Insulation detection circuit

Abstract

The utility model relates to the technical field of safety detection, in particular to an insulation detection circuit, which comprises an equivalent insulation load module of which the first end is connected with the anode of an external power supply end, the second end is connected with the cathode of the external power supply end, and the third end is grounded; the first end of the insulation detection module is connected with the anode of the external power supply end, the second end is connected with the cathode of the external power supply end, and the third end is grounded for detecting the resistance value of the equivalent insulation load module; the grounding switch is arranged between the third end of the insulation detection module and the ground end; the first diagnosis module comprises a first load element, a second load element and a second detection module, the first load element and the second load element are connected in series, the second detection module is used for measuring a voltage value between the first load element and the second load element, one end of the first diagnosis module is grounded, and the other end is connected with a cathode of an external power supply end or an anode of the external power supply end. According to the utility model, the effectiveness of the grounding switch in the insulation circuit can be detected, thereby improving the safety.

Description

Technical Field

[0001] The utility model relates to the technical field of safety detection, in particular to an insulation detection circuit. Background Art

[0002] In the high-voltage battery system of electric vehicles, the stability and reliability of insulation testing are very important. Under normal conditions, the positive and negative busbars of the battery system have good insulation performance with the vehicle body or the shell of the equipment. However, due to aging, moisture, corrosion and other problems, the insulation is damaged, affecting the safety of passengers and operators. Therefore, in the insulation testing of such high-voltage battery systems, it is particularly important to test the functional stability and reliability of the insulation components.

[0003] However, the current battery management system (BMS) does not have the effectiveness to detect the conduction of the grounding switch in the insulation circuit. Once the grounding switch fails or cannot be turned on, it will cause the insulation sampling system to misjudge, affecting the safety of the ride. Utility Model Content

[0004] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model proposes an insulation detection circuit that can detect the effectiveness of the grounding switch in the insulation circuit of the high-voltage battery system, avoid misjudgment of the insulation sampling system when the grounding switch fails or cannot be turned on, thereby improving the safety of the vehicle.

[0005] According to an insulation detection circuit of an embodiment of the utility model, the insulation detection circuit includes:

[0006] An equivalent insulating load module, wherein a first end of the equivalent insulating load module is connected to a positive electrode of an external power supply end, a second end of the equivalent insulating load module is connected to a negative electrode of the external power supply end, and a third end of the equivalent insulating load module is grounded;

[0007] An insulation detection module, wherein a first end of the insulation detection module is connected to a positive electrode of an external power supply end, a second end of the insulation detection module is connected to a negative electrode of the external power supply end, a third end of the insulation detection module is grounded, and the insulation detection module is used to detect the resistance value of the equivalent insulation load module;

[0008] A grounding switch, arranged between the third terminal of the insulation detection module and the ground terminal;

[0009] The first diagnostic module includes a first load element and a second load element connected in series and a second detection module, wherein the second detection module is used to measure the voltage value between the first load element and the second load element, and one end of the first diagnostic module is grounded, and the other end is connected to the negative pole of the external power supply end or the positive pole of the external power supply end.

[0010] The insulation detection circuit according to the embodiment of the utility model has at least the following beneficial effects:

[0011] When the grounding switch can be turned on normally, the insulation detection module can calculate the real-time resistance value of the equivalent insulation load module. When the grounding switch does not respond to the closing command or fails to be turned on, the insulation detection module cannot calculate the real resistance value of the equivalent insulation load module. At this time, whether the grounding switch is working normally is judged by whether the first detection module in the first diagnostic module has periodic voltage changes. When the voltage detected by the first detection module remains unchanged, it can be judged that the grounding switch is abnormal. In this way, the effectiveness of the grounding switch conduction in the insulation circuit of the high-voltage battery system can be detected to avoid misjudgment of the insulation sampling system when the grounding switch fails or cannot be turned on, thereby improving the safety of the vehicle.

[0012] According to some embodiments of the present utility model, the equivalent insulation load module includes:

[0013] A first insulation resistor and a second insulation resistor, wherein the first insulation resistor includes a first pin and a second pin, the second insulation resistor includes a third pin and a fourth pin, the first pin is connected to the positive pole of the external power supply end, the second pin is connected to the third pin, the fourth pin is connected to the negative pole of the external power supply end, and the second pin is grounded.

