Insulation impedance detection circuit, detection method thereof and storage medium

Abstract

The application relates to the field of power electronic detection, and discloses an insulation impedance detection circuit, a detection method thereof and a storage medium, which adopts a single operational amplifier differential amplification circuit and realizes double-channel sampling detection, has few components, simple layout, high reliability, and first establishes a non-coupling ideal model, combines multiple measurement working conditions of the insulation impedance detection circuit, determines a non-coupling ideal relationship of the ground insulation impedance under an ideal condition, and then carries out decoupling calculation through a coupling mapping matrix, actual sampling voltages under various measurement working conditions and the non-coupling ideal relationship, that is, the influence of coupling factors in the detection process is considered, effective correction of ideal sampling voltages in the non-coupling ideal relationship is realized, the sampling coupling effect introduced by the common ground of the operational amplifier is eliminated in principle, and high-precision insulation impedance measurement can be realized under the premise of controlling the cost of the control circuit, keeping the circuit simple and facilitating integration.

Description

Technical Field

[0001] This invention relates to the field of power electronics testing, and in particular to an insulation impedance testing circuit, its testing method, and a storage medium. Background Technology

[0002] In high-voltage DC systems such as electric vehicles and energy storage power stations, the insulation performance between the DC bus and the vehicle chassis directly affects personal safety and normal equipment operation. Therefore, insulation impedance detection is a key technology to ensure system safety. In applications where multiple operational amplifiers share a power supply, existing technologies assume that each sampling channel is independent. However, based on circuit theory analysis, the two sampling operational amplifiers are coupled to ground at their output terminals and have negative feedback loops, resulting in coupling loops between both in-phase and out-of-phase operational amplifiers. This coupling effect means that the output signal of each operational amplifier not only contains the measured information of its own branch but also interference components from other branches. If the coupling components are ignored, systematic deviations will occur under high-precision measurement requirements. To solve this problem, hardware isolation solutions (such as optocouplers and isolated operational amplifiers) are currently used to cut off the coupling path, but this significantly increases hardware costs, PCB size, and design complexity. Summary of the Invention

[0003] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, this invention proposes an insulation impedance detection circuit, its detection method, and a storage medium, which can achieve high-precision insulation impedance measurement while controlling circuit cost, maintaining circuit simplicity, and facilitating integration.

[0004] In a first aspect, embodiments of the present invention provide an insulation impedance detection circuit, comprising: The first detection branch has one end connected to the positive bus and the other end connected to the grounding point. The first detection branch includes a first switch, a first sampling resistor, and a first ground bridge arm resistor group connected in series. The second detection branch has one end connected to the negative busbar and the other end connected to the grounding point. The second detection branch includes a second switch, a second sampling resistor, and a second ground bridge arm resistor group connected in series for voltage division. The first differential sampling unit includes a first operational amplifier, the input terminal of which is connected in parallel across the first sampling resistor; The second differential sampling unit includes a second operational amplifier, the input terminal of which is connected in parallel across the second sampling resistor; The first differential sampling unit and the second differential sampling unit are both connected to the reference ground.

[0005] Optionally, in one embodiment of the present invention, the first sampling resistor and the second sampling resistor have the same resistance value, and the first ground bridge arm resistor group and the second ground bridge arm resistor group have the same resistance value.

[0006] Secondly, embodiments of the present invention provide a detection method for the insulation impedance detection circuit as described in the first aspect, comprising the following steps: Step S1: Determine the uncoupled ideal relationship based on the pre-constructed uncoupled ideal model and multiple measurement conditions of the insulation impedance detection circuit; Each of the measurement conditions corresponds to one of the open / closed states of the first switch and the second switch. The uncoupled ideal relationship characterizes the numerical correlation between the insulation impedance to ground of the insulation impedance detection circuit and the ideal sampling voltage corresponding to each of the measurement conditions. Step S2: Determine the coupling mapping matrix based on the ideal sampling voltage and the obtained simulated sampling voltage under each of the measurement conditions; Step S3: Based on the coupling mapping matrix and the actual sampling voltage under each measurement condition, and the uncoupled ideal relationship, perform decoupling calculation to obtain the measured value of the ground insulation impedance.

