Fault detection method and device for heating loop of power battery system and vehicle

Abstract

The invention discloses a fault detection method and device for a heating loop of a power battery system and a vehicle, and the method comprises the steps: determining that the power battery system completes the high voltage, or responding to a control instruction of the high-voltage power-off of a whole vehicle; controlling the direct-current converter to output a preset current for a preset time; within the preset time, a current value detected by a current detection device is obtained, and the current detection device is connected with the direct-current converter and a heating loop and used for detecting the sum of currents flowing through the direct-current converter and the heating loop; according to the current value, whether the power battery system heating loop breaks down or not is determined, the hardware cost can be reduced, the high-voltage coupling problem caused by a high-voltage detection circuit is avoided, and therefore the follow-up troubleshooting and maintenance cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of power batteries, and in particular to a method, a device and a vehicle for detecting a fault in a heating circuit of a power battery system. Background Art

[0002] The charging and discharging performance of the power battery system at low temperatures is worse than that at normal temperatures. In order to ensure battery performance, the power battery system often adds a heater to heat the battery to a suitable temperature to improve its charging and discharging capabilities. In the prior art, the heater usually uses a resistive heating film, and the general battery will make the shell on the surface of the battery charged for some kind of protection. In order to prevent the heating film from leaking electricity, an insulating film will be added to the surface of the heating film. However, foreign matter introduced during the production process may puncture the battery heating film and the insulating film on the surface of the heating film, causing the heating film to be turned on without heating, and continuously heating a part of the battery, causing the battery temperature difference to be too large, or even unexpected overheating; on the other hand, the heating contactor in the power battery system may be stuck, causing the heating to be turned on all the time. These faults will pose a threat to the safety of the vehicle. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention aims to provide a method, device, vehicle and storage medium for detecting a fault in a heating circuit of a power battery system.

[0004] The present invention proposes a method for fault detection of a heating circuit of a power battery system, comprising: determining that the power battery system has completed high voltage, or responding to a control instruction of high voltage power reduction of the entire vehicle; controlling a DC converter to output a preset current for a preset time; obtaining a current value detected by a current detection device within the preset time, wherein the current detection device is respectively connected to the DC converter and the heating circuit, and is used to detect the sum of the currents flowing through the DC converter and the heating circuit; and determining whether a fault occurs in the heating circuit of the power battery system according to the current value.

[0005] In addition, the method for fault detection of a power battery system heating circuit according to an embodiment of the present invention may also have the following additional technical features:

[0006] Further, the heating circuit includes a heating element for heating the power battery, and determining whether the power battery system heating circuit fails based on the current value includes: when the current value is greater than a first preset current threshold, determining that the heating element has a short circuit failure.

[0007] Furthermore, after determining that a short circuit fault occurs in the heating element, the method further includes: controlling a main positive contactor and a main negative contactor of the power battery system to be disconnected, and controlling an output current of the DC converter to be zero.

[0008] Furthermore, after determining that a short circuit fault occurs in the heating element, the method further includes: issuing a first alarm signal for indicating the short circuit fault of the heating element.

[0009] Furthermore, the heating circuit also includes: a heating contactor connected to the heating element, the heating contactor being used to control the start and stop of the heating element, and the method also includes: when the current value is greater than a second preset current threshold, determining that the heating contactor has a adhesion fault; wherein the first preset current threshold is greater than the second preset current threshold.

[0010] Furthermore, after determining that the heating contactor has an adhesion failure, the method further includes: controlling the main positive contactor and the main negative contactor of the power battery system to be disconnected, and controlling the output current of the DC converter to be zero.

[0011] Furthermore, after determining that the heating contactor has an adhesion fault, the method further includes: issuing a second alarm signal for indicating the adhesion fault of the heating contactor.