[0014] According to some embodiments of the present utility model, the insulation detection module includes:

[0015] a first resistor, a second resistor, a third resistor and a fourth resistor, wherein the first resistor includes a fifth pin and a sixth pin, the second resistor includes a seventh pin and an eighth pin, the third resistor includes a ninth pin and a tenth pin, the fourth resistor includes an eleventh pin and a twelfth pin, the fifth pin is connected to the positive electrode of the external power supply end, the sixth pin is connected to the seventh pin, the eighth pin is connected to the ninth pin, the tenth pin is connected to the eleventh pin, and the twelfth pin is connected to the negative electrode of the external power supply end, wherein a first connection point is included between the first insulation resistor and the second insulation resistor, and a second connection point is included between the second resistor and the third resistor;

[0016] a bridge arm switch, the bridge arm switch being arranged between the sixth pin and the twelfth pin, the bridge arm switch being connected in parallel to a branch formed by the second resistor, the third resistor and the fourth resistor in series, the eighth pin being grounded via the grounding switch, and the grounding switch being arranged between the first connection point and the second connection point;

[0017] The first detection module is connected to the twelfth pin of the fourth resistor and is used to obtain the voltage value of the twelfth pin when the bridge arm switch is opened and closed.

[0018] According to some embodiments of the present utility model, the first diagnostic module includes:

[0019] A first load element, a second load element and a second detection module, wherein the first load element includes a thirteenth pin and a fourteenth pin, and the second load element includes a fifteenth pin and a sixteenth pin; wherein,

[0020] The thirteenth pin is grounded, the fourteenth pin is connected to the fifteenth pin, the sixteenth pin is connected to the negative electrode of the external power supply end, the second detection module is connected to the fifteenth pin, and the second detection module is used to detect the voltage value change at the fifteenth pin;

[0021] or,

[0022] The thirteenth pin is connected to the positive electrode of the external power supply end, the fourteenth pin is connected to the fifteenth pin, the sixteenth pin is grounded, and the second detection module is connected to the fifteenth pin.

[0023] According to some embodiments of the present utility model, the insulation detection circuit further includes a second diagnostic module, and the second diagnostic module includes:

[0024] A third load element, a fourth load element and a third detection module, wherein the third load element includes a seventeenth pin and an eighteenth pin, and the fourth load includes a nineteenth pin and a twenty-first pin; wherein,

[0025] The seventeenth pin is connected to the positive electrode of the external power supply end, the eighteenth pin is connected to the nineteenth pin, the twenty-third pin is grounded, the third detection module is connected to the eighteenth pin, and the third detection module is used to detect the voltage value change at the eighteenth pin, the first diagnosis module is connected to the negative electrode of the external power supply end, and the second diagnosis module is connected to the positive electrode of the external power supply end;

[0026] or,

[0027] The seventeenth pin is grounded, the eighteenth pin is connected to the nineteenth pin, the twentieth pin is connected to the negative pole of the external power supply end, the third detection module is connected to the eighteenth pin, the first diagnostic module is connected to the positive pole of the external power supply end, and the second diagnostic module is connected to the negative pole of the external power supply end.

[0028] According to some embodiments of the present utility model, in the first diagnostic module:

[0029] The first load element is a resistor or a capacitor;

[0030] The second load element is a resistor or a capacitor;

[0031] In the second diagnostic module:

[0032] The third load element is a resistor or a capacitor;

[0033] The fourth load element is a resistor or a capacitor.

[0034] According to some embodiments of the present invention, the first diagnostic module further includes a fifth resistor and a first capacitor, the fifth resistor is arranged between the first load element and the second detection module, and the second detection module is grounded via the first capacitor.

[0035] According to some embodiments of the present invention, a sixth resistor is further provided between the positive electrode of the external power supply terminal and the eighth pin of the second resistor.

[0036] According to some embodiments of the present utility model, the insulation detection circuit further includes a detection unit, and the first detection module and the second detection module are integrated in the detection unit.

