Vehicle insulation resistance detection system and detection method

Abstract

The present invention provides a vehicle insulation resistance detection system and detection method, belonging to the field of automobile technology, the system includes: an insulation resistance diagnosis module, including a controller and a resistance module for simulating the degree of high-voltage insulation failure of a whole vehicle; the resistance module is respectively connected to the test piece and the whole vehicle electrical environment electrode, the resistance module includes multiple resistors, the controller is used to select the resistor connection mode in the resistance module and adjust the resistance value; the insulation resistance monitoring module is used to detect the insulation resistance of the test piece, and determine the insulation resistance error based on the insulation resistance, and when the insulation resistance error is less than the preset error threshold, obtain the insulation resistance response time, and perform compliance calibration on the insulation resistance response time. The present invention adjusts the connection mode and resistance value of each resistor in the resistance module through the controller, completes the insulation resistance detection of the new energy vehicle, and solves the technical problem that the insulation resistance value of the existing HIL simulation test of the new energy vehicle has errors.

Description

Technical Field

[0001] The present invention relates to the field of automobile technology, and in particular to a vehicle insulation resistance detection system and a detection method. Background Art

[0002] At present, the market demand for new energy commercial vehicles is increasing, and its insulation resistance is an indispensable key parameter, which also directly affects personal safety. The hardware technology of the high-voltage insulation online detection system on the market is relatively mature, but in different high-voltage environments, the insulation resistance software strategy affects the insulation resistance value reporting response time and error size. There is no physical diagnosis, so the reporting response time and reporting error size are directly affected by the software strategy design.

[0003] The existing software strategy test only uses HIL (hardware-in-the-loop) simulation to determine the insulation resistance reporting error. However, after the new product is integrated into the vehicle, due to interference from other electronic components on the vehicle, the insulation resistance value reporting response time and error will be greater than the error obtained by HIL simulation.

[0004] In summary, the existing HIL simulation test of the insulation resistance of new energy vehicles has a long response time and low accuracy, and the test results have certain errors, which still brings a certain risk of high-voltage electrical insulation failure and inability to accurately report. Summary of the invention

[0005] In view of this, it is necessary to provide a vehicle insulation resistance detection system and detection method to solve the technical problem that the existing solution has errors in testing the insulation resistance of new energy vehicles.

[0006] In order to solve the above problems, on the one hand, the present invention provides a vehicle insulation resistance detection system, comprising:

[0007] The insulation resistance diagnostic module includes a controller and a resistance module for simulating the degree of high-voltage insulation failure of the whole vehicle; the resistance module is respectively connected to the tested device and the electrical environment electrode of the whole vehicle, the resistance module includes a plurality of resistors, and the controller is used to select the connection mode of the resistors in the resistance module and adjust the resistance value;

[0008] The insulation resistance monitoring module is used to detect the insulation resistance of the device under test, and determine the insulation resistance error based on the insulation resistance. When the insulation resistance error is less than a preset error threshold, the insulation resistance response time is obtained, and the insulation resistance response time is calibrated for compliance.

[0009] In a possible implementation, the resistance module includes: a first resistor, a second resistor and a third resistor; the insulation resistance diagnosis module also includes: a selection switch device and a grounding device;

[0010] The positive electrode of the device under test, the first resistor, the positive electrode of the vehicle electrical environment electrode, the selection switch device, the third resistor and the grounding device are connected in sequence;

[0011] The negative electrode of the device under test, the second resistor, the negative electrode of the vehicle electrical environment electrode, the selection switch device, the third resistor and the grounding device are connected in sequence;

[0012] The selection switch device is used to control the third resistor to be energized with the positive electrode of the whole vehicle electrical environment electrode, or to be energized with the negative electrode of the whole vehicle electrical environment electrode.

[0013] In a possible implementation, the insulation resistance diagnostic module further includes: a capacitor module for simulating an equivalent circuit of a whole vehicle; the capacitor module includes a first capacitor and a second capacitor;

[0014] The first capacitor and the first resistor are connected in parallel, and the second capacitor and the second resistor are connected in parallel.

[0015] In a possible implementation manner, both the first capacitor and the second capacitor are variable capacitors;

[0016] The capacitance range of the variable capacitor is 0.5 μF to 2.5 μF.

[0017] In a possible implementation manner, the first resistor, the second resistor, and the third resistor are all variable resistors.