[0007] Optionally, in one embodiment of the present invention, step S3 includes the following steps: Step S31: Based on the coupling mapping matrix and the actual sampling voltage under each measurement condition, correct the ideal sampling voltage to obtain the sampling voltage correction value; Step S32: Replace the ideal sampling voltage with the sampling voltage correction value and substitute it into the uncoupled ideal relationship to calculate the measured value of the ground insulation impedance.

[0008] Optionally, in one embodiment of the present invention, the measurement conditions include a first measurement condition, a second measurement condition, and a third measurement condition, wherein the first measurement condition corresponds to both the first switch and the second switch being closed, the second measurement condition corresponds to the first switch being closed and the second switch being open, and the third measurement condition corresponds to the first switch being open and the second switch being closed; Step S1 includes the following steps: Step S11: Based on the first measurement condition and the first sampling resistor and the first ground bridge arm resistor group, determine the numerical correlation between the DC bus voltage of the insulation impedance detection circuit and the first ideal sampling voltage, wherein the first ideal sampling voltage is the ideal sampling voltage corresponding to the first measurement condition. Step S12: Determine the second ideal sampling voltage based on the DC bus voltage and the second measurement condition, and determine the third ideal sampling voltage based on the DC bus voltage and the third measurement condition, wherein the second ideal sampling voltage is the ideal sampling voltage corresponding to the second measurement condition, and the third ideal sampling voltage is the ideal sampling voltage corresponding to the third measurement condition; Step S13: Determine the uncoupled ideal relationship based on the numerical correlation between the DC bus voltage and the first ideal sampling voltage, the second ideal sampling voltage, and the third ideal sampling voltage.

[0009] Optionally, in one embodiment of the present invention, the ground insulation impedance includes the positive terminal to ground insulation impedance and the negative terminal to ground insulation impedance, and the uncoupled ideal relationship is as follows: ; in, The positive electrode's insulation resistance to ground is [value missing]. The insulation resistance of the negative terminal to ground is [value missing]. The first ideal sampling voltage corresponds to the first sampling resistor. The first ideal sampling voltage corresponding to the second sampling resistor. The second ideal sampling voltage corresponds to the first sampling resistor. The third ideal sampling voltage corresponds to the second sampling resistor. The first sampling resistor, This is the first pair of ground bridge arm resistor groups.

[0010] Optionally, in one embodiment of the present invention, the coupling mapping matrix includes a first coupling mapping matrix, a second coupling mapping matrix, and a third coupling mapping matrix, and step S2 includes the following steps: Step S21: Based on the correspondence between the first ideal sampling voltage and the obtained simulated sampling voltage under the first measurement condition, determine the first coupling mapping matrix; based on the correspondence between the second ideal sampling voltage and the obtained simulated sampling voltage under the second measurement condition, determine the second coupling mapping matrix; and based on the correspondence between the third ideal sampling voltage and the obtained simulated sampling voltage under the third measurement condition, determine the third coupling mapping matrix.

[0011] Optionally, in one embodiment of the present invention, the first coupling mapping matrix, the second coupling mapping matrix, and the third coupling mapping matrix are as follows: ; ; ; in, This is a simulated sampling voltage of the first sampling resistor under the first measurement condition. This is another simulated sampling voltage of the first sampling resistor under the first measurement condition. The second sampling resistor corresponds to The simulated sampling voltage, The second sampling resistor corresponds to The simulated sampling voltage; For corresponding The first ideal sampling voltage, For corresponding The first ideal sampling voltage, For corresponding The first ideal sampling voltage, For corresponding The first ideal sampling voltage; The simulated sampling voltage of the first sampling resistor under the second measurement condition. The simulated sampling voltage of the second sampling resistor under the second measurement condition. For corresponding The second ideal sampling voltage; The simulated sampling voltage of the first sampling resistor under the third measurement condition. The simulated sampling voltage of the second sampling resistor under the third measurement condition. For corresponding The third ideal sampling voltage.

