Insulation detection method and insulation detection circuit

Abstract

The invention provides an insulation detection method and an insulation detection circuit, and the method comprises the steps: obtaining a first unsteady-state voltage array and a second unsteady-state voltage array collected in a sampling period, the first unsteady-state voltage array comprises a plurality of first voltages at the two ends of a first insulation resistor, the second unsteady-state voltage array comprises a plurality of detection voltages, and the first voltage is greater than the detection voltages; the detection voltage refers to voltage obtained by detecting partial impedance of the first insulation impedance; processing the first unsteady-state voltage array and the second unsteady-state voltage array by using a steady-state voltage algorithm to obtain a first steady-state voltage and a second steady-state voltage; according to the first steady-state voltage, the second steady-state voltage and a second voltage determined according to the first steady-state voltage, the first insulation impedance and the second insulation impedance are determined, and the second voltage refers to the voltage at the two ends of the second insulation impedance. According to the insulation detection circuit, the circuit is simple, and the detection efficiency is improved while the detection cost is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of insulation detection, and in particular to an insulation detection method and an insulation detection circuit. Background Art

[0002] The traditional bridge insulation detection circuit is relatively complex, which increases the insulation detection cost and occupies space. In addition, the existing bridge insulation detection circuit has cumbersome detection steps. When the battery system has large capacitance to ground and insulation resistance, the voltage time constant after the switch action is long, resulting in a long insulation detection cycle, which affects the response time of the battery system. Summary of the invention

[0003] In view of this, the purpose of the present application is to at least provide an insulation detection circuit and a method for determining a steady-state voltage, which can reduce the detection cost and improve the detection efficiency through a simple insulation detection circuit.

[0004] This application mainly includes the following aspects:

[0005] In a first aspect, an embodiment of the present application provides an insulation detection method for detecting a target insulation impedance in a battery system, wherein the target insulation impedance includes a first insulation impedance and a second insulation impedance, and the method includes: obtaining a first non-steady-state voltage array and a second non-steady-state voltage array collected within a sampling period, wherein the first non-steady-state voltage array includes a plurality of first voltages across the first insulation impedance, and the second non-steady-state voltage array includes a plurality of detection voltages, wherein the detection voltage refers to a voltage obtained by detecting a portion of the impedance of the first insulation impedance; using a steady-state voltage algorithm to process the first non-steady-state voltage array and the second non-steady-state voltage array, respectively, to obtain a first steady-state voltage and a second steady-state voltage; determining the first insulation impedance and the second insulation impedance according to the first steady-state voltage and the second steady-state voltage and a second voltage determined according to the first steady voltage, wherein the second voltage refers to the voltage across the second insulation impedance.

[0006] In a possible implementation, the first non-steady-state voltage array and the second non-steady-state voltage array are processed respectively using a steady-state voltage algorithm to obtain the first steady-state voltage and the second steady-state voltage, the steps comprising: sampling the first non-steady-state voltage array at a preset sampling interval to obtain a plurality of first voltage arrays to be processed and sampling the second non-steady-state voltage array to obtain a plurality of second voltage arrays to be processed, each first voltage array to be processed includes a plurality of target first voltages, and each second voltage array to be processed includes a plurality of target detection voltages; determining a first calculated steady-state voltage corresponding to each first voltage array to be processed and a second calculated steady-state voltage corresponding to each second voltage array to be processed; determining a first steady-state voltage according to the plurality of first calculated steady-state voltages and determining a second steady-state voltage according to the plurality of second calculated steady-state voltages.

[0007] In a possible implementation, the method further includes: determining a first voltage difference between a first voltage corresponding to a preset quantile value and a last first voltage from among a plurality of first voltages; if the first voltage difference is less than a first preset steady-state difference, directly determining the last first voltage as the first steady-state voltage; if the first voltage difference is greater than or equal to the first preset steady-state difference, determining whether the number of first voltages between the first voltage corresponding to the preset quantile value and the last first voltage is greater than a preset number; if the number of first voltages between the first voltage corresponding to the preset quantile value and the last first voltage is greater than a preset number, adding a preset quantile increment to the preset quantile value, obtaining an updated preset quantile value, and returning to redetermine the first voltage difference; if the number of first voltages between the first voltage corresponding to the preset quantile value and the last first voltage is less than or equal to a preset number, sampling the first non-steady-state voltage array at a preset sampling interval to obtain a plurality of first voltage arrays to be processed and sampling the second non-steady-state voltage array to obtain a plurality of second voltage arrays to be processed.

[0008] In one possible implementation, multiple first voltage arrays to be processed are determined by performing multiple extraction processes on multiple first voltages, and each extraction process is performed according to a preset sampling interval, wherein each extraction process includes: determining whether the number of the multiple first voltages to be extracted meets the extraction conditions; if the number of the first voltages to be extracted meets the extraction conditions, extracting multiple target first voltages to form a corresponding first voltage array to be processed; if the number of the remaining first voltages does not meet the extraction conditions, stopping sampling.

[0009] In a possible implementation manner, the plurality of target first voltages include three target first voltages, wherein the first calculated steady-state voltage corresponding to each first to-be-processed voltage array is determined by the following formula:

[0010]

[0011] U1 , U2 and U3 respectively represent three target first voltages in the first to-be-processed voltage array.

