Insulation resistance detection system and vehicle

Abstract

The invention provides an insulation resistance detection system and a vehicle, and belongs to the technical field of vehicles. The insulation resistance detection system comprises a detection circuit, a first selection switch, a second selection switch and a controller. The controller is used for performing insulation resistance detection on the HV1 positive electrode interface and the HV1 negative electrode interface based on the control circuit when a detection instruction of a target vehicle is received, so as to obtain a first positive electrode insulation resistance and a first negative electrode insulation resistance; performing insulation resistance detection on the HV2 positive electrode interface and the HV2 negative electrode interface based on the control circuit to obtain a second positive electrode insulation resistance and a second negative electrode insulation resistance; insulation resistance detection is carried out on the positive electrode interface and the negative electrode interface of the vehicle-mounted charger based on the control circuit, and third positive electrode insulation resistance and third negative electrode insulation resistance are obtained. By adopting the method and the device, technical detection can be performed on the potential safety hazard of each part under the condition that the vehicle is not powered on, so that the safety of the target vehicle is improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of vehicles, and in particular, to an insulation resistance detection system and a vehicle. Background Art

[0002] Insulation resistance detection is an important function to ensure the insulation safety of a vehicle, and its performance is directly related to the safety of passengers.

[0003] Generally, insulation resistance detection is to detect the insulation resistance between the positive and negative poles of HV1 of the power battery of the vehicle before the vehicle is powered on, that is, to detect the insulation resistance of the power battery before the vehicle is powered on, and then to determine whether the current vehicle is safe based on the detected insulation resistance of the power battery.

[0004] However, the above insulation resistance detection is relatively rough and there are still many potential safety hazards. Summary of the Invention

[0005] The present disclosure provides an insulation resistance detection system and a vehicle, which can increase the safety detection of potential hazards, thereby improving the safety of the target vehicle. The technical solutions are as follows:

[0006] On the one hand, the present disclosure provides an insulation resistance detection system, which includes a detection circuit, a first selection switch, a second selection switch, and a controller;

[0007] The detection circuit has a positive detection interface and a negative detection interface;

[0008] The controller is electrically connected to the detection circuit, the first selection switch, and the second selection switch. The controller is configured to:

[0009] When receiving a detection instruction of the target vehicle, control the first selection switch to electrically connect the positive detection interface to the HV1 positive interface of the power battery of the target vehicle, control the second selection switch to electrically connect the negative detection interface to the HV1 negative interface of the power battery, and perform insulation resistance detection on the HV1 positive interface and the HV1 negative interface based on the control circuit to obtain a first positive insulation resistance and a first negative insulation resistance;

[0010] Control the first selection switch to electrically connect the positive detection interface to the HV2 positive interface of the target load powered by the power battery, control the second selection switch to electrically connect the negative detection interface to the HV2 negative interface of the target load, and perform insulation resistance detection on the HV2 positive interface and the HV2 negative interface based on the control circuit to obtain a second positive insulation resistance and a second negative insulation resistance;

[0011] Control the first selection switch to electrically connect the positive detection interface to the positive interface of the on-vehicle charger of the target vehicle, control the second selection switch to electrically connect the negative detection interface to the negative interface of the on-vehicle charger, and perform insulation resistance detection on the positive interface and the negative interface of the on-vehicle charger based on the control circuit to obtain a third positive insulation resistance and a third negative insulation resistance;

[0012] Based on the first positive insulation resistance, the first negative insulation resistance, the second positive insulation resistance, the second negative insulation resistance, the third positive insulation resistance, the third negative insulation resistance, and a preset detection standard, perform insulation detection on the target vehicle.

[0013] In a possible implementation manner, the controller is configured to:

[0014] When receiving a detection instruction of the target vehicle, control the main positive switch between the HV1 positive interface and the HV2 positive interface, and the main negative switch between the HV1 negative interface and the HV2 negative interface to be in an off state.

[0015] In a possible implementation manner, the controller is further configured to:

[0016] When controlling the first selection switch to electrically connect the positive detection interface to the HV2 positive interface and controlling the second selection switch to electrically connect the negative detection interface to the HV2 negative interface, control the power device of the target vehicle to perform reverse pre-charge power supply to the target load.

[0017] In a possible implementation manner, the target load includes a motor;

[0018] The controller is configured to:

[0019] When controlling the first selection switch to electrically connect the positive detection interface to the HV2 positive interface and controlling the second selection switch to electrically connect the negative detection interface to the HV2 negative interface, provide a preset control id current or a preset control iq current to the motor, and control the motor to be in a stopped rotation state.

[0020] In a possible implementation manner, the target load includes a heater;

[0021] The controller is configured to:

[0022] When controlling the first selection switch to electrically connect the positive detection interface to the HV2 positive interface and controlling the second selection switch to electrically connect the negative detection interface to the HV2 negative interface, a preset low duty cycle current is provided to the heater.

[0023] In a possible implementation, the controller is configured to:

[0024] When controlling the first selection switch to electrically connect the positive detection interface to the HV2 positive interface and controlling the second selection switch to electrically connect the negative detection interface to the HV2 negative interface, control the battery and the DCDC (Direct Current-to-Direct Current converter) to perform reverse pre-charge power supply to the target load.