[0012] Thirdly, embodiments of the present invention provide an electronic device, characterized in that it includes: At least one processor; At least one memory for storing at least one program; When at least one of the programs is executed by at least one of the processors, the detection method of the insulation resistance detection circuit as described in the second aspect is implemented.

[0013] Fourthly, embodiments of the present invention provide a computer-readable storage medium storing a processor-executable program, which, when executed by a processor, is used to implement the detection method of the insulation impedance detection circuit as described in the second aspect.

[0014] This invention proposes an insulation impedance detection circuit, its detection method, and a storage medium. It employs a single operational amplifier differential amplifier circuit and achieves dual-channel sampling detection. It features fewer components, a simpler layout, and higher reliability. In particular, it first establishes an uncoupled ideal model and, combined with multiple measurement conditions of the insulation impedance detection circuit, determines the uncoupled ideal relationship of the insulation impedance to ground under ideal conditions. Then, it performs decoupling calculations by combining the actual sampling voltage under each measurement condition with the uncoupled ideal relationship through a coupling mapping matrix. This considers the influence of coupling factors during the detection process and effectively corrects the ideal sampling voltage in the uncoupled ideal relationship, effectively eliminating the sampling coupling effect introduced by the operational amplifier's common ground. The entire process avoids complex theoretical derivations, considers all non-ideal factors, requires no hardware isolation devices, and achieves high-precision measurement solely through algorithm correction. It combines cost and performance advantages, thus enabling high-precision insulation impedance measurement while controlling circuit cost, maintaining circuit simplicity, and facilitating integration. Attached Figure Description

[0015] Figure 1 This is a schematic block diagram of an insulation resistance detection circuit provided in an embodiment of the present invention; Figure 2 This is a circuit topology schematic diagram of an insulation resistance detection circuit provided in an embodiment of the present invention; Figure 3 This is a flowchart of a detection method for an insulation resistance detection circuit provided in an embodiment of the present invention; Figure 4(a) is an equivalent ideal circuit diagram of the insulation impedance detection circuit provided in an embodiment of the present invention under the first measurement condition; Figure 4(b) is an equivalent ideal circuit diagram of the insulation impedance detection circuit provided in an embodiment of the present invention under the second measurement condition; Figure 4(c) is an equivalent ideal circuit diagram of the insulation impedance detection circuit provided in an embodiment of the present invention under the third measurement condition; Figure 5 yes Figure 3 The flowchart of step S1 in the process; Figure 6 This is a schematic diagram of the equivalent coupling circuit of an insulation impedance detection circuit provided in an embodiment of the present invention; Figure 7 yes Figure 3 The flowchart of step S3 in the process; Figure 8 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0017] It should be noted that although functional modules are divided in the device schematic diagram and the logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the device or the order in the flowchart.

[0018] Figure 1 This is a schematic block diagram of an insulation resistance detection circuit provided in an embodiment of the present invention. Figure 2 The circuit topology diagram of an insulation impedance detection circuit provided in an embodiment of the present invention is shown.

[0019] like Figure 1 and Figure 2 As shown, the insulation resistance detection circuit may include, but is not limited to: The first detection branch 100 is connected at one end to the positive bus and at the other end to the grounding point PE. The first detection branch 100 includes a first switch K1, a first sampling resistor Rs2 and a first ground bridge arm resistor group connected in series for voltage division. The second detection branch 200 is connected to the negative busbar at one end and to the grounding point PE at the other end. The second detection branch 200 includes a second switch K2, a second sampling resistor Rs5 and a second ground bridge arm resistor group connected in series for voltage division. The first differential sampling unit 300 includes a first operational amplifier U1, the input terminal of which is connected in parallel across the first sampling resistor Rs2; The second differential sampling unit 400 includes a second operational amplifier U2, the input terminal of which is connected in parallel across the second sampling resistor Rs5; The first differential sampling unit 300 and the second differential sampling unit 400 are both connected to the reference ground GND1.