[0012] In one possible implementation, the step of determining the first steady-state voltage based on multiple first calculated steady-state voltages includes: calculating the absolute difference between the maximum first calculated steady-state voltage and the minimum first calculated steady-state voltage among the multiple first calculated steady-state voltages; comparing the absolute difference with a second preset steady-state difference, and if the absolute difference is less than or equal to the second preset steady-state difference, determining the average corresponding to the maximum first calculated steady-state voltage and the minimum first calculated steady-state voltage as the first target steady-state voltage; if the absolute difference is greater than the second preset steady-state difference, dividing all the first calculated steady-state voltages, and determining the first steady-state voltage based on the division result.

[0013] In one possible implementation, if the absolute difference is greater than a second preset steady-state difference, all first calculated steady-state voltages are divided, and based on the division result, the step of determining the first steady-state voltage includes: for all first calculated steady-state voltages, using the second preset steady-state difference as a division interval, obtaining a plurality of calculation intervals, each calculation interval including at least one first calculated steady-state voltage; determining the mode corresponding to each calculation interval, the mode referring to the first calculated steady-state voltage that appears the most times in the calculation interval; and determining the first calculated steady-state voltage indicated by the largest mode as the first steady-state voltage.

[0014] In a possible implementation, the first insulation impedance is connected in parallel with the detection circuit, and the detection circuit includes a first resistor and a second resistor connected in series with each other, wherein the first insulation impedance is determined by the following formula:

[0015]

[0016] Among them, R p Indicates the first insulation resistance, U n1 Represents the second voltage, U n1 =UU p1 , U is the DC voltage source voltage, U p1 represents the first steady-state voltage, R1 represents the first resistor, R2 represents the second resistor, U - Indicates the negative half-bridge voltage of the battery system, U + Represents the positive half-bridge voltage of the battery system.

[0017] in, U p2 represents the second steady-state voltage, The second insulation resistance is determined by the following formula:

[0018]

[0019] R n Indicates the second insulation resistance.

[0020] In a possible implementation, the insulation detection circuit includes a first insulation impedance, a second insulation impedance, a DC voltage source, a first control switch, a second control switch, a first resistor and a voltage detection sensor, wherein the positive electrode of the DC voltage source is connected to the input end of the first insulation impedance, the output end of the first insulation impedance is respectively connected to the input end of the second insulation impedance and the first connection end of the first control switch, and the output end of the second insulation impedance is connected to the negative electrode of the DC voltage source; one end of the first resistor is respectively connected to the positive electrode of the DC voltage source and the input end of the voltage detection sensor, the other end of the first resistor is connected to the first connection end of the second control switch, and the second connection end of the second control switch is respectively connected to the second connection end of the first control switch and the first output end of the voltage detection sensor; the control end of the first control switch, the control end of the second control switch and the second output end of the voltage detection sensor are respectively connected to the controller.

[0021] In a possible implementation, the insulation detection circuit further includes a second resistor, wherein one end of the second resistor is respectively connected to the second connection end of the second control switch and the first output end of the voltage detection sensor, and the other end of the second resistor is connected to the second connection end of the first control switch.

[0022] In a possible implementation, the first insulation impedance includes a first insulation resistor and a first capacitor, wherein one end of the first insulation resistor is connected to one end of the first capacitor and then connected to the positive electrode of the DC voltage source, and the other end of the first insulation resistor is connected to the other end of the first capacitor and then connected to the input end of the second insulation impedance.

[0023] In a possible implementation, the first insulation impedance includes a second insulation resistor and a second capacitor, wherein one end of the second insulation resistor is connected to one end of the second capacitor and then connected to the other end of the first insulation resistor, and the other end of the second insulation resistor is connected to the other end of the second capacitor and then connected to the negative pole of the DC voltage source.

[0024] In a possible implementation, the insulation detection circuit also includes an amplification module, wherein a first input terminal of the amplification module is connected to one end of the first resistor, a second input terminal of the amplification module is connected to a second connection terminal of the second control switch, and an output terminal of the amplification module is connected to an input terminal of the voltage detection sensor.

[0025] In a possible implementation, the amplification module includes a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a first operational amplifier and a second operational amplifier, wherein one end of the third resistor is connected to one end of the first resistor, the other end of the third resistor is respectively connected to one end of the fourth resistor and the negative input end of the first operational amplifier, and the positive input end of the first operational amplifier is respectively connected to the second connection end of the second control switch and the positive input end of the second operational amplifier; the output end of the first operational amplifier is respectively connected to the other end of the fourth resistor and one end of the fifth resistor, the other end of the fifth resistor is respectively connected to one end of the sixth resistor and the negative input end of the second operational amplifier, and the output end of the second operational amplifier is respectively connected to the other end of the sixth resistor and the input end of the voltage detection sensor.

[0026] An insulation detection method and insulation detection circuit provided by an embodiment of the present application include: obtaining a first non-steady-state voltage array and a second non-steady-state voltage array collected within a sampling period, wherein the first non-steady-state voltage array includes a plurality of first voltages at both ends of a first insulation impedance, and the second non-steady-state voltage array includes a plurality of detection voltages, wherein the detection voltage refers to the voltage obtained by detecting a portion of the impedance of the first insulation impedance; using a steady-state voltage algorithm to process the first non-steady-state voltage array and the second non-steady-state voltage array respectively to obtain a first steady-state voltage and a second steady-state voltage; determining the first insulation impedance and the second insulation impedance according to the first steady-state voltage and the second steady-state voltage and the second voltage determined according to the first steady-state voltage, wherein the second voltage refers to the voltage at both ends of the second insulation impedance. The insulation detection circuit of the present application has a simple circuit, reduces detection costs, and improves detection efficiency.