[0018] In a possible implementation, the range specifications of the variable resistor include 15 MΩ and 1 MΩ.

[0019] On the other hand, the present invention further provides a method for detecting insulation resistance of a vehicle, the method being applied to any of the above-mentioned systems, the method comprising:

[0020] Based on the controller, a resistor connection mode in the resistor module is selected, and the resistance value is adjusted, and a first positive insulation resistance to ground and a first negative insulation resistance to ground of the device under test in a steady state are obtained;

[0021] When the device under test is in a steady state, based on the controller, the parallel resistance in the resistance module is increased, the resistance value of the increased parallel resistance is adjusted, and a second positive insulation resistance to ground and a second negative insulation resistance to ground of the device under test are obtained;

[0022] Determine the insulation resistance of the device under test based on the first positive insulation resistance to ground and the first negative insulation resistance to ground, and the second positive insulation resistance to ground and the second negative insulation resistance to ground;

[0023] An insulation resistance error is determined based on the insulation resistance of the measured device, and when the insulation resistance error is less than a preset error threshold, an insulation resistance response time is obtained, and compliance calibration is performed on the insulation resistance response time.

[0024] In a possible implementation, the insulation resistance of the device under test includes: a theoretical value of a positive insulation resistance to ground and a theoretical value of a negative insulation resistance to ground;

[0025] Determining the insulation resistance of the device under test based on the first positive insulation resistance to ground and the first negative insulation resistance to ground, and the second positive insulation resistance to ground and the second negative insulation resistance to ground, includes:

[0026] The product of the first insulation resistance to ground and the second insulation resistance to ground is divided by the sum of the first insulation resistance to ground and the second insulation resistance to ground to obtain a theoretical value of the insulation resistance to ground;

[0027] The product of the first negative insulation resistance to ground and the second negative insulation resistance to ground is divided by the sum of the first negative insulation resistance to ground and the second negative insulation resistance to ground to obtain a theoretical value of the negative insulation resistance to ground.

[0028] In a possible implementation manner, determining the insulation resistance error based on the insulation resistance of the device under test includes:

[0029] The insulation resistance error is obtained by dividing the difference between the theoretical value of the insulation resistance to ground and the second insulation resistance to ground by the theoretical value of the insulation resistance to ground.

[0030] In a possible implementation, before selecting the resistor connection mode in the resistor module based on the controller, the method further includes:

[0031] The capacitor module is configured based on the controller to simulate the equivalent circuit environment of the entire vehicle.

[0032] The beneficial effect of adopting the above implementation method is: the vehicle insulation resistance detection system and detection method provided by the present invention simulates the degree of high-voltage insulation failure of the whole vehicle through a resistance module composed of multiple resistors, the resistance module is connected to the test piece, and the test piece is the high-voltage system of the new energy vehicle. The connection mode and resistance value of each resistor in the resistance module are adjusted by the controller, and then the insulation resistance of the test piece is detected by the insulation resistance monitoring module to complete the insulation resistance detection of the new energy vehicle. Then the corresponding insulation resistance error is determined by the actual detected insulation resistance. If the error is small, the response time of the insulation resistance is continued to be obtained, and the response time is calibrated for compliance, that is, when the response time is less than the preset threshold, it is determined that the calibration is passed. The calibration passing indicates that the insulation resistance error is small and the response time is short, thereby solving the technical problem that the insulation resistance value of the existing HIL simulation test of new energy vehicles has errors. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 A schematic diagram of an embodiment of a vehicle insulation resistance detection system provided by the present invention;

[0035] Figure 2 A schematic diagram of another embodiment of the vehicle insulation resistance detection system provided by the present invention;

[0036] Figure 3 The present invention is a flowchart of an embodiment of a vehicle insulation resistance detection method provided by the present invention. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0038] In the description of the embodiments of the present application, unless otherwise specified, “plurality” means two or more than two.

[0039] The terms "including" and "having" and any variations thereof in the embodiments of the present invention are intended to cover non-exclusive inclusions. For example, a process, method, apparatus, product or equipment comprising a series of steps or modules is not necessarily limited to those steps or modules clearly listed, but may include other steps or modules not clearly listed or inherent to these processes, methods, products or equipment.