[0012] Furthermore, the fault detection method of the power battery system heating circuit also includes: when it is determined that the power battery system has completed high voltage and it is determined that the power battery system heating circuit has not failed, controlling the power battery system to discharge normally, or, when the power battery system responds to the control instruction of the whole vehicle high voltage power-down and it is determined that the power battery system heating circuit has not failed, controlling the main positive contactor and the main negative contactor of the power battery system to be disconnected.

[0013] According to the fault detection method of the heating circuit of the power battery system of the embodiment of the present invention, by determining that the power battery system has completed the high voltage, or, in response to the control instruction of the high voltage power-off of the whole vehicle; determining that the power battery system has completed the high voltage, or, in response to the control instruction of the high voltage power-off of the whole vehicle; controlling the DC converter to output a preset current, and for a preset time; obtaining the current value detected by the current detection device within the preset time, wherein the current detection device is respectively connected to the DC converter and the heating circuit, and is used to detect the sum of the currents flowing through the DC converter and the heating circuit; determining whether the heating circuit of the power battery system has a fault according to the current value can reduce the hardware cost and avoid the high voltage coupling problem caused by the high voltage detection circuit, thereby reducing the cost of subsequent troubleshooting and maintenance; further, by outputting a fixed preset current through the DC converter, the unstable power consumption of the relevant controller of the whole vehicle and the like can be eliminated, thereby improving the reliability of fault diagnosis; further, by accurately setting the first preset current threshold and the second preset current threshold, the accuracy of the heating circuit fault detection can be improved.

[0014] In response to the above-mentioned problems, the present invention also proposes a fault detection device for a heating circuit of a power battery system, comprising: a first determination module, used to determine whether the power battery system has completed high voltage, or, in response to a control instruction for high voltage power reduction of the whole vehicle; a control module, used to control the DC converter to output a preset current, and for a preset time; an acquisition module, used to acquire a current value detected by a current detection device within a preset time, wherein the current detection device is respectively connected to the DC converter and the heating circuit, and is used to detect the sum of the currents flowing through the DC converter and the heating circuit; a second determination module, used to determine whether a fault occurs in the heating circuit of the power battery system according to the current value.

[0015] According to the fault detection device of the heating circuit of the power battery system of the embodiment of the present invention, by determining that the power battery system has completed the high voltage, or, in response to the control instruction of the high voltage power-off of the whole vehicle; determining that the power battery system has completed the high voltage, or, in response to the control instruction of the high voltage power-off of the whole vehicle; controlling the DC converter to output a preset current, and for a preset time; obtaining the current value detected by the current detection device within the preset time, wherein the current detection device is respectively connected to the DC converter and the heating circuit, and is used to detect the sum of the currents flowing through the DC converter and the heating circuit; determining whether the heating circuit of the power battery system has a fault according to the current value can reduce the hardware cost and avoid the high voltage coupling problem caused by the high voltage detection circuit, thereby reducing the cost of subsequent troubleshooting and maintenance; further, by outputting a fixed preset current through the DC converter, the unstable power consumption of the relevant controller of the whole vehicle and the like can be eliminated, thereby improving the reliability of fault diagnosis; further, by accurately setting the first preset current threshold and the second preset current threshold, the accuracy of heating circuit fault detection can be improved.

[0016] In view of the above-mentioned problems, the present invention further proposes a vehicle, which includes the fault detection device for the heating circuit of the power battery system described in the above-mentioned embodiment.

[0017] According to the vehicle of the embodiment of the present invention, by determining that the power battery system has completed the high voltage, or, in response to the control instruction of the high voltage power-down of the whole vehicle; determining that the power battery system has completed the high voltage, or, in response to the control instruction of the high voltage power-down of the whole vehicle; controlling the DC converter to output a preset current, and for a preset time; within the preset time, obtaining the current value detected by the current detection device, wherein the current detection device is respectively connected to the DC converter and the heating circuit, and is used to detect the sum of the currents flowing through the DC converter and the heating circuit; determining whether the heating circuit of the power battery system fails according to the current value can reduce hardware costs and avoid high voltage coupling problems caused by the high voltage detection circuit, thereby reducing the cost of subsequent troubleshooting and maintenance; further, by outputting a fixed preset current through the DC converter, the unstable power consumption of the relevant controllers of the whole vehicle can be eliminated, thereby improving the reliability of fault diagnosis; further, by accurately setting the first preset current threshold and the second preset current threshold, the accuracy of heating circuit fault detection can be improved.