[0027] The benefits of this application are:

[0028] 1. Compared with the traditional insulation detection scheme, the number of components such as relays and voltmeters is reduced, so it has cost advantages over the traditional scheme;

[0029] 2. Reducing the number of components also reduces the demand for structural space in hardware design, making the detection device more flexible and convenient to integrate;

[0030] 3. When determining the steady-state voltage, the present application can flexibly set the sampling interval. Too small an interval will result in a large error in estimating the steady-state voltage. Only when the steady-state voltage is not in a steady state can continuous equal-interval voltage data be used to predict the steady-state voltage, thereby achieving rapid detection of the steady-state voltage.

[0031] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 One of the structural schematic diagrams of an insulation detection circuit provided in an embodiment of the present application is shown;

[0034] Figure 2 A second structural schematic diagram of an insulation detection circuit provided in an embodiment of the present application is shown;

[0035] Figure 3 A flowchart showing the steps of an insulation detection method provided by an embodiment of the present application is shown;

[0036] Figure 4 A flowchart showing the steps of a method for determining a steady-state voltage provided by an embodiment of the present application;

[0037] Figure 5 A functional module schematic diagram of an insulation detection device provided in an embodiment of the present application is shown;

[0038] Figure 6 A schematic structural diagram of an electronic device provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0039] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the drawings in the present application only serve the purpose of explanation and description and are not used to limit the scope of protection of the present application. In addition, it should be understood that the schematic drawings are not drawn in real proportion. The flowchart used in this application shows the operations implemented according to some embodiments of the present application. It should be understood that the operations of the flowchart can be implemented out of sequence, and the steps without logical context can be reversed in order or implemented simultaneously. In addition, those skilled in the art, under the guidance of the content of the present application, can add one or more other operations to the flowchart, or remove one or more operations from the flowchart.

[0040] In addition, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0041] The traditional bridge insulation detection circuit is relatively complex and the detection steps are cumbersome. When the battery system has large capacitance to ground and insulation resistance, the voltage time constant after the switch is actuated is relatively long, resulting in a long insulation detection cycle, which affects the response time of the battery system.

[0042] Based on this, the embodiment of the present application provides an insulation detection method and an insulation detection circuit, which implements insulation detection of a battery through a simple insulation detection circuit, thereby reducing detection costs and improving detection efficiency, as follows:

[0043] See also Figure 1 , Figure 1 FIG. 1 shows one of the structural schematic diagrams of an insulation detection circuit provided in an embodiment of the present application. Figure 1 As shown, the insulation detection circuit provided in the embodiment of the present application includes a first insulation impedance 1, a second insulation impedance 2, a DC voltage source DC, a first control switch K1, a second control switch K2, a first resistor R1 and a voltage detection sensor 3, wherein the first insulation impedance 1 is the insulation impedance of the positive pole of the DC voltage source DC to the ground, and the second insulation impedance 2 is the insulation impedance of the negative pole of the DC voltage source DC to the ground.

[0044] Preferably, the positive pole of the DC voltage source DC is connected to the input end of the first insulation resistor 1, the output end of the first insulation resistor 1 is respectively connected to the input end of the second insulation resistor 2 and the first connection end of the first control switch K1, and the output end of the second insulation resistor 2 is connected to the negative pole of the DC voltage source DC.

[0045] One end of the first resistor R1 is respectively connected to the positive electrode of the DC voltage source DC and the input end of the voltage detection sensor 3, the other end of the first resistor R1 is connected to the first connection end of the second control switch K2, and the second connection end of the second control switch K2 is respectively connected to the second connection end of the first control switch K1 and the first output end of the voltage detection sensor 3.

[0046] The control end of the first control switch K1, the control end of the second control switch K2 and the second output end of the voltage detection sensor 3 are respectively connected to a controller (not shown in the figure).

[0047] In the present application, the DC voltage source DC is equivalent to the battery system. Specifically, the positive electrode of the DC voltage source DC is the positive electrode of the battery system, the negative electrode of the DC voltage source DC is the negative electrode of the battery system, and the voltage detection sensor 3 can be a voltmeter.

[0048] See also Figure 2 , Figure 2 FIG. 2 shows a second structural diagram of an insulation detection circuit provided in an embodiment of the present application. Figure 2 As shown, the insulation detection circuit also includes a second resistor R2, one end of which is respectively connected to the second connection end of the second control switch K2 and the first output end of the voltage detection sensor 3, and the other end of the second resistor R2 is connected to the second connection end of the first control switch K1.

[0049] Preferably, Figure 2 As shown, the first insulation impedance 1 includes a first insulation resistance R p And the first capacitor C1, the positive electrode to ground insulation resistance R p One end of the first capacitor C1 is connected to the positive electrode of the DC voltage source DC, and the first insulation resistor R p The other end of is connected to the other end of the first capacitor C1 and then connected to the input end of the second insulation impedance 2.

[0050] Preferably, the second insulation impedance 2 includes a second insulation resistance R n and the second capacitor C2, the second insulation resistor R n One end of the second capacitor C2 is connected to the positive electrode insulation resistor R p The other end, the second insulation resistance R n The other end of is connected to the other end of the second capacitor C2 and then connected to the negative electrode of the DC voltage source DC.