[0037] According to some embodiments of the present utility model, the insulation detection circuit is further provided with an alarm unit, and the alarm unit is connected to the first detection unit or the second detection unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0039] Figure 1 It is an insulation sampling circuit diagram in the related technology of the embodiment of the utility model;

[0040] Figure 2 This is an insulation detection circuit diagram shown in an embodiment of the utility model;

[0041] Figure 3 Another insulation detection circuit diagram shown in an embodiment of the utility model;

[0042] Figure 4 A schematic diagram of voltage changes detected by the second detection module shown in an embodiment of the utility model;

[0043] Figure 5 Another circuit diagram of the first diagnostic module shown in an embodiment of the utility model;

[0044] Figure 6Another circuit diagram of the first diagnostic module shown in an embodiment of the utility model;

[0045] Figure 7 Another circuit diagram of the first diagnostic module shown in an embodiment of the utility model;

[0046] Figure 8 Another circuit diagram of the first diagnostic module shown in an embodiment of the utility model;

[0047] Fig. 9 Another circuit diagram of the insulation detection circuit shown in the embodiment of the utility model;

[0048] Fig.10 Another circuit diagram of the insulation detection circuit shown in the embodiment of the utility model;

[0049] Fig.11 This is another circuit diagram of the insulation detection circuit shown in an embodiment of the present utility model.

[0050] Reference numerals:

[0051] Insulation detection circuit 100,

[0052] Equivalent insulation load module 110, first insulation resistor 111, second insulation resistor 112,

[0053] Insulation detection module 120, first resistor 121, second resistor 122, third resistor 123, fourth resistor 124, sixth resistor 125,

[0054] Ground switch 131, bridge arm switch 132,

[0055] The first detection module 140,

[0056] A first diagnostic module 150, a first load element 151, a second load element 152, a second detection module 153, a fifth resistor 154, a first capacitor 155,

[0057] The second diagnostic module 160, the third load element 161, the fourth load element 162, the third detection module 163,

[0058] Detection unit 170,

[0059] Alarm unit 180. DETAILED DESCRIPTION

[0060] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0061] In the description of the present invention, it should be understood that descriptions involving orientation, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0062] In the description of the present utility model, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0063] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0064] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0065] The Battery Management System (BMS) is used to monitor and manage the high-voltage battery system of electric vehicles. The BMS can detect faults in the battery pack and take corresponding protective measures. For example, when the battery pack has abnormal conditions such as excessive temperature, excessive or low voltage, excessive current, etc., the BMS can issue an alarm or take measures such as power off to protect the safety of the battery system and the vehicle. Under normal conditions, the positive and negative busbars of the battery system have good insulation properties from the vehicle body (or the outer shell of the equipment), but during use, due to vibration, device aging, moisture, corrosion and other problems, the insulation is damaged, affecting the safety of the people in the car. Therefore, in the high-voltage battery management system, it is very necessary to detect the insulation performance of the system in real time.

[0066] In the related technology, the insulation detection circuit is usually designed based on the unbalanced bridge principle to measure the insulation resistance of electric vehicles. Figure 1 As shown, the grounding switch 131 is kept in a closed and conducting state during operation, and the equivalent insulation load module 110 is incorporated into the acquisition circuit together with the ground, wherein the equivalent insulation load module 110 includes a first insulation resistor 111 and a second insulation resistor 112. As the bridge arm switch 132 alternates between the conducting and disconnecting states, the first detection module 140 can respectively collect two sets of different voltage values. When the bridge arm switch 132 is closed, the voltage value collected by the first detection module 140 is:

[0067]

[0068] When the bridge arm switch 132 is disconnected, the voltage value collected by the first detection module 140 is:

[0069]

[0070] Where Vbat is the voltage value provided by the external power supply terminal, RP is the resistance value of the first insulation resistor 111, RN is the resistance value of the second insulation resistor, R1, R2, R3 and R4 respectively represent the resistance values ​​of the first resistor 121, the second resistor 122, the third resistor 123 and the fourth resistor 124, and " / / " indicates that the electronic components are in parallel. By inputting the two sets of voltage values ​​into the algorithm, the real-time insulation resistance value of the vehicle body can be calculated.

[0071] However, when the grounding switch 131 does not respond to the closing instruction or cannot be turned on, that is, the branch where the grounding switch 131 is located is open, the first insulation resistor 111 and the second insulation resistor 112 are equivalent to infinite resistance connected to the insulation detection circuit 100, and the resistance of the equivalent insulation load module 110 calculated by the two sets of voltage values ​​collected by the first detection module 140 is the maximum value. If the actual resistance value of the equivalent insulation load module 110 decreases at this time, the resistance value of the equivalent insulation load module 110 calculated by the first detection module 140 through the two sets of voltage values ​​collected by the first detection module 140 is still the maximum value, so the resistance value of the equivalent insulation load module 110 cannot be correctly calculated, and the leakage fault cannot be reported in time.

