Insulation resistance detection circuit and detection method and device thereof

Abstract

The invention provides an insulation resistance detection circuit and a detection method and device thereof. The insulation resistance detection circuit comprises a control unit, an upper bridge arm, a lower bridge arm and a switching bridge, the upper bridge arm is connected between a positive electrode of a circuit to be detected and a ground wire, the lower bridge arm is connected between a negative electrode of the circuit to be detected and the ground wire, the upper bridge arm comprises a first resistor, the lower bridge arm comprises a second resistor, and the resistance value of the first resistor is the same as that of the second resistor; the switching bridge comprises a resistor unit and a switching unit, and the resistor unit is provided with a sampling point used for being connected with the sampling circuit; the switching unit comprises a first switch and a second switch; the control unit is used for controlling the first switch and the second switch in the switching unit, so that the resistor unit is connected with the upper bridge arm or the lower bridge arm in parallel; the sampling circuit is used for sampling a first voltage when the resistor unit is connected with the upper bridge arm in parallel and sampling a second voltage when the resistor unit is connected with the lower bridge arm in parallel; and the control unit is also used for determining the insulation resistance of the circuit to be detected according to the first voltage and the second voltage.

Description

Technical Field

[0001] The present application relates to circuit technology, and in particular to an insulation resistance detection circuit and a detection method and device thereof. Background Art

[0002] When a circuit is working and encounters a circuit fault or an extreme working environment, the circuit energy storage system will increase the probability of leakage fault, which seriously threatens the stability and reliability of the entire circuit. For the safety of equipment and personnel, insulation testing of the circuit is very important.

[0003] At present, most commonly used insulation detection devices are external resistance switching methods. Although this method is simple and effective, it is not suitable for real-time monitoring of circuits, and its insulation resistance performance will be reduced when detecting the insulation resistance state. Summary of the invention

[0004] In view of this, an embodiment of the present application provides an insulation resistance detection circuit and a detection method and device thereof, which can perform real-time insulation detection on a circuit without affecting the insulation resistance performance of the circuit.

[0005] The technical solution of the embodiment of the present application is implemented as follows:

[0006] The embodiment of the present application provides an insulation resistance detection circuit, including: a control unit, an upper bridge arm, a lower bridge arm and a switching bridge, wherein the upper bridge arm is connected between the positive electrode of the circuit to be tested and the ground wire, and the lower bridge arm is connected between the negative electrode of the circuit to be tested and the ground wire, the upper bridge arm includes a first resistor, and the lower bridge arm includes a second resistor, and the resistance value of the first resistor and the second resistor are the same; the switching bridge includes a resistance unit and a switching unit, and the resistance unit is provided with a sampling point for connecting to a sampling circuit; wherein,

[0007] The switching unit includes a first switch and a second switch, the first switch and the second switch are connected in series between the positive electrode and the negative electrode of the circuit to be tested, and the resistance unit is connected between the ground line and the connection line between the first switch and the second switch;

[0008] The control unit is used to control the opening or closing of the first switch and the second switch in the switching unit so that the resistance unit is connected in parallel with the upper bridge arm or in parallel with the lower bridge arm;

[0009] The sampling circuit is used to sample a first voltage at the sampling point when the resistance unit is connected in parallel with the upper bridge arm, and to sample a second voltage at the sampling point when the resistance unit is connected in parallel with the lower bridge arm;

[0010] The control unit is further used to determine the insulation resistance of the circuit to be tested according to the first voltage and the second voltage.

[0011] In the above solution, the resistance unit includes a first resistance unit and a second resistance unit connected in parallel, the first resistance unit includes a third resistor and a third switch connected in series, the first voltage includes a first sub-voltage and a second sub-voltage, and the second voltage includes a third sub-voltage and a fourth sub-voltage;

[0012] The control unit is further used to control the opening or closing of the third switch;

[0013] The sampling circuit is further used for sampling a first sub-voltage of the sampling point when the resistance unit is connected in parallel with the upper bridge arm and the third switch is closed, and sampling a second sub-voltage of the sampling point when the resistance unit is connected in parallel with the upper bridge arm and the third switch is opened; sampling a third sub-voltage of the sampling point when the resistance unit is connected in parallel with the lower bridge arm and the third switch is closed, and sampling a fourth sub-voltage of the sampling point when the resistance unit is connected in parallel with the lower bridge arm and the third switch is opened;

[0014] The second resistor unit includes a fourth resistor and a fifth resistor connected in series, and the sampling point is located on a connection line between the second resistor and the third resistor.

[0015] In the above solution, a fourth switch is further connected in series between the connection line between the resistance unit and the first switch and the second switch;

[0016] The control unit is further used to control the closing or opening of the fourth switch.

[0017] In the above solution, the upper bridge arm further includes a fifth switch connected in series with the first resistor, and the lower bridge arm further includes a sixth switch connected in series with the second resistor;

[0018] The control unit is further used to control the closing or opening of the fifth switch and the sixth switch.

