Insulation detection method and apparatus

Abstract

Provided in the embodiments of the present application are an insulation detection method and apparatus, which can improve the accuracy of insulation detection. The insulation detection method comprises: by means of an insulation detection circuit, acquiring N first sampling voltages of a first electrode of an energy storage device relative to a preset point, wherein the N first sampling voltages respectively correspond to N first sampling periods of the insulation detection circuit, and N is greater than or equal to 3; and on the basis of the N first sampling voltages, determining a first insulation resistance value of the first electrode relative to the preset point.

Description

Insulation testing methods and apparatus Cross-references to related applications

[0001] This application claims priority to Chinese Patent Application No. 202411052273.0, entitled “Method and Apparatus for Insulation Detection”, filed on August 1, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of insulation testing technology, and in particular to a method and apparatus for insulation testing. Background Technology

[0003] Insulation testing of energy storage systems is a crucial step in ensuring their safe and reliable operation. Since energy storage systems typically involve high-voltage DC power sources, such as lithium-ion battery packs, the quality of insulation directly affects the system's performance, including stability.

[0004] Therefore, how to accurately perform insulation testing on energy storage systems is an urgent problem to be solved. Summary of the Invention

[0005] This application provides a method and apparatus for insulation testing, which can improve the accuracy of insulation testing.

[0006] In a first aspect, an insulation detection method is provided, comprising: acquiring N first sampling voltages of a first electrode of an energy storage device relative to a preset point through an insulation detection circuit, wherein the N first sampling voltages correspond to N first sampling periods of the insulation detection circuit, and N is greater than or equal to 3; and determining a first insulation resistance value of the first electrode relative to the preset point based on the N first sampling voltages.

[0007] In this embodiment, the resistance value of the first electrode relative to the preset point is determined based on at least three first sampling voltages of the first electrode of the energy storage device relative to the preset point obtained in at least three sampling periods. That is, the insulation resistance value of the first electrode relative to the preset point is determined based on multiple first sampling voltages, so that the accuracy of the determined insulation resistance value of the first electrode relative to the preset point is high.

[0008] In some possible implementations, determining the first insulation resistance value of the first electrode relative to the preset point based on the N first sampling voltages includes: determining a first sampling voltage convergence value based on the N first sampling voltages; and determining the first insulation resistance value based on the first sampling voltage convergence value.

[0009] Typically, the convergence value of the first sampling voltage eliminates the influence of the time constant to a certain extent in the above-mentioned technical solution. Therefore, the above-mentioned technical solution determines the first insulation resistance value based on the convergence value of the first sampling voltage, which can reduce the influence of the time constant in the insulation detection circuit on the first insulation resistance value, such as reducing the influence of the Y capacitor in the PCS system or other parasitic capacitors in the energy storage system, thereby making the obtained first insulation resistance value more accurate.

[0010] In some possible implementations, the insulation detection circuit includes a first resistor and a second resistor. A first end of the first resistor is connected to the positive terminal of the energy storage device, and a second end of the first resistor is connected to the first end of the second resistor and the sampling chip. The second end of the second resistor is connected to the preset point. Determining the first insulation resistance value based on the first sampled voltage convergence value includes: determining the first insulation resistance value based on the first sampled voltage convergence value, the resistance value of the first resistor, the resistance value of the second resistor, and the voltage value of the energy storage device.

[0011] The above technical solution includes a first resistor and a second resistor in the insulation detection circuit. Since resistors are relatively inexpensive, the cost of insulation detection can be effectively reduced. Furthermore, the insulation detection circuit is relatively simple, thus reducing the complexity of insulation detection.

[0012] In some possible implementations, when N=3, the convergence value of the first sampled voltage satisfies the following formula:

[0013] Among them, U fp U is the convergence value of the first sampled voltage. p1 U p2 And U p3 These are the three first sample voltages acquired during the three first sampling periods.

[0014] The above technical solution, on the one hand, reduces the number of sampled voltages when N=3, lowering the computational complexity of determining the convergence value of the sampled voltage and effectively improving the efficiency of insulation detection. On the other hand, the expression for the obtained first sampled voltage convergence value does not include the time constant, thus eliminating its influence. Therefore, determining the first insulation resistance value based on the first sampled voltage convergence value can, to some extent, reduce the influence of the time constant in the insulation detection circuit on the first insulation resistance value, resulting in a more accurate first insulation resistance value.

[0015] In some possible implementations, the method further includes: obtaining M second sampling voltages of the second electrode of the energy storage device relative to the preset point through the insulation detection circuit, wherein the M second sampling voltages correspond to M second sampling periods of the insulation detection circuit, the M second sampling periods are different from the N first sampling periods, the second electrode is the reverse electrode of the first electrode, and M is greater than or equal to 3; and determining a second insulation resistance value of the second electrode relative to the preset point based on the M second sampling voltages.

[0016] If only the first insulation resistance value of the first electrode pair relative to a preset point is determined, misjudgment of the insulation performance of the energy storage system may occur, potentially leading to safety accidents within the system. The aforementioned technical solution, in addition to determining the first insulation resistance value, also determines the second insulation resistance value of the second electrode relative to the preset point based on multiple second sampling voltages. On one hand, the accuracy of the determined second insulation resistance value is high; on the other hand, the accuracy of determining the insulation performance of the energy storage system based on the first and second insulation resistance values ​​is high, reducing the probability of misjudging the insulation performance of the energy storage system.

[0017] In some possible implementations, determining the second insulation resistance value of the second electrode relative to the preset point based on the M second sampling voltages includes: determining a second sampling voltage convergence value based on the M second sampling voltages; determining the second insulation resistance value based on the second sampling voltage convergence value and the first sampling voltage convergence value corresponding to the N first sampling voltages; determining the first insulation resistance value of the first electrode relative to the preset point based on the N first sampling voltages includes: determining the first insulation resistance value based on the first sampling voltage convergence value corresponding to the N first sampling voltages and the second sampling voltage convergence value.

[0018] Typically, the convergence value of the second sampling voltage eliminates the influence of the time constant on the above-mentioned technical solution to a certain extent. Therefore, the above-mentioned technical solution can reduce the influence of the time constant on the second insulation resistance value in the insulation detection circuit by determining the second insulation resistance value based on the convergence value of the second sampling voltage. For example, it can reduce the influence of the Y capacitor in the PCS system or other parasitic capacitors in the energy storage system, thereby making the obtained second insulation resistance value more accurate.

[0019] In some possible implementations, when M=3, the convergence value of the second sampled voltage satisfies the following formula:

[0020] Among them, U fn U is the convergence value of the second sampled voltage. n1 U n2And U n3 These are the three second sample voltages acquired during the three second sampling periods.

