.

[0052] Energy storage system refers to a system that uses specific equipment and technology to store energy and convert the stored energy back into electrical energy for use when needed. For example, the energy storage system can be composed of multiple parallel battery clusters, where the battery cluster can be composed of multiple strings (usually more than 400) of energy storage batteries connected in series, as well as control equipment, collection harnesses and power harnesses, relays, etc.

[0053] In energy storage systems, insulation performance is one of the key indicators for evaluating the safety and stability of energy storage systems. Insulation performance can not only directly reflect whether there is a potential leakage problem in the battery in the energy storage system, but also provide timely safety warnings for the energy storage system. At the same time, good insulation performance can also significantly reduce the self-discharge rate of the battery in the energy storage system, slow down the aging process of the battery, thereby extending the overall service life of the battery and laying a solid foundation for the long-term stable operation of the energy storage system. Therefore, testing the insulation performance of the energy storage system is an important part of ensuring the safe and stable operation of the system.

[0054] At present, the insulation performance of the energy storage system is determined by detecting the insulation resistance of the energy storage system. Among them, the insulation resistance refers to the DC resistance of the energy storage DC positive bus and negative bus to the shell (i.e., the earth). At present, there are two methods for insulation detection of energy storage systems: the bridge method and the injection method. The bridge method includes the balanced bridge method and the unbalanced bridge method. The bridge method is widely used for its simplicity, high precision and low cost.

[0055] The following describes how to use the bridge method to perform insulation testing in the prior art.

[0056] Figure 1 Figure 1 is a schematic diagram of insulation detection of an energy storage system. Figure 1 As shown, the energy storage system includes multiple battery clusters connected in parallel. Figure 1 This is a schematic diagram taking 12 battery clusters as an example.

[0057] Each battery cluster includes a positive bus bar and a negative bus bar, a ground wire, an insulation resistor 1, an insulation resistor 2, a relay 1+, and a relay 1-.

[0058] by Figure 1 For example, insulation resistor 1 may be R1p, insulation resistor 2 may be R1n, relay 1+ may be S1+, and relay 1- may be S1-.

[0059] In the battery cluster, one end of relay 1+ is connected to the positive busbar, and the other end is connected to insulation resistor 1; one end of insulation resistor 1 is connected to relay 1+, and the other end is connected to insulation resistor 2; one end of insulation resistor 2 is connected to insulation resistor 1, and the other end is connected to relay 1-; one end of relay 1- is connected to insulation resistor 2, and the other end is connected to the negative busbar. A ground wire is connected between insulation resistor 1 and insulation resistor 2.

[0060] Each battery cluster also has a Y-type filter capacitor (hereinafter referred to as Y capacitor) and parasitic capacitor. Among them, the Y capacitor refers to the capacitor connected between the busbar and the ground wire, which plays a role in suppressing industrial mode interference; the generation of parasitic capacitors is mainly due to the mutual capacitance effect between electronic components, electrical components, and wiring harnesses. As the effects of these devices accumulate, they will produce an effect like a capacitor. For the convenience of description, the following will equate the Y capacitor and parasitic capacitor to one capacitor, referred to as equivalent capacitor.

[0061] Each battery cluster includes a positive side equivalent capacitor and a negative side equivalent capacitor. Figure 1 For example, the positive side equivalent capacitor may be C1+, and the negative side equivalent capacitor may be C1-. The positive side equivalent capacitor is connected in parallel with insulation resistor 1, and the negative side equivalent capacitor is connected in parallel with insulation resistor 2.

[0062] The positive busbar, ground wire and negative busbar of each battery cluster are connected correspondingly to realize parallel connection between battery clusters. Multiple battery clusters are connected in parallel to form an energy storage system.

[0063] The execution subject of the insulation detection of the energy storage system may include an insulation device and an insulation detection device, which may be integrated on a circuit board or connected in any way that can achieve electrical connection, and this application does not limit this.

[0064] The insulating device includes: a first bridge and a second bridge. The first bridge includes resistor 1, resistor 2, relay 1 and relay 2; the second bridge includes resistor 3, resistor 4, relay 3 and relay 4; and the busbar includes a positive busbar and a negative busbar.

[0065] by Figure 1 For example, resistor 1 and resistor 2 may be resistors with larger resistance, such as 8M; resistor 3 and resistor 4 may be resistors with smaller resistance, such as 1.2M; relay 1 may be S01, relay 2 may be S02, relay 3 may be S03, and relay 4 may be S04.

[0066] In the insulation device, one end of relay 1 is connected to the positive busbar, and the other end is connected to resistor 1; one end of resistor 1 is connected to relay 1, and the other end is connected to resistor 2; one end of resistor 2 is connected to resistor 1, and the other end is connected to relay 2; one end of relay 2 is connected to resistor 2, and the other end is connected to the negative busbar. A ground wire is connected between resistor 1 and resistor 2.