[0019] The present application embodiment provides a detection method based on the insulation resistance detection circuit provided by the present application embodiment, including:

[0020] After controlling the switching unit to connect the resistance unit in parallel with the upper bridge arm, controlling the sampling circuit to sample the sampling point to obtain a first voltage;

[0021] After controlling the switching unit to connect the resistance unit in parallel with the lower bridge arm, controlling the sampling circuit to sample the sampling point to obtain a second voltage;

[0022] The insulation resistance of the circuit to be tested is determined according to the first voltage and the second voltage.

[0023] In the above solution, the control switching unit makes the resistance unit connected in parallel with the upper bridge arm, including:

[0024] Controlling the first switch of the switching unit to close and the second switch to open, so that the resistance unit is connected in parallel with the upper bridge arm;

[0025] The control switching unit connects the resistance unit in parallel with the lower bridge arm, including:

[0026] The first switch of the switching unit is controlled to be opened and the second switch is controlled to be closed, so that the resistance unit is connected in parallel with the lower bridge arm.

[0027] In the above solution, after the control switching unit connects the resistance unit in parallel with the upper bridge arm, the control sampling circuit samples the sampling point to obtain the first voltage, including:

[0028] When the first to sixth switches are all disconnected, the fifth and sixth switches are controlled to be closed, and the fourth switch is controlled to be closed after a delay of the first time;

[0029] After the fourth switch is closed, delaying the second time to control the first switch and the third switch to be closed;

[0030] Delaying for a third time, controlling the sampling circuit to sample the sampling point, and obtaining a first sub-voltage;

[0031] Delaying the fourth time, and controlling the third switch to be disconnected;

[0032] Delaying for a fifth time, controlling the sampling circuit to sample the sampling point, and obtaining a second sub-voltage.

[0033] In the above solution, after the control switching unit connects the resistance unit in parallel with the lower bridge arm, the control sampling circuit samples the sampling point to obtain the second voltage, including:

[0034] Delaying for a sixth time, and controlling the first switch to be disconnected;

[0035] Delaying for a seventh time to control the second switch and the third switch to close;

[0036] Delaying for an eighth time, controlling the sampling circuit to sample the sampling point, and obtaining a third sub-voltage;

[0037] Delaying for a ninth time, and controlling the third switch to be disconnected;

[0038] Delaying for a tenth time, controlling the sampling circuit to sample the sampling point, and obtaining a fourth sub-voltage.

[0039] In the above solution, determining the insulation resistance of the circuit to be tested according to the first voltage and the second voltage includes:

[0040] A first insulation resistance between the positive electrode and the ground wire and a second insulation resistance between the negative electrode and the ground wire of the circuit to be tested are calculated according to the value of the third resistor in the resistance unit, the power supply voltage of the circuit to be tested, the first voltage and the second voltage.

[0041] The embodiment of the present application provides a detection device based on the insulation resistance detection circuit provided in the embodiment of the present application, including:

[0042] A first control module, configured to control a switching unit to connect the resistance unit in parallel with the upper bridge arm, and then control a sampling circuit to sample a sampling point to obtain a first voltage;

[0043] A second control module, configured to control the switching unit to connect the resistance unit in parallel with the lower bridge arm, and then control the sampling circuit to sample the sampling point to obtain a second voltage;

[0044] A determination module is used to determine the insulation resistance of the circuit to be tested according to the first voltage and the second voltage.

[0045] An embodiment of the present application provides an electronic device, including:

[0046] A memory for storing executable instructions;

[0047] The processor is used to implement the detection method of the insulation resistance detection circuit provided in the embodiment of the present application when executing the executable instructions stored in the memory.

[0048] An embodiment of the present application provides a computer-readable storage medium storing executable instructions for causing a processor to execute instructions to implement a detection method for an insulation resistance detection circuit provided in the embodiment of the present application.

[0049] An embodiment of the present application provides a computer program product storing a computer program for implementing the detection method of the insulation resistance detection circuit provided in the embodiment of the present application when executed by a processor.

[0050] The embodiment of the present application performs insulation resistance detection on the circuit to be tested through a balancing bridge (including an upper bridge arm and a lower bridge arm) and a switching bridge. Through the coordinated control of the first switch and the second switch, the resistance unit is switched between being connected in parallel with the upper bridge arm and being connected in parallel with the lower bridge arm, so that the insulation resistance of the circuit to be tested is determined by the first voltage and the second voltage sampled under the two connection modes. The detection mode does not affect the path of the circuit to be tested, and can effectively reduce interference factors such as voltage difference and voltage fluctuation, and does not affect the insulation resistance of the circuit to be tested. It can not only detect two-pole grounding and multi-point grounding faults, but also has high speed and high accuracy, thereby realizing real-time insulation detection of the circuit without affecting the insulation resistance performance of the circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In the drawings, which are not necessarily drawn to scale, the same reference numerals may describe similar components in different views. The same numerals with different letter suffixes may represent different instances of similar components. The drawings generally illustrate various embodiments discussed in this document by way of example and not limitation.