[0040] The naming or numbering of the steps in the embodiments of the present invention does not mean that the steps in the method flow must be executed in the time / logical sequence indicated by the naming or numbering. The execution order of the named or numbered process steps can be changed according to the technical purpose to be achieved, as long as the same or similar technical effects can be achieved.

[0041] Reference to an "embodiment" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0042] The present invention provides a vehicle insulation resistance detection system and detection method, which are respectively described below.

[0043] like Figure 1 As shown, the present invention provides a vehicle insulation resistance detection system 10, which includes:

[0044] The insulation resistance diagnostic module 12 includes a controller and a resistance module for simulating the degree of high-voltage insulation failure of the entire vehicle; Figure 2 , the resistance module is connected to the device under test 16 and the vehicle electrical environment electrode respectively, the resistance module includes a plurality of resistors, and the controller is used to select the connection mode of the resistors in the resistance module and adjust the resistance value;

[0045] The insulation resistance monitoring module 11 is used to detect the insulation resistance of the device under test 16, and determine the insulation resistance error based on the insulation resistance, and when the insulation resistance error is less than a preset error threshold, obtain the insulation resistance response time and perform compliance calibration on the insulation resistance response time.

[0046] It is understandable that the purpose of the insulation resistance monitoring system for new energy vehicles of the present invention is to solve the risk of high-voltage insulation failure caused by the defects of long reporting response time and large precision error of the insulation resistance of new energy commercial vehicles, so as to reduce the safety risk caused by high-voltage insulation failure during the use of the whole vehicle. In order to achieve that the insulation performance of the tested component 16 (i.e., the high-voltage component of the new energy vehicle) detected by the insulation resistance detection system is consistent with the actual insulation state, the vehicle insulation resistance detection system provided by the present invention includes an insulation resistance diagnosis module 12 and an insulation resistance monitoring module 11.

[0047] The insulation resistance monitoring module 11 includes a high-voltage insulation online detection system and a diagnostic module interface, which adds a diagnostic module interface to the high-voltage insulation online detection system. The insulation resistance diagnostic module 12 includes an all-in-one controller uploading insulation resistance response time diagnosis and insulation resistance accuracy diagnosis. The insulation resistance diagnostic module 12 includes a capacitor and a resistor. The insulation resistance diagnostic module 12 is connected to the insulation resistance monitoring module 11 through the diagnostic module interface on the insulation resistance monitoring module 11. Through the control strategy of the all-in-one controller, the response time and insulation resistance accuracy reported by the insulation resistance detection system of the new energy vehicle in use meet the technical requirements, thereby ensuring the high voltage safety of the vehicle.

[0048] The vehicle insulation resistance detection system 10 is provided with a first signal interface 13 for communicating with the outside, the insulation resistance monitoring module 11 is provided with a second signal interface 14 , and the insulation resistance diagnosis module 12 is provided with a third signal interface 15 , and the second signal interface 14 and the third signal interface 15 are communicatively connected.

[0049] In some embodiments, the resistance module includes: a first resistor 1211, a second resistor 1212 and a third resistor 1213; the insulation resistance diagnosis module 12 also includes: a selection switch device 123 and a grounding device 124;

[0050] The positive electrode of the device under test 16, the first resistor 1211, the positive electrode 121 of the vehicle electrical environment electrode, the selection switch device 123, the third resistor 1213 and the grounding device 124 are connected in sequence to form a positive interference circuit 21;

[0051] The negative electrode of the device under test 16, the second resistor 1212, the negative electrode 122 of the vehicle electrical environment electrode, the selection switch device 123, the third resistor 1213 and the grounding device 124 are connected in sequence to form a negative electrode interference circuit 22;

[0052] The selection switch device 123 is used to control the third resistor 1213 to be energized with the positive electrode 121 of the whole vehicle electrical environment electrode, or to be energized with the negative electrode 122 of the whole vehicle electrical environment electrode.

[0053] In some embodiments, the insulation resistance diagnostic module 12 further includes: a capacitor module for simulating an equivalent circuit of a whole vehicle; the capacitor module includes a first capacitor 1221 and a second capacitor 1222;

[0054] The first capacitor 1221 and the first resistor 1211 are connected in parallel, and the second capacitor 1222 and the second resistor 1212 are connected in parallel.

[0055] In some embodiments, the first capacitor 1221 and the second capacitor 1222 are both variable capacitors;

[0056] The capacitance range of the variable capacitor is 0.5 μF to 2.5 μF.