[0021] The above technical solution, on the one hand, reduces the number of sampled voltages when M=3, lowering the computational complexity of determining the convergence value of the sampled voltage and effectively improving the efficiency of insulation detection. On the other hand, the expression for the obtained second sampled voltage convergence value does not include the time constant, thus eliminating its influence. Therefore, determining the second insulation resistance value based on the second sampled voltage convergence value can, to some extent, reduce the influence of the time constant in the insulation detection circuit on the second insulation resistance value, resulting in a more accurate second insulation resistance value.

[0022] In some possible implementations, the insulation detection circuit includes a first switch, a second switch, a third switch, a first resistor, and a second resistor. The first terminal of the first switch is connected to the positive terminal of the energy storage device, the second terminal of the first switch is connected to the first terminal of the second switch, the second terminal of the second switch is connected to the negative terminal of the energy storage device, the first terminal of the third switch is connected to the second terminals of the first and second switches, the second terminal of the third switch is connected to the first terminal of the first resistor, the second terminal of the first resistor is connected to the first terminal of the second resistor and the sampling chip, and the second terminal of the second resistor is connected to the preset point.

[0023] The above technical solution includes an insulation detection circuit comprising a first resistor, a second resistor, a first switch, a second switch, and a third switch. Since the resistors and switches are relatively inexpensive, the cost of insulation detection can be effectively reduced. Furthermore, the first and second insulation resistance values ​​can be determined using only one insulation detection circuit, further reducing the cost of insulation detection. In addition, the insulation detection circuit is relatively simple, thus reducing the complexity of insulation detection.

[0024] In some possible implementations, acquiring N first sampling voltages of the first electrode of the energy storage device relative to a preset point through the insulation detection circuit includes: controlling the first switch and the third switch to close, and controlling the second switch to open; and acquiring the N first sampling voltages respectively within the N first sampling periods. Acquiring M second sampling voltages of the second electrode of the energy storage device relative to the preset point through the insulation detection circuit includes: controlling the second switch and the third switch to close, and controlling the first switch to open; and acquiring the M second sampling voltages respectively within the M second sampling periods.

[0025] The above technical solution achieves the acquisition of N first sampling voltages and M second sampling voltages by controlling the switch in the insulation detection circuit, which is simple and easy to control.

[0026] In some possible implementations, determining the second insulation resistance value based on the second sampled voltage convergence value and the first sampled voltage convergence values ​​corresponding to the N first sampled voltages includes: determining the second insulation resistance value and the first insulation resistance value based on the first sampled voltage convergence value, the second sampled voltage convergence value, the resistance value of the first resistor, the resistance value of the second resistor, and the voltage value of the energy storage device.

[0027] In some possible implementations, the first insulation resistance value R P Satisfy the following formula:

[0028] The second insulation resistance value R n Satisfy the following formula:

[0029] Where R1 is the resistance value of the first resistor, R2 is the resistance value of the second resistor, U0 is the voltage value of the energy storage device, and U fp U is the convergence value of the first sampled voltage. fn This is the convergence value of the second sampled voltage.

[0030] In some possible implementations, the method further includes: determining whether the insulation performance of the energy storage system in which the energy storage device is located meets the insulation requirements based on the first insulation resistance value.

[0031] The above technical solution has a high accuracy in determining the first insulation resistance value. Therefore, the accuracy of determining whether the insulation performance of the energy storage system meets the insulation requirements based on the first insulation resistance value is also high.

[0032] In some possible implementations, the method further includes: when it is determined that the insulation performance of the energy storage system does not meet the insulation requirements, determining the insulation fault level of the energy storage system based on the first insulation resistance value; and executing a corresponding processing strategy on the energy storage system based on the insulation fault level.

[0033] The above technical solution determines the insulation fault level of the energy storage system based on the first insulation resistance value, and executes a corresponding processing strategy on the energy storage system based on the determined insulation fault level. This ensures that the executed processing strategy is as compatible as possible with the current insulation performance of the energy storage system, reducing the possibility of over-processing or under-processing the energy storage system.

[0034] Secondly, an insulation detection device is provided, comprising: a sampling unit for acquiring N first sampling voltages of a first electrode of an energy storage device relative to a preset point through an insulation detection circuit, wherein the N first sampling voltages correspond to N first sampling periods of the insulation detection circuit, and N is greater than or equal to 3; and a processing unit for determining a first insulation resistance value of the first electrode relative to the preset point based on the N first sampling voltages.

[0035] In some possible implementations, the processing unit is specifically used to: determine a first sampling voltage convergence value based on the N first sampling voltages; and determine the first insulation resistance value based on the first sampling voltage convergence value.

[0036] In some possible implementations, the insulation detection circuit includes a first resistor and a second resistor. The first end of the first resistor is connected to the positive terminal of the energy storage device, the second end of the first resistor is connected to the first end of the second resistor and the sampling chip, and the second end of the second resistor is connected to the preset point. The processing unit is specifically used to: determine the first insulation resistance value based on the first sampling voltage convergence value, the resistance value of the first resistor, the resistance value of the second resistor, and the voltage value of the energy storage device.

[0037] In some possible implementations, when N=3, the convergence value of the first sampled voltage satisfies the following formula:

[0038] Among them, U fp U is the convergence value of the first sampled voltage. p1 U p2 And U p3 These are the three first sample voltages acquired during the three first sampling periods.

[0039] In some possible implementations, the sampling unit is further configured to: acquire M second sampling voltages of the second electrode of the energy storage device relative to the preset point through the insulation detection circuit, wherein the M second sampling voltages correspond to M second sampling periods of the insulation detection circuit, the M second sampling periods are different from the N first sampling periods, the second electrode is the reverse electrode of the first electrode, and M is greater than or equal to 3; the processing unit is further configured to: determine the second insulation resistance value of the second electrode relative to the preset point based on the M second sampling voltages.

[0040] In some possible implementations, the processing unit is specifically used to: determine a second sampling voltage convergence value based on the M second sampling voltages; determine a second insulation resistance value based on the second sampling voltage convergence value and the first sampling voltage convergence value corresponding to the N first sampling voltages; and determine a first insulation resistance value based on the first sampling voltage convergence value corresponding to the N first sampling voltages and the second sampling voltage convergence value.

[0041] In some possible implementations, when M=3, the convergence value of the second sampled voltage satisfies the following formula:

[0042] Among them, U fn U is the convergence value of the second sampled voltage. n1 U n2 And U n3 These are the three second sample voltages acquired during the three second sampling periods.

[0043] In some possible implementations, the insulation detection circuit includes a first switch, a second switch, a third switch, a first resistor, and a second resistor. The first terminal of the first switch is connected to the positive terminal of the energy storage device, the second terminal of the first switch is connected to the first terminal of the second switch, the second terminal of the second switch is connected to the negative terminal of the energy storage device, the first terminal of the third switch is connected to the second terminals of the first and second switches, the second terminal of the third switch is connected to the first terminal of the first resistor, the second terminal of the first resistor is connected to the first terminal of the second resistor and the sampling chip, and the second terminal of the second resistor is connected to the preset point.