[0067] The connection relationship of the second bridge is consistent with that of the first bridge, and will not be described in detail here. The positive busbars, ground wires, and negative busbars of the first bridge and the second bridge are connected correspondingly to realize the connection between the first bridge and the second bridge.

[0068] The insulation detection device is connected to the insulation device to control the opening and closing of the insulation device and the relay in the battery cluster. For the sake of example, Figure 1 This connection relationship is not shown in FIG.

[0069] Optionally, the voltage between the positive busbar and the ground at both ends of the insulation resistor can be called the positive side voltage, and the voltage between the negative busbar and the ground at both ends of the insulation resistor can be called the negative side voltage. Figure 1 Taking battery cluster 1 as an example, R1p of battery cluster 1 is located between the positive bus and the ground, so the voltage across R1p is the positive side voltage of battery cluster 1, and R1n of battery cluster 1 is located between the negative bus and the ground, so the voltage across R1n is the negative side voltage of battery cluster 1.

[0070] Taking battery cluster 1 as an example, the insulation detection process of the insulation detection device using the bridge method is as follows:

[0071] 1. Control the S01, S02, S1+, and S1- relays to close and connect the balancing bridge of the insulation device to the battery cluster.

[0072] Since S01 and S02 are both closed, resistors 1 and 2 are both connected to the circuit, and the resistance between the positive bus and the ground is the same as the resistance between the negative bus and the ground, thus forming a balanced bridge.

[0073] 2. Collect the positive side voltage V1p and the negative side voltage V1n of the insulation resistance, and the following formula (1) can be obtained:

[0074] V1p / (8M|R1p)=V1n / (8M|R1n) (1)

[0075] 3. Control the S03 or S04 relay to close, and connect an unbalanced bridge between the positive bus or negative bus and the ground. Taking the control of the S03 relay to close as an example, connect an unbalanced bridge between the positive bus and the ground.

[0076] Since only one of the relays S03 or S04 is controlled to be closed, the resistance between the positive bus and the ground wire is different from the resistance between the negative bus and the ground wire, thus forming an unbalanced bridge.

[0077] 4. Collect the positive side voltage V2p and the negative side voltage V2n of the insulation resistance, and the following formula (2) can be obtained:

[0078] V2p / (8M|1.2M|R1p)=V2n / (8M|R1n) (2)

[0079] By combining formula (1) and formula (2), the insulation resistance R1p of the positive electrode side and the insulation resistance R1n of the negative electrode side of the battery cluster can be calculated.

[0080] In practical applications, the equivalent capacitance will affect the time it takes to obtain the voltage of the battery cluster. Figure 2 This is a curve diagram of the voltage boost of the battery cluster provided in the embodiment of the present application. Figure 2 As shown, the horizontal axis represents time, and the vertical axis represents the positive side voltage or negative side voltage of the battery cluster. Taking the vertical axis representing the positive side voltage of the battery cluster as an example, Figure 2 The straight line in the middle represents that when the equivalent capacitance is not considered, the positive side voltage of the battery cluster can reach the stable value U after a certain period of time; the curved line represents that when the equivalent capacitance is considered, the positive side voltage of the battery cluster needs a longer time to reach the stable value U. Figure 3 A curve diagram of the voltage drop of a battery cluster is provided for the embodiment of the present application. Figure 2 The same, no further elaboration here.

[0081] Therefore, in a large-capacity energy storage system composed of multiple battery clusters in parallel, each time a battery cluster is added, the equivalent capacitance of the entire energy storage system will be connected in parallel. As more and more battery clusters are added, the insulation collection time will gradually increase due to the increase in equivalent capacitance.

[0082] For example, Figure 1 For example, the energy storage system consists of 12 battery clusters. When performing insulation detection, the time for each insulation acquisition is fixed, such as 15 seconds. This acquisition time can be obtained based on actual tests or experience, but since the conditions of different battery clusters are not exactly the same, the embodiment of the present application does not limit this acquisition time.

[0083] Considering the acquisition time, the insulation acquisition process of the energy storage system is as follows:

[0084] 1. First close the S01 and S02 relays of the insulating device.

[0085] 2. Close the two relays (S1+ and S1-) of battery cluster 1, wait until time t0, and then collect the positive and negative voltages of battery cluster 1.

[0086] 3. Close S03 or S04, wait for time t1, and then collect the positive and negative voltages of battery cluster 1 again.

[0087] During this process, the total time between t0 and t1 is 15 seconds.

[0088] 4. The positive and negative voltages of battery cluster 2 are collected, which is consistent with the above-mentioned collection of the positive and negative voltages of battery cluster 1, and will not be repeated here. This process also takes 15 seconds.

[0089] 5. This process is repeated in this way until the positive and negative voltages of the 12 battery clusters are collected.