[0057] It can be understood that the capacitor module is used to simulate the equivalent circuit of the whole vehicle, and the capacitors in the capacitor module include Y capacitors and X capacitors. The specifications of the capacitors include 0.5μF, 1μF, 1.5μF, 2μF, and 2.5μF.

[0058] In some embodiments, the first resistor 1211, the second resistor 1212 and the third resistor 1213 are all variable resistors, and the range specifications of the variable resistors include 15MΩ and 1MΩ.

[0059] The capacitor devices and resistor devices in the insulation resistance diagnostic module 12 are respectively connected in parallel, and devices of different specifications can be selected through an all-in-one controller. After being connected to the insulation resistance monitoring module 11, the battery management system is controlled by the all-in-one controller strategy to report the insulation resistance value of the high-voltage system, thereby realizing the diagnosis of the response time and insulation accuracy of the insulation resistance monitoring module 11.

[0060] In summary, the vehicle insulation resistance detection system provided by the present invention includes: an insulation resistance diagnostic module 12, including a controller and a resistance module for simulating the degree of high-voltage insulation failure of the whole vehicle; the resistance module is respectively connected to the device under test 16 and the electrical environment electrode of the whole vehicle, the resistance module includes multiple resistors, and the controller is used to select the resistor connection method in the resistance module and adjust the resistance value; the insulation resistance monitoring module 11 is used to detect the insulation resistance of the device under test 16, and determine the insulation resistance error based on the insulation resistance, and when the insulation resistance error is less than a preset error threshold, obtain the insulation resistance response time, and perform compliance calibration on the insulation resistance response time.

[0061] The vehicle insulation resistance detection system provided by the present invention simulates the degree of high-voltage insulation failure of the whole vehicle through a resistance module composed of multiple resistors. The resistance module is connected to the test piece 16, which is the high-voltage system of the new energy vehicle. The connection mode and resistance value of each resistor in the resistance module are adjusted by the controller, and then the insulation resistance of the test piece 16 is detected by the insulation resistance monitoring module 11 to complete the insulation resistance detection of the new energy vehicle. Then the corresponding insulation resistance error is determined by the actual detected insulation resistance. If the error is small, the response time of the insulation resistance is continuously obtained, and the response time is calibrated for compliance. That is, when the response time is less than the preset threshold, it is determined that the calibration is passed. The calibration passing indicates that the insulation resistance error is small and the response time is short, thereby solving the technical problem that the insulation resistance value of the existing HIL simulation test of new energy vehicles has errors.

[0062] The present invention also provides a method for detecting insulation resistance of a vehicle, which is applied to any of the above-mentioned systems. Figure 3 As shown, the method comprises:

[0063] S301, selecting a resistor connection mode in a resistor module based on a controller, adjusting the resistor value, and obtaining a first positive insulation resistance to ground and a first negative insulation resistance to ground of the device under test 16 in a steady state;

[0064] S302, when the device under test 16 is in a steady state, based on the controller, increase the parallel resistance in the resistance module, adjust the resistance value of the increased parallel resistance, and obtain a second positive insulation resistance to ground and a second negative insulation resistance to ground of the device under test 16;

[0065] S303, determining the insulation resistance of the device under test 16 based on the first positive insulation resistance to ground and the first negative insulation resistance to ground, and the second positive insulation resistance to ground and the second negative insulation resistance to ground;

[0066] S304, determining an insulation resistance error based on the insulation resistance of the device under test 16, and when the insulation resistance error is less than a preset error threshold, obtaining an insulation resistance response time, and performing compliance calibration on the insulation resistance response time.

[0067] In some embodiments, the insulation resistance of the device under test 16 includes: a theoretical value of positive insulation resistance to ground and a theoretical value of negative insulation resistance to ground;

[0068] Determining the insulation resistance of the device under test 16 based on the first positive insulation resistance to ground and the first negative insulation resistance to ground, and the second positive insulation resistance to ground and the second negative insulation resistance to ground, includes:

[0069] The product of the first insulation resistance to ground and the second insulation resistance to ground is divided by the sum of the first insulation resistance to ground and the second insulation resistance to ground to obtain a theoretical value of the insulation resistance to ground;

[0070] The product of the first negative insulation resistance to ground and the second negative insulation resistance to ground is divided by the sum of the first negative insulation resistance to ground and the second negative insulation resistance to ground to obtain a theoretical value of the negative insulation resistance to ground.