[0020] Specifically, such as Figure 2 As shown, the first detection branch 100 is: positive bus P—first resistor Rs1—first switch K1—first sampling resistor Rs2—third resistor Rs3—grounding point PE; the second detection branch 200 is: negative bus N—sixth resistor Rs6—second switch K2—second sampling resistor Rs5—fourth resistor Rs4—grounding point PE; the first differential sampling unit 300 has a seventh resistor Rs7 at the non-inverting input terminal and an eighth resistor Rs8 at the inverting input terminal. The non-inverting input terminal is also connected to the reference ground GND1 through a ninth resistor Rs9, and the inverting input terminal is also connected to its output terminal through a tenth resistor Rs10. Its output terminal is used to output the sampling signal. The second differential sampling unit 400 has the same structure as the first differential sampling unit 300, and will not be described in detail here.

[0021] In one embodiment, such as Figure 1 and Figure 2 As shown, the insulation impedance detection circuit may also include, but is not limited to, a power supply unit 500, which is connected to the first differential sampling unit 300 and the second differential sampling unit 400 respectively to provide power; and a high-voltage DC system, which is connected to the positive and negative busbars respectively, and may, but is not limited to, adopt... Figure 2 The battery module BT1 shown is shown.

[0022] In one embodiment, the first sampling resistor Rs2 and the second sampling resistor Rs5 have the same resistance value, and the first ground bridge arm resistor group and the second ground bridge arm resistor group have the same resistance value, wherein, reference Figure 1 and Figure 2 The first pair of ground bridge arm resistors is the sum of all voltage divider resistors in the first detection branch 100, that is... Similarly, the second pair of ground bridge arm resistors is... .

[0023] It will be understood by those skilled in the art that Figure 1 or Figure 2 The insulation resistance detection circuit shown does not constitute a limitation on the embodiments of the present invention. It may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0024] Based on the structure of the insulation impedance detection circuit shown above, various embodiments of the detection method of the insulation impedance detection circuit of the present invention are proposed, and the variable definitions used in the following embodiments are given: Sampling resistor value ; First ground-to-bridge arm resistor group / Second ground-to-bridge arm resistor group ; Positive electrode to ground insulation resistance ; Negative electrode insulation resistance to ground .

[0025] like Figure 3 As shown, a detection method for an insulation resistance detection circuit is described. This insulation resistance detection circuit can be applied to, but is not limited to, applications... Figure 1 or Figure 2 The insulation impedance detection circuit shown may include, but is not limited to, steps S1 to S3. The execution entity of this method can be configured according to different scenarios, for example, referring to... Figure 1 It is implemented using an MCU with built-in storage media.

[0026] Step S1: Determine the uncoupled ideal relationship based on the pre-constructed uncoupled ideal model and multiple measurement conditions of the insulation impedance detection circuit; Each measurement condition corresponds to one of the open or closed states of the first switch and the second switch. The uncoupled ideal relationship characterizes the numerical correlation between the insulation impedance to ground of the insulation impedance detection circuit and the ideal sampling voltage corresponding to each measurement condition. Step S2: Determine the coupling mapping matrix based on the ideal sampling voltage and the simulated sampling voltages obtained under various measurement conditions; Step S3: Based on the coupling mapping matrix and the actual sampling voltage under each measurement condition, and the uncoupled ideal relationship, perform decoupling calculations to obtain the measured value of the insulation impedance to ground.

[0027] In this step, a single operational amplifier differential amplifier circuit is used to achieve dual-channel sampling and detection. This method has fewer components, a simpler layout, and higher reliability. In particular, an uncoupled ideal model is first established and combined with multiple measurement conditions of the insulation impedance detection circuit to determine the uncoupled ideal relationship of the insulation impedance to ground under ideal conditions. Then, a decoupling calculation is performed by combining the actual sampling voltage under each measurement condition and the uncoupled ideal relationship through a coupling mapping matrix. This takes into account the influence of coupling factors in the detection process and achieves effective correction of the ideal sampling voltage in the uncoupled ideal relationship. This is equivalent to eliminating the sampling coupling effect introduced by the common ground of the operational amplifier in principle. The whole process avoids complex theoretical derivation, considers all non-ideal factors, does not require hardware isolation devices, and achieves high-precision measurement only through algorithm correction. It has both cost and performance advantages. Therefore, it can achieve high-precision insulation impedance measurement while controlling circuit cost, keeping the circuit simple and easy to integrate.