[0090] Therefore, in the process of insulation detection of the entire energy storage system, the total time consumed for insulation acquisition of the positive side voltage and the negative side voltage is 12*15=180 seconds.

[0091] It can be seen from this that in the prior art, when performing insulation testing on the energy storage system, each battery cluster needs t0 time for parallel connection, and insulation acquisition needs t1 time, so each battery cluster needs (t0+t1) time. When there are 12 battery clusters in parallel, insulation acquisition requires T=(t0+t1)*12 time, and this process has the disadvantage of being time-consuming.

[0092] Based on this, the present application hopes to shorten the time of insulation testing on the energy storage system and improve the efficiency of insulation testing on the energy storage system.

[0093] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0094] Figure 4 A schematic flow chart of an insulation detection method for an energy storage system provided in an embodiment of the present application. The method comprises:

[0095] S101 . Perform insulation detection on a first battery cluster of at least two battery clusters by using a balanced bridge method and an unbalanced bridge method.

[0096] Optionally, the first battery cluster from left to right in all battery clusters in the energy storage system can be used as the first battery cluster, or a battery cluster can be randomly selected from the energy storage system as the first battery cluster, which is not limited in this application. Exemplarily, the use of the balanced bridge method and the unbalanced bridge method to perform insulation detection on the first battery cluster is consistent with the above-mentioned method for detecting the insulation resistance of R1p and R1n, which is not described in detail.

[0097] S102. For any battery cluster other than the first battery cluster among the at least two battery clusters, if the insulation test of the battery cluster preceding it passes, insulation test of the battery cluster is performed by an unbalanced bridge method using the positive electrode side insulation resistance values ​​and the negative electrode side insulation resistance values ​​obtained during the insulation test of all battery clusters preceding the battery cluster.

[0098] Since the battery cluster itself contains resistance, it is similar to the unbalanced bridge in the insulation device, that is, it is equivalent to the second bridge in the insulation device. Therefore, if the insulation test of the battery cluster before this battery cluster passes, the insulation test of the battery cluster can be performed on the positive electrode side insulation resistance and the negative electrode side insulation resistance obtained during the insulation test of all battery clusters before this battery cluster and the battery cluster itself by the unbalanced bridge method.

[0099] Therefore, unlike the insulation detection method for the first cluster, which requires closing the relay of the insulating device twice, in the solution of the present application, for any battery cluster other than the first battery cluster among the at least two battery clusters, when performing insulation detection on it, it is only necessary to close the relay of the battery cluster itself to complete the insulation detection of the battery cluster, that is, only the unbalanced bridge method detection is required.

[0100] Therefore, when the solution of the present application is used for insulation testing, a shorter time can be used to perform insulation testing on any battery cluster except the first battery cluster. Therefore, compared with the existing solution, the insulation testing of the present application takes less time.

[0101] Optionally, if the insulation test of the previous battery cluster fails, the insulation test of the subsequent battery clusters of the energy storage system is stopped. Alternatively, if the insulation test of the previous battery cluster fails, the battery cluster that fails the insulation test is disconnected, that is, the relay of the battery cluster is disconnected so that the battery cluster is no longer connected in parallel with other battery clusters in the energy storage system, and only the battery cluster that previously passed the insulation test is used to perform insulation tests on subsequent battery clusters.

[0102] In the embodiment of the present application, when performing insulation detection on the energy storage system, except for the first battery cluster, when subsequent battery clusters are connected in parallel, the unbalanced bridge of the insulation device itself no longer operates, and the resistance values ​​of the insulation resistance on the positive side and the insulation resistance on the negative side of all battery clusters before the battery cluster and the battery cluster itself act as a bridge, thereby reducing the time for insulation voltage collection and shortening the time for insulation detection.

[0103] Furthermore, the use of the balanced bridge method and the unbalanced bridge method to detect the resistance value of the insulation resistance on the positive electrode side and the resistance value of the insulation resistance on the negative electrode side of the first battery cluster among the at least two battery clusters is further described. Figure 5 A schematic diagram of a process for detecting the insulation resistance of a first battery cluster provided in an embodiment of the present application. The method includes:

[0104] S201 , connecting a balancing bridge of an insulating device to a first battery cluster, and obtaining a positive electrode side voltage and a negative electrode side voltage of the first battery cluster.

[0105] by Figure 1 For example, the S01, S02, S1+, and S1- relays are closed to connect the balancing bridge of the insulating device to the battery cluster 1, and the positive side voltage V1p and the negative side voltage V1n of the battery cluster 1 are obtained.

[0106] S202 , controlling the unbalanced bridge of the insulating device to be connected to the first battery cluster, and obtaining the positive side voltage and the negative side voltage of the first battery cluster again.