[0025] In a possible implementation, after performing insulation detection on the target vehicle, the controller is further configured to:

[0026] Control the DCDC to discharge the battery.

[0027] In a possible implementation, the preset detection standard includes a first standard insulation resistance range corresponding to the power battery, a second standard insulation resistance range corresponding to the target load, and a third standard insulation resistance range corresponding to the on-vehicle charger;

[0028] The controller is configured to:

[0029] If the first positive insulation resistance and the first negative insulation resistance meet the first standard insulation resistance range, the second positive insulation resistance and the second negative insulation resistance meet the second standard insulation resistance range, and the third positive insulation resistance and the third negative insulation resistance meet the third standard insulation resistance range, it is determined that the first positive insulation resistance, the first negative insulation resistance, the second positive insulation resistance, the second negative insulation resistance, the third positive insulation resistance, and the third negative insulation resistance are in a safe state.

[0030] In a possible implementation, the controller is further configured to:

[0031] If the first positive insulation resistance and the first negative insulation resistance do not meet the first standard insulation resistance range, and / or the second positive insulation resistance and the second negative insulation resistance do not meet the second standard insulation resistance range, and / or the third positive insulation resistance and the third negative insulation resistance do not meet the third standard insulation resistance range, an alarm message is issued.

[0032] On the other hand, the present disclosure provides a vehicle, which includes the insulation resistance detection system as described in any one of the above.

[0033] The technical solution provided by the present disclosure at least includes the following beneficial effects:

[0034] The present disclosure provides an insulation resistance detection system, which can detect not only the first positive pole insulation resistance and the first negative pole insulation resistance corresponding to the power battery of the target vehicle, but also the second positive pole insulation resistance and the second negative pole insulation resistance corresponding to the target load, as well as the third positive pole insulation resistance and the third negative pole insulation resistance of the on-vehicle charger of the target vehicle. In this way, the potential safety hazards of each component in the target vehicle can be detected skillfully all day long when the vehicle is not powered on, thereby improving the safety of the target vehicle.

[0035] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present disclosure. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0037] Figure 1 is a schematic diagram of the circuit topology of an insulation resistance detection system shown in an embodiment of the present disclosure;

[0038] Figure 2 is a schematic diagram of the circuit topology of a power battery and a target load shown in an embodiment of the present disclosure;

[0039] Figure 3 is a schematic diagram of the circuit topology of an insulation resistance detection system shown in an embodiment of the present disclosure;

[0040] Figure 4 is a schematic diagram of the circuit topology of an insulation resistance detection system shown in an embodiment of the present disclosure;

[0041] Figure 5 is a system block diagram of a power device of a target vehicle shown in an embodiment of the present disclosure.

[0042] LEGEND DESCRIPTION

[0043] 1. Detection circuit; 11. Positive pole detection interface; 12. Negative pole detection interface; 13. Vehicle body interface;

[0044] 2. First selection switch; 21. First interface; 22. Second interface; 23. Third interface; 24. Fourth interface;

[0045] 3. Second selection switch; 31. Fifth interface; 32. Sixth interface; 33. Seventh interface; 34. Eighth interface;

[0046] 4. Power battery;

[0047] 5. Target load;

[0048] 6. On-vehicle charger;

[0049] 7. Storage battery. Specific embodiments

[0050] Unless otherwise defined, the technical terms or scientific terms used herein shall have the ordinary meanings as understood by those of ordinary skill in the art to which this disclosure pertains. The terms "first", "second", "third" and similar terms used in the specification and claims of this patent application of the disclosure do not denote any order, quantity or importance, but are only used to distinguish different components. Similarly, terms such as "a" or "an" do not denote a quantity limitation, but mean that there is at least one. The terms "comprising" or "including" and similar terms are intended to mean that the elements or items appearing before "comprising" or "including" cover the elements or items listed after "comprising" or "including" and their equivalents, without excluding other elements or items. The terms "connected" or "coupled" and similar terms are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The terms "upper", "lower", "left", "right", etc. are only used to indicate relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationships may also change accordingly.

[0051] To make the objectives, technical solutions and advantages of this disclosure clearer, the embodiments of this disclosure will be further described in detail below with reference to the accompanying drawings.

[0052] The embodiments of this disclosure provide an insulation resistance detection system. Refer to Figure 1 , the insulation resistance detection system includes a detection circuit 1, a first selection switch 2, a second selection switch 3 and a controller.

[0053] The detection circuit 1 has a positive detection interface 11 and a negative detection interface 12, and the positive detection interface 11 and the negative detection interface 12 are used to connect the detection circuit 1 to both the positive and negative sides of the device to be detected, so as to perform insulation resistance detection on the device to be detected through the detection circuit 1.

[0054] The first selection switch 2 and the second selection switch 3 are switches that can select electrical connections among multiple items.