[0028] In one embodiment, the measurement conditions may include, but are not limited to, a first measurement condition (referred to as condition A in the following embodiments), a second measurement condition (referred to as condition B in the following embodiments), and a third measurement condition (referred to as condition C in the following embodiments). As shown in FIG4(a), condition A corresponds to both the first and second switches being closed, and the ideal sampling voltage is... , As shown in Figure 4(b), operating condition B corresponds to the first switch being closed and the second switch being open. At this time, there is no current in the second detection branch. The ideal sampling voltage is 0. As shown in Figure 4(c), operating condition C corresponds to the first switch being open and the second switch being closed. At this time, there is no current in the first detection branch. The ideal sampling voltage is 0. .

[0029] like Figure 5 As shown, in one embodiment of the present invention, step S1 may include, but is not limited to, the following steps: Step S11: Based on the first measurement condition and the first sampling resistor and the first ground bridge arm resistor group, determine the numerical correlation between the DC bus voltage of the insulation impedance detection circuit and the first ideal sampling voltage, wherein the first ideal sampling voltage is the ideal sampling voltage corresponding to the first measurement condition. Step S12: Determine the second ideal sampling voltage based on the DC bus voltage and the second measurement condition, and determine the third ideal sampling voltage based on the DC bus voltage and the third measurement condition, wherein the second ideal sampling voltage is the ideal sampling voltage corresponding to the second measurement condition, and the third ideal sampling voltage is the ideal sampling voltage corresponding to the third measurement condition. Step S13: Determine the uncoupled ideal relationship based on the numerical correlation between the DC bus voltage and the first ideal sampling voltage, the second ideal sampling voltage, and the third ideal sampling voltage.

[0030] Specifically, combining Figures 4(a), 4(b), and 4(c), the following relationship can be derived based on the fundamental theorems of circuits: Operating condition A, DC bus voltage for: ; Operating Condition B: ; Operating Condition C: ; Combining the above equations, we can obtain the uncoupled ideal relation as follows: ; in, The first ideal sampling voltage corresponds to the first sampling resistor. The first ideal sampling voltage corresponds to the second sampling resistor. The second ideal sampling voltage corresponds to the first sampling resistor. This is the third ideal sampling voltage corresponding to the second sampling resistor.

[0031] In one embodiment of the present invention, since the coupling effect exhibits different behaviors under each measurement condition (i.e., different switching states correspond to different circuit topologies), independent coupling mapping matrices are defined for conditions A, B, and C respectively. , and ,Right now ; ; .

[0032] Based on this, step S2 may include, but is not limited to, the following steps: Step S21: Based on the correspondence between the first ideal sampling voltage and the obtained simulated sampling voltage under the first measurement condition, determine the first coupling mapping matrix; based on the correspondence between the second ideal sampling voltage and the obtained simulated sampling voltage under the second measurement condition, determine the second coupling mapping matrix; and based on the correspondence between the third ideal sampling voltage and the obtained simulated sampling voltage under the third measurement condition, determine the third coupling mapping matrix.