[0044] In some possible implementations, the system further includes: a control unit for controlling the first switch and the third switch to close, and controlling the second switch to open; the sampling unit is specifically used to collect the N first sampling voltages respectively within the N first sampling periods; the control unit is also used to control the second switch and the third switch to close, and control the first switch to open; the sampling unit is specifically used to collect the M second sampling voltages respectively within the M second sampling periods.

[0045] In some possible implementations, the processing unit is specifically used to: determine the second insulation resistance value and the first insulation resistance value based on the first sampled voltage convergence value, the second sampled voltage convergence value, the resistance value of the first resistor, the resistance value of the second resistor, and the voltage value of the energy storage device.

[0046] In some possible implementations, the first insulation resistance value R P Satisfy the following formula:

[0047] The second insulation resistance value R n Satisfy the following formula:

[0048] Where R1 is the resistance value of the first resistor, R2 is the resistance value of the second resistor, U0 is the voltage value of the energy storage device, and U fp U is the convergence value of the first sampled voltage. fn This is the convergence value of the second sampled voltage.

[0049] In some possible implementations, the processing unit is further configured to: determine whether the insulation performance of the energy storage system in which the energy storage device is located meets the insulation requirements based on the first insulation resistance value.

[0050] In some possible implementations, the processing unit is further configured to: determine the insulation fault level of the energy storage system based on the first insulation resistance value when it is determined that the insulation performance of the energy storage system does not meet the insulation requirements; and execute a corresponding processing strategy on the energy storage system based on the insulation fault level.

[0051] Thirdly, an insulation detection device is provided, comprising a processor and a memory, wherein the memory is used to store a computer program, and the processor is used to invoke the computer program to execute the methods described in the first aspect or its various implementations.

[0052] Fourthly, a computer-readable storage medium is provided for storing a computer program that causes a computer to perform the methods described in the first aspect or its implementations. Attached Figure Description

[0053] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0054] The accompanying drawings are not drawn to scale.

[0055] Figure 1 shows a schematic flowchart of an insulation detection method according to an embodiment of this application.

[0056] Figure 2 shows a schematic diagram of an insulation detection circuit according to an embodiment of this application.

[0057] Figure 3 shows a schematic diagram of another insulation detection circuit according to an embodiment of this application.

[0058] Figure 4 shows a schematic diagram of another insulation detection circuit according to an embodiment of this application.

[0059] Figure 5 shows a schematic block diagram of an insulation detection device according to an embodiment of this application.

[0060] Figure 6 shows a schematic block diagram of another insulation detection device according to an embodiment of this application. Detailed Implementation

[0061] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0062] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the specification of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings of this application are used to distinguish different objects, rather than to describe a specific order or hierarchy.

[0063] The directional terms used in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of this application. It should also be noted in the description of this application that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0064] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0065] In this application, "multiple" refers to two or more (including two), and similarly, "multiple groups" refers to two or more (including two), and "multiple pieces" refers to two or more (including two).

[0066] With the widespread application of new energy sources such as solar and wind power, energy storage technology has developed accordingly. An energy storage system is a device or system capable of storing energy and releasing it when needed. In the field of new energy, energy storage systems typically refer to devices that can store electrical energy and release it during peak electricity demand periods. Energy storage systems play multiple roles in the power system, including load balancing, frequency regulation, backup power, peak-valley pricing management, and improving grid stability. With the rapid development of renewable energy, the importance of energy storage systems is increasing daily.

[0067] Insulation testing is typically required for energy storage systems to ensure safe operation and extend their lifespan. Firstly, energy storage systems usually contain high-voltage batteries and other electronic components. Problems with the insulation materials can lead to electrical short circuits, or even fires or explosions. Insulation testing can detect potential insulation faults in a timely manner, preventing accidents. Secondly, insulation testing helps ensure the system operates stably at its design and specified voltages, avoiding performance issues caused by deteriorating insulation. Furthermore, regular insulation testing helps identify signs of early aging or damage, allowing for timely repair or replacement and extending the overall lifespan of the energy storage system. Finally, insulation testing can prevent serious failures and costly repairs, helping to reduce the long-term maintenance costs of energy storage systems.

[0068] However, current insulation testing methods typically do not take into account the capacitors in the power conversion system (PCS), such as Y capacitors. During the charging and discharging of the PCS system, due to the charging and discharging characteristics of the capacitors, the voltage takes a long time to reach a stable state, or even fails to reach a stable state. Therefore, accurate voltage measurement is impossible, leading to significant errors in the obtained insulation resistance value, which can cause various problems. For example, the actual insulation resistance value may be within the normal range, but the obtained resistance value is lower than the normal range, potentially causing a false insulation fault and leading to the shutdown of the energy storage system. Alternatively, the actual insulation resistance value may be lower than the normal range, but the obtained resistance value is within the normal range, thus failing to trigger alarms or other abnormal warnings. This could result in a safety accident caused by poor insulation.

[0069] Based on this, this application provides an insulation detection method. Through an insulation detection circuit, N first sampling voltages of the first electrode of an energy storage device relative to a preset point are acquired, and a first insulation resistance value of the first electrode relative to the preset point is determined based on the N first sampling voltages. The N first sampling voltages correspond to N first sampling periods of the insulation detection circuit, and N is greater than or equal to 3. In this embodiment, the first insulation resistance value of the first electrode relative to the preset point is determined based on at least three first sampling voltages of the first electrode of the energy storage device relative to the preset point acquired within at least three sampling periods, resulting in high accuracy of the determined first insulation resistance value.

[0070] Figure 1 shows a schematic flowchart of an insulation detection method 100 according to an embodiment of this application. Indicatively, when method 100 is applied to an energy storage system, method 100 can be executed by the central control unit of the energy storage system, such as by the master battery management unit (MBMU). As shown in Figure 1, method 100 may include at least some of the following:

[0071] S110: The insulation detection circuit acquires N first sampling voltages of the first electrode of the energy storage device relative to a preset point. These N first sampling voltages correspond to N first sampling cycles of the insulation detection circuit, where N is greater than or equal to 3.

[0072] S120: Determine the first insulation resistance value of the first electrode relative to a preset point based on N first sampling voltages.

[0073] In this embodiment, the first insulation resistance value of the first electrode relative to the preset point is determined based on at least three first sampling voltages of the first electrode of the energy storage device relative to the preset point obtained in at least three sampling periods. That is, the first insulation resistance value of the first electrode relative to the preset point is determined based on multiple first sampling voltages, so that the accuracy of the determined first insulation resistance value of the first electrode relative to the preset point is high.