[0051] like Figure 2 The insulation detection circuit also includes an amplifier module 4, a first input end of the amplifier module 4 is connected to one end of the first resistor R1, a second input end of the amplifier module 4 is connected to a second connection end of the second control switch K2, and an output end of the amplifier module 4 is connected to an input end of the voltage detection sensor 3.

[0052] In a preferred embodiment, the amplification module 4 includes a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a first operational amplifier LM1 and a second operational amplifier LM2.

[0053] Among them, one end of the third resistor R3 is connected to one end of the first resistor R1, the other end of the third resistor R3 is respectively connected to one end of the fourth resistor R4 and the negative input end of the first operational amplifier LM1, and the positive input end of the first operational amplifier LM1 is respectively connected to the second connection end of the second control switch K2 and the positive input end of the second operational amplifier LM2.

[0054] The output end of the first operational amplifier LM1 is respectively connected to the other end of the fourth resistor R4 and one end of the fifth resistor R5, the other end of the fifth resistor R5 is respectively connected to one end of the sixth resistor R6 and the negative input end of the second operational amplifier LM2, and the output end of the second operational amplifier LM2 is respectively connected to the other end of the sixth resistor R6 and the input end of the voltage detection sensor 3.

[0055] The first operational amplifier LM1 and the second operational amplifier LM2 are both inverting operational amplifiers.

[0056] In a specific implementation, in order to avoid damage caused by the voltage detection sensor 3 directly collecting high voltage, the voltage is first scaled by the amplification module. For example, the voltage can be first reduced to -0.0001 times by using the first operational amplifier LM1, and then scaled to -1 times by the second operational amplifier LM2, so as to achieve a 10000 times reduction of the high voltage signal. That is to say, in this case, the operational amplifier multiple G1 of the first operational amplifier LM1 is:

[0057]

[0058] The operational amplifier multiple G2 of the second operational amplifier LM2 is:

[0059]

[0060] In the above case:

[0061] V out =0.0001V in

[0062] Among them, V in is the battery system voltage collected before inputting into the amplifier module, V out It is the voltage obtained after being amplified by the amplifier module.

[0063] Based on the above insulation detection circuit, the embodiment of the present application also provides an insulation detection method for detecting the target insulation impedance of the battery system, the target insulation impedance includes a first insulation impedance 1 and a second insulation impedance 2, see Figure 3 , Figure 3 A flowchart showing the steps of an insulation detection method provided by an embodiment of the present application is shown. Figure 3 As shown, the method includes:

[0064] S100, obtaining a first non-steady-state voltage array and a second non-steady-state voltage array collected within a sampling period.

[0065] The first non-steady-state voltage array includes a plurality of first voltages at both ends of the first insulation resistor, and the second non-steady-state voltage array includes a plurality of detection voltages, where the detection voltage refers to a voltage obtained by detecting a portion of the impedance of the first insulation resistor.

[0066] S200 , using a steady-state voltage algorithm to process the first non-steady-state voltage array and the second non-steady-state voltage array respectively to obtain a first steady-state voltage and a second steady-state voltage.

[0067] S300 , determining a first insulation impedance and a second insulation impedance according to the first steady-state voltage and the second steady-state voltage and a second voltage determined according to the first steady-state voltage.

[0068] The second voltage refers to the voltage across the second insulation impedance, which is collected by the BMS.

[0069] In step S100, within a sampling period, the first control switch K1 is first controlled to be closed, and the second control switch K2 is opened, and a first non-steady-state voltage array is obtained by collecting through the voltage detection sensor 3. Within another sampling period, the first control switch K1 is controlled to be closed, and the second control switch K2 is controlled to be closed, and a second non-steady-state voltage array is obtained through the voltage detection sensor 3. At this time, the detection voltage is the voltage across the first resistor R1. For example, if the sampling period of the voltage detection sensor 3 is 50ms and the preset time period is 5s, the first non-steady-state voltage array finally formed includes 100 first voltages, and the second non-steady-state voltage array includes 100 detection voltages.

[0070] In a preferred embodiment, see Figure 4 , Figure 4 A flow chart showing the steps of a method for determining a steady-state voltage provided by an embodiment of the present application is shown. Figure 4 As shown, step S200 includes:

[0071] S210 , sampling the first non-steady-state voltage array at a preset sampling interval to obtain a plurality of first voltage arrays to be processed and sampling the second non-steady-state voltage array to obtain a plurality of second voltage arrays to be processed.

[0072] Each first voltage array to be processed includes a plurality of target first voltages, and each second voltage array to be processed includes a plurality of target detection voltages;

[0073] S220 , respectively determining a first calculated steady-state voltage corresponding to each first voltage array to be processed and a second calculated steady-state voltage corresponding to each second voltage array to be processed.

[0074] S230 , determining a first steady-state voltage according to the plurality of first calculated steady-state voltages and determining a second steady-state voltage according to the plurality of second calculated steady-state voltages.

[0075] Specifically, before sampling the first non-steady-state voltage array at preset sampling intervals, it is necessary to perform steady-state prejudgment on the first non-steady-state voltage array, and the method includes:

[0076] From multiple first voltages, determine the first voltage difference between the first voltage corresponding to the preset quantile value and the last first voltage; if the first voltage difference is less than the first preset steady-state difference, directly determine the last first voltage as the first steady-state voltage; if the first voltage difference is greater than or equal to the first preset steady-state difference, determine whether the number of first voltages between the first voltage corresponding to the preset quantile value and the last first voltage is greater than the preset number; if the number of first voltages between the first voltage corresponding to the preset quantile value and the last first voltage is greater than the preset number, add a preset quantile increment to the preset quantile value, obtain the updated preset quantile value, return to re-determine the first voltage difference; if the number of first voltages between the first voltage corresponding to the preset quantile value and the last first voltage is less than or equal to the preset number, return to execute step S210.