[0107] Optionally, closing any one of the relays S03 or S04 realizes the connection between the unbalanced bridge of the insulating device and the battery cluster 1. In the embodiment of the present application, closing the S03 relay is used as an example to realize the connection between the unbalanced bridge of the insulating device and the battery cluster 1, and the positive side voltage V2p and the negative side voltage V2n of the battery cluster 1 are obtained again.

[0108] S203, calculating the insulation resistance of the positive electrode side and the insulation resistance of the negative electrode side of the first battery cluster according to the positive electrode side voltage and the negative electrode side voltage of the first battery cluster obtained twice, the resistance of the resistor in the balanced bridge, and the resistance of the resistor in the unbalanced bridge.

[0109] The method is consistent with the above formula (1) and formula (2), and will not be repeated here. The insulation resistance R1p of the positive electrode side and the insulation resistance R1n of the negative electrode side of the battery cluster 1 are calculated.

[0110] S204 , controlling the unbalanced bridge of the insulation device to be disconnected from the first battery cluster.

[0111] Optionally, disconnecting any one of the relays S03 or S04 realizes disconnection between the unbalanced bridge of the insulating device and the battery cluster 1. In the embodiment of the present application, disconnecting the relay S03 is used as an example to realize disconnection between the unbalanced bridge of the insulating device and the battery cluster 1.

[0112] During insulation data collection, it is necessary to wait for the positive side voltage or the negative side voltage of the battery cluster to stabilize before data collection can be performed. However, due to the existence of equivalent capacitance, the positive side voltage and the negative side voltage will not stabilize immediately, but will take a certain amount of time to stabilize.

[0113] Optionally, a preset time length method may be used to collect the positive side voltage and the negative side voltage of the battery cluster 1. For example, the preset time length may be 15 seconds, and the positive side voltage and the negative side voltage of the battery cluster 1 are collected at 15 seconds.

[0114] Optionally, the positive side voltage and the negative side voltage may be dynamically collected, and stable voltage values ​​may be selected as the positive side voltage and the negative side voltage through a preset threshold. Figure 6 A schematic flow chart of a method for obtaining the positive electrode side voltage and the negative electrode side voltage of a battery cluster provided in an embodiment of the present application. The method comprises:

[0115] S401 , collecting the initial positive electrode side voltage and the initial negative electrode side voltage of the battery cluster.

[0116] Optionally, the initial positive side voltage Vp11 and the initial negative side voltage Vn11 of the battery cluster are collected in real time, and the collection period may be 10 ms.

[0117] S402 , obtaining a positive side voltage change rate and a negative side voltage change rate according to the collected initial positive side voltage and the initial negative side voltage, and the last collected initial positive side voltage and the initial negative side voltage of the battery cluster.

[0118] Optionally, the positive side voltage change rate ΔVp1 is calculated based on the collected initial positive side voltage Vp11 and the last collected initial positive side voltage Vp01 of the battery cluster. Optionally, the positive side voltage change rate ΔVp1 may be the difference between the last collected initial positive side voltage Vp01 and the initial positive side voltage Vp11 of the battery cluster, or may be the ratio of the difference between the last collected initial positive side voltage Vp01 and the initial positive side voltage Vp11 of the battery cluster to the collection period.

[0119] The negative voltage change rate ΔVn1 is calculated based on the collected initial negative voltage Vn11 and the last collected initial negative voltage Vn01 of the battery cluster. The calculation rule of the negative voltage change rate ΔVn1 is the same as that of the initial positive voltage Vp01, which will not be repeated here.

[0120] S403: When the voltage change rates are all less than or equal to the preset threshold, the initial positive side voltage collected this time is used as the positive side voltage of the battery cluster, and the initial negative side voltage collected this time is used as the negative side voltage of the battery cluster.

[0121] Optionally, if the positive side voltage change rate ΔVp1 is less than or equal to a preset threshold, the initial positive side voltage Vp11 collected this time is used as the positive side voltage of the battery cluster. If the negative side voltage change rate ΔVn1 is less than or equal to a preset threshold, the initial negative side voltage Vn11 collected this time is used as the negative side voltage of the battery cluster.

[0122] In the embodiment of the present application, the collection time of the positive side voltage and the negative side voltage is dynamically adjusted, and the time is automatically adjusted to the most accurate collection state. Compared with using a preset time length to collect the positive side voltage and the negative side voltage, the time for insulation detection can be reduced.

[0123] Furthermore, the insulation test of the battery cluster is further described by using the unbalanced bridge method using the insulation resistance values ​​of the positive electrode side and the insulation resistance values ​​of the negative electrode side obtained during the insulation test of all battery clusters before the battery cluster.

[0124] When the balancing bridge of the insulating device is connected to all battery clusters before the battery cluster, the resistance value of the insulation resistance on the positive electrode side and the insulation resistance value on the negative electrode side of the battery cluster are obtained in the following manner: Figure 7 A flow chart of a method for performing insulation detection on a battery cluster by an unbalanced bridge method provided in an embodiment of the present application, the method comprising:

[0125] S301, controlling the relay on the target pole side of the battery cluster to close, wherein the target pole is the positive pole or the negative pole.