[0071] In some embodiments, determining the insulation resistance error based on the insulation resistance of the device under test 16 includes:

[0072] The insulation resistance error is obtained by dividing the difference between the theoretical value of the insulation resistance to ground and the second insulation resistance to ground by the theoretical value of the insulation resistance to ground.

[0073] In some embodiments, before selecting the resistor connection mode in the resistor module based on the controller, the method further includes:

[0074] The capacitor module is configured based on the controller to simulate the equivalent circuit environment of the entire vehicle.

[0075] In other embodiments, the detection method provided by the present invention is not only applicable to the insulation resistance monitoring of new energy vehicle assemblies, but also applicable to the insulation resistance monitoring of high-voltage components of new energy vehicles. The specific steps are as follows:

[0076] Step 1: Vehicle electrical environment configuration:

[0077] For the device under test 16 (voltage system on the new energy vehicle), the insulation resistance diagnostic module 12 is configured through the all-in-one controller. The specifications of the capacitor components are configured according to the vehicle conditions, the vehicle electrical environment is simulated, and the insulation resistance of the positive and negative ground of the high-voltage system under test is recorded.

[0078] Step 2: Configuration of steady-state insulation resistance of high-voltage system:

[0079] After the vehicle electrical environment configuration is qualified, the variable resistor is configured through the all-in-one controller, and a 15 MΩ variable resistor is connected in parallel in the positive and negative ground circuits respectively. The parallel resistances are measured to include at least 15 MΩ, 13 MΩ, and 10 MΩ. After the variable resistors are connected in parallel, the insulation resistance is stable within 1 minute (this time can be set), which is considered that the software's ability to report insulation resistance meets the requirements. Record the reported positive insulation resistance R1 (i.e., the first positive insulation resistance to ground) and negative insulation resistance R2 (i.e., the first negative insulation resistance to ground) respectively.

[0080] Step 3: Variable resistor configuration:

[0081] On the basis of step 2, connect variable resistors in parallel, adjust the resistance value of the variable resistors in parallel to 1MΩ or 0.25MΩ, and record the positive insulation resistance R3 (i.e., the second positive insulation resistance to ground) and the negative insulation resistance R4 (i.e., the second negative insulation resistance to ground) reported by the system respectively.

[0082] Step 4: Insulation resistance error calibration:

[0083] The theoretical resistance value in steps 1 to 3 is R2. The system reading error (i.e., insulation resistance error) is w. Taking the resistance value of 1MΩ and the insulation resistance to ground as an example, the insulation resistance error calculation formula is as follows:

[0084] R2=R1*R3 / (R1+R3);

[0085] w=(R2-R3) / R2, the calculation result is a positive number.

[0086] When w is not greater than 20%, the insulation resistance error meets the requirements, and the battery management system software strategy meets the requirements for insulation resistance detection performance.

[0087] Step 5: Insulation resistance response time compliance calibration:

[0088] Insulation resistance response time compliance calibration in case of primary insulation fault.

[0089] When step 4 meets the requirements, carry out the insulation resistance response time calibration for the first-level insulation fault. The insulation resistance response time refers to the time from the resistor being connected in parallel to the high-voltage system to the time when the battery management system reports the target insulation resistance value. Adjust the resistance value to 0.2MΩ, connect it in parallel to the high-voltage system, and record the time required for the positive or negative insulation resistance to ground reported by the battery management system to be no greater than 0.2MΩ. The time should not exceed 20s, otherwise the calibration will fail.

[0090] Insulation resistance response time compliance calibration in case of secondary insulation fault.

[0091] When the insulation resistance response time calibration for the first-level insulation fault meets the requirements, the insulation resistance response time calibration for the second-level insulation fault is carried out. The insulation resistance response time refers to the time from the time the resistor is connected in parallel to the high-voltage system to the time when the battery management system reports the target insulation resistance value. The resistance value is adjusted to 0.01MΩ, connected in parallel to the high-voltage system, and the time required for the positive or negative insulation resistance to ground reported by the battery management system to be no greater than 0.01MΩ is recorded. The time should not exceed 10s, otherwise the calibration will fail.

[0092] In one embodiment, the insulation resistance monitoring system of sample A is tested at an ambient temperature of 25°C±10°C.