[0055] See Figure 1 Figure 1 , the first selection switch 2 has a first interface 21, a second interface 22, a third interface 23, and a fourth interface 24. The first interface 21 is electrically connected to the positive electrode detection interface 11. The second interface 22 is electrically connected to the HV1 positive electrode interface of the power battery 4 of the target vehicle (i.e., Figure 1 the HV1+ shown), the third interface 23 is electrically connected to the HV2 positive electrode interface of the target load 5 powered by the power battery 4 (i.e., Figure 1 the HV2+ shown), and the fourth interface 24 is electrically connected to the positive electrode interface of the on-vehicle charger 6 of the target vehicle (i.e., Figure 1 the ACL shown).

[0056] Among them, the first selection switch 2 can, under the instruction of the controller, control the first interface 21 to be electrically connected to the second interface 22 to realize the electrical connection between the positive electrode detection interface 11 and the HV1 positive electrode interface, or control the first interface 21 to be electrically connected to the third interface 23 to realize the electrical connection between the positive electrode detection interface 11 and the HV2 positive electrode interface, or control the first interface 21 to be electrically connected to the fourth interface 24 to realize the electrical connection between the positive electrode detection interface 11 and the positive electrode interface of the on-vehicle charger 6.

[0057] The second selection switch 3 has a fifth interface 31, a sixth interface 32, a seventh interface 33, and an eighth interface 34. The fifth interface 31 is electrically connected to the negative electrode detection interface 12. The sixth interface 32 is electrically connected to the HV1 negative electrode interface of the power battery 4 (i.e., Figure 1 the HV1- shown), the seventh interface 33 is electrically connected to the HV2 negative electrode interface of the target load 5 (i.e., Figure 1 the HV2- shown), and the eighth interface 34 is electrically connected to the negative electrode interface of the on-vehicle charger 6 (i.e., Figure 1 the ACN shown).

[0058] Among them, the second selection switch 3 can, under the instruction of the controller, control the fifth interface 31 to be electrically connected to the sixth interface 32 to realize the electrical connection between the negative electrode detection interface 12 and the HV1 negative electrode interface, or control the fifth interface 31 to be electrically connected to the seventh interface 33 to realize the electrical connection between the negative electrode detection interface 12 and the HV2 negative electrode interface, or control the fifth interface 31 to be electrically connected to the eighth interface 34 to realize the electrical connection between the negative electrode detection interface 12 and the negative electrode interface of the on-vehicle charger 6.

[0059] The controller is electrically connected to the detection circuit 1, the first selection switch 2, and the second selection switch 3. The controller can be a BMS (Battery Management System) or a controller in other forms, and the embodiments of the present disclosure do not limit it. The controller is used for:

[0060] When receiving a detection instruction of the target vehicle, control the first selection switch 2 to electrically connect the positive detection interface 11 to the HV1 positive interface of the power battery 4 of the target vehicle, control the second selection switch 3 to electrically connect the negative detection interface 12 to the HV1 negative interface of the power battery 4, and perform insulation resistance detection on the HV1 positive interface and the HV1 negative interface based on the control circuit to obtain the first positive insulation resistance and the first negative insulation resistance.

[0061] Control the first selection switch 2 to electrically connect the positive detection interface 11 to the HV2 positive interface of the target load 5 powered by the power battery 4, control the second selection switch 3 to electrically connect the negative detection interface 12 to the HV2 negative interface of the target load 5, and perform insulation resistance detection on the HV2 positive interface and the HV2 negative interface based on the control circuit to obtain the second positive insulation resistance and the second negative insulation resistance.

[0062] Control the first selection switch 2 to electrically connect the positive detection interface 11 to the positive interface of the on-vehicle charger 6 of the target vehicle, control the second selection switch 3 to electrically connect the negative detection interface 12 to the negative interface of the on-vehicle charger 6, and perform insulation resistance detection on the positive interface and the negative interface of the on-vehicle charger 6 based on the control circuit to obtain the third positive insulation resistance and the third negative insulation resistance.

[0063] Perform insulation detection on the target vehicle based on the first positive insulation resistance, the first negative insulation resistance, the second positive insulation resistance, the second negative insulation resistance, the third positive insulation resistance, the third negative insulation resistance, and the preset detection standard.

[0064] In implementation, the detection instruction of the target vehicle can be a power-on instruction or a wake-up instruction, etc. When the controller detects a detection prompt of the target vehicle, before controlling the power-on or wake-up of the target vehicle, etc., it is possible to detect the first positive insulation resistance of the HV1 positive interface of the power battery 4 of the target vehicle and the first negative insulation resistance of the HV1 negative interface of the power battery 4. The detection method is: See Figure 1, the controller controls the first interface 21 and the second interface 22 to conduct, so as to electrically connect the positive electrode detection interface 11 of the detection circuit 1 with the HV1 positive electrode interface, and controls the fifth interface 31 and the sixth interface 32 to conduct, so as to electrically connect the negative electrode detection interface 12 of the detection circuit 1 with the HV1 negative electrode interface. Then, the controller can control each device inside the detection circuit 1, and use the detection circuit 1 to detect the insulation resistance of the HV1 positive electrode interface and the HV1 negative electrode interface, so as to obtain the first positive electrode insulation resistance and the first negative electrode insulation resistance.