[0072] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model proposes an insulation detection circuit, which adds a first diagnostic module 150 after the grounding switch 131 on the basis of calculating the equivalent insulation load module 110, and can identify the effectiveness of the grounding switch 131, thereby ensuring the effectiveness of the collected resistance value, avoiding misjudgment of the insulation detection circuit 100 when the grounding switch 131 fails or cannot be turned on, and improving the safety of riding.

[0073] The utility model is further described below in conjunction with the accompanying drawings:

[0074] like Figure 2 As shown, an insulation detection circuit 100 according to the first aspect of the present utility model includes:

[0075] The equivalent insulating load module 110 has a first end connected to the positive electrode of the external power supply end, a second end connected to the negative electrode of the external power supply end, and a third end grounded.

[0076] Among them, the external power supply end is used to provide the power required by the circuit. The main power source of electric vehicles is a high-voltage battery pack, which is usually composed of lithium-ion batteries. The high-voltage battery pack stores a large amount of electrical energy to power electric vehicles. It is usually located in the chassis or underbody of the vehicle and is monitored and managed by the battery management system (BMS). The high-voltage battery pack provides power to the electric motor through the electronic control unit to drive the vehicle.

[0077] In some embodiments, when the insulation detection circuit 100 of the utility model is applied to an electric vehicle, the equivalent insulation load module 110 is arranged in the body of the electric vehicle, and is an important parameter for detecting the insulation condition of the body. The main function of the equivalent insulation load module 110 is to prevent accidental circuit short circuits between the electrical components of the vehicle and the body, ensure the normal operation of the electrical system of the vehicle and ensure the safety of the passengers. By measuring the resistance value of the equivalent insulation load module 110, the insulation performance of the body can be evaluated. If the resistance value of the equivalent insulation load module 110 is low, it may mean that there is a leakage problem or insulation damage in the body.

[0078] like Figure 3 As shown, according to some embodiments of the present invention, the equivalent insulation load module 110 includes:

[0079] A first insulation resistor 111 and a second insulation resistor 112, wherein the first insulation resistor 111 includes a first pin and a second pin, and the second insulation resistor 112 includes a third pin and a fourth pin, the first pin is connected to the positive electrode of the external power supply end, the second pin is connected to the third pin, the fourth pin is connected to the negative electrode of the external power supply end, and the second pin is grounded.

[0080] The insulation detection module 120 has a first end connected to the positive pole of the external power supply end, a second end connected to the negative pole of the external power supply end, and a third end connected to the ground. The insulation detection module 120 is used to detect the resistance value of the equivalent insulation load module 110.

[0081] like Figure 3As shown, according to some embodiments of the present utility model, the insulation detection module 120 includes:

[0082] A first resistor 121, a second resistor 122, a third resistor 123 and a fourth resistor 124, wherein the first resistor 121 includes a fifth pin and a sixth pin, the second resistor 122 includes a seventh pin and an eighth pin, the third resistor 123 includes a ninth pin and a tenth pin, the fourth resistor 124 includes an eleventh pin and a twelfth pin, the fifth pin is connected to the positive electrode of the external power supply end, the sixth pin is connected to the seventh pin, the eighth pin is connected to the ninth pin, the tenth pin is connected to the eleventh pin, and the twelfth pin is connected to the negative electrode of the external power supply end, wherein a first connection point is included between the first insulation resistor 111 and the second insulation resistor 112, and a second connection point is included between the second resistor 122 and the third resistor 123.

[0083] The bridge arm switch 132 is arranged between the sixth pin and the twelfth pin. The bridge arm switch 132 is connected in parallel to a branch formed by the second resistor 122, the third resistor 123 and the fourth resistor 124 in series. The eighth pin is grounded via the grounding switch 131. The grounding switch 131 is arranged between the first connection point and the second connection point. The voltage between the third resistor 123 and the fourth resistor 124 is changed by periodically turning on and off the bridge arm switch 132, so as to calculate the voltage value of the equivalent insulation load module 110.

[0084] The first detection module 140 is connected to the twelfth pin of the fourth resistor 124, and is used to obtain the voltage value at the twelfth pin when the bridge arm switch 132 is opened and closed. As the bridge arm switch 132 is turned on and off, the first detection module 140 can collect two sets of different voltage values. The two sets of voltage values ​​are input into the algorithm to calculate the resistance value of the equivalent insulation load module 110 at this time. Commonly used voltage detection modules include: ADC (analog-to-digital converter) module, voltage divider module or integrated circuit (IC) voltage monitoring module, and the specific voltage detection module selection is not limited in the present utility model.