[0093] First, configure the 1μF vehicle electrical environment for the positive and negative grounds through the all-in-one controller, and then configure the 15MΩ high-voltage system steady-state insulation resistance for the positive and negative grounds, and record the positive-to-ground insulation resistance R1=13271 kΩ reported by the battery management system. Only configure the variable resistor R=0.25MΩ for the positive ground, and record the positive-to-ground insulation resistance R3=219.54kΩ reported by the battery management system. Calculate the insulation resistance R2=245.37kΩ of the high-voltage system after interference. The calculated test error of the positive-to-ground insulation resistance of the battery system of sample A is 10.53%. The insulation accuracy tested by the insulation resistance monitoring system meets the requirements.

[0094] In one embodiment, the insulation resistance monitoring system of sample A is tested at an ambient temperature of 25°C±10°C.

[0095] First, configure the 2μF vehicle electrical environment for the positive and negative grounds through the all-in-one controller, and then configure the 15MΩ high-voltage system steady-state insulation resistance for the positive and negative grounds, and record the negative insulation resistance R2=2710kΩ reported by the battery management system. Only configure the variable resistor R=0.25MΩ for the negative ground, and record the positive insulation resistance R4=210kΩ reported by the battery management system. Calculate the insulation resistance R2=228.89kΩ of the high-voltage system after interference. The calculated test error of the positive insulation resistance of the battery system of sample A is 8.25%. The insulation accuracy tested by the insulation resistance monitoring system meets the requirements.

[0096] In one embodiment, the insulation resistance monitoring system of sample A is tested at an ambient temperature of 25°C±10°C.

[0097] First, use the all-in-one controller to configure the 2μF vehicle electrical environment for the positive and negative grounds, and then configure the 15MΩ high-voltage system steady-state insulation resistance for the positive and negative grounds. Only the variable resistor R=0.2MΩ is configured for the negative ground, and the high-voltage system starts with the variable resistor in parallel. It takes 18s until the battery management system reports that the insulation resistance between the negative and ground is 0.18MΩ. Only the variable resistor R=0.2MΩ is configured for the positive ground, and the high-voltage system starts with the variable resistor in parallel. It takes 16s until the battery management system reports that the insulation resistance between the negative and ground is 0.18MΩ. The response time of the insulation resistance monitoring system test meets the requirements.

[0098] In one embodiment, the insulation resistance monitoring system of sample A is tested at an ambient temperature of 25°C±10°C.

[0099] First, use the all-in-one controller to configure the 2μF vehicle electrical environment for the positive and negative grounds, and then configure the 15MΩ high-voltage system steady-state insulation resistance for the positive and negative grounds. Only the variable resistor R=0.01MΩ is configured for the negative ground, and the high-voltage system starts with the variable resistor in parallel. It takes 11s until the battery management system reports that the insulation resistance between the negative and ground is 0.01MΩ. Only the variable resistor R=0.01MΩ is configured for the positive ground, and the high-voltage system starts with the variable resistor in parallel. It takes 13s until the battery management system reports that the insulation resistance between the negative and ground is 0.009MΩ. The response time of the insulation resistance monitoring system test does not meet the requirements, and the software control strategy needs to be revised.