[0065] Among them, referring to Figure 2 , the HV1 positive electrode interface and the HV1 negative electrode interface of the power battery 4 are the interfaces at both ends of the positive and negative electrodes of the power battery 4 when the target vehicle is not powered on or not awakened (that is, Figure 2 the main positive switch S1 and the main negative switch S2 in are both in the off state). The first positive electrode insulation resistance is the resistance value between the positive electrode end interface of the power battery 4 (that is, the HV1 positive electrode interface) and the vehicle body end interface of the target vehicle (that is, Figure 1 the vehicle body interface 13 in). The first negative electrode insulation resistance is the resistance value between the negative electrode end interface of the power battery 4 (that is, the HV1 negative electrode interface) and the vehicle body end interface of the target vehicle (that is, the vehicle body interface 13).

[0066] It can be understood that when the first interface 21 and the second interface 22 conduct, the first interface 21 and the third interface 23 are in the off state, and the first interface 21 and the fourth interface 24 are also in the off state. Similarly, when the fifth interface 31 and the sixth interface 32 conduct, the fifth interface 31 and the seventh interface 33 are in the off state, and the fifth interface 31 and the eighth interface 34 are also in the off state.

[0067] In the embodiment of the present disclosure, before controlling the target vehicle to be powered on or awakened and other operations, the second positive electrode insulation resistance of the HV2 positive electrode interface of the target load 5 powered by the power battery 4 of the target vehicle, and the second negative electrode insulation resistance of the HV2 negative electrode interface of the target load 5 can also be detected. The detection method is: referring to Figure 3 , the controller controls the first interface 21 and the third interface 23 to conduct, so as to electrically connect the positive electrode detection interface 11 of the detection circuit 1 with the HV2 positive electrode interface, and controls the fifth interface 31 and the seventh interface 33 to conduct, so as to electrically connect the negative electrode detection interface 12 of the detection circuit 1 with the HV2 negative electrode interface. Then, the controller can control each device inside the detection circuit 1, and use the detection circuit 1 to detect the insulation resistance of the HV2 positive electrode interface and the HV2 negative electrode interface, so as to obtain the second positive electrode insulation resistance and the second negative electrode insulation resistance.

[0068] When detecting the second positive insulation resistance and the second negative insulation resistance as described above, the target vehicle is still in an unpowered state, that is Figure 2 the main positive switch S1 and the main negative switch S2 in Figure 2 are both in the off state, and the power battery 4 does not supply power to drive the target load 5. Therefore, in the embodiments of the present disclosure, before detecting the second positive insulation resistance and the second negative insulation resistance, the controller can control the power device to supply power to the target load 5, so as to simulate the situation after the target vehicle is powered on, and then detect the accurate second positive insulation resistance and the second negative insulation resistance. The specific method will be described in detail below and will not be elaborated here.

[0069] Among them, the above-mentioned target load 5 can be any load combination among all the loads powered by the power battery 4 in the target vehicle, or can directly be all the loads powered by the power battery 4 in the target vehicle.

[0070] It can be understood that when the first interface 21 is electrically connected to the third interface 23, the first interface 21 is in a disconnected state from the second interface 22, and the first interface 21 is also in a disconnected state from the fourth interface 24. Similarly, when the fifth interface 31 is electrically connected to the seventh interface 33, the fifth interface 31 is in a disconnected state from the sixth interface 32, and the fifth interface 31 is also in a disconnected state from the eighth interface 34.

[0071] In the embodiments of the present disclosure, before controlling the target vehicle to be powered on or awakened, etc., it is also possible to detect the third positive insulation resistance of the positive electrode interface of the on-vehicle charger 6 of the target vehicle and the third negative insulation resistance of the negative electrode interface of the on-vehicle charger 6. The detection method is as follows: Refer to Figure 4 , the controller controls the first interface 21 to be electrically connected to the fourth interface 24 to realize the electrical connection between the positive electrode detection interface 11 of the detection circuit 1 and the positive electrode interface of the on-vehicle charger, and controls the fifth interface 31 to be electrically connected to the eighth interface 34 to realize the electrical connection between the negative electrode detection interface 12 of the detection circuit 1 and the negative electrode interface of the on-vehicle charger. Then, the controller can control each device inside the detection circuit 1, and use the detection circuit 1 to detect the insulation resistance of the positive electrode interface and the negative electrode interface of the on-vehicle charger, and then obtain the third positive insulation resistance and the third negative insulation resistance.

[0072] It can be understood that when the first interface 21 is electrically connected to the fourth interface 24, the first interface 21 is in a disconnected state from the second interface 22, and the first interface 21 is also in a disconnected state from the third interface 23. Similarly, when the fifth interface 31 is electrically connected to the eighth interface 34, the fifth interface 31 is in a disconnected state from the sixth interface 32, and the fifth interface 31 is also in a disconnected state from the seventh interface 33.

[0073] In this way, through the insulation resistance detection system, the first positive pole insulation resistance, the first negative pole insulation resistance, the second positive pole insulation resistance, the second negative pole insulation resistance, the third positive pole insulation resistance, and the third negative pole insulation resistance can be obtained. Thus, before the target vehicle is powered on, the insulation resistance of both the positive and negative poles of the power battery 4, the positive and negative poles of the target load 5, and the positive and negative poles of the on-vehicle charger 6 are detected. Thereby, safety detection of the devices such as the power battery 4, the target load 5, and the on-vehicle charger 6 on the target vehicle that may pose safety hazards is set up. It is possible to perform all-weather skilled detection of the safety hazards of each component on the target vehicle when the target vehicle is not powered on, thereby improving the safety of the target vehicle.