[0085] The grounding switch 131 is arranged between the third end of the insulation detection module and the ground end. The grounding switch 131 is arranged between the first connection point and the second connection point. During the measurement process of the equivalent insulation load module 110, the grounding switch 131 remains in the on state during operation, and the voltage between the third resistor 123 and the fourth resistor 124 is changed by periodically turning on and off the bridge arm switch 132. In the insulation detection circuit 100, the first resistor 121, the second resistor 122, the third resistor 123 and the fourth resistor 124 are resistors with determined resistance values. In the insulation detection circuit 100, the voltage division mode of the first resistor 121, the second resistor 122, the third resistor 123 and the fourth resistor 124 is changed by opening and closing the bridge arm switch, thereby changing the voltage value detected by the first detection module 140 and the second detection module 153, and calculating the resistance value of the equivalent insulation load module 110 and diagnosing the effectiveness of the grounding switch 131 according to the voltage value.

[0086] The first diagnostic module 150 includes a first load element 151 and a second load element 152 connected in series and a second detection module 153. The second detection module 153 is used to measure the voltage value between the first load element 151 and the second load element 152. One end of the first diagnostic module 150 is grounded, and the other end is connected to the negative pole of the external power supply end or the positive pole of the external power supply end.

[0087] like Figure 3 As shown, according to some embodiments of the present invention, the first diagnostic module 150 includes:

[0088] A first load element 151, a second load element 152 and a second detection module 153, wherein the first load element 151 includes a thirteenth pin and a fourteenth pin, the second load element 152 includes a fifteenth pin and a sixteenth pin, the thirteenth pin is grounded, the fourteenth pin is connected to the fifteenth pin, the sixteenth pin is connected to the negative pole of the external power supply end, the second detection module 153 is connected to the fifteenth pin, and the second detection module 153 is used to detect the change in voltage value at the fifteenth pin as the bridge arm switch 132 is periodically turned on and off.

[0089] The first diagnostic module 150 may also be configured as follows: Figure 4 The method shown is connected in the insulation detection circuit 100, wherein the thirteenth pin is connected to the positive pole of the external power supply end, the fourteenth pin is connected to the fifteenth pin, the sixteenth pin is grounded, and the second detection module 153 is connected to the fifteenth pin. The second detection module 153 is used to detect the change in the voltage value at the fifteenth pin as the bridge arm switch 132 is periodically turned on and off.

[0090] When the grounding switch 131 remains closed and the bridge arm switch 132 is periodically turned on and off, the voltage at the grounding switch 131 will also generate a periodically changing voltage as the bridge arm switch 132 is periodically turned on and off. After voltage division by the first load element 151 and the second load element 152, the periodically changing voltage will also be collected at the second detection module 153. If the grounding switch 131 fails, the voltage at the second detection module 153 is the voltage divided by the first load element 151, the second load element 152 and the first insulation resistor 111, and the second insulation resistor 112. At this time, the voltage will not change as the bridge arm switch 132 is turned on and off. Therefore, the effectiveness of the grounding switch 131 can be diagnosed by identifying the voltage value collected by the second detection module 153. Figure 6 As shown, the horizontal axis represents time, and the vertical axis represents the voltage value detected by the second detection module 153. It can be seen that as the bridge arm switch 132 is periodically disconnected and turned on, the second detection module 153 also collects voltage values ​​that change periodically in the time periods T1 and T2. At this time, it can be determined that the grounding switch 131 is in an effective closed state; when the second detection module 153 detects a continuously unchanged voltage value, it can be determined that the grounding switch 131 is invalid or abnormal. Through the first diagnostic module 150, only the voltage changes collected by the second detection module 153 need to be collected to diagnose the effectiveness of the grounding switch 131, avoiding the safety hazard caused by the insulation detection circuit 100 misjudging the resistance value of the equivalent insulation load module 110 when the grounding switch 131 fails.

[0091] like Figure 6 As shown, according to some embodiments of the utility model, the insulation detection circuit 100 also includes a second diagnostic module 160, the second diagnostic module 160 includes a third load element 161, a fourth load element 162 and a third detection module 163, wherein the third load 161 includes a seventeenth pin and an eighteenth pin, the fourth load 162 includes a nineteenth pin and a twentieth pin, the seventeenth pin is connected to the positive pole of the external power supply end, the eighteenth pin is connected to the nineteenth pin, the twentieth pin is grounded, the third detection module 163 is connected to the eighteenth pin, and the third detection module 163 is used to detect the change in voltage value at the eighteenth pin as the bridge arm switch 132 is periodically turned on and off. When the second diagnostic module 160 is connected as described above, the first diagnostic module 150 is connected to the negative pole of the external power supply end.