[0126] by Figure 1 For example, taking the detection of the insulation resistance of battery cluster 2 as an example, when the balancing bridge of the insulating device is connected to battery cluster 1, S2+ is closed to connect battery cluster 2 to the positive electrode. When the balancing bridge of the insulating device is connected to battery cluster 1, S2- is closed to connect battery cluster 2 to the negative electrode.

[0127] S302: Obtain the positive electrode side voltage and the negative electrode side voltage of the battery cluster.

[0128] Taking battery cluster 2 as an example, close S2+ to obtain the positive side voltage of the battery cluster, and close S2- to obtain the negative side voltage of the battery cluster.

[0129] Consistent with the above-mentioned acquisition of the positive side voltage and the negative side voltage of the battery cluster, a method of preset time or a method of dynamic acquisition may be adopted.

[0130] Taking the preset time as an example, a fixed collection time is preset, for example, 8 seconds. This preset fixed collection time can be obtained based on actual tests or experience. After closing the S03 relay, wait for the preset fixed collection time (for example, 8 seconds) to start collecting the positive side voltage and the negative side voltage of the battery cluster. This preset time is shorter than the waiting time required in the prior art, so the insulation detection time can be shortened.

[0131] The method of dynamic collection is the same as above and will not be repeated here.

[0132] S303, calculating the resistance of the target electrode side insulation resistance of the battery cluster according to the positive electrode side voltage and the negative electrode side voltage of the battery cluster, the resistance values ​​of the positive electrode side insulation resistance and the negative electrode side insulation resistance of all battery clusters before the battery cluster, and the resistance value of the resistor in the balancing bridge.

[0133] The method of formula (1) and formula (2) above is consistent with the calculation of the insulation resistance R2p of the positive electrode side and the insulation resistance R2n of the negative electrode side of the battery cluster 2, which will not be repeated here. The insulation resistance value of the subsequent battery cluster is consistent with this method, which will not be repeated here.

[0134] S304: Determine the insulation detection result of the battery cluster based on the insulation resistance value of the target pole side of the battery cluster.

[0135] Optionally, the insulation resistance of the battery cluster is compared with a standard value, and if the insulation resistance of the battery cluster is greater than the standard value, the insulation test is determined to have passed. If the insulation resistance of the battery cluster is less than the standard value, the insulation test is determined to have failed.

[0136] In the embodiment of the present application, when the energy storage system is subjected to insulation detection and multiple battery clusters are connected in parallel, the subsequently added battery clusters will no longer trigger the unbalanced bridge of the insulation device to operate. Instead, they will use the total resistance of the insulation resistance on the positive and negative sides of all previously connected battery clusters and the battery cluster itself to build the bridge. This approach effectively reduces the time required for collecting the insulation voltage, thereby speeding up the overall insulation detection process.

[0137] On the basis of the above embodiment, the mapping relationship in the insulation detection process can also be recorded to facilitate subsequent insulation detection of similar batteries. The method is as follows:

[0138] First, the acquisition time of the initial positive side voltage and the initial negative side voltage whose voltage change rate is less than or equal to the preset threshold is recorded. Taking the positive pole as an example, the acquisition time T0 of the initial positive side voltage whose voltage change rate is less than or equal to the preset threshold is recorded.

[0139] Secondly, according to the collection time and the relay closing time of the target electrode side of the battery cluster, the collection duration is obtained. Taking the positive electrode as an example, according to the collection time T0 and the relay closing time T1 of the positive electrode of the battery cluster, the collection duration of the positive electrode of the battery cluster can be obtained as (TI-T0).

[0140] Finally, the mapping relationship between the acquisition time, the target side relay, and the battery cluster is stored. Taking the positive electrode as an example, the mapping relationship between the acquisition time (TI-T0), the positive electrode relay, and the battery cluster is stored.

[0141] By recording the mapping relationship in the insulation detection process, the embodiment of the present application can directly use the collection time to collect the positive side voltage and the negative side voltage of the battery cluster when performing insulation detection on the same energy storage system in the future, thereby simplifying the iterative process of collecting target and side voltages and more accurately collecting the target pole side voltage.

[0142] Furthermore, after performing insulation detection on the battery cluster by using an unbalanced bridge method, the method further includes:

[0143] If the battery cluster insulation test fails, the test result of the energy storage system insulation test failure is output. There are multiple output methods. Optionally, the warning message of the insulation test failure can be directly displayed on the control panel of the energy storage system or the display screen of the monitoring center; different color indicator lights (such as red, yellow, etc.) can be used to indicate the status of the insulation test. When the insulation test fails, the corresponding indicator light will light up or flash to attract attention; an alarm sound can be issued through a buzzer, speaker or other sound device to output the result of the insulation test failure.