[0077] In a specific embodiment, if the first non-steady-state voltage array includes U1-U 100 There are 100 first voltages in total. Taking the preset percentile value as 50 as an example, calculate the U corresponding to the preset percentile value 50. 50 With the last first voltage U 100 The first voltage difference is compared with the first preset steady-state voltage difference, and subsequent processing is performed according to the comparison result.

[0078] Specifically, when the first voltage difference is less than the first preset steady-state voltage difference, it is considered that the current battery system is in a stable state. At this time, the last first voltage U 100 A first steady-state voltage corresponding to the entire insulation detection circuit is determined.

[0079] When the first voltage difference is greater than or equal to the first preset steady-state voltage difference, it is necessary to further narrow the sampling interval formed by the sampling voltage corresponding to the preset quantile value and the last sampling voltage. Specifically, the preset quantile value can be changed, that is, a preset quantile increment is added to the preset quantile value. For example, if the current preset quantile value is 50 and the preset quantile increment is 5, the updated preset quantile value is 55.

[0080] In the present application, before updating, it is necessary to determine the number of first voltages in the sampling interval formed by the first voltage corresponding to the preset quantile value and the last sampled voltage. For example, in the above embodiment, the number of first voltages in the sampling interval formed by the first voltage corresponding to the preset quantile value of 50 and the last sampled voltage is 50. Compare it with the preset number. If the number of first voltages in the sampling interval is greater than the preset number, then add a preset quantile increment to the preset quantile value. If the number of first voltages in the sampling interval is less than or equal to the preset number, for example, the preset number is 6 and the preset quantile value is 95, the number of sampled voltages in the sampling interval formed at this time is 5, which is less than the preset number 6. At this time, if the calculated first voltage difference is still less than the first preset steady-state difference, step S200 needs to be executed.

[0081] In the present application, the second non-steady-state voltage array also needs to be pre-judged in a steady state. The steady-state pre-judgment process is similar to that of the second non-steady-state voltage array and will not be described in detail here.

[0082] In step S200, multiple first voltage arrays to be processed are determined by performing multiple extraction processes on multiple first voltages, and each extraction process is performed according to a preset sampling interval, wherein each extraction process includes: determining whether the number of the multiple first voltages to be extracted meets the extraction conditions; if the number of the first voltages to be extracted meets the extraction conditions, extracting multiple target first voltages to form a corresponding first voltage array to be processed; if the number of the remaining first voltages does not meet the extraction conditions, stopping sampling.

[0083] Specifically, if the preset sampling interval is 3, then among the multiple first voltages, every three are extracted once, and in the present application, every three first voltages extracted are automatically classified into a to-be-processed voltage array. Therefore, each time extraction is performed, it is necessary to determine whether the remaining number of first voltages meets the next extraction. Specifically, the required grouping number corresponding to the to-be-processed voltage array to which the first voltage extracted next time belongs can be confirmed first. The required grouping number is related to the remaining unextracted target first voltage number of the to-be-processed voltage array to which the first voltage extracted next time belongs. The required grouping number is equal to 3 times the unextracted target first voltage number. If the remaining unextracted first voltage number is greater than or equal to the required grouping number corresponding to the first voltage extracted next time, extraction can continue to form the corresponding first to-be-processed voltage array. If the remaining unextracted first voltage number is less than the required grouping number corresponding to the first voltage extracted next time, it is determined that the remaining first voltage number does not meet the next extraction and sampling is stopped.

[0084] For example, when the preset sampling interval is 3 and the number of first voltages in the first voltage array to be processed is 3, if the number of remaining unextracted target first voltages corresponding to the first voltage array to be processed to which the sampled voltage to be extracted next time belongs is 2, then the number of remaining first voltages should be greater than or equal to 6 before extraction can continue, otherwise extraction stops.

[0085] The process of determining the second voltage array to be processed is similar to the process of determining the first voltage array to be processed, and will not be described in detail here.

[0086] The plurality of target first voltages include three target first voltages, wherein the first calculated steady-state voltage corresponding to each first to-be-processed voltage array is determined by the following formula:

[0087]

[0088] U1 , U2 and U3 respectively represent three target first voltages in the first to-be-processed voltage array.

[0089] Similarly, each second to-be-processed voltage array includes three target detection voltages sampled successively.

[0090] In another preferred embodiment, step 220 includes:

[0091] An absolute difference between a maximum first calculated steady-state voltage and a minimum first calculated steady-state voltage among a plurality of first calculated steady-state voltages is calculated, and the absolute difference is compared with a second preset steady-state difference; if the absolute difference is less than or equal to the second preset steady-state difference, an average value corresponding to the maximum first calculated steady-state voltage and the minimum first calculated steady-state voltage is determined as the first target steady-state voltage; if the absolute difference is greater than the second preset steady-state difference, all first calculated steady-state voltages are divided, and the first steady-state voltage is determined according to the division result.