[0052] Figure 1 is an optional structural diagram of an insulation resistance detection circuit provided in an embodiment of the present application;

[0053] Figure 2 is an optional structural diagram of an insulation resistance detection circuit provided in an embodiment of the present application;

[0054] Figure 3 is an optional structural diagram of an insulation resistance detection circuit provided in an embodiment of the present application;

[0055] Figure 4 is an optional structural diagram of an insulation resistance detection circuit provided in an embodiment of the present application;

[0056] Figure 5 is an optional structural diagram of an electronic device 500 provided in an embodiment of the present application;

[0057] Figure 6 It is an optional flow chart of a detection method of an insulation resistance detection circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0058] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings. The described embodiments should not be regarded as limiting the present application. All other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of this application.

[0059] In the following description, reference is made to “some embodiments”, which describe a subset of all possible embodiments, but it will be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0060] In the following description, the terms "first\second\third" involved are merely used to distinguish similar objects and do not represent a specific ordering of the objects. It can be understood that "first\second\third" can be interchanged with a specific order or sequence where permitted, so that the embodiments of the present application described here can be implemented in an order other than that illustrated or described here.

[0061] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

[0062] The embodiments of the present application provide an insulation resistance detection circuit and a detection method and device thereof, which can perform real-time insulation detection on a circuit without affecting the insulation resistance performance of the circuit.

[0063] First, the insulation resistance detection circuit provided in the embodiment of the present application is described. Figure 1 , Figure 1 It is an optional structural diagram of the insulation resistance detection circuit provided in an embodiment of the present application. The insulation resistance detection circuit 100 includes: a control unit (not shown), an upper bridge arm 101, a lower bridge arm 102 and a switching bridge 103, wherein the upper bridge arm 101 is connected between the positive electrode of the circuit to be tested 110 and the ground wire PE, and the lower bridge arm 102 is connected between the negative electrode of the circuit to be tested 110 and the ground wire PE, the upper bridge arm 101 includes a first resistor R1, and the lower bridge arm 102 includes a second resistor R2, and the resistance values ​​of the first resistor R1 and the second resistor R2 are the same; the switching bridge 103 includes a resistance unit 1031 and a switching unit 1032, and a sampling point for connecting to a sampling circuit (not shown) is provided in the resistance unit 1031; wherein the switching unit 1032 includes a first switch K1 and a second switch K2, and the first switch K1 and the second switch K2 are connected in series. The first switch K1 and the second switch K2 are connected between the positive electrode and the negative electrode of the circuit to be tested 110, and the resistance unit 1031 is connected between the ground line PE and the connection line between the first switch K1 and the second switch K2; the control unit is used to control the opening or closing of the first switch K1 and the second switch K2 of the switching unit 1032, so that the resistance unit 1031 is connected in parallel with the upper bridge arm 101 or in parallel with the lower bridge arm 102; the sampling circuit is used to sample the first voltage of the sampling point when the resistance unit 1031 is connected in parallel with the upper bridge arm 101, and to sample the second voltage of the sampling point when the resistance unit 1031 is connected in parallel with the lower bridge arm 102; the control unit is also used to determine the insulation resistance of the circuit to be tested 110 according to the first voltage and the second voltage.

[0064] In the embodiment of the present application, the positive electrode of the circuit to be tested 110 may be the positive electrode of the power supply in the circuit to be tested 110, and the negative electrode of the circuit to be tested 110 may be the negative electrode of its power supply. In one embodiment, the circuit to be tested 110 may be a self-consistent energy intelligent router, which includes a lithium battery, then the positive electrode of the circuit to be tested 110 is the positive electrode of the lithium battery, and the negative electrode of the circuit to be tested 110 is the negative electrode of the lithium battery. The insulation resistance of the circuit to be tested 110 includes a first insulation resistance R connected between the positive electrode and the ground wire PEp And the second insulation resistance R between the negative pole and the ground wire PE n .

[0065] In the embodiment of the present application, the upper bridge arm 101 includes a first resistor R1 (not shown), and the lower bridge arm 102 includes a second resistor R2 (not shown), and the first resistor R1 has the same resistance as the second resistor R2. By using R1 and R2 with equal resistance, the large fluctuation of the bus voltage caused by the switch switching in the insulation resistance detection circuit 100 can be avoided, and the charging and discharging time of the parasitic capacitance and the safety capacitor can be effectively reduced. In actual implementation, a sampling point for connecting to a sampling circuit is provided in the resistance unit 1031. Here, the sampling device can be an analog-to-digital converter (ADC). The ADC samples the voltage of the sampling point of the circuit to be tested 110 through the sampling circuit to obtain a sampled voltage.

[0066] In actual implementation, the first switch K1 and the second switch K2 can both sample MOS tubes. In actual scenarios, the selection of switches in the circuit needs to consider its insulation withstand voltage capability, and the selection of resistors mainly considers accuracy, power and withstand voltage capability. The control unit can control the opening or closing of the first switch K1 in the switching unit 1032, and control the opening or closing of the second switch K2. When the first switch K1 is controlled to be closed and the second switch K2 is controlled to be opened, the resistance unit 1031 is connected in parallel with the upper bridge arm 101. At this time, the sampling circuit can be used to sample the voltage of the sampling point in the resistance unit 1031 to obtain the first voltage. When the first switch K1 is controlled to be opened and the second switch K2 is controlled to be closed, the resistance unit 1031 is connected in parallel with the lower bridge arm 102. At this time, the sampling circuit can be used to sample the voltage of the sampling point in the resistance unit 1031 to obtain the second voltage. After sampling the first voltage and the second voltage, the sampling circuit can send the first voltage and the second voltage to the control unit. The control unit can calculate the insulation resistance of the circuit to be tested 110 according to the first voltage and the second voltage, and the resistance value of the relevant resistor in the resistance unit 1031. In the embodiment of the present application, the first switch K1 and the second switch K2 may be mutually exclusive to avoid the first switch K1 and the second switch K2 being closed at the same time, thereby short-circuiting the power supply of the circuit under test 110 .