[0074] It can be understood that the insulation resistance detection system provided by the embodiments of the present disclosure does not specifically limit the detection sequence of the above three detection methods in practical applications. The above description sequence is only one of the possible implementation manners listed, and the sequence can be set according to actual situations and requirements.

[0075] After obtaining the first positive pole insulation resistance, the first negative pole insulation resistance, the second positive pole insulation resistance, the second negative pole insulation resistance, the third positive pole insulation resistance, and the third negative pole insulation resistance, the controller can perform insulation detection on the target vehicle based on the obtained first positive pole insulation resistance, first negative pole insulation resistance, second positive pole insulation resistance, second negative pole insulation resistance, third positive pole insulation resistance, third negative pole insulation resistance, and the preset detection standard.

[0076] In one possible implementation manner, the preset detection standard includes the first standard insulation resistance range corresponding to the power battery 4, the second standard insulation resistance range corresponding to the target load 5, and the third standard insulation resistance range corresponding to the on-vehicle charger 6.

[0077] The controller is configured to: if the first positive pole insulation resistance and the first negative pole insulation resistance conform to the first standard insulation resistance range, the second positive pole insulation resistance and the second negative pole insulation resistance conform to the second standard insulation resistance range, and the third positive pole insulation resistance and the third negative pole insulation resistance conform to the third standard insulation resistance range, then determine that the first positive pole insulation resistance, the first negative pole insulation resistance, the second positive pole insulation resistance, the second negative pole insulation resistance, the third positive pole insulation resistance, and the third negative pole insulation resistance are in a safe state.

[0078] In implementation, after obtaining the first positive pole insulation resistance, the first negative pole insulation resistance, the second positive pole insulation resistance, the second negative pole insulation resistance, the third positive pole insulation resistance, and the third negative pole insulation resistance, the controller can determine whether the first positive pole insulation resistance and the first negative pole insulation resistance meet the first standard insulation resistance range, determine whether the second positive pole insulation resistance and the second negative pole insulation resistance meet the second standard insulation resistance range, and determine whether the third positive pole insulation resistance and the third negative pole insulation resistance meet the third standard insulation resistance range. If all of the above three determinations are met, it is determined that the first positive pole insulation resistance, the first negative pole insulation resistance, the second positive pole insulation resistance, the second negative pole insulation resistance, the third positive pole insulation resistance, and the third negative pole insulation resistance are in a safe state, indicating that the power battery 4, the target load 5, and the on-vehicle charger 6 of the target vehicle are in a safe state, and there are no short circuits, leakage, or other situations occurring.

[0079] After determining that the above six insulation resistances are all in a safe state, the controller can control the target vehicle to perform subsequent power-on processing.

[0080] In a possible implementation manner, the controller is further configured to: if the first positive pole insulation resistance and the first negative pole insulation resistance do not meet the first standard insulation resistance range, and / or, the second positive pole insulation resistance and the second negative pole insulation resistance do not meet the second standard insulation resistance range, and / or, the third positive pole insulation resistance and the third negative pole insulation resistance do not meet the third standard insulation resistance range, then send out an alarm message.

[0081] In implementation, if at least one of the above three determinations does not meet, it indicates that one or more of the power battery 4, the target load 5, and the on-vehicle charger 6 of the target vehicle are in an unsafe state, that is, a short circuit, leakage, or other situations may have occurred. At this time, the target vehicle can send out an alarm message to remind the user that there is a problem with the target vehicle and maintenance is required.

[0082] Specific situations are as follows: If the first positive pole insulation resistance and the first negative pole insulation resistance do not meet the first standard insulation resistance range while others meet the requirements, it indicates that there is a problem with the power battery 4 of the target vehicle; if the second positive pole insulation resistance and the second negative pole insulation resistance do not meet the second standard insulation resistance range while others meet the requirements, it indicates that there is a problem with the target load 5 of the target vehicle; if the third positive pole insulation resistance and the third negative pole insulation resistance do not meet the third standard insulation resistance range while others meet the requirements, it indicates that there is a problem with the on-vehicle charger 6 of the target vehicle; if the first positive pole insulation resistance and the first negative pole insulation resistance do not meet the first standard insulation resistance range, and the second positive pole insulation resistance and the second negative pole insulation resistance do not meet the second standard insulation resistance range while others meet the requirements, it indicates that there are problems with the power battery 4 and the target load 5 of the target vehicle; if the first positive pole insulation resistance and the first negative pole insulation resistance do not meet the first standard insulation resistance range, and the third positive pole insulation resistance and the third negative pole insulation resistance do not meet the third standard insulation resistance range while others meet the requirements, it indicates that there are problems with the power battery 4 and the on-vehicle charger 6 of the target vehicle; if the second positive pole insulation resistance and the second negative pole insulation resistance do not meet the second standard insulation resistance range, and the third positive pole insulation resistance and the third negative pole insulation resistance do not meet the third standard insulation resistance range while others meet the requirements, it indicates that there are problems with the target load 5 and the on-vehicle charger 6 of the target vehicle; if the first positive pole insulation resistance and the first negative pole insulation resistance do not meet the first standard insulation resistance range, the second positive pole insulation resistance and the second negative pole insulation resistance do not meet the second standard insulation resistance range, and the third positive pole insulation resistance and the third negative pole insulation resistance do not meet the third standard insulation resistance range, it indicates that there are problems with the power battery 4, the target load 5, and the on-vehicle charger 6 of the target vehicle.