[0092] In one example, if the maximum first calculated steady-state voltage U fmax First calculate the steady-state voltage with the minimum U fmin The absolute difference between |U fmax -U fmin | is less than or equal to the second preset steady-state difference ε, it is determined that when the first control switch K1 is closed and the second control switch K2 is opened, the first steady-state voltage

[0093] In another preferred embodiment, if the absolute difference is greater than the second preset steady-state difference, all first calculated steady-state voltages are divided, and according to the division result, the step of determining the first steady-state voltage includes:

[0094] For all first calculated steady-state voltages, a second preset steady-state difference is used as a dividing interval to obtain multiple calculation intervals, each calculation interval includes at least one first calculated steady-state voltage, and the mode corresponding to each calculation interval is determined, the mode refers to the first calculated steady-state voltage that appears the most times in the calculation interval, and the first calculated steady-state voltage indicated by the largest mode is determined as the first steady-state voltage.

[0095] If |U fmax -U fmin |>ε, the calculated steady-state voltage indicated by the maximum value of the mode in the divided calculation interval is determined as the first steady-state voltage.

[0096] The second steady-state voltage is determined in the same manner as the first steady-state voltage, and will not be described in detail herein.

[0097] In this application, according to the first steady-state voltage U p1 and the second steady-state voltage U p2 , the first insulation resistance can be calculated by the following formula:

[0098]

[0099] In this formula, R p Indicates the first insulation resistance, U n1 Represents the second voltage, U n1 =UU p1 , U is the DC voltage source voltage, U p1 represents the first steady-state voltage, R1 represents the first resistor, R2 represents, U_- represents the negative half-bridge voltage of the battery system, and U_+ represents the positive half-bridge voltage of the battery system, where:

[0100]

[0101]

[0102] The second insulation resistance can be calculated by the following formula:

[0103]

[0104] Based on the same application concept, an insulation detection device corresponding to the insulation detection method provided in the above embodiment is also provided in the embodiment of the present application. Since the principle of solving the problem by the device in the embodiment of the present application is similar to the steady-state voltage determination method in the above embodiment of the present application, the implementation of the device can refer to the implementation of the method, and the repeated parts will not be repeated.

[0105] See also Figure 5 , Figure 5 FIG. 1 is a functional module diagram of an insulation detection device provided in an embodiment of the present application. Figure 5As shown, the device is used to detect the target insulation impedance in the battery system, the target insulation impedance includes a first insulation impedance and a second insulation impedance, and the device includes:

[0106] The acquisition module 400 is used to acquire a first non-steady-state voltage array and a second non-steady-state voltage array collected within a preset time period, wherein the first non-steady-state voltage array includes a plurality of first voltages across a first insulation resistor, and the second non-steady-state voltage array includes a plurality of detection voltages, wherein the detection voltage refers to a voltage obtained by detecting a portion of the impedance of the first insulation resistor.

[0107] The processing module 410 is used to process the first non-steady-state voltage array and the second non-steady-state voltage array respectively by using a steady-state voltage algorithm to obtain a first steady-state voltage and a second steady-state voltage.

[0108] The determination module 420 is used to determine the first insulation impedance and the second insulation impedance according to the first steady-state voltage and the second steady-state voltage and the second voltage determined according to the first steady-state voltage, where the second voltage refers to the voltage across the second insulation impedance.

[0109] Optionally, the processing module 410 is also used to: sample the first non-steady-state voltage array according to a preset sampling interval to obtain a plurality of first voltage arrays to be processed and sample the second non-steady-state voltage array to obtain a plurality of second voltage arrays to be processed, each first voltage array to be processed includes a plurality of target first voltages, and each second voltage array to be processed includes a plurality of target detection voltages; determine a first calculated steady-state voltage corresponding to each first voltage array to be processed and a second calculated steady-state voltage corresponding to each second voltage array to be processed; determine a first steady-state voltage based on the plurality of first calculated steady-state voltages and determine a second steady-state voltage based on the plurality of second calculated steady-state voltages.

[0110] Optionally, the processing module 410 is also used to: determine a first voltage difference between a first voltage corresponding to a preset quantile value and a last first voltage from multiple first voltages; if the first voltage difference is less than a first preset steady-state difference, directly determine the last first sampling voltage as the first steady-state voltage; if the first voltage difference is greater than or equal to the first preset steady-state difference, determine whether the number of first voltages between the first voltage corresponding to the preset quantile value and the last first voltage is greater than a preset number; if the number of first voltages between the first voltage corresponding to the preset quantile value and the last first voltage is greater than a preset number, add a preset quantile increment to the preset quantile value, obtain an updated preset quantile value, and return to redetermine the first voltage difference; if the number of first voltages between the first voltage corresponding to the preset quantile value and the last first voltage is less than or equal to a preset number, extract multiple target first voltages from multiple first voltages according to a preset data extraction interval.

[0111] Optionally, the processing module 410 is also used to: continuously extract multiple target first voltages from multiple first voltages according to a preset sampling interval, and form a corresponding first array of voltages to be processed; determine whether the number of remaining first voltages meets the requirements for the next extraction, and if so, continue to extract and form a corresponding array of first voltages to be processed; if the number of remaining first voltages does not meet the requirements for the next extraction, stop sampling to obtain multiple arrays of first voltages to be processed.

[0112] Optionally, each first voltage array to be processed includes three target first voltages sampled successively, wherein the processing module 410 is further configured to determine a first calculated steady-state voltage corresponding to each first voltage array to be processed by the following formula:

[0113]

[0114] U1, U2 and U3 respectively represent the target first voltages sampled successively in the first voltage array to be processed.