[0074] The energy storage device can be, for example, a battery. Exemplarily, the energy storage device may include multiple batteries, which may include four rows of batteries. Each row of batteries may be divided into two parallel battery clusters. Each battery cluster 220 may include four batteries, and each battery 221 may include 104 battery cells connected in series. One battery cluster may correspond to one slave battery management unit (SBMU), and multiple battery clusters may correspond to one master battery management unit (MBMU).

[0075] The first electrode can be a positive electrode, or it can be a negative electrode.

[0076] The preset point can be ground. In this case, the first sampling voltage is the voltage of the first electrode relative to the ground sampling point, and the first insulation resistance value is the insulation resistance value of the first electrode relative to this point. Alternatively, the preset point can also be an electrical box, in which the energy storage device is installed.

[0077] For example, the first sampling period can be 10ms, 20ms, 30ms, etc. The first sampling period can be determined based on the capabilities of the sampling chip. Alternatively, the first sampling period can also be determined based on the state parameters of the energy storage device; for example, the first sampling period can be determined based on the temperature, state of charge (SOC), etc. of the energy storage device. As another example, the first sampling period can be determined based on the performance of the electronic components in the insulation detection circuit.

[0078] Optionally, the duration of each of the N first sampling periods is the same. For example, the duration of each first sampling period is 10ms.

[0079] Optionally, the N first sampling periods can be consecutive or non-consecutive. For example, if N = 4, the four first sampling periods are the first, third, fourth, and sixth first sampling periods, respectively.

[0080] N is greater than or equal to 3. Further, N can be greater than or equal to 6, or N can be greater than or equal to 8, or N can be greater than or equal to 10. For ease of description, the embodiments of this application will be described below using N=3 as an example.

[0081] The first sampled voltage acquired in a first sampling period can be the voltage obtained by sampling once within the first sampling period, or it can be the voltage obtained by sampling multiple times within the first sampling period. In the case of sampling multiple times, the first sampled voltage can be any one of the multiple voltages, or it can be the average value of the multiple voltages, or it can be the minimum or maximum value of the multiple voltages, etc.

[0082] In some embodiments, determining the first insulation resistance value of the first electrode relative to a preset point based on three first sampling voltages may specifically include: determining a first sampling voltage convergence value based on the three first sampling voltages, and then determining the first insulation resistance value based on the first sampling voltage convergence value.

[0083] The convergence value of the first sampling voltage can represent the stable voltage value corresponding to the first sampling voltage after the capacitor has completed charging and discharging.

[0084] Alternatively, the convergence value of the first sampling voltage can be determined based on the three first sampling voltages and the formula for the total response of the first-order circuit.

[0085] The formula for the total response of a first-order circuit can be:

[0086] Among them, U t U represents the sampling voltage collected by the sampling chip at the sampling point. f For U t The final convergence value, For U t The initial value is RC, which is the time constant of the insulation detection circuit.

[0087] Let the three sampling periods be three equal sampling periods t1, t2, and t3. The sampled voltage obtained within sampling period t1 is U. t1 The sampled voltage obtained within the sampling period t2 is U t2 The sampled voltage obtained within the sampling period t3 is U. t3 .

[0088] Let the convergence value of the sampled voltage be U. f , will U t1 U t2 U t3 Substituting into formula (1) above, we get:

[0089] According to formulas (2)-(4), we can obtain:

[0090] Since t1 = t2 = t3, that is, t2 - t1 = t3 - t2 = t3 - t1, therefore, based on formulas (5) - (7), we can obtain:

[0091] Based on the first equation in formula (8), the expression for the convergence value of the first sampled voltage can be obtained:

[0092] The convergence value of the first sampling voltage can be obtained from the three first sampling voltages and formula (9).

[0093] As can be seen from the above formula, the expression for the final converged value of the first sampled voltage does not include the time constant, thus eliminating its influence. Therefore, determining the first insulation resistance value based on the converged value of the first sampled voltage can, to some extent, reduce the influence of the time constant on the first insulation resistance value in the insulation detection circuit, such as reducing the influence of the Y capacitor in the PCS system or other parasitic capacitors in the energy storage system, thereby making the obtained first insulation resistance value more accurate.

[0094] It should be noted that the above explanation is based on N=3 as an example. When N=3, the number of sampled voltages is smaller, which reduces the computational complexity of determining the convergence value of the sampled voltage and effectively improves the efficiency of insulation detection.

[0095] As mentioned above, N can also be greater than 3, for example, N = 4. In the case of N = 4, in addition to formulas (2)-(4), we can also obtain formula (10):

[0096] Among them, U t4 The sampled voltage is obtained within the sampling period t4. In formulas (2)-(4) and (10), the expression for the convergence value of the sampled voltage can be obtained by any of the three formulas. The specific calculation process can be referred to formulas (5)-(9). For the sake of brevity, it will not be elaborated here.

[0097] For example, when N=5, in addition to formulas (2)-(4) and (10), we can also obtain formula (11):

[0098] Among them, U t5 The sampled voltage obtained within the sampling period t5 is represented by the expression for the convergence value of the sampled voltage obtained from any of the three formulas (2)-(4), (10) and (11).

[0099] In some embodiments, as shown in FIG2, the insulation detection circuit 20 may include a first resistor R1 and a second resistor R2. The first end of the first resistor R1 is connected to the positive terminal of the energy storage device B1, the second end of the first resistor R1 is connected to the first end of the second resistor R2 and the sampling chip S1, and the second end of the second resistor R2 is connected to a preset point.

[0100] In Figure 2, the preset point is ground, B+ and B- are the positive and negative terminals of the energy storage device B1, respectively, RP is the insulation resistance of the first electrode to ground, and Y is the sampling point of the sampling chip S1.

[0101] In this scenario, the first insulation resistance value can be determined based on the convergence value of the first sampling voltage, the resistance value of the first resistor, the resistance value of the second resistor, and the voltage value of the energy storage device. Furthermore, the insulation detection circuit is relatively simple, thus reducing the complexity of insulation detection.

[0102] The above technical solution includes an insulation detection circuit comprising a first resistor and a second resistor. Since resistors are inexpensive, the cost of insulation detection can be effectively reduced.

[0103] If only the first insulation resistance value of the first electrode relative to a preset point is determined, misjudgment of the insulation performance of the energy storage system may occur. For example, since energy storage devices have positive and negative terminals, it is possible that the first insulation resistance value is within the normal range, but the resistance value of the other electrode relative to the preset point is not within the normal range. In reality, the energy storage system has experienced an insulation fault, but the insulation performance of the energy storage system determined based on the first insulation resistance value meets the requirements. This prevents personnel from taking timely and effective measures, which may lead to safety accidents in the energy storage system.

[0104] In view of the above problems, the method 100 may further include: obtaining a second sampling voltage of the second electrode of the energy storage device relative to a preset point through an insulation detection circuit, and determining a second insulation resistance value of the second electrode relative to the preset point based on the second sampling voltage.