[0033] Specifically, such as Figure 6 As shown, the operational amplifier in each differential sampling unit is considered an ideal operational amplifier and is equivalently represented using a voltage-controlled voltage source (VCVS) model. Due to the coupling path, the ideal sampling output signal becomes a linear combination of the two signals output by the actual operational amplifier. Under various operating conditions, the relationship between the actual sampling voltage and the ideal sampling voltage is as follows: ; The ideal sampling voltage on the left can be obtained through theoretical calculation without considering operational amplifier coupling, while the actual sampling voltage on the right can be obtained through hardware simulation or actual measurement. Taking the simulated sampling voltage as an example, firstly, based on the actual circuit parameters of the insulation impedance detection circuit, a simulation model completely consistent with the insulation impedance detection circuit is established in the circuit simulation software. This part is well known to those skilled in the art and will not be elaborated upon. Then, the following steps are determined: , and Generally speaking, determine and All that is needed is a set of simulation data. At least two sets of simulation data are required; For operating condition B, The value is 0. Combining this with the above uncoupled ideal relation, we can obtain... ; Therefore, we can obtain ; From the symmetry of the circuit, we can obtain Thus determine for: ; For operating condition C, Since it is 0, and combining with the above uncoupled ideal relation, we can similarly obtain, ; From the symmetry of the circuit, we can obtain Thus determine for: ; For operating condition A, two sets of simulated sampling voltages were collected. , , and (corresponding to different) , (Combined), by solving the system of linear equations, we can obtain: ; in, This is a simulated sampling voltage of the first sampling resistor under the first measurement condition. This is another simulated sampling voltage of the first sampling resistor under the first measurement condition. The second sampling resistor corresponds to The simulated sampling voltage, The second sampling resistor corresponds to The simulated sampling voltage; For corresponding The first ideal sampling voltage, For corresponding The first ideal sampling voltage, For corresponding The first ideal sampling voltage, For corresponding The first ideal sampling voltage; The simulated sampling voltage of the first sampling resistor under the second measurement condition. The second sampling resistor represents the simulated sampling voltage under the second measurement condition. For corresponding The second ideal sampling voltage; This represents the simulated sampling voltage of the first sampling resistor under the third measurement condition. This is the simulated sampling voltage of the second sampling resistor under the third measurement condition. For corresponding The third ideal sampling voltage.

[0034] It should be noted that the simulated sampling voltages in the above embodiments are all based on known voltages. , and DC bus voltage The simulation is performed, for example, but not limited to, using relevant historical voltage data for simulation. Obviously, the historical voltage data corresponds to... , and It is known and clearly defined.

[0035] like Figure 7 As shown, in one embodiment of the present invention, step S3 may include, but is not limited to, the following steps: Step S31: Based on the coupling mapping matrix and the actual sampling voltage under each measurement condition, correct the ideal sampling voltage to obtain the corrected sampling voltage value. Step S32: Replace the ideal sampling voltage with the sampling voltage correction value and substitute it into the uncoupled ideal relationship to calculate the measured value of the insulation impedance to ground.

[0036] In this step, after calculating the corresponding coupling mapping matrix based on specific measurement conditions, the ideal sampling voltage can be corrected by combining the coupling mapping matrix with the actual sampling voltage under each measurement condition. Then, the corrected sampling voltage value is used to replace the ideal sampling voltage and is substituted into the uncoupled ideal relationship for solution. This yields an accurate measurement value of the insulation impedance to ground. Overall, this avoids complex theoretical derivation, facilitates effective application, and can be directly used for product development, significantly reducing development difficulty.

[0037] Specifically, firstly, the actual sampling voltages corresponding to operating conditions A, B, and C are measured respectively; then, the voltages determined in the above embodiments are identified respectively. , and Finally, the ideal sampling voltage is corrected based on the actual sampling voltage under each operating condition. ; ; ; Thus, the corresponding sampled voltage correction value is obtained; Finally, the ideal sampling voltage is replaced with the corrected sampling voltage value, and then substituted into the uncoupled ideal relation for calculation to obtain the result. , The measured value.

[0038] Figure 8 This is a schematic diagram of the structure of an electronic device 1000 provided in an embodiment of the present invention. For example... Figure 8 As shown, the electronic device 1000 includes a memory 1100 and a processor 1200. The number of memories 1100 and processors 1200 can be one or more. Figure 8 Taking a memory 1100 and a processor 1200 as an example; the memory 1100 and the processor 1200 in the device can be connected via a bus or other means. Figure 8 Taking the example of a connection between China and Israel via a bus.

[0039] The memory 1100, as a computer-readable storage medium, can be used to store software programs, computer-executable programs, and modules, such as the program instructions / modules corresponding to the detection method of the insulation impedance detection circuit provided in any embodiment of the present invention. The processor 1200 implements the above-mentioned detection method of the insulation impedance detection circuit by running the software programs, instructions, and modules stored in the memory 1100.