[0092] or,

[0093] The seventeenth pin is grounded, the eighteenth pin is connected to the nineteenth pin, the twentieth pin is connected to the negative pole of the external power supply end, the third detection module 163 is connected to the eighteenth pin, and the third detection module 163 is used to detect the change in the voltage value at the eighteenth pin as the bridge arm switch 132 is periodically turned on and off. When the second diagnostic module 160 is connected as described in the above connection method, the first diagnostic module 150 is connected to the positive pole of the external power supply end.

[0094] When the grounding switch 131 remains closed and the bridge arm switch 132 is periodically turned on and off, the voltage at the grounding switch 131 will also generate a periodically changing voltage as the bridge arm switch 132 is periodically turned on and off. After the voltage is divided by the third load element 161 and the fourth load element 162, the third detection module 163 will also collect the periodically changing voltage. If the grounding switch 131 fails, the voltage at the third detection module 163 is the voltage divided by the third load element 161, the fourth load element 162, the first insulation resistor 111, and the second insulation resistor 112. At this time, the voltage will not change with the on and off of the bridge arm switch 132. Therefore, the effectiveness of the grounding switch 131 can be diagnosed by identifying the voltage value collected by the third detection module 163. When the third detection module 163 detects a voltage change of a periodic proportion, it can be determined that the grounding switch 131 is normally closed and turned on; when the third detection module 163 detects a voltage value that remains unchanged, it can be determined that the grounding switch 131 is failed or abnormal. Through the second diagnostic module 160, only the voltage changes collected by the third detection module 163 need to be collected to diagnose the effectiveness of the grounding switch 131, thereby avoiding the safety hazard caused by the insulation detection circuit 100 misjudging the resistance value of the equivalent insulation load module 110 when the grounding switch 131 fails.

[0095] Among them, the role played by the second diagnostic module 160 in the insulation detection circuit 100 is the same as that of the first diagnostic module 150. A suitable diagnostic circuit can be selected according to actual needs, and the embodiment of the present disclosure is not limited. By integrating two diagnostic circuits, it can be ensured that when one diagnostic circuit fails, the other diagnostic circuit can continue to perform normal judgment and diagnostic operations to ensure the accuracy of insulation detection. In addition, in order to ensure the effect of dual diagnosis, fault detection and fault switching mechanisms can be considered in circuit design. In this way, when a diagnostic circuit fails, it can be switched to another available diagnostic circuit in time, and maintaining normal operation helps to enhance the performance and stability of the insulation detection circuit 100.

[0096] According to some embodiments of the present invention, in the first diagnostic module 150: the first load element 151 is a resistor or a capacitor, and the second load element 152 is a resistor or a capacitor;

[0097] In the second diagnostic module 160 , the third load element 161 is a resistor or a capacitor, and the fourth load element 162 is a resistor or a capacitor.

[0098] like Figure 7 As shown in the figure, the first load element 151 and the second load element 152 are resistors, and the third load element 161 and the fourth load element 162 are capacitors. The first load element 151 and the third load element 161 can also be set as resistors, and the second load element 152 and the fourth load element 162 can be set as capacitors. These load elements can be selected in combination with other elements in the insulation detection circuit to realize the function of the diagnosis circuit.

[0099] like Figure 8 As shown, according to some embodiments of the utility model, the first diagnostic module 150 also includes a fifth resistor 154 and a first capacitor 155, the fifth resistor 154 is arranged between the first load element 151 and the second detection module 153, and the second detection module 153 is grounded via the first capacitor 155. The fifth resistor 154 and the first capacitor 155 together constitute a filter circuit, the fifth resistor 154 is used to control the size of the current passing through the first load element 151, and realize voltage division in the circuit, and the first capacitor 155 is used to filter or smooth the voltage signal to reduce the influence of noise or interference, so as to provide a more stable measurement result. The filter circuit can be used to remove the current of interference or noise in the circuit. By using an appropriate combination of resistors and capacitors, it is possible to filter the signal within a specific frequency range. When designing the circuit, it is necessary to comprehensively consider factors such as the signal frequency range, noise source, bandwidth requirements, and select appropriate resistor and capacitor parameters. This can improve the quality and accuracy of the signal and ensure the reliability of the measurement result.