[0105] As an example, an insulation detection circuit can acquire at least one second sampling voltage within a second sampling period and determine the second insulation resistance value based on the at least one second sampling voltage. For instance, the second insulation resistance value can be determined based on the average value of the at least one second sampling voltage.

[0106] As another example, an insulation detection circuit can be used to obtain M second sampling voltages of the second electrode of the energy storage device relative to a preset point, and the second insulation resistance value of the second electrode relative to the preset point can be determined based on the M second sampling voltages.

[0107] Among them, the M second sampling voltages correspond to the M second sampling periods of the insulation detection circuit. The M second sampling periods are different from the N first sampling periods, and M is greater than or equal to 3.

[0108] In addition to determining the first insulation resistance value, the above technical solution also determines the second insulation resistance value of the second electrode relative to a preset point based on multiple second sampling voltages. On the one hand, the accuracy of the determined second insulation resistance value of the second electrode relative to the preset point is high; on the other hand, the accuracy of the insulation performance of the energy storage system determined based on the first insulation resistance value and the second insulation resistance value is high, reducing the probability of misjudging the insulation performance of the energy storage system.

[0109] The second electrode is the reverse electrode of the first electrode. When the first electrode is positive, the second electrode is negative; when the first electrode is negative, the second electrode is negative.

[0110] M is greater than or equal to 3. Furthermore, M can be greater than or equal to 5, or M can be greater than or equal to 7, or M can be greater than or equal to 8.

[0111] M can be equal to N, or it can be different from N. For ease of description, the embodiments of this application will be described below with M=N=3 as an example.

[0112] The difference between the M second sampling periods and the N first sampling periods can be understood as follows: the M second sampling periods and the N first sampling periods do not overlap in time. For example, the M second sampling periods can precede the N first sampling periods, meaning that the N first sampling voltages are collected after the M second sampling voltages are acquired. Alternatively, the N first sampling periods can precede the M second sampling periods, meaning that the M second sampling voltages are collected after the N first sampling voltages are acquired. Or, a first sampling voltage can be acquired, followed by a second sampling voltage, then another first sampling voltage, and so on, until both the N first sampling voltages and the M second sampling voltages have been acquired.

[0113] The duration of the second sampling period can be the same as or different from that of the first sampling period.

[0114] For example, the second sampling period can be 10ms, 20ms, 30ms, etc. The second sampling period can be determined based on the capabilities of the sampling chip. Alternatively, the second sampling period can be determined based on the state parameters of the energy storage device, such as the temperature, state of charge (SOC), etc. of the energy storage device. As another example, the second sampling period can be determined based on the performance of the electronic components in the insulation detection circuit.

[0115] Optionally, each of the M second sampling periods has the same duration. For example, the duration of each second sampling period can be 15ms.

[0116] Optionally, the M second sampling periods can be consecutive or non-consecutive. For example, M = 6, where the 6 sampling periods are the first, second, third, fourth, sixth, and eighth second sampling periods, respectively.

[0117] The second sampled voltage acquired in a second sampling period can be the voltage obtained from a single sampling within that second sampling period, or it can be the voltage obtained from multiple samplings within that second sampling period. In the case of multiple samplings, the second sampled voltage can be any one of the multiple voltages, or it can be the average of the multiple voltages, or it can be the minimum, maximum, or median value among the multiple voltages, etc.

[0118] Similar to the first insulation resistance value, in some embodiments, the second sampling voltage convergence value can be determined based on M second sampling voltages, and the second insulation resistance value can be determined based on the second sampling voltage convergence value and the first sampling voltage convergence values ​​corresponding to N first sampling voltages.

[0119] At this point, the first insulation resistance value can be determined based on the convergence values ​​of the first and second sampling voltages corresponding to the N first sampling voltages.

[0120] Similar to the convergence value of the first sampling voltage, the convergence value of the second sampling voltage can be obtained based on the three second sampling voltages and formula (9).

[0121] The above technical solution determines the convergence value of the second sampling voltage based on the total response formula of a first-order circuit, that is, it uses the principle of the total response of a first-order circuit to determine the convergence value of the second sampling voltage. This can, to some extent, eliminate the influence of the time constant on the convergence value of the second sampling voltage. Therefore, determining the second insulation resistance value based on the convergence value of the second sampling voltage can reduce the influence of the time constant in the insulation detection circuit on the second insulation resistance value, such as reducing the influence of the Y capacitor in the PCS system or other parasitic capacitors in the energy storage system, thus making the obtained second insulation resistance value more accurate.

[0122] In some embodiments, the insulation detection circuit 20 of this application may include two circuits, and a first insulation resistance value and a second insulation resistance value can be determined based on the two insulation detection circuits 20. Each insulation detection circuit 20 may include a first resistor R1, a second resistor R2, and a sampling chip S1, and the sampling point Y is located at the connection point between the sampling chip S1 and the first resistor R1 and the second resistor R2.

[0123] For example, the two insulation detection circuits 20 can be the insulation detection circuit shown in Figure 2 and the insulation detection circuit shown in Figure 3, respectively. Similar to Figure 2, the preset point of the insulation detection circuit 20 shown in Figure 3 is also ground. As shown in Figure 3, the first end of the first resistor R1 is connected to the second end of the second resistor R2 and the sampling chip S1. The first resistor R1 and the second end are connected to the negative terminal of the energy storage device B1, and the first end of the second resistor R2 is connected to the preset point. Wherein, Rn is the insulation resistance of the second electrode to ground.

[0124] In some other embodiments, the insulation detection circuit 20 of this application may include only one, and the first insulation resistance value and the second insulation resistance value can be determined according to the one insulation detection circuit 20.

[0125] Figure 4 shows a possible schematic diagram of the insulation detection circuit 20. As shown in Figure 4, in addition to the first resistor R1, the second resistor R2, and the sampling chip S1, the insulation detection circuit 20 may also include a first switch K1, a second switch K2, and a third switch K3. The sampling point in Figure 4 is also Y. Specifically, the first terminal of the first switch K1 is connected to the positive terminal of the energy storage device B1, the second terminal of the first switch K1 is connected to the first terminal of the second switch K2, the second terminal of the second switch K2 is connected to the negative terminal of the energy storage device B1, the first terminal of the third switch K3 is connected to the second terminals of the first switch K1 and the second switch K2, the second terminal of the third switch K3 is connected to the first terminal of the first resistor R1, the second terminal of the first resistor R1 is connected to the first terminal of the second resistor R2 and the sampling chip S1, and the second terminal of the second resistor R2 is grounded.

[0126] Where Rp is the insulation resistance of the first electrode to ground, and Rn is the insulation resistance of the second electrode to ground. As can be seen from Figure 4, the first electrode is the positive electrode, and the second electrode is the negative electrode.