[0115] Optionally, the processing module 410 is also used to determine the first steady-state voltage in the following manner: calculate the absolute difference between the maximum first calculated steady-state voltage and the minimum first calculated steady-state voltage; compare the absolute difference with a second preset steady-state difference, and if the absolute difference is less than or equal to the second preset steady-state difference, determine the average corresponding to the maximum first calculated steady-state voltage and the minimum first calculated steady-state voltage as the first target steady-state voltage; if the absolute difference is greater than the second preset steady-state difference, divide all the first calculated steady-state voltages, and determine the first steady-state voltage based on the division result.

[0116] Optionally, the processing module 410 is also used to: for all first calculated steady-state voltages, use the second preset steady-state difference as a dividing interval to obtain multiple calculation intervals, each calculation interval including at least one first calculated steady-state voltage; determine the mode corresponding to each calculation interval, the mode refers to the first calculated steady-state voltage that appears the most times in the calculation interval; and determine the first calculated steady-state voltage indicated by the largest mode as the first steady-state voltage.

[0117] Optionally, the determination module 420 is used to determine the first insulation impedance by using the following formula:

[0118]

[0119] Among them, R p Indicates the first insulation resistance, U n1 Represents the second voltage, U n1 =UU p1 , U is the DC voltage source voltage, U p1 represents the first steady-state voltage, R1 represents the first resistance, and R2 represents the second resistance.

[0120] U_ represents the negative half-bridge voltage of the battery system, U + Represents the positive half-bridge voltage of the battery system.

[0121] in, U p2 represents the second steady-state voltage,

[0122] The second insulation resistance is determined by the following formula:

[0123]

[0124] R n Indicates the second insulation resistance.

[0125] Based on the same application idea, please refer to Figure 6 , Figure 6 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application is shown, wherein the electronic device 500 comprises: a processor 510, a memory 520 and a bus 530, wherein the memory 520 stores machine-readable instructions executable by the processor 510, and when the electronic device 500 is running, the processor 510 communicates with the memory 520 via the bus 530, and the machine-readable instructions are executed by the processor 510 when running, such as the steps of the steady-state voltage determination method provided in any of the above embodiments.

[0126] Based on the same application concept, an embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the steady-state voltage determination method provided in the above embodiment are executed.

[0127] Those skilled in the art can clearly understand that, for the convenience and simplicity of description, the specific working process of the system and device described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here. In the several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0128] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0129] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0130] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a non-volatile computer-readable storage medium that is executable by a processor. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, etc., various media that can store program codes.

[0131] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. An insulation detection method, characterized in that: For detecting a target insulation impedance in a battery system, the target insulation impedance comprising a first insulation impedance and a second insulation impedance, the method comprising: Acquire a first non-steady-state voltage array and a second non-steady-state voltage array collected within a preset time period, wherein the first non-steady-state voltage array includes a plurality of first voltages across the first insulation resistor, and the second non-steady-state voltage array includes a plurality of detection voltages, wherein the detection voltage refers to a voltage obtained by detecting a portion of the impedance of the first insulation resistor; Using a steady-state voltage algorithm to process the first non-steady-state voltage array and the second non-steady-state voltage array respectively, to obtain a first steady-state voltage and a second steady-state voltage; The first insulation impedance and the second insulation impedance are determined according to the first steady-state voltage and the second steady-state voltage and a second voltage determined according to the first steady-state voltage, wherein the second voltage refers to a voltage across the second insulation impedance.

2. The method according to claim 1, characterized in that: The step of processing the first non-steady-state voltage array and the second non-steady-state voltage array respectively by using a steady-state voltage algorithm to obtain a first steady-state voltage and a second steady-state voltage comprises: The first non-steady-state voltage array is sampled at a preset sampling interval to obtain a plurality of first voltage arrays to be processed and the second non-steady-state voltage array is sampled to obtain a plurality of second voltage arrays to be processed, each of the first voltage arrays to be processed includes a plurality of target first voltages, and each of the second voltage arrays to be processed includes a plurality of target detection voltages; Respectively determining a first calculated steady-state voltage corresponding to each first voltage array to be processed and a second calculated steady-state voltage corresponding to each second voltage array to be processed; A first steady-state voltage is determined based on the plurality of first calculated steady-state voltages and a second steady-state voltage is determined based on the plurality of second calculated steady-state voltages.

3. The method according to claim 2, characterized in that The method further comprises: Determine, from the plurality of first voltages, a first voltage difference between a first voltage corresponding to a preset percentile value and a last first voltage; If the first voltage difference is less than the first preset steady-state difference, directly determining the last first voltage as the first steady-state voltage; If the first voltage difference is greater than or equal to the first preset steady-state difference, determining whether the number of first voltages between the first voltage corresponding to the preset quantile value and the last first voltage is greater than a preset number; If the number of first voltages between the first voltage corresponding to the preset quantile value and the last first voltage is greater than the preset number, adding a preset quantile increment to the preset quantile value, obtaining an updated preset quantile value, and returning to re-determine the first voltage difference; If the number of first voltages between the first voltage corresponding to the preset percentile value and the last first voltage is less than or equal to the preset number, the first non-steady-state voltage array is sampled according to the preset sampling interval to obtain multiple first voltage arrays to be processed and the second non-steady-state voltage array is sampled to obtain multiple second voltage arrays to be processed.