[0144] In a possible implementation, if a battery cluster fails the insulation test, the insulation test of subsequent battery clusters is terminated, and a test result indicating that the energy storage system fails the insulation test is output.

[0145] In another possible implementation, if a battery cluster fails the insulation test, the relay of the battery cluster is disconnected, and the insulation resistance values ​​of subsequent battery clusters are continuously tested using all the battery clusters that have passed the insulation test.

[0146] When the battery cluster insulation test fails, the embodiment of the present application timely outputs the test result that the energy storage system insulation test fails, which can provide a timely warning and improve the safety of the energy storage system.

[0147] by Figure 1 As an example, the insulation detection method provided in the embodiment of the present application is illustrated by way of example:

[0148] 1. Control the S01, S02, S1+, and S1- relays to close and connect the balancing bridge of the insulation device to battery cluster 1.

[0149] 2. Collect the positive side voltage V1p and the negative side voltage V1n of the insulation resistance.

[0150] 3. Control the S03 or S04 relay to close, and connect an unbalanced bridge between the positive bus or negative bus and the ground. Taking the control of the S03 relay to close as an example, connect an unbalanced bridge between the positive bus and the ground.

[0151] 4. Collect the positive side voltage V2p and the negative side voltage V2n of the insulation resistance.

[0152] 5. Calculate the insulation resistance R1p of the positive electrode side and the insulation resistance R1n of the negative electrode side of battery cluster 1.

[0153] 6. Control S03 or S04 relay to disconnect.

[0154] 7. Determine whether the battery cluster has passed the insulation test. If so, proceed to the next step; if not, stop the insulation test on the subsequent battery clusters, or only use the battery cluster that has passed the insulation test to perform insulation test on the subsequent battery clusters.

[0155] 8. Control S2+ relay to close.

[0156] 9. Dynamically collect the initial positive side voltage V22p and the initial negative side voltage V22n of the insulation resistance, with a collection period of 10 milliseconds.

[0157] 10. Obtain the positive side voltage change rate or the negative side voltage change rate ΔVp2 based on the collected initial positive side voltage V22p and initial negative side voltage V22n, and the last collected initial positive side voltage V20p and initial negative side voltage V20n of the battery cluster.

[0158] 11. Compare ΔVp2 with a preset threshold value to determine whether the voltage value is stable. Take the stable voltage value as the positive electrode side voltage and the negative electrode side voltage of the battery cluster 2.

[0159] 12. Calculate the insulation resistance R2p of the positive electrode side of the battery cluster 2.

[0160] 13. Execute step 7.

[0161] 14. Control S2-relay to close and repeat steps 9-13.

[0162] 15. Calculate the insulation resistance R2p of the negative electrode side of battery cluster 2.

[0163] 16. Execute step 7.

[0164] 17. Repeat steps 8-16 to calculate the insulation resistance values ​​of the positive electrode side and the insulation resistance values ​​of the negative electrode side of all subsequent battery clusters, thereby completing the insulation detection.

[0165] In summary, the embodiment of the present application improves the insulation detection method of the energy storage system in the prior art. When performing insulation detection on the energy storage system, except for the first battery cluster, when the subsequent battery clusters are connected in parallel, the unbalanced bridge of the insulation device itself no longer operates, and the resistance values ​​of the insulation resistance on the positive side and the insulation resistance on the negative side of all battery clusters before the battery cluster are used as a bridge, which reduces the time for insulation voltage collection and shortens the time for insulation detection. At the same time, by realizing dynamic detection of the positive side voltage and the negative side voltage, it is possible to automatically identify whether the voltage is stable, accurately obtain the positive side voltage and the negative side voltage, thereby improving the accuracy of insulation detection.

[0166] The above is an embodiment of the method provided by the present application. The following is a description of the device provided by the present application.

[0167] Figure 8 This is a schematic diagram of the structure of an insulation detection device for an energy storage system provided in an embodiment of the present application. Figure 8 As shown, the insulation detection device 500 of the energy storage system may include, for example: a first detection module 501 and a second detection module 502 .

[0168] A first detection module 501 is used to perform insulation detection on a first battery cluster of at least two battery clusters by using a balanced bridge method and an unbalanced bridge method;

[0169] The second detection module 502 is used to perform insulation detection on any battery cluster other than the first battery cluster among the at least two battery clusters by using the unbalanced bridge method, using the positive electrode side insulation resistance values ​​and the negative electrode side insulation resistance values ​​obtained during the insulation detection of all battery clusters before the battery cluster, if the insulation detection of the previous battery cluster passes.