[0100] The vehicle insulation resistance detection system and detection method provided by the present invention are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for technical personnel in this field, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A vehicle insulation resistance detection system, characterized in that: include: The insulation resistance diagnostic module includes a controller and a resistance module for simulating the degree of high-voltage insulation failure of the whole vehicle; the resistance module is respectively connected to the tested device and the electrical environment electrode of the whole vehicle, the resistance module includes a plurality of resistors, and the controller is used to select the connection mode of the resistors in the resistance module and adjust the resistance value; An insulation resistance monitoring module is used to detect the insulation resistance of the device under test, and determine the insulation resistance error based on the insulation resistance, and when the insulation resistance error is less than a preset error threshold, obtain the insulation resistance response time, and perform compliance calibration on the insulation resistance response time; The insulation resistance response time refers to the time from when the resistance module is connected in parallel with the positive-to-ground or negative-to-ground circuit of the device under test to when the battery management system reports the target insulation resistance value; The vehicle insulation resistance detection system is used for: Based on the controller, a resistor connection mode in the resistor module is selected, and the resistance value is adjusted, and a first positive insulation resistance to ground and a first negative insulation resistance to ground of the device under test in a steady state are obtained; When the device under test is in a steady state, based on the controller, the parallel resistance in the resistance module is increased, the resistance value of the increased parallel resistance is adjusted, and a second positive insulation resistance to ground and a second negative insulation resistance to ground of the device under test are obtained; Determine the insulation resistance of the device under test based on the first positive insulation resistance to ground and the first negative insulation resistance to ground, and the second positive insulation resistance to ground and the second negative insulation resistance to ground; Determining an insulation resistance error based on the insulation resistance of the measured device, and when the insulation resistance error is less than a preset error threshold, obtaining an insulation resistance response time, and performing compliance calibration on the insulation resistance response time; The insulation resistance of the measured device includes: a theoretical value of the positive insulation resistance to ground and a theoretical value of the negative insulation resistance to ground; Determining the insulation resistance of the device under test based on the first positive insulation resistance to ground and the first negative insulation resistance to ground, and the second positive insulation resistance to ground and the second negative insulation resistance to ground, includes: The product of the first insulation resistance to ground and the second insulation resistance to ground is divided by the sum of the first insulation resistance to ground and the second insulation resistance to ground to obtain a theoretical value of the insulation resistance to ground; The product of the first negative insulation resistance to ground and the second negative insulation resistance to ground is divided by the sum of the first negative insulation resistance to ground and the second negative insulation resistance to ground to obtain a theoretical value of the negative insulation resistance to ground; Determining an insulation resistance error based on the insulation resistance of the device under test includes: Based on the difference between the theoretical value of the insulation resistance to ground and the second insulation resistance to ground, divided by the theoretical value of the insulation resistance to ground, an insulation resistance error is obtained; The resistance module includes: a first resistor, a second resistor and a third resistor; the insulation resistance diagnosis module also includes: a selection switch device and a grounding device; The positive electrode of the device under test, the first resistor, the positive electrode of the vehicle electrical environment electrode, the selection switch device, the third resistor and the grounding device are connected in sequence; The negative electrode of the device under test, the second resistor, the negative electrode of the vehicle electrical environment electrode, the selection switch device, the third resistor and the grounding device are connected in sequence; The selection switch device is used to control the third resistor to be energized with the positive electrode of the whole vehicle electrical environment electrode, or to be energized with the negative electrode of the whole vehicle electrical environment electrode.

2. The vehicle insulation resistance detection system according to claim 1, characterized in that: The insulation resistance diagnostic module further includes: a capacitor module for simulating an equivalent circuit of a whole vehicle; the capacitor module includes a first capacitor and a second capacitor; The first capacitor and the first resistor are connected in parallel, and the second capacitor and the second resistor are connected in parallel.

3. The vehicle insulation resistance detection system according to claim 2, characterized in that: The first capacitor and the second capacitor are both variable capacitors; The capacitance range of the variable capacitor is 0.5 μF to 2.5 μF.

4. The vehicle insulation resistance detection system according to claim 1, characterized in that: The first resistor, the second resistor and the third resistor are all variable resistors.

5. The vehicle insulation resistance detection system according to claim 4, characterized in that: The range specifications of the variable resistor include 15MΩ and 1MΩ.

6. A method for detecting insulation resistance of a vehicle, characterized in that: The method is applied to the system according to any one of claims 1 to 5, and the method comprises: Based on the controller, a resistor connection mode in the resistor module is selected, and the resistance value is adjusted, and a first positive insulation resistance to ground and a first negative insulation resistance to ground of the device under test in a steady state are obtained; When the device under test is in a steady state, based on the controller, the parallel resistance in the resistance module is increased, the resistance value of the increased parallel resistance is adjusted, and a second positive insulation resistance to ground and a second negative insulation resistance to ground of the device under test are obtained; Determine the insulation resistance of the device under test based on the first positive insulation resistance to ground and the first negative insulation resistance to ground, and the second positive insulation resistance to ground and the second negative insulation resistance to ground; An insulation resistance error is determined based on the insulation resistance of the measured device, and when the insulation resistance error is less than a preset error threshold, an insulation resistance response time is obtained, and compliance calibration is performed on the insulation resistance response time.

7. The vehicle insulation resistance detection method according to claim 6, characterized in that: Before selecting the resistor connection method in the resistor module based on the controller, it also includes: The capacitor module is configured based on the controller to simulate the equivalent circuit environment of the entire vehicle.

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