[0127] It should be noted that Rp and Rn in Figures 2-4 are the equivalent insulation resistances of the energy storage system. For example, the insulation resistance of the energy storage system can be the insulation resistance of the entire container in the energy storage system.

[0128] The above technical solution includes an insulation detection circuit comprising a first resistor, a second resistor, a first switch, a second switch, and a third switch. Since the resistors and switches are relatively inexpensive, the cost of insulation detection can be effectively reduced. Furthermore, the first and second insulation resistance values ​​can be determined using only one insulation detection circuit, further reducing the cost of insulation detection. In addition, the insulation detection circuit is relatively simple, thus reducing the complexity of insulation detection.

[0129] Based on Figure 4, the second insulation resistance value and the first insulation resistance value can be determined according to the first sampling voltage convergence value, the second sampling voltage convergence value, the resistance value of the first resistor, the resistance value of the second resistor, and the voltage value of the energy storage device.

[0130] Optionally, the first switch K1 and the third switch K3 can be closed, and the second switch K2 can be opened, so that three first sampling voltages are collected in three first sampling periods respectively. Then, the second switch K2 and the third switch K3 can be closed, and the first switch K1 can be opened, so that three second sampling voltages are collected in three second sampling periods respectively.

[0131] Specifically, first, by closing the first switch K1 and the third switch K3, and opening the second switch K2, the circuit shown in Figure 2 can be obtained. For point A, according to Kirchhoff's current law, the following formula can be obtained:

[0132] Where U0 is the voltage value of energy storage device B1, U p For R p The voltage values ​​at both ends.

[0133] From Figure 2, we can also obtain:

[0134] Voltages are acquired within three equal first sampling periods to obtain three first sampled voltages U. p1 U p2 And U p3 The convergence value U of the first sampling voltage can be obtained according to formula (9). fp :

[0135] Then, by closing the second switch K2 and the third switch K3, and opening the first switch K1, the circuit shown in Figure 3 can be obtained. For point A, according to Kirchhoff's current law, the following formula can be obtained:

[0136] Among them, U n For R n The voltage values ​​at both ends.

[0137] From Figure 3, we can also conclude that:

[0138] Voltages are sampled within three equal second sampling periods to obtain three second sampled voltages U. n1 U n2 And U n3 According to formula (9), the convergence value U of the second sampling voltage is obtained. fn Satisfy the following formula:

[0139] Based on formulas (12), (13), (15), and (16), we can conclude that:

[0140] By further combining formulas (14) and (17)-(19), the final first insulation resistance value and the second insulation resistance value can be obtained.

[0141] It should be noted that, in the embodiments of this application, the convergence value of the second sampling voltage may be negative.

[0142] It should also be noted that the embodiments of this application do not limit the order in which the first sampling voltage and the second sampling voltage are collected. The first sampling voltage can be collected first, followed by the second sampling voltage, as described above, or the second sampling voltage can be collected first, followed by the first sampling voltage.

[0143] The above technical solution achieves the acquisition of N first sampling voltages and M second sampling voltages by controlling the switch in the insulation detection circuit, which is simple and easy to control.

[0144] After calculating the first insulation resistance value and the second insulation resistance value, method 100 may further include: determining whether the insulation performance of the energy storage system in which the energy storage device is located meets the insulation requirements based on the first insulation resistance value and / or the second insulation resistance value.

[0145] The above technical solution has high accuracy in determining the first and second insulation resistance values. Therefore, the accuracy of determining whether the insulation performance of the energy storage system meets the insulation requirements is also high.

[0146] Whether the insulation performance of the energy storage system meets the insulation requirements can be determined solely based on the first insulation resistance value or the second insulation resistance value. If either the first or second insulation resistance value is within a preset range, then the insulation performance of the energy storage system is considered to meet the insulation requirements.

[0147] Alternatively, the insulation performance of the energy storage system can be determined simultaneously based on both the first and second insulation resistance values. In this case, if either the first or second insulation resistance value is outside the preset range, it can be determined that the insulation performance of the energy storage system does not meet the insulation requirements.

[0148] If the insulation performance of the energy storage system is determined solely based on the first insulation resistance value, and if the insulation performance of the energy storage system is determined to be unsatisfactory, the insulation fault level of the energy storage system can be determined based on the first insulation resistance value.

[0149] If the insulation performance of the energy storage system is determined solely based on the second insulation resistance value, and if the insulation performance of the energy storage system is determined to be non-compliant with the insulation requirements, the insulation fault level of the energy storage system can be determined based on the second insulation resistance value.

[0150] If the insulation performance of the energy storage system is determined to meet the insulation requirements based on both the first and second insulation resistance values, and the insulation performance of the energy storage system does not meet the insulation requirements, the insulation fault level of the energy storage system can be determined arbitrarily based on either the first or second insulation resistance value. Alternatively, the insulation fault level of the energy storage system can be determined based on the smaller of the first and second insulation resistance values. Or, the insulation fault level of the energy storage system can be determined based on the larger of the first and second insulation resistance values.

[0151] Subsequently, based on the insulation fault level, corresponding handling strategies are implemented for the energy storage system.

[0152] Optionally, in the embodiments of this application, the insulation fault level can be divided into a first level and a second level, and the insulation resistance value corresponding to the first level is less than the insulation resistance value corresponding to the second level.

[0153] If the insulation fault level of the energy storage system is Level 1, the system can be powered down. If the insulation fault level is Level 2, an early warning can be issued. For example, an early warning can be issued through the energy storage system's display devices (such as a screen or speaker) so that the user can take appropriate action.

[0154] It should be understood that the insulation fault levels mentioned above are divided into first level and second level. However, in addition to the first level and second level, the insulation fault levels can be further subdivided into third level, fourth level, etc. The embodiments of this application do not specifically limit this.

[0155] The above technical solution determines the insulation fault level of the energy storage system based on the first insulation resistance value, and executes a corresponding processing strategy on the energy storage system based on the determined insulation fault level. This ensures that the executed processing strategy is as compatible as possible with the current insulation performance of the energy storage system, reducing the possibility of over-processing or under-processing the energy storage system.

[0156] In the embodiments of this application, the order of the above-mentioned process numbers does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0157] Furthermore, without conflict, the various embodiments and / or technical features described in this application can be arbitrarily combined with each other, and the resulting technical solutions should also fall within the protection scope of this application.

[0158] The insulation detection method according to embodiments of this application has been described in detail above. The insulation detection apparatus according to embodiments of this application will now be described. It should be understood that the insulation detection apparatus in the embodiments of this application can perform the insulation detection method in the embodiments of this application.