[0067] In the embodiment of the present application, the insulation resistance of the circuit to be tested is detected by a balancing bridge (including an upper bridge arm and a lower bridge arm) and a switching bridge. The first switch and the second switch are coordinated and controlled to switch the resistance unit between being connected in parallel with the upper bridge arm and being connected in parallel with the lower bridge arm. The insulation resistance of the circuit to be tested is determined by the first voltage and the second voltage sampled under the two connection modes. The detection mode does not affect the path of the circuit to be tested, and can effectively reduce interference factors such as voltage difference and voltage fluctuation, and does not affect the insulation resistance of the circuit to be tested. It can not only detect two-pole grounding and multi-point grounding faults, but also has fast speed and high accuracy, thereby realizing real-time insulation detection of the circuit without affecting the insulation resistance performance of the circuit.

[0068] In some embodiments, see Figure 2 , Figure 2 It is an optional structural diagram of the insulation resistance detection circuit provided in the embodiment of the present application. The resistance unit 1031 includes a first resistance unit 10311 and a second resistance unit 10312 connected in parallel, the first resistance unit 10311 includes a third resistor R3 and a third switch K3 connected in series, the first voltage includes a first sub-voltage V1 and a second sub-voltage V1′, and the second voltage includes a third sub-voltage V2 and a fourth sub-voltage V2′; the control unit is also used to control the opening or closing of the third switch K3; the sampling circuit is also used to sample the first sub-voltage V1 of the sampling point when the resistance unit 1031 is connected in parallel with the upper bridge arm 101 and the third switch K3 is closed, and the first sub-voltage V1 of the sampling point is sampled when the resistance unit 1031 is connected in parallel with the upper bridge arm 101 and the third switch K3 is closed. The resistance unit 1031 is connected in parallel with the upper bridge arm 101 and the third switch K3 is disconnected, and the second sub-voltage V1′ of the sampling point is sampled; when the resistance unit 1031 is connected in parallel with the lower bridge arm 102 and the third switch K3 is closed, the third sub-voltage V2 of the sampling point is sampled; when the resistance unit 1031 is connected in parallel with the lower bridge arm 102 and the third switch K3 is disconnected, the fourth sub-voltage V2′ of the sampling point is sampled; the second resistance unit 10312 includes a fourth resistor R4 and a fifth resistor R5 connected in series, and the sampling point is set on the connection line between the lower bridge arm 102 and the third resistor R3.

[0069] In actual implementation, the first resistor unit 10311 includes a third resistor R3 and a third switch K3 connected in series. The second resistor unit 10312 includes a fourth resistor R4 and a fifth resistor R5 connected in series. The sampling point is set on the connecting line of the fourth resistor R4 and the fifth resistor R5 for ADC sampling. Here, the fourth resistor R4 and the fifth resistor R5 are ADC front-end voltage-dividing sampling resistors, and the values ​​need to be taken in combination with the sampling voltage of the ADC and the bus voltage range. In one embodiment, the bus voltage can be rated at 750V, ranging between 600V and 900V, and the corresponding total resistance value is between one megohm and more than ten megohms. In the embodiment of the present application, the resistance values ​​of the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4 and the fifth resistor R5 should be appropriately selected, and too small a resistance value is insensitive to changes in insulation resistance.

[0070] In the embodiment of the present application, the control unit can also control the first switch K1 to be closed, the third switch K3 to be closed, and the second switch K2 to be opened, so that the third resistor R3, the fourth resistor R4 and the fifth resistor R5 connected in series are connected to the first insulation resistor R p In parallel, the sampling circuit samples the voltage at the sampling point to obtain the first sub-voltage V1. Then, the third switch K3 is disconnected, and the sampling circuit samples the voltage at the sampling point to obtain the second sub-voltage V1′. Next, the first switch K1 is disconnected, and the second switch K2 and the third switch K3 are closed, so that the third resistor R3, the fourth resistor R4 and the fifth resistor R5 connected in series are connected to the second insulation resistor R n The third switch K3 is connected in parallel, and the sampling circuit samples the voltage at the sampling point to obtain the third sub-voltage V2. Then, the third switch K3 is disconnected, and the sampling circuit samples the voltage at the sampling point to obtain the fourth sub-voltage V2'.