[0083] Based on the above judgments, the alarm information can prompt the device with problems among the power battery 4, the target load 5, and the on-vehicle charger 6, so that users can perform precise maintenance.

[0084] In the embodiment of the present disclosure, the first standard insulation resistance range includes the first positive pole standard insulation resistance range and the first negative pole standard insulation resistance range. If the obtained first positive pole insulation resistance meets the first positive pole standard insulation resistance range and the first negative pole insulation resistance meets the first negative pole standard insulation resistance range, it indicates that the first positive pole insulation resistance and the first negative pole insulation resistance meet the first standard insulation resistance range. If the first positive pole insulation resistance does not meet the first positive pole standard insulation resistance range and / or the first negative pole insulation resistance does not meet the first negative pole standard insulation resistance range, it indicates that the first positive pole insulation resistance and the first negative pole insulation resistance do not meet the first standard insulation resistance range.

[0085] Similarly, the second standard insulation resistance range includes a second positive standard insulation resistance range and a second negative standard insulation resistance range. If the obtained second positive insulation resistance meets the second positive standard insulation resistance range and the second negative insulation resistance meets the second negative standard insulation resistance range, it indicates that the second positive insulation resistance and the second negative insulation resistance meet the second standard insulation resistance range. If the second positive insulation resistance does not meet the second positive standard insulation resistance range, and / or the second negative insulation resistance does not meet the second negative standard insulation resistance range, it indicates that the second positive insulation resistance and the second negative insulation resistance do not meet the second standard insulation resistance range.

[0086] Similarly, the third standard insulation resistance range includes a third positive standard insulation resistance range and a third negative standard insulation resistance range. If the obtained third positive insulation resistance meets the third positive standard insulation resistance range and the third negative insulation resistance meets the third negative standard insulation resistance range, it indicates that the third positive insulation resistance and the third negative insulation resistance meet the third standard insulation resistance range. If the third positive insulation resistance does not meet the third positive standard insulation resistance range, and / or the third negative insulation resistance does not meet the third negative standard insulation resistance range, it indicates that the third positive insulation resistance and the third negative insulation resistance do not meet the third standard insulation resistance range.

[0087] In a possible implementation manner, as described above, the three detection methods in the embodiments of the present disclosure are performed before the target vehicle is powered on. Therefore, in the embodiments of the present disclosure, the controller is further configured to: when receiving a detection instruction of the target vehicle, control the main positive switch ( Figure 2 S1 shown) between the HV1 positive interface and the HV2 positive interface, and the main negative switch ( Figure 2 S2 shown) between the HV1 negative interface and the HV2 negative interface to be in an off state.

[0088] In implementation, the controller needs to control both the main positive switch S1 and the main negative switch S2 to be in an off state before performing the above three detections. In this way, the above detections are performed each time before the target vehicle is powered on. If a problem is found, the user can perform maintenance in time, improving the safety of the target vehicle.

[0089] In a possible implementation manner, as described above, before detecting the second positive insulation resistance and the second negative insulation resistance, the controller can control the power device to supply power to the target load, so as to simulate the situation after the target vehicle is powered on. Therefore, in the embodiments of the present disclosure, the controller is further configured to: when controlling the first selection switch 2 to electrically connect the positive detection interface 11 to the HV2 positive interface and controlling the second selection switch 3 to electrically connect the negative detection interface 12 to the HV2 negative interface, control the power device of the target vehicle to perform reverse pre-charge power supply to the target load 5.

[0090] In implementation, the controller can control the power device of the target vehicle to perform reverse pre-charge power supply for the target load 4, so that the reverse pre-charge power supply does not power on the target vehicle while being sufficient to support the insulation resistance detection system to detect the insulation resistance of the HV2 positive interface and the HV2 negative interface.

[0091] Furthermore, the target load 5 in the target vehicle can include a motor.

[0092] The controller is configured to: when controlling the first selection switch 2 to electrically connect the positive detection interface 11 to the HV2 positive interface and controlling the second selection switch 3 to electrically connect the negative detection interface 12 to the HV2 negative interface, provide a preset control id current or a preset control iq current to the motor and control the motor to be in a stopped rotation state.

[0093] In implementation, the above scenario of performing reverse pre-charge power supply for the target load 5 can include providing a preset control id current or a preset control iq current to the motor. The preset control id current or the preset control iq current can support the presence of current in the motor when the insulation resistance detection system detects the insulation resistance of the HV2 positive interface and the HV2 negative interface, but the motor does not rotate. In this way, safety detection can be achieved while realizing insulation resistance detection.