[0170] Optionally, the second detection module 502 is specifically used to obtain the resistance value of the insulation resistance on the positive electrode side and the insulation resistance on the negative electrode side of the battery cluster respectively in the following manner when the balancing bridge of the insulation detection circuit is connected to all battery clusters before the battery cluster: control the relay on the target electrode side of the battery cluster to be closed. The target electrode is the positive electrode or the negative electrode. Obtain the positive electrode side voltage and the negative electrode side voltage of the battery cluster. According to the positive electrode side voltage and the negative electrode side voltage of the battery cluster, the resistance value of the insulation resistance on the positive electrode side and the insulation resistance value of the negative electrode side of all battery clusters before the battery cluster, and the resistance value of the resistor in the balancing bridge, calculate the resistance value of the insulation resistance on the target electrode side of the battery cluster. Based on the resistance value of the insulation resistance on the target electrode side of the battery cluster, determine the insulation detection result of the battery cluster.

[0171] For example, the second detection module 502 is specifically used to collect the initial positive side voltage and the initial negative side voltage of the battery cluster. According to the collected initial positive side voltage and the initial negative side voltage, and the last collected initial positive side voltage and the initial negative side voltage of the battery cluster, the positive side voltage change rate and the negative side voltage change rate are obtained. When the voltage change rates are both less than or equal to the preset threshold value, the initial positive side voltage collected this time is used as the positive side voltage of the battery cluster, and the initial negative side voltage collected this time is used as the negative side voltage of the battery cluster.

[0172] Furthermore, the second detection module 502 is also used to record the acquisition time of the initial positive side voltage and the initial negative side voltage whose voltage change rate is less than or equal to the preset threshold. According to the acquisition time and the closing time of the relay on the target side of the battery cluster, the acquisition time is obtained. The mapping relationship between the acquisition time, the target side relay, and the battery cluster is stored.

[0173] Optionally, the second detection module 502 is further configured to output a detection result indicating that the energy storage system insulation test has failed, if the insulation test of the battery cluster fails after the insulation test of the battery cluster is performed using an unbalanced bridge method.

[0174] Optionally, the first detection module 501 is specifically used to connect the balanced bridge of the insulation detection circuit to the first battery cluster to obtain the positive side voltage and the negative side voltage of the first battery cluster. Control the unbalanced bridge of the insulation detection circuit to be connected to the first battery cluster to obtain the positive side voltage and the negative side voltage of the first battery cluster again. According to the positive side voltage and the negative side voltage of the first battery cluster obtained twice, the resistance value of the resistor in the balanced bridge, and the resistance value of the resistor in the unbalanced bridge, calculate the resistance value of the insulation resistance on the positive side and the insulation resistance on the negative side of the first battery cluster. Control the unbalanced bridge of the insulation detection circuit to be disconnected from the first battery cluster.

[0175] The insulation detection device for an energy storage system provided in an embodiment of the present application can be used to implement the insulation detection method for an energy storage system in any of the aforementioned embodiments. The implementation principle and technical effects are similar and will not be described in detail here.

[0176] Fig. 9 The electronic device 900 is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. The electronic device 900 may be, for example, the aforementioned insulation device and insulation detection device.

[0177] like Fig. 9 As shown, the electronic device 900 may include: a memory 901, a processor 902, and a transceiver 903, wherein the memory 901 and the processor 902 communicate with each other; exemplarily, the memory 901, the processor 902, and the transceiver 903 may communicate with each other via a communication bus 904, the memory 901 is used to store a computer program, and the processor 902 executes the computer program to implement the method of the above embodiment.

[0178] Optionally, the processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), etc. A general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc. The steps in the method embodiments disclosed in the present application may be directly implemented as being executed by a hardware processor, or may be implemented by a combination of hardware and software modules in the processor.

[0179] An embodiment of the present application further provides a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, a method in any of the above method embodiments is implemented.

[0180] An embodiment of the present application also provides a computer program product, including a computer program, which implements the method in any of the above method embodiments when the computer program is executed by a processor.

[0181] All or part of the steps of the above-mentioned method embodiments can be completed by hardware related to program instructions. The above-mentioned program can be stored in a readable memory. When the program is executed, the steps of the above-mentioned method embodiments are executed; and the above-mentioned memory (storage medium) includes: read-only memory (ROM), RAM, flash memory, hard disk, solid state drive, magnetic tape, floppy disk, optical disc and any combination thereof.

[0182] The embodiments of the present application are described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processing unit of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processing unit of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0183] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0184] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0185] Obviously, those skilled in the art can make various changes and modifications to the embodiments of the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the embodiments of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

[0186] In the present application, the term "include" and its variations may refer to non-restrictive inclusion; the term "or" and its variations may refer to "and / or". The terms "first", "second", etc. in the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. In the present application, "plurality" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may mean: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the previously associated objects are in an "or" relationship.