[0071] In actual implementation, the first insulation resistance R is calculated based on the first sub-voltage V1, the second sub-voltage V1′, the third sub-voltage V2, and the fourth sub-voltage V2′. p And the second insulation resistance R n Specifically, the insulation resistance is calculated as follows:

[0072]

[0073] Among them, R′ p and R′ n For R p and R n The value after connecting R3 in parallel. That is, R' p =(R p R3) / (R p +R3), R′ n =(R n R3) / (R n +R3).

[0074] According to the above formula (1), R p and R n The value of is used to obtain the insulation resistance of the circuit to be tested.

[0075] In some embodiments, see Figure 3 , Figure 3 A fourth switch K4 is connected in series between the resistor unit 1031 and the connection line between the first switch K1 and the second switch K2; the control unit is also used to control the closing or opening of the fourth switch K4.

[0076] Here, the fourth switch K4 can be a MOS tube. In actual implementation, the fourth switch K4 connected in series between the resistor unit 1031 and the connection lines of the first switch K1 and the second switch K2 can facilitate circuit delay and conveniently disconnect the resistor unit 1031 from the circuit to avoid damage to the sampling circuit.

[0077] In some embodiments, see Figure 4 , Figure 4 It is an optional structural diagram of the insulation resistance detection circuit provided in an embodiment of the present application. The upper bridge arm 101 further includes a fifth switch K5 connected in series with the first resistor R1, and the lower bridge arm 102 further includes a sixth switch K6 connected in series with the second resistor R2; the control unit is also used to control the closing or opening of the fifth switch K5 and the sixth switch K6.

[0078] Here, the fifth switch K5 and the sixth switch K6 may also be MOS tubes. In actual implementation, the control unit may control the connection and disconnection between the upper bridge arm 101 or the lower bridge arm 102 and the circuit by controlling the closing or opening of the fifth switch K5 and the sixth switch K6, thereby effectively protecting the circuit.

[0079] The electronic device provided in the embodiment of the present application for implementing the detection method of the above insulation resistance detection circuit is described below.

[0080] See also Figure 5 , Figure 5 1 is an optional structural diagram of an electronic device 500 provided in an embodiment of the present application. In the embodiment of the present application, the electronic device 100 is a control unit in the insulation resistance detection circuit 100. In practical applications, the electronic device 100 can be implemented as a microcontroller. Figure 5The electronic device 500 shown includes: at least one processor 501 and a memory 502. The various components in the electronic device 500 are coupled together via a bus system 503. It is understood that the bus system 503 is used to achieve connection and communication between these components. In addition to the data bus, the bus system 503 also includes a power bus, a control bus, and a status signal bus. However, for the sake of clarity, the bus system 503 is not described in detail. Figure 5 Various buses are labeled as bus system 503.

[0081] Processor 501 can be an integrated circuit chip with signal processing capabilities, such as a general-purpose processor, a digital signal processor (DSP), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc., where the general-purpose processor can be a microprocessor or any conventional processor, etc.

[0082] The memory 502 may be removable, non-removable, or a combination thereof. Exemplary hardware devices include solid-state memory, hard disk drives, optical disk drives, etc. The memory 502 may optionally include one or more storage devices that are physically remote from the processor 501.

[0083] The memory 502 includes a volatile memory or a non-volatile memory, and may also include both volatile and non-volatile memories. The non-volatile memory may be a read-only memory (ROM), and the volatile memory may be a random access memory (RAM). The memory 502 described in the embodiments of the present application is intended to include any suitable type of memory.

[0084] In some embodiments, the memory 502 can store data to support various operations. Examples of these data include programs, modules, and data structures, or subsets or supersets thereof. In the embodiment of the present application, the memory 502 stores an operating system 5021 and a detection device 5022 based on an insulation resistance detection circuit; specifically,

[0085] Operating system 5021, including system programs for processing various basic system services and performing hardware-related tasks, such as framework layer, core library layer, driver layer, etc., for implementing various basic services and processing hardware-based tasks;

[0086] In some embodiments, the detection device based on the insulation resistance detection circuit provided in the embodiments of the present application can be implemented in a software manner. Figure 5The detection device 5022 based on the insulation resistance detection circuit stored in the memory 502 is shown, which can be software in the form of a program and a plug-in, including the following software modules: a first control module 50221, a second control module 50222 and a determination module 50223. These modules are logical, so they can be arbitrarily combined or further split according to the functions implemented. The functions of each module will be described below.

[0087] In other embodiments, the detection device based on the insulation resistance detection circuit provided in the embodiment of the present application can be implemented in hardware. As an example, the detection device based on the insulation resistance detection circuit provided in the embodiment of the present application can be a processor in the form of a hardware decoding processor, which is programmed to execute the detection method based on the insulation resistance detection circuit provided in the embodiment of the present application. For example, the processor in the form of a hardware decoding processor can adopt one or more application-specific integrated circuits (ASICs), DSPs, programmable logic devices (PLDs), complex programmable logic devices (CPLDs), field programmable gate arrays (FPGAs) or other electronic components.

[0088] The detection method of the insulation resistance detection circuit provided in the embodiment of the present application will be described below in combination with the exemplary application and implementation of the control unit provided in the embodiment of the present application.