[0159] Figure 5 shows a schematic block diagram of an insulation testing apparatus 500 according to an embodiment of this application. As shown in Figure 5, the insulation testing apparatus 500 may include:

[0160] The sampling unit 510 is used to obtain N first sampling voltages of the first electrode of the energy storage device relative to a preset point through the insulation detection circuit. The N first sampling voltages correspond to N first sampling cycles of the insulation detection circuit, and N is greater than or equal to 3.

[0161] The processing unit 520 is used to determine the first insulation resistance value of the first electrode relative to the preset point based on the N first sampling voltages.

[0162] Optionally, in this embodiment of the application, the processing unit 520 is specifically used to: determine a first sampling voltage convergence value based on the N first sampling voltages; and determine the first insulation resistance value based on the first sampling voltage convergence value.

[0163] Optionally, in this embodiment, the insulation detection circuit includes a first resistor and a second resistor. The first end of the first resistor is connected to the positive terminal of the energy storage device, the second end of the first resistor is connected to the first end of the second resistor and the sampling chip, and the second end of the second resistor is connected to the preset point. The processing unit 520 is specifically used to: determine the first insulation resistance value based on the first sampling voltage convergence value, the resistance value of the first resistor, the resistance value of the second resistor, and the voltage value of the energy storage device.

[0164] Optionally, in this embodiment of the application, when N=3, the convergence value of the first sampled voltage satisfies the following formula:

[0165] Among them, U fp U is the convergence value of the first sampled voltage. p1 U p2 And U p3 The three first sampled voltages are acquired during the three first sampling periods.

[0166] Optionally, in this embodiment, the sampling unit 510 is further configured to: obtain M second sampling voltages of the second electrode of the energy storage device relative to the preset point through the insulation detection circuit, wherein the M second sampling voltages correspond to M second sampling periods of the insulation detection circuit, the M second sampling periods are different from the N first sampling periods, the second electrode is the reverse electrode of the first electrode, and M is greater than or equal to 3; the processing unit 520 is further configured to: determine the second insulation resistance value of the second electrode relative to the preset point based on the M second sampling voltages.

[0167] Optionally, in this embodiment of the application, the processing unit 520 is specifically used to: determine a second sampling voltage convergence value based on the M second sampling voltages; determine a second insulation resistance value based on the second sampling voltage convergence value and the first sampling voltage convergence value corresponding to the N first sampling voltages; and determine a first insulation resistance value based on the first sampling voltage convergence value corresponding to the N first sampling voltages and the second sampling voltage convergence value.

[0168] Optionally, in this embodiment, when M=3, the convergence value of the second sampled voltage satisfies the following formula:

[0169] Among them, U fn U is the convergence value of the second sampled voltage. n1 U n2 And U n3 These are the three second sample voltages acquired during the three second sampling periods.

[0170] Optionally, in this embodiment, the insulation detection circuit includes a first switch, a second switch, a third switch, a first resistor, and a second resistor. The first end of the first switch is connected to the positive terminal of the energy storage device, the second end of the first switch is connected to the first end of the second switch, the second end of the second switch is connected to the negative terminal of the energy storage device, the first end of the third switch is connected to the second ends of the first switch and the second switch, the second end of the third switch is connected to the first end of the first resistor, the second end of the first resistor is connected to the first end of the second resistor and the sampling chip, and the second end of the second resistor is connected to the preset point.

[0171] Optionally, in this embodiment of the application, it further includes: a control unit, configured to control the first switch and the third switch to close, and control the second switch to open; the sampling unit 510 is specifically configured to collect the N first sampling voltages respectively within the N first sampling periods; the control unit is also configured to control the second switch and the third switch to close, and control the first switch to open; the sampling unit 510 is specifically configured to collect the M second sampling voltages respectively within the M second sampling periods.

[0172] Optionally, in this embodiment of the application, the processing unit 520 is specifically used to: determine the second insulation resistance value and the first insulation resistance value based on the first sampled voltage convergence value, the second sampled voltage convergence value, the resistance value of the first resistor, the resistance value of the second resistor, and the voltage value of the energy storage device.

[0173] Optionally, in this embodiment of the application, the first insulation resistance value R P Satisfy the following formula:

[0174] The second insulation resistance value R n Satisfy the following formula:

[0175] Where R1 is the resistance value of the first resistor, R2 is the resistance value of the second resistor, U0 is the voltage value of the energy storage device, and Ufp U is the convergence value of the first sampled voltage. fn This is the convergence value of the second sampled voltage.

[0176] Optionally, in this embodiment of the application, the processing unit 520 is further configured to: determine whether the insulation performance of the energy storage system in which the energy storage device is located meets the insulation requirements based on the first insulation resistance value.

[0177] Optionally, in this embodiment of the application, the processing unit 520 is further configured to: determine the insulation fault level of the energy storage system based on the first insulation resistance value when it is determined that the insulation performance of the energy storage system does not meet the insulation requirements; and execute a corresponding processing strategy on the energy storage system based on the insulation fault level.

[0178] It should be understood that the insulation detection device 500 can perform the corresponding operations in method 100, and for the sake of brevity, it will not be described in detail here.

[0179] Figure 6 is a schematic diagram of the hardware structure of an insulation detection device 600 according to an embodiment of this application. The insulation detection device 600 includes a memory 601, a processor 602, a communication interface 603, and a bus 604. The memory 601, the processor 602, and the communication interface 603 are interconnected via the bus 604.

[0180] The memory 601 may be a read-only memory (ROM), a static storage device, or a random access memory (RAM). The memory 601 may store a program, and when the program stored in the memory 601 is executed by the processor 602, the processor 602 and the communication interface 603 are used to execute the various steps of the insulation detection method of the embodiments of this application.

[0181] The processor 602 may be a general-purpose central processing unit (CPU), microprocessor, application-specific integrated circuit (ASIC), graphics processing unit (GPU), or one or more integrated circuits, used to execute relevant programs to achieve the functions required by the units in the apparatus of this application embodiment, or to execute the insulation detection method of this application embodiment.

[0182] The processor 602 can also be an integrated circuit chip with signal processing capabilities. In implementation, each step of the insulation detection method in this embodiment can be completed by the integrated logic circuitry in the processor 602 or by software instructions.

[0183] The processor 602 described above can also be a general-purpose processor, a digital signal processor (DSP), an ASIC, a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly implemented by the hardware processor, or implemented by a combination of hardware and software modules in the processor. The software modules can be located in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory 601. The processor 602 reads the information in memory 601 and, in conjunction with its hardware, completes the functions required by the units included in the insulation detection device 600 of the embodiments of this application, or executes the insulation detection method of the embodiments of this application.

[0184] The communication interface 603 uses a transceiver device, such as, but not limited to, a transceiver, to enable communication between the insulation detection device 600 and other devices or communication networks.

[0185] Bus 604 may include a pathway for transmitting information between various components of the insulation detection device 600 (e.g., memory 601, processor 602, communication interface 603).