[0094] Among them, the duration of providing the preset control id current or the preset control iq current to the motor can be a preset duration. For example, it can be 20 ms, 30 ms, etc., and the preset duration is sufficient to support the completion of insulation resistance detection.

[0095] It can be understood that the above scenario of providing the preset control id current or the preset control iq current to the motor is applicable to all target loads 5 with motors in the target vehicle, such as drive motors, air conditioners, air compressors, etc.

[0096] The target load 5 can include a heater.

[0097] The controller is configured to: when controlling the first selection switch 2 to electrically connect the positive detection interface 11 to the HV2 positive interface and controlling the second selection switch 3 to electrically connect the negative detection interface 12 to the HV2 negative interface, provide a preset low duty cycle current to the heater.

[0098] In implementation, the scenario of reverse pre-charging power supply for the target load 5 described above may include providing a preset low-duty-cycle current to the heater. The preset low-duty-cycle current is a current with a relatively low duty cycle (e.g., 1%, etc.). In this way, the preset low-duty-cycle current can support the passage of current through the heater when the insulation resistance detection system detects the insulation resistance between the HV2 positive interface and the HV2 negative interface, but the heater is not sufficient to perform heating, thereby realizing safety detection while detecting the insulation resistance.

[0099] Similarly, the duration of providing the preset low-duty-cycle current to the heater can be a preset duration.

[0100] In a possible implementation manner, as described above, before detecting the second positive insulation resistance and the second negative insulation resistance, the controller can control the power device to supply power to the target load 5. The power device can be a pre-charging circuit provided between the power battery 4 and the target load 5.

[0101] The controller can be used to: when controlling the first selection switch to electrically connect the positive detection interface to the HV2 positive interface and controlling the second selection switch to electrically connect the negative detection interface to the HV2 negative interface, control the pre-charging circuit to conduct so that the power battery 4 can pre-charge the target load 5.

[0102] In another possible implementation manner, the power device can be the battery 7 and the DCDC in the target vehicle, see Figure 5 (the DCDC is not shown).

[0103] The controller can be used to: when controlling the first selection switch to electrically connect the positive detection interface to the HV2 positive interface and controlling the second selection switch to electrically connect the negative detection interface to the HV2 negative interface, control the battery 7 and the DCDC to perform reverse pre-charging power supply to the target load 5, that is, the battery 7 can supply power to the target load 5 through the DCDC. In this way, there is no need to set up a pre-charging circuit anymore, thus saving costs.

[0104] After realizing the insulation detection through the above method, the controller is further used to: control the DCDC to discharge the battery 7.

[0105] In implementation, after performing the above insulation detection on the target vehicle, the controller can control the DCDC to discharge the battery, thereby realizing energy recovery. Subsequently, the controller can perform the power-on process of the target vehicle or the process of sending an alarm message.

[0106] In the embodiments of the present disclosure, the circuit topology of the detection circuit 1 can be any reasonable insulation resistance detection circuit. For example, the detection circuit 1 can be Figure 1The circuit topology shown is introduced by taking the example of the insulation resistance detection of the positive electrode interface and the negative electrode interface of HV1 by the detection circuit 1:

[0107] In this detection circuit, R3 = R6 and R4 = R5. In this case, RP is the first positive electrode insulation resistance to be detected, RN is the first negative electrode insulation resistance to be detected, the controller obtains U1 and U3, and U2 can be calculated from U3 and the voltage of the power battery 4.

[0108] First, control Q1 and Q2 to disconnect, so as to measure U1 and U2 at this time.

[0109] When U1 > U2, according to the principle of resistor voltage division, it is obtained that R+ > R-. At this time, control Q1 to disconnect and control Q2 to conduct, and measure U1' and U2'.

[0110] List the formulas according to Ohm's law as follows:

[0111]

[0112] According to the above formulas (3) and (4), the first positive electrode insulation resistance RP and the first negative electrode insulation resistance RN can be calculated.

[0113] When U1 < U2, according to the principle of resistor voltage division, it is obtained that R+ > R-. At this time, keep Q2 disconnected, control Q1 to conduct, and measure U1” and U2”.

[0114] List the formulas according to Ohm's law as follows:

[0115]

[0116] According to the above formulas (5) and (6), the first positive electrode insulation resistance RP and the first negative electrode insulation resistance RN can be calculated.

[0117] The above is only one possible calculation method corresponding to the circuit topology of the detection circuit 1 listed. The detection circuit 1 can also be other reasonable circuit topologies, and the embodiments of the present disclosure do not limit this.

[0118] The technical solution provided by the present disclosure at least includes the following beneficial effects:

[0119] The present disclosure provides an insulation resistance detection system. In addition to being able to detect the first positive electrode insulation resistance and the first negative electrode insulation resistance corresponding to the power battery 4 of the target vehicle, it can also detect the second positive electrode insulation resistance and the second negative electrode insulation resistance corresponding to the target load 5, as well as the third positive electrode insulation resistance and the third negative electrode insulation resistance of the on-vehicle charger 6 of the target vehicle. In this way, the safety detection of these potential hazards is increased, thereby improving the safety of the target vehicle.

[0120] The above are only alternative embodiments of the present disclosure and are not intended to limit the present disclosure. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present disclosure shall be included within the protection scope of the present disclosure.