[0089] See also Figure 6 , Figure 6 is an optional flow chart of the detection method of the insulation resistance detection circuit provided in the embodiment of the present application, which will be combined with Figure 6 The steps shown are explained.

[0090] Step 601, controlling the switching unit to connect the resistance unit in parallel with the upper bridge arm, and then controlling the sampling circuit to sample the sampling point to obtain a first voltage;

[0091] Step 602, after controlling the switching unit to connect the resistance unit in parallel with the lower bridge arm, controlling the sampling circuit to sample the sampling point to obtain a second voltage;

[0092] Step 603: Determine the insulation resistance of the circuit to be tested according to the first voltage and the second voltage.

[0093] In actual implementation, the control unit first controls the switching unit to connect the resistance unit in parallel with the upper bridge arm, and then sends a sampling control instruction to the sampling circuit, so that the sampling circuit samples the sampling point to obtain a first voltage. Then, the switching unit is controlled to connect the resistance unit in parallel with the lower bridge arm, and then the sampling circuit is controlled to sample the sampling point to obtain a second voltage. Then, the insulation resistance of the circuit to be tested is calculated based on the first voltage and the second voltage.

[0094] In some embodiments, after the control switching unit connects the resistance unit in parallel with the upper bridge arm, the sampling circuit is controlled to sample the sampling point to obtain the first voltage, including: when the first switch K1 to the sixth switch K6 are all disconnected, the fifth switch K5 and the sixth switch K6 are controlled to be closed, and the fourth switch K4 is controlled to be closed after a first delay; after the fourth switch K4 is closed, the first switch K1 and the third switch K3 are controlled to be closed after a second delay; after a third delay, the sampling circuit is controlled to sample the sampling point to obtain the first sub-voltage V1; after a fourth delay, the third switch K3 is controlled to be disconnected; after a fifth delay, the sampling circuit is controlled to sample the sampling point to obtain the second sub-voltage V1′.

[0095] In actual implementation, the control unit can control the fifth switch K5 and the sixth switch K6 to close when the first switch K1 to the sixth switch K6 are all disconnected, so that the first resistor R1 and the second resistor R2 are connected to the circuit. Then, the fourth switch K4 is controlled to close by delaying the first time. Here, the first time is, for example, 5ms. Then, after the fourth switch K4 is closed, the first switch K1 and the third switch K3 are controlled to close by delaying the second time, so that the resistance unit is connected in parallel with the first insulation resistor. Here, the second time can be, for example, 5ms. Then, the third time is delayed, and the sampling circuit is controlled to sample the sampling point to obtain the first sub-voltage V1. Here, the third time can be, for example, 1500ms. After obtaining the first sub-voltage V1, the fourth time is delayed, the third switch K3 is controlled to be disconnected, so that the third resistor R3 is disconnected from the circuit, and the fifth time is delayed, and the sampling circuit is controlled to sample the sampling point to obtain the second sub-voltage V1′. Here, the fourth time can be 5ms, and the fifth time can be 1500ms. The embodiment of the present application can control the circuit in an orderly manner by delaying the closing of the control switch to avoid the circuit from failing to complete the connection conversion successfully. Through delayed sampling, sampling can be performed after the circuit voltage is stabilized, making the sampled first voltage more accurate.

[0096] In some embodiments, after the control switching unit connects the resistance unit in parallel with the lower bridge arm, the sampling circuit is controlled to sample the sampling point to obtain the second voltage, including: delaying for a sixth time to control the first switch K1 to be disconnected; delaying for a seventh time to control the second switch K2 and the third switch K3 to be closed; delaying for an eighth time to control the sampling circuit to sample the sampling point to obtain the third sub-voltage V2; delaying for a ninth time to control the third switch K3 to be disconnected; delaying for a tenth time to control the sampling circuit to sample the sampling point to obtain the fourth sub-voltage V2′.

[0097] In actual implementation, the sixth time is delayed, and the first switch K1 is controlled to be disconnected, so that the resistance unit is disconnected from the parallel connection with the first insulation resistor. Then, the seventh time is delayed, and the second switch K2 and the third switch K3 are controlled to be closed, so that the resistance unit is connected in parallel with the second insulation resistor. Here, the sixth time and the seventh time can both be 5ms. Then, the eighth time is delayed, and the sampling circuit is controlled to sample the sampling point to obtain the third sub-voltage V2. Here, the eighth time can be 1500ms. Then, the ninth time is delayed, and the third switch K3 is controlled to be disconnected, so that the third resistor R3 is disconnected from the circuit, and the tenth time is delayed, and the sampling circuit is controlled to sample the sampling point to obtain the fourth sub-voltage V2′. Here, the ninth time can be 5ms, and the tenth time can be 1500ms. The sampled second voltage can be made more accurate through delay control.

[0098] In some embodiments, determining the insulation resistance of the circuit to be tested based on the first voltage and the second voltage includes: calculating the first insulation resistance between the positive electrode and the ground wire and the second insulation resistance between the negative electrode and the ground wire PE of the circuit to be tested based on the value of the third resistor R3 in the resistance unit, the power supply voltage of the circuit to be tested, the first voltage and the second voltage.