[0100] like Fig. 9 As shown, according to some embodiments of the present invention, a sixth resistor 125 is further provided between the positive electrode of the external power supply terminal and the eighth pin of the second resistor 122. For example, when the first insulation resistor 111 is much smaller than the second insulation resistor 112, the voltage value collected by the first detection module 140 and the second detection module 153 will be very small, which will cause the detection module to make an error in judgment. By adding the sixth resistor 125, the voltage of the first detection module 140 and the second detection module 153 can be raised, thereby increasing the accuracy of the voltage detection by the detection module.

[0101] According to some embodiments of the utility model, the resistance range of the equivalent insulation load module is 10K-50MΩ. The equivalent insulation load module is one of the key components used to evaluate the insulation performance of the vehicle body. It is generally used to measure the resistance value between the vehicle body and the ground to evaluate the degree of insulation between the vehicle body and the ground. The higher the resistance value of the equivalent insulation load module, the better the insulation effect between the vehicle body and the ground. When the detected resistance value is less than 10KΩ, it is determined that the insulation resistance does not meet the requirements or there is an insulation fault. This means that the insulation performance between the vehicle body and the ground is insufficient. The lower insulation resistance value indicates that there is a current leakage path or poor connection between the vehicle body and the ground, which may cause electrical failure, risk of electric shock or other safety issues. Therefore, when the resistance value of the equivalent insulation load module is detected to be less than the preset minimum threshold, troubleshooting is required immediately.

[0102] like Fig.10 As shown, according to some embodiments of the utility model, the insulation detection circuit 100 further includes a detection unit 170, and the first detection module 140 and the second detection module 153 are integrated in the detection unit 170. In some embodiments, in order to simplify the design, reduce costs or improve efficiency, multiple detection functions can be integrated into one detection unit 170. Doing so can reduce the complexity of the circuit, simplify the layout of the system, and better manage and control signal processing. By sharing the same detection unit, consistent signal processing and data acquisition can be achieved, thereby improving the consistency and reliability of the system. In addition, the number of components and connection lines required can be reduced, saving space and simplifying the installation process.

[0103] like Fig.11 As shown, according to some embodiments of the utility model, the insulation detection circuit 100 may also include an alarm unit 180, which is connected to the first detection module 140 or the second detection module 153. The alarm unit 180 includes an alarm trigger unit (not shown in the figure) and a warning unit (not shown in the figure). When the first detection module 140 detects an insulation abnormality or when the second detection module 153 detects an abnormal grounding switch, the alarm can be triggered by the alarm trigger unit and the warning unit can send a warning signal to remind the operator or maintenance personnel that there is a problem and to perform troubleshooting in time. In order to prevent further damage or danger caused by insulation abnormality, the insulation detection circuit 100 can automatically disconnect the power supply or shut down the relevant circuit. This can prevent the fault from expanding and protect the safety of equipment and personnel.

[0104] This article uses specific examples to illustrate the principles and implementation methods of the utility model. The above examples are only used to help understand the core idea of ​​the utility model. The above are only preferred implementation methods of the utility model. It should be pointed out that due to the limitations of textual expression, there are objectively infinite specific structures. For ordinary technicians in this technical field, without departing from the principle of the utility model, they can make several improvements, modifications or changes, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the concept and technical solution of the utility model to other occasions without improvement, should be regarded as the protection scope of the utility model.

Claims

1. An insulation detection circuit, characterized in that: The insulation detection circuit comprises: An equivalent insulating load module, wherein a first end of the equivalent insulating load module is connected to a positive electrode of an external power supply end, a second end of the equivalent insulating load module is connected to a negative electrode of the external power supply end, and a third end of the equivalent insulating load module is grounded; An insulation detection module, wherein a first end of the insulation detection module is connected to a positive electrode of an external power supply end, a second end of the insulation detection module is connected to a negative electrode of the external power supply end, a third end of the insulation detection module is grounded, and the insulation detection module is used to detect the resistance value of the equivalent insulation load module; A grounding switch, arranged between the third terminal of the insulation detection module and the ground terminal; The first diagnostic module includes a first load element and a second load element connected in series and a second detection module, wherein the second detection module is used to measure the voltage value between the first load element and the second load element, and one end of the first diagnostic module is grounded, and the other end is connected to the negative pole of the external power supply end or the positive pole of the external power supply end.