[0040] The memory 1100 may primarily include a program storage area and a data storage area, wherein the program storage area may store the operating system and application programs required for at least one function. Furthermore, the memory 1100 may include high-speed random access memory and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other non-volatile solid-state storage device. In some instances, the memory 1100 may further include memory remotely located relative to the processor 1200, and these remote memories can be connected to the device via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0041] An embodiment of the present invention also provides a computer-readable storage medium storing computer-executable instructions for performing a detection method of an insulation impedance detection circuit as provided in any embodiment of the present invention.

[0042] An embodiment of the present invention also provides a computer program product, including a computer program or computer instructions, which are stored in a computer-readable storage medium. A processor of a computer device reads the computer program or computer instructions from the computer-readable storage medium and executes the computer program or computer instructions, causing the computer device to perform a detection method for an insulation impedance detection circuit as provided in any embodiment of the present invention.

[0043] The electronic devices and application scenarios described in the embodiments of this invention are for the purpose of more clearly illustrating the technical solutions of the embodiments of this invention, and do not constitute a limitation on the technical solutions provided by the embodiments of this invention. As those skilled in the art will know, with the evolution of electronic devices and the emergence of new application scenarios, the technical solutions provided by the embodiments of this invention are also applicable to similar technical problems.

[0044] Those skilled in the art will understand that all or some of the steps in the methods disclosed above, as well as the functional modules / units in the systems and devices, can be implemented as software, firmware, hardware, or suitable combinations thereof.

[0045] In hardware implementations, the division between functional modules / units mentioned in the above description does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed collaboratively by several physical components. Some or all physical components may be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, as is known to those skilled in the art, communication media typically contain computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

[0046] The terms “component,” “module,” “system,” etc., used in this specification are used to refer to computer-related entities, hardware, firmware, combinations of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, an execution thread, a program, or a computer. As illustrated, applications running on computing devices and computing devices can both be components. One or more components may reside in a process or execution thread, and components may be located on a single computer or distributed among two or more computers. Furthermore, these components can be executed from various computer-readable media on which various data structures are stored. Components can communicate, for example, via local or remote processes based on signals having one or more data packets (e.g., data from two components interacting with another component between a local system, a distributed system, or a network, such as the Internet interacting with other systems via signals).