Claims

1. An insulation resistance detection system, characterized in that, The insulation resistance detection system includes a detection circuit (1), a first selection switch (2), a second selection switch (3), and a controller; The detection circuit (1) has a positive detection interface (11) and a negative detection interface (12); The controller is electrically connected to the detection circuit (1), the first selection switch (2), and the second selection switch (3). The controller is configured to: When receiving a detection instruction of the target vehicle, control the first selection switch (2) to electrically connect the positive detection interface (11) to the HV1 positive interface of the power battery (4) of the target vehicle, and control the second selection switch (3) to electrically connect the negative detection interface (12) to the HV1 negative interface of the power battery (4), and perform insulation resistance detection on the HV1 positive interface and the HV1 negative interface based on the control circuit to obtain a first positive insulation resistance and a first negative insulation resistance; Control the first selection switch (2) to electrically connect the positive detection interface (11) to the HV2 positive interface of the target load (5) powered by the power battery (4), and control the second selection switch (3) to electrically connect the negative detection interface (12) to the HV2 negative interface of the target load (5), and perform insulation resistance detection on the HV2 positive interface and the HV2 negative interface based on the control circuit to obtain a second positive insulation resistance and a second negative insulation resistance; Control the first selection switch (2) to electrically connect the positive detection interface (11) to the positive interface of the on-vehicle charger (6) of the target vehicle, and control the second selection switch (3) to electrically connect the negative detection interface (12) to the negative interface of the on-vehicle charger (6), and perform insulation resistance detection on the positive interface and the negative interface of the on-vehicle charger (6) based on the control circuit to obtain a third positive insulation resistance and a third negative insulation resistance; Perform insulation detection on the target vehicle based on the first positive insulation resistance, the first negative insulation resistance, the second positive insulation resistance, the second negative insulation resistance, the third positive insulation resistance, the third negative insulation resistance, and a preset detection standard.

2. The insulation resistance detection system according to claim 1, wherein The controller is configured to: When receiving a detection instruction of the target vehicle, control the main positive switch between the HV1 positive interface and the HV2 positive interface, and the main negative switch between the HV1 negative interface and the HV2 negative interface to be in an off state.

3. The insulation resistance detection system according to claim 1, wherein, The controller is further configured to: When controlling the first selection switch (2) to electrically connect the positive detection interface (11) to the HV2 positive interface and controlling the second selection switch (3) to electrically connect the negative detection interface (12) to the HV2 negative interface, control the power device of the target vehicle to perform reverse pre-charge power supply to the target load (5).

4. The insulation resistance detection system according to claim 3, wherein, The target load (5) includes a motor; The controller is configured to: When controlling the first selection switch (2) to electrically connect the positive detection interface (11) to the HV2 positive interface and controlling the second selection switch (3) to electrically connect the negative detection interface (12) to the HV2 negative interface, a preset control id current or a preset control iq current is provided for the motor, and the motor is controlled to be in a stopped state.

5. The insulation resistance detection system according to claim 3, wherein The target load (5) includes a heater; The controller is configured to: When controlling the first selection switch (2) to electrically connect the positive detection interface (11) to the HV2 positive interface and controlling the second selection switch (3) to electrically connect the negative detection interface (12) to the HV2 negative interface, a preset low duty cycle current is provided for the heater.

6. The insulation resistance detection system according to claim 3, wherein, The controller is configured to: When controlling the first selection switch (2) to electrically connect the positive detection interface (11) to the HV2 positive interface and controlling the second selection switch (3) to electrically connect the negative detection interface (12) to the HV2 negative interface, the battery (7) and the DCDC are controlled to perform reverse pre-charge power supply to the target load (5).

7. The insulation resistance detection system according to claim 6, characterized in that, After performing insulation detection on the target vehicle, the controller is further configured to: Control the DCDC to discharge the battery (7).

8. The insulation resistance detection system according to claim 1, wherein The preset detection standard includes a first standard insulation resistance range corresponding to the power battery (4), a second standard insulation resistance range corresponding to the target load (5), and a third standard insulation resistance range corresponding to the on-vehicle charger (6); The controller is configured to: If the first positive insulation resistance and the first negative insulation resistance conform to the first standard insulation resistance range, the second positive insulation resistance and the second negative insulation resistance conform to the second standard insulation resistance range, and the third positive insulation resistance and the third negative insulation resistance conform to the third standard insulation resistance range, it is determined that the first positive insulation resistance, the first negative insulation resistance, the second positive insulation resistance, the second negative insulation resistance, the third positive insulation resistance, and the third negative insulation resistance are in a safe state.

9. The insulation resistance detection system according to claim 1, wherein, The controller is further configured to: If the first positive insulation resistance and the first negative insulation resistance do not conform to the first standard insulation resistance range, and / or the second positive insulation resistance and the second negative insulation resistance do not conform to the second standard insulation resistance range, and / or the third positive insulation resistance and the third negative insulation resistance do not conform to the third standard insulation resistance range, an alarm message is issued.

10. A vehicle, characterized in that, The vehicle includes the insulation resistance detection system according to any one of claims 1-9.

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