2. The insulation detection circuit according to claim 1, characterized in that: The equivalent insulation load module comprises: A first insulation resistor and a second insulation resistor, wherein the first insulation resistor includes a first pin and a second pin, the second insulation resistor includes a third pin and a fourth pin, the first pin is connected to the positive pole of the external power supply end, the second pin is connected to the third pin, the fourth pin is connected to the negative pole of the external power supply end, and the second pin is grounded.

3. The insulation detection circuit according to claim 2, characterized in that: The insulation detection module comprises: a first resistor, a second resistor, a third resistor and a fourth resistor, wherein the first resistor includes a fifth pin and a sixth pin, the second resistor includes a seventh pin and an eighth pin, the third resistor includes a ninth pin and a tenth pin, the fourth resistor includes an eleventh pin and a twelfth pin, the fifth pin is connected to the positive electrode of the external power supply end, the sixth pin is connected to the seventh pin, the eighth pin is connected to the ninth pin, the tenth pin is connected to the eleventh pin, and the twelfth pin is connected to the negative electrode of the external power supply end, wherein a first connection point is included between the first insulation resistor and the second insulation resistor, and a second connection point is included between the second resistor and the third resistor; a bridge arm switch, the bridge arm switch being arranged between the sixth pin and the twelfth pin, the bridge arm switch being connected in parallel to a branch formed by the second resistor, the third resistor and the fourth resistor in series, the eighth pin being grounded via the grounding switch, and the grounding switch being arranged between the first connection point and the second connection point; The first detection module is connected to the twelfth pin of the fourth resistor and is used to obtain the voltage value of the twelfth pin when the bridge arm switch is opened and closed.

4. The insulation detection circuit according to claim 1, characterized in that: The first diagnostic module comprises: A first load element, a second load element and a second detection module, wherein the first load element includes a thirteenth pin and a fourteenth pin, and the second load element includes a fifteenth pin and a sixteenth pin; wherein, The thirteenth pin is grounded, the fourteenth pin is connected to the fifteenth pin, the sixteenth pin is connected to the negative electrode of the external power supply end, the second detection module is connected to the fifteenth pin, and the second detection module is used to detect the voltage value change at the fifteenth pin; or, The thirteenth pin is connected to the positive electrode of the external power supply end, the fourteenth pin is connected to the fifteenth pin, the sixteenth pin is grounded, and the second detection module is connected to the fifteenth pin.

5. The insulation detection circuit according to claim 4, characterized in that: The insulation detection circuit further includes a second diagnostic module, wherein the second diagnostic module includes: A third load element, a fourth load element and a third detection module, wherein the third load element includes a seventeenth pin and an eighteenth pin, and the fourth load includes a nineteenth pin and a twenty-first pin; wherein, The seventeenth pin is connected to the positive electrode of the external power supply end, the eighteenth pin is connected to the nineteenth pin, the twenty-third pin is grounded, the third detection module is connected to the eighteenth pin, and the third detection module is used to detect the voltage value change at the eighteenth pin, the first diagnosis module is connected to the negative electrode of the external power supply end, and the second diagnosis module is connected to the positive electrode of the external power supply end; or, The seventeenth pin is grounded, the eighteenth pin is connected to the nineteenth pin, the twentieth pin is connected to the negative pole of the external power supply end, the third detection module is connected to the eighteenth pin, the first diagnostic module is connected to the positive pole of the external power supply end, and the second diagnostic module is connected to the negative pole of the external power supply end.

6. The insulation detection circuit according to claim 5, characterized in that: include: In the first diagnostic module: The first load element is a resistor or a capacitor; The second load element is a resistor or a capacitor; In the second diagnostic module: The third load element is a resistor or a capacitor; The fourth load element is a resistor or a capacitor.

7. The insulation detection circuit according to claim 1, characterized in that: The first diagnosis module further includes a fifth resistor and a first capacitor. The fifth resistor is disposed between the first load element and the second detection module. The second detection module is grounded via the first capacitor.

8. The insulation detection circuit according to claim 3, characterized in that: A sixth resistor is further provided between the positive electrode of the external power supply terminal and the eighth pin of the second resistor.

9. The insulation detection circuit according to claim 3, characterized in that: The insulation detection circuit further includes a detection unit, in which the first detection module and the second detection module are integrated.

10. The insulation detection circuit according to claim 3, characterized in that: The insulation detection circuit is further provided with an alarm unit, and the alarm unit is connected to the first detection module or the second detection module.

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