Claims

1. An insulation detection method for an energy storage system, characterized in that: The energy storage system includes at least two battery clusters connected in parallel, and the method includes: Performing insulation detection on a first battery cluster of the at least two battery clusters by using a balanced bridge method and an unbalanced bridge method; For any battery cluster other than the first battery cluster among the at least two battery clusters, if the insulation test of the battery cluster preceding it passes, the insulation test of the battery cluster is performed by an unbalanced bridge method using the positive electrode side insulation resistance values ​​and the negative electrode side insulation resistance values ​​obtained during the insulation test of all the battery clusters preceding the battery cluster.

2. The method according to claim 1, characterized in that The method of performing insulation testing on the battery cluster by an unbalanced bridge method using the insulation resistance values ​​of the positive electrode side and the insulation resistance values ​​of the negative electrode side of all battery clusters preceding the battery cluster obtained during insulation testing comprises: When the balancing bridge of the insulating device is connected to all battery clusters before the battery cluster, the insulation resistance values ​​of the positive electrode side and the insulation resistance values ​​of the negative electrode side of the battery cluster are respectively obtained in the following manner: Controlling the relay on the target pole side of the battery cluster to close; wherein the target pole is a positive pole or a negative pole; Obtaining the positive side voltage and the negative side voltage of the battery cluster; Calculate the resistance of the insulation resistance on the target electrode side of the battery cluster according to the positive electrode side voltage and the negative electrode side voltage of the battery cluster, the resistance values ​​of the insulation resistance on the positive electrode side and the insulation resistance values ​​on the negative electrode side of all battery clusters before the battery cluster, and the resistance value of the resistor in the balancing bridge; Based on the insulation resistance value of the target pole side of the battery cluster, an insulation detection result of the battery cluster is determined.

3. The method according to claim 2, characterized in that The step of obtaining the positive electrode side voltage and the negative electrode side voltage of the battery cluster includes: collecting an initial positive electrode side voltage and an initial negative electrode side voltage of the battery cluster; Obtaining a positive electrode side voltage change rate and a negative electrode side voltage change rate according to the collected initial positive electrode side voltage and the initial negative electrode side voltage, and the last collected initial positive electrode side voltage and the initial negative electrode side voltage of the battery cluster; When the voltage change rates are all less than or equal to the preset threshold, the initial positive side voltage collected this time is used as the positive side voltage of the battery cluster, and the initial negative side voltage collected this time is used as the negative side voltage of the battery cluster.

4. The method according to claim 3, characterized in that The method further comprises: Recording the acquisition time of the initial positive side voltage and the initial negative side voltage when the voltage change rate is less than or equal to the preset threshold; According to the collection time and the closing time of the relay on the target pole side of the battery cluster, the collection duration is obtained; The mapping relationship among the acquisition duration, the target-side relay, and the battery cluster is stored.

5. The method according to claim 2, characterized in that: After performing insulation testing on the battery cluster by using an unbalanced bridge method, the method further includes: If the battery cluster insulation test fails, a test result indicating that the energy storage system insulation test fails is output.

6. The method according to any one of claims 1 to 5, characterized in that: The method of using a balanced bridge method and an unbalanced bridge method to detect the insulation resistance value of the positive electrode side and the insulation resistance value of the negative electrode side of the first battery cluster of the at least two battery clusters includes: Connecting a balancing bridge of the insulating device to the first battery cluster to obtain a positive side voltage and a negative side voltage of the first battery cluster; Controlling the unbalanced bridge of the insulation device to be connected to the first battery cluster, and obtaining the positive side voltage and the negative side voltage of the first battery cluster again; Calculate the insulation resistance value of the positive electrode side and the insulation resistance value of the negative electrode side of the first battery cluster according to the positive electrode side voltage and the negative electrode side voltage of the first battery cluster obtained twice, the resistance value of the resistor in the balanced bridge, and the resistance value of the resistor in the unbalanced bridge; The unbalanced bridge controlling the isolating device is disconnected from the first battery cluster.

7. An insulation detection device for an energy storage system, characterized in that: The energy storage system comprises at least two battery clusters connected in parallel, and the device comprises: A first detection module, configured to perform insulation detection on a first battery cluster of the at least two battery clusters by using a balanced bridge method and an unbalanced bridge method; The second detection module is used to perform insulation detection on any battery cluster other than the first battery cluster among the at least two battery clusters by an unbalanced bridge method using the resistance values ​​of the positive electrode side insulation resistance and the negative electrode side insulation resistance of all battery clusters before the battery cluster obtained during the insulation detection, if the insulation detection of the previous battery cluster passes.

8. An electronic device, characterized in that: include: a processor, and a memory communicatively connected to the processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory to implement the method according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, which are used to implement the method according to any one of claims 1 to 6 when executed by a processor.

10. A computer program product, characterized in that The invention comprises a computer program, which implements the method according to any one of claims 1 to 6 when being executed by a processor.

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