[0099] In actual implementation, the first insulation resistance and the second insulation resistance can be calculated by the above formula (1), which will not be described in detail here.

[0100] The following further describes an exemplary structure of the detection device 5022 of the insulation resistance detection circuit provided in the embodiment of the present application implemented as a software module. In some embodiments, Figure 1 As shown, the software modules stored in the detection device 5022 of the insulation resistance detection circuit of the memory 502 may include:

[0101] A first control module 50221 is used for controlling the switching unit to connect the resistance unit in parallel with the upper bridge arm, and then controlling the sampling circuit to sample the sampling point to obtain a first voltage;

[0102] A second control module 50222 is used to control the switching unit to connect the resistance unit in parallel with the lower bridge arm, and then control the sampling circuit to sample the sampling point to obtain a second voltage;

[0103] The determination module 50223 is used to determine the insulation resistance of the circuit to be tested according to the first voltage and the second voltage.

[0104] In some embodiments, the first control module 50221 is further used to control the fifth switch K5 and the sixth switch K6 to close when the first switch K1 to the sixth switch K6 are all opened, and delay the first time to control the fourth switch K4 to close; after the fourth switch K4 is closed, delay the second time to control the first switch K1 and the third switch K3 to close; delay the third time to control the sampling circuit to sample the sampling point to obtain the first sub-voltage V1; delay the fourth time to control the third switch K3 to open; delay the fifth time to control the sampling circuit to sample the sampling point to obtain the second sub-voltage V1′.

[0105] In some embodiments, the second control module 50222 is further used to delay for a sixth time to control the first switch K1 to be disconnected; delay for a seventh time to control the second switch K2 and the third switch K3 to be closed; delay for an eighth time to control the sampling circuit to sample the sampling point to obtain the third sub-voltage V2; delay for a ninth time to control the third switch K3 to be disconnected; delay for a tenth time to control the sampling circuit to sample the sampling point to obtain the fourth sub-voltage V2′.

[0106] In some embodiments, the determination module 50223 is also used to calculate the first insulation resistance between the positive electrode and the ground wire of the circuit to be tested and the second insulation resistance between the negative electrode and the ground wire PE based on the value of the third resistor R3 in the resistance unit, the power supply voltage of the circuit to be tested, the first voltage and the second voltage.

[0107] It should be noted that the description of the device of the embodiment of the present application is similar to the description of the above-mentioned method embodiment, and has similar beneficial effects as the method embodiment, so it will not be repeated.

[0108] The embodiment of the present application provides a computer program product, which includes computer instructions, and the computer instructions are stored in a computer-readable storage medium. The processor of the computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computer device executes the detection method of the insulation resistance detection circuit described in the embodiment of the present application.

[0109] An embodiment of the present application provides a computer-readable storage medium storing executable instructions, wherein executable instructions are stored. When the executable instructions are executed by a processor, the processor will execute the detection method of the insulation resistance detection circuit provided in the embodiment of the present application.

[0110] In some embodiments, the computer-readable storage medium may be a memory such as FRAM, ROM, PROM, EPROM, EEPROM, flash memory, magnetic surface storage, optical disk, or CD-ROM; or it may be various devices including one or any combination of the above memories.

[0111] In some embodiments, executable instructions may be in the form of a program, software, software module, script or code, written in any form of programming language (including compiled or interpreted languages, or declarative or procedural languages), and may be deployed in any form, including as a stand-alone program or as a module, component, subroutine or other unit suitable for use in a computing environment.

[0112] As an example, executable instructions may, but do not necessarily, correspond to a file in a file system, may be stored as part of a file that stores other programs or data, for example, in one or more scripts in a HyperText Markup Language (HTML) document, in a single file dedicated to the program in question, or in multiple coordinated files (for example, files storing one or more modules, subroutines, or code portions).

[0113] By way of example, executable instructions may be deployed to be executed on one computing device, or on multiple computing devices located at one site, or on multiple computing devices distributed across multiple sites and interconnected by a communication network.

[0114] In summary, the embodiments of the present application can perform real-time insulation detection on a circuit without affecting the insulation resistance performance of the circuit.

[0115] The above is only an embodiment of the present application and is not intended to limit the protection scope of the present application. Any modifications, equivalent substitutions and improvements made within the spirit and scope of the present application are included in the protection scope of the present application.

Claims

1. An insulation resistance detection circuit, characterized in that: include: A control unit, an upper bridge arm, a lower bridge arm and a switching bridge, wherein the upper bridge arm is connected between the positive electrode of the circuit to be tested and the ground wire, the lower bridge arm is connected between the negative electrode of the circuit to be tested and the ground wire, the upper bridge arm includes a first resistor, the lower bridge arm includes a second resistor, and the resistance value of the first resistor and the second resistor are the same; the switching bridge includes a resistance unit and a switching unit, and the resistance unit is provided with a sampling point for connecting to a sampling circuit; wherein, The switching unit includes a first switch and a second switch, the first switch and the second switch are connected in series between the positive electrode and the negative electrode of the circuit to be tested, and the resistance unit is connected between the ground line and the connection line between the first switch and the second switch; The control unit is used to control the opening or closing of the first switch and the second switch in the switching unit so that the resistance unit is connected in parallel with the upper bridge arm or in parallel with the lower bridge arm; The sampling circuit is used to sample the first voltage of the sampling point when the resistance unit is connected in parallel with the upper bridge arm, and to sample the second voltage of the sampling point when the resistance unit is connected in parallel with the lower bridge arm; The control unit is further used to determine the insulation resistance of the circuit to be tested according to the first voltage and the second voltage.