4. The method according to claim 2, characterized in that: A plurality of first voltage arrays to be processed are determined by performing multiple extraction processes on the plurality of first voltages, wherein each extraction process is performed according to the preset sampling interval, Among them, each extraction process includes: determining whether the number of multiple first voltages to be extracted meets the extraction conditions; if the number of first voltages to be extracted meets the extraction conditions, extracting multiple target first voltages to form a corresponding first voltage array to be processed; if the number of remaining first voltages does not meet the extraction conditions, stopping sampling.

5. The method according to claim 2, characterized in that: The plurality of target first voltages include three target first voltages, The first calculated steady-state voltage corresponding to each first voltage array to be processed is determined by the following formula: U1 , U2 and U3 respectively represent three target first voltages in the first to-be-processed voltage array.

6. The method according to claim 2, characterized in that The step of determining the first steady-state voltage according to the plurality of first calculated steady-state voltages comprises: calculating an absolute difference between a maximum first calculated steady-state voltage and a minimum first calculated steady-state voltage among the plurality of first calculated steady-state voltages; comparing the absolute difference with a second preset steady-state difference; If the absolute difference is less than or equal to the second preset steady-state difference, determining the average value corresponding to the maximum first calculated steady-state voltage and the minimum first calculated steady-state voltage as the first steady-state voltage; If the absolute difference is greater than the second preset steady-state difference, all first calculated steady-state voltages are divided, and the first steady-state voltage is determined according to the division result.

7. The method according to claim 6, characterized in that If the absolute difference is greater than the second preset steady-state difference, all first calculated steady-state voltages are divided, and according to the division result, the step of determining the first steady-state voltage includes: For all first calculated steady-state voltages, a second preset steady-state difference is used as a division interval to obtain a plurality of calculation intervals, each calculation interval including at least one first calculated steady-state voltage; Determine a mode corresponding to each calculation interval, wherein the mode refers to the first calculated steady-state voltage that appears most times in the calculation interval; A first calculated steady-state voltage indicated by the largest magnitude is determined as a first steady-state voltage.

8. The method according to claim 1, characterized in that The first insulation impedance is connected in parallel with a detection circuit, and the detection circuit includes a first resistor and a second resistor connected in series. The first insulation resistance is determined by the following formula: Among them, R p Indicates the first insulation resistance, U n1 Represents the second voltage, U n1 =UU p1 , U is the DC voltage source voltage, U p1 represents the first steady-state voltage, R1 represents the first resistance, R2 represents the second resistance, U _ Indicates the negative half-bridge voltage of the battery system, U + Represents the positive half-bridge voltage of the battery system, in, U p2 represents the second steady-state voltage, The second insulation resistance is determined by the following formula: R n Indicates the second insulation resistance.

9. An insulation detection circuit, characterized in that: The insulation detection circuit includes a first insulation impedance, a second insulation impedance, a DC voltage source, a first control switch, a second control switch, a first resistor and a voltage detection sensor. The positive electrode of the DC voltage source is connected to the input end of the first insulation resistor, the output end of the first insulation resistor is respectively connected to the input end of the second insulation resistor and the first connection end of the first control switch, and the output end of the second insulation resistor is connected to the negative electrode of the DC voltage source; One end of the first resistor is connected to the positive electrode of the DC voltage source and the input end of the voltage detection sensor respectively, the other end of the first resistor is connected to the first connection end of the second control switch, and the second connection end of the second control switch is connected to the second connection end of the first control switch and the first output end of the voltage detection sensor respectively; The control end of the first control switch, the control end of the second control switch and the second output end of the voltage detection sensor are respectively connected to a controller.

10. The insulation detection circuit according to claim 9, characterized in that: The insulation detection circuit further includes a second resistor, One end of the second resistor is connected to the second connection end of the second control switch and the first output end of the voltage detection sensor respectively, and the other end of the second resistor is connected to the second connection end of the first control switch.

11. The insulation detection circuit according to claim 9, characterized in that: The first insulation impedance includes a first insulation resistance and a first capacitance, Among them, one end of the first insulation resistor is connected to one end of the first capacitor and then connected to the positive electrode of the DC voltage source, and the other end of the first insulation resistor is connected to the other end of the first capacitor and then connected to the input end of the second insulation resistor.

12. The insulation detection circuit according to claim 11, characterized in that: The first insulation impedance includes a second insulation resistance and a second capacitance, Among them, one end of the second insulation resistor is connected to one end of the second capacitor and then connected to the other end of the first insulation resistor, and the other end of the second insulation resistor is connected to the other end of the second capacitor and then connected to the negative electrode of the DC voltage source.

13. The insulation detection circuit according to claim 9, characterized in that: The insulation detection circuit also includes an amplification module. The first input end of the amplifying module is connected to one end of the first resistor, the second input end of the amplifying module is connected to the second connection end of the second control switch, and the output end of the amplifying module is connected to the input end of the voltage detection sensor.

14. The insulation detection circuit according to claim 13, characterized in that: The amplification module includes a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a first operational amplifier and a second operational amplifier. Wherein, one end of the third resistor is connected to one end of the first resistor, the other end of the third resistor is respectively connected to one end of the fourth resistor and the negative input end of the first operational amplifier, and the positive input end of the first operational amplifier is respectively connected to the second connection end of the second control switch and the positive input end of the second operational amplifier; The output end of the first operational amplifier is respectively connected to the other end of the fourth resistor and one end of the fifth resistor, the other end of the fifth resistor is respectively connected to one end of the sixth resistor and the negative input end of the second operational amplifier, and the output end of the second operational amplifier is respectively connected to the other end of the sixth resistor and the input end of the voltage detection sensor.

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