[0186] It should be noted that although the insulation detection device 600 described above only shows a memory, processor, and communication interface, those skilled in the art should understand that in specific implementations, the insulation detection device 600 may also include other devices necessary for normal operation. Furthermore, depending on specific needs, those skilled in the art should understand that the insulation detection device 600 may also include hardware devices for implementing other additional functions. In addition, those skilled in the art should understand that the insulation detection device 600 may only include the devices necessary for implementing the embodiments of this application, and not necessarily all the devices shown in FIG. 6.

[0187] This application also provides a computer-readable storage medium for storing a computer program for performing the methods described in the various embodiments of this application.

[0188] The aforementioned computer-readable storage medium may be a transient computer-readable storage medium or a non-transitory computer-readable storage medium.

[0189] This application also provides a computer program product, which includes a computer program stored on a computer-readable storage medium. The computer program includes program instructions that, when executed by a computer, cause the computer to perform the above-described insulation detection method.

[0190] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method of insulation detection, characterized in that, The method comprises: acquiring, by an insulation detection circuit, N first sampling voltages of a first electrode of an energy storage device relative to a preset point, the N first sampling voltages respectively corresponding to N first sampling periods of the insulation detection circuit, N being greater than or equal to 3; determining a first insulation resistance value of the first electrode relative to the preset point according to the N first sampling voltages.

2. The method of claim 1, wherein, The determining of the first insulation resistance value of the first electrode relative to the preset point according to the N first sampling voltages comprises: determining a first sampling voltage convergence value according to the N first sampling voltages; determining the first insulation resistance value according to the first sampling voltage convergence value.

3. The method of claim 2, wherein, The insulation detection circuit comprises a first resistor and a second resistor, a first end of the first resistor being connected to a positive electrode of the energy storage device, a second end of the first resistor and a first end of the second resistor being connected to a sampling chip, and a second end of the second resistor being connected to the preset point. The determining of the first insulation resistance value according to the first sampling voltage convergence value comprises: determining the first insulation resistance value according to the first sampling voltage convergence value, a resistance value of the first resistor, a resistance value of the second resistor, and a voltage value of the energy storage device.

4. The method according to claim 2 or 3, characterized in that, In the case of N=3, the first sampling voltage convergence value satisfies the following formula: Wherein, U fp is the first sampling voltage convergence value, U p1 , U p2 and U p3 are three first sampling voltages collected in three first sampling periods.

5. The method according to any one of claims 1 to 4, characterized in that, The method further comprises: acquiring, by the insulation detection circuit, M second sampling voltages of a second electrode of the energy storage device relative to the preset point, the M second sampling voltages respectively corresponding to M second sampling periods of the insulation detection circuit, the M second sampling periods being different from the N first sampling periods, the second electrode being a reverse electrode of the first electrode, M being greater than or equal to 3; determining a second insulation resistance value of the second electrode relative to the preset point according to the M second sampling voltages.

6. The method of claim 5, wherein, The determining of the second insulation resistance value of the second electrode relative to the preset point according to the M second sampling voltages comprises: determining a second sampling voltage convergence value according to the M second sampling voltages; determining the second insulation resistance value according to the second sampling voltage convergence value and a first sampling voltage convergence value corresponding to the N first sampling voltages; The determining of the first insulation resistance value of the first electrode relative to the preset point according to the N first sampling voltages comprises: determining the first insulation resistance value according to the first sampling voltage convergence value corresponding to the N first sampling voltages and the second sampling voltage convergence value.

7. The method of claim 6, wherein, In the case of M=3, the second sampling voltage convergence value satisfies the following formula: wherein U fn is the second sampling voltage convergence value, U n1 , U n2 , and U n3 are three second sampling voltages collected in three second sampling periods.

8. The method according to claim 6 or 7, characterized in that, The insulation detection circuit comprises a first switch, a second switch, a third switch, a first resistor, and a second resistor, a first end of the first switch being connected to a positive electrode of the energy storage device, a second end of the first switch being connected to a first end of the second switch, a second end of the second switch being connected to a negative electrode of the energy storage device, a first end of the third switch being connected to the second end of the first switch and the first end of the second switch, a second end of the third switch being connected to a first end of the first resistor, a second end of the first resistor and a first end of the second resistor being connected to a sampling chip, and a second end of the second resistor being connected to the preset point.

9. The method of claim 8, wherein, The N first sampling voltages of the first electrode of the energy storage device relative to the preset point are acquired by the insulation detection circuit, and the method comprises the steps of: The first switch and the third switch are controlled to be closed, and the second switch is controlled to be opened; The N first sampling voltages are collected respectively in the N first sampling periods; The M second sampling voltages of the second electrode of the energy storage device relative to the preset point are acquired by the insulation detection circuit, and the method comprises the steps of: The second switch and the third switch are controlled to be closed, and the first switch is controlled to be opened; The M second sampling voltages are collected respectively in the M second sampling periods.

10. The method according to claim 8 or 9, characterized in that, The second insulation resistance value is determined according to the second sampling voltage convergence value and the first sampling voltage convergence value corresponding to the N first sampling voltages, and the method comprises the steps of: The second insulation resistance value and the first insulation resistance value are determined according to the first sampling voltage convergence value, the second sampling voltage convergence value, the resistance value of the first resistance, the resistance value of the second resistance and the voltage value of the energy storage device.

11. The method of claim 10, wherein, The first insulation resistance value R P satisfies the following equation: The second insulation resistance value R n satisfies the following equation: wherein R1 is a resistance value of the first resistor, R2 is a resistance value of the second resistor, U0 is a voltage value of the energy storage device, U fp is the first sampling voltage convergence value, and U fn is the second sampling voltage convergence value.

12. The method according to any one of claims 1 to 11, characterized in that, The method further comprises: According to the first insulation resistance value, it is determined whether the insulation performance of the energy storage system in which the energy storage device is located meets the insulation requirement.

13. The method of claim 12, wherein, The method further comprises: In the case that the insulation performance of the energy storage system does not meet the insulation requirement, the insulation fault level of the energy storage system is determined according to the first insulation resistance value; Based on the insulation fault level, a corresponding processing strategy is performed on the energy storage system.

14. An apparatus for insulation detection, characterized by Comprise: A sampling unit is configured to acquire N first sampling voltages of a first electrode of an energy storage device relative to a preset point by an insulation detection circuit, wherein the N first sampling voltages correspond to N first sampling periods of the insulation detection circuit respectively, and N is greater than or equal to 3; A processing unit is configured to determine a first insulation resistance value of the first electrode relative to the preset point according to the N first sampling voltages.

15. An apparatus for insulation detection, characterized by Comprise: A memory is configured to store a program; A processor is configured to execute the program stored in the memory, and when the program stored in the memory is executed, the processor is configured to execute the insulation detection method according to any one of claims 1 to 13.

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