2. The circuit according to claim 1, characterized in that The resistance unit includes a first resistance unit and a second resistance unit connected in parallel, the first resistance unit includes a third resistor and a third switch connected in series, the first voltage includes a first sub-voltage and a second sub-voltage, and the second voltage includes a third sub-voltage and a fourth sub-voltage; The control unit is further used to control the opening or closing of the third switch; The sampling circuit is further used for sampling a first sub-voltage of the sampling point when the resistance unit is connected in parallel with the upper bridge arm and the third switch is closed, and sampling a second sub-voltage of the sampling point when the resistance unit is connected in parallel with the upper bridge arm and the third switch is opened; sampling a third sub-voltage of the sampling point when the resistance unit is connected in parallel with the lower bridge arm and the third switch is closed, and sampling a fourth sub-voltage of the sampling point when the resistance unit is connected in parallel with the lower bridge arm and the third switch is opened; The second resistor unit includes a fourth resistor and a fifth resistor connected in series, and the sampling point is located on a connection line between the second resistor and the third resistor.

3. The circuit according to claim 1, characterized in that A fourth switch is also connected in series between the resistor unit and the connection line between the first switch and the second switch; The control unit is further used to control the closing or opening of the fourth switch.

4. The circuit according to claim 1, characterized in that The upper bridge arm further includes a fifth switch connected in series with the first resistor, and the lower bridge arm further includes a sixth switch connected in series with the second resistor; The control unit is further used to control the closing or opening of the fifth switch and the sixth switch.

5. A detection method based on the insulation resistance detection circuit according to any one of claims 1 to 4, characterized in that: include: After controlling the switching unit to connect the resistance unit in parallel with the upper bridge arm, controlling the sampling circuit to sample the sampling point to obtain a first voltage; After controlling the switching unit to connect the resistance unit in parallel with the lower bridge arm, controlling the sampling circuit to sample the sampling point to obtain a second voltage; The insulation resistance of the circuit to be tested is determined according to the first voltage and the second voltage.

6. The detection method according to claim 5, characterized in that: The control switching unit connects the resistance unit in parallel with the upper bridge arm, including: Controlling the first switch of the switching unit to close and the second switch to open, so that the resistance unit is connected in parallel with the upper bridge arm; The control switching unit connects the resistance unit in parallel with the lower bridge arm, including: The first switch of the switching unit is controlled to be opened and the second switch is controlled to be closed, so that the resistance unit is connected in parallel with the lower bridge arm.

7. The detection method according to claim 5, characterized in that: After the control switching unit connects the resistance unit in parallel with the upper bridge arm, the control sampling circuit samples the sampling point to obtain the first voltage, including: When the first to sixth switches are all disconnected, the fifth and sixth switches are controlled to be closed, and the fourth switch is controlled to be closed after a delay of the first time; After the fourth switch is closed, delaying the second time to control the first switch and the third switch to be closed; Delaying for a third time, controlling the sampling circuit to sample the sampling point, and obtaining a first sub-voltage; Delaying the fourth time, and controlling the third switch to be disconnected; Delaying for a fifth time, controlling the sampling circuit to sample the sampling point, and obtaining a second sub-voltage.

8. The detection method according to claim 7, characterized in that: After the control switching unit connects the resistance unit in parallel with the lower bridge arm, the control sampling circuit samples the sampling point to obtain the second voltage, including: Delaying for a sixth time, and controlling the first switch to be disconnected; Delaying for a seventh time to control the second switch and the third switch to close; Delaying for an eighth time, controlling the sampling circuit to sample the sampling point, and obtaining a third sub-voltage; Delaying for a ninth time, and controlling the third switch to be disconnected; Delaying for a tenth time, controlling the sampling circuit to sample the sampling point, and obtaining a fourth sub-voltage.

9. The detection method according to claim 5, characterized in that: The step of determining the insulation resistance of the circuit to be tested according to the first voltage and the second voltage includes: A first insulation resistance between the positive electrode and the ground wire and a second insulation resistance between the negative electrode and the ground wire of the circuit to be tested are calculated according to the value of the third resistor in the resistance unit, the power supply voltage of the circuit to be tested, the first voltage and the second voltage.

10. A detection device based on the insulation resistance detection circuit according to any one of claims 1 to 4, characterized in that: include: A first control module, configured to control a switching unit to connect the resistance unit in parallel with the upper bridge arm, and then control a sampling circuit to sample a sampling point to obtain a first voltage; A second control module, configured to control the switching unit to connect the resistance unit in parallel with the lower bridge arm, and then control the sampling circuit to sample the sampling point to obtain a second voltage; A determination module is used to determine the insulation resistance of the circuit to be tested according to the first voltage and the second voltage.

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