Claims

1. A detection method of an insulation impedance detection circuit, characterized by, The insulation impedance detection circuit includes: a first detection branch, one end connected to the positive busbar and the other end connected to a grounding point, wherein the first detection branch includes a first switch, a first sampling resistor, and a first ground bridge arm resistor group connected in series; a second detection branch, one end connected to the negative busbar and the other end connected to a grounding point, wherein the second detection branch includes a second switch, a second sampling resistor, and a second ground bridge arm resistor group connected in series; a first differential sampling unit, including a first operational amplifier, the input terminal of the first operational amplifier being connected in parallel across the first sampling resistor; a second differential sampling unit, including a second operational amplifier, the input terminal of the second operational amplifier being connected in parallel across the second sampling resistor; the first differential sampling unit and the second differential sampling unit are connected to a reference ground; the first sampling resistor and the second sampling resistor have the same resistance value, and the first ground bridge arm resistor group and the second ground bridge arm resistor group have the same resistance value; The method includes the following steps: Step S1: Determine the uncoupled ideal relationship based on the pre-constructed uncoupled ideal model and multiple measurement conditions of the insulation impedance detection circuit; Each of the measurement conditions corresponds to one of the open / closed states of the first switch and the second switch. The uncoupled ideal relationship characterizes the numerical correlation between the insulation impedance to ground of the insulation impedance detection circuit and the ideal sampling voltage corresponding to each of the measurement conditions. Step S2: Determine the coupling mapping matrix based on the ideal sampling voltage and the obtained simulated sampling voltage under each of the measurement conditions; Step S3: Based on the coupling mapping matrix and the actual sampling voltage under each measurement condition, and the uncoupled ideal relationship, perform decoupling calculation to obtain the measured value of the ground insulation impedance; The measurement conditions include a first measurement condition, a second measurement condition, and a third measurement condition. The first measurement condition corresponds to both the first switch and the second switch being closed. The second measurement condition corresponds to the first switch being closed and the second switch being open. The third measurement condition corresponds to the first switch being open and the second switch being closed. Step S1 includes the following steps: Step S11: Based on the first measurement condition and the first sampling resistor and the first ground bridge arm resistor group, determine the numerical correlation between the DC bus voltage of the insulation impedance detection circuit and the first ideal sampling voltage, wherein the first ideal sampling voltage is the ideal sampling voltage corresponding to the first measurement condition. Step S12: Determine the second ideal sampling voltage based on the DC bus voltage and the second measurement condition, and determine the third ideal sampling voltage based on the DC bus voltage and the third measurement condition, wherein the second ideal sampling voltage is the ideal sampling voltage corresponding to the second measurement condition, and the third ideal sampling voltage is the ideal sampling voltage corresponding to the third measurement condition; Step S13: Determine the uncoupled ideal relationship based on the numerical correlation between the DC bus voltage and the first ideal sampling voltage, the second ideal sampling voltage, and the third ideal sampling voltage; The ground insulation impedance includes the positive terminal ground insulation impedance and the negative terminal ground insulation impedance, and the uncoupled ideal relationship is as follows: ； wherein, is the positive electrode-to-ground insulation impedance, is the negative electrode-to-ground insulation impedance, is the first ideal sampling voltage corresponding to the first sampling resistor, is the first ideal sampling voltage corresponding to the second sampling resistor, is the second ideal sampling voltage corresponding to the first sampling resistor, is the third ideal sampling voltage corresponding to the second sampling resistor, is the first sampling resistor, is the first ground bridge arm resistor group; The coupling mapping matrix includes a first coupling mapping matrix, a second coupling mapping matrix, and a third coupling mapping matrix. Step S2 includes the following steps: Step S21: Based on the correspondence between the first ideal sampling voltage and the obtained simulated sampling voltage under the first measurement condition, determine the first coupling mapping matrix; based on the correspondence between the second ideal sampling voltage and the obtained simulated sampling voltage under the second measurement condition, determine the second coupling mapping matrix; based on the correspondence between the third ideal sampling voltage and the obtained simulated sampling voltage under the third measurement condition, determine the third coupling mapping matrix. The first coupling mapping matrix, the second coupling mapping matrix, and the third coupling mapping matrix are shown below: ； ； ； in, This is a simulated sampling voltage of the first sampling resistor under the first measurement condition. This is another simulated sampling voltage of the first sampling resistor under the first measurement condition. The second sampling resistor corresponds to The simulated sampling voltage, The second sampling resistor corresponds to The simulated sampling voltage; For corresponding The first ideal sampling voltage, For corresponding The first ideal sampling voltage, For corresponding The first ideal sampling voltage, For corresponding The first ideal sampling voltage; The simulated sampling voltage of the first sampling resistor under the second measurement condition. The simulated sampling voltage of the second sampling resistor under the second measurement condition. For corresponding The second ideal sampling voltage; The simulated sampling voltage of the first sampling resistor under the third measurement condition. The simulated sampling voltage of the second sampling resistor under the third measurement condition. For corresponding The third ideal sampling voltage.

2. The detection method according to claim 1, characterized in that, Step S3 includes the following steps: Step S31: Based on the coupling mapping matrix and the actual sampling voltage under each measurement condition, correct the ideal sampling voltage to obtain the corrected sampling voltage value; Step S32: Replace the ideal sampling voltage with the sampling voltage correction value and substitute it into the uncoupled ideal relationship to calculate the measured value of the ground insulation impedance.

3. An electronic device, characterized in that, include: At least one processor; At least one memory for storing at least one program; The detection method of the insulation resistance detection circuit as described in claim 1 or 2 is implemented when at least one of the programs is executed by at least one of the processors.

4. A computer-readable storage medium, characterized in that, It stores a processor-executable program, which, when executed by the processor, is used to implement the detection method of the insulation impedance detection circuit as described in claim 1 or 2.

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