[0018] In response to the above-mentioned problems, the present invention also proposes a computer-readable storage medium, on which a fault detection program for a heating circuit of a power battery system is stored. When the fault detection program for the heating circuit of a power battery system is executed by a processor, a fault detection method for a heating circuit of a power battery system as described in any of the above-mentioned embodiments is implemented.

[0019] According to the computer-readable storage medium of an embodiment of the present invention, when the fault detection program of the heating circuit of the power battery system stored thereon is executed by the processor, it is determined that the power battery system has completed the high voltage, or, in response to the control instruction of the high voltage power-down of the whole vehicle; it is determined that the power battery system has completed the high voltage, or, in response to the control instruction of the high voltage power-down of the whole vehicle; the DC converter is controlled to output a preset current, and it lasts for a preset time; within the preset time, the current value detected by the current detection device is obtained, wherein the current detection device is respectively connected to the DC converter and the heating circuit, and is used to detect the sum of the currents flowing through the DC converter and the heating circuit; determining whether the heating circuit of the power battery system has a fault according to the current value can reduce hardware costs and avoid high voltage coupling problems caused by the high voltage detection circuit, thereby reducing the cost of subsequent troubleshooting and maintenance; further, by outputting a fixed preset current through the DC converter, the unstable power consumption of the relevant controller of the whole vehicle can be eliminated, thereby improving the reliability of fault diagnosis; further, by accurately setting the first preset current threshold and the second preset current threshold, the accuracy of heating circuit fault detection can be improved.

[0020] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0022] Figure 1 is a schematic diagram of the hardware circuit structure of a power battery system according to an embodiment of the present invention;

[0023] Figure 2 is a schematic diagram of a hardware circuit structure of a power battery system according to another embodiment of the present invention;

[0024] Figure 3 is a flow chart of a method for detecting a fault in a heating circuit of a power battery system according to an embodiment of the present invention;

[0025] Figure 4 The figure is a schematic structural diagram of a fault detection device for a heating circuit of a power battery system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0026] Embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. Embodiments of the present invention are described in detail below.

[0027] First combine Figure 1 and Figure 2 The hardware circuit structure of the power battery system of the embodiment of the present invention is described. Figure 1 As shown, the power battery system includes a battery pack, a main positive contactor, a main negative contactor, a pre-charging contactor, a pre-charging resistor, a current detection device, a heating contactor and a heating element. The BMS (Battery Management System) at the vehicle end is respectively connected to the main positive contactor, the main negative contactor, the pre-charging contactor and the heating contactor, and is used to control the closing or opening of the main positive contactor, the main negative contactor, the pre-charging contactor and the heating contactor. When the BMS controls the heating contactor and the main negative contactor to close, the battery pack, the heating contactor, the heating element, the main negative contactor and the current detection device form a heating circuit, and the heating element heats the battery pack to improve its charging and discharging performance when the power battery system is in a low temperature environment. It should be noted that Figure 2 Power battery system and Figure 1 The hardware components of the power battery system are the same, the difference is that the heating branch composed of the heating contactor and the heating element is connected differently in the power battery system. Figure 1 One end of the heating branch is connected to the positive electrode of the battery pack, and the other end is connected to the rear end of the negative electrode contactor. Figure 2 One end of the heating branch in the circuit is connected to the rear end of the main positive contactor, and the other end is connected to the rear end of the negative contactor. Figure 2 When the heating element in the battery pack heats the battery pack, the BMS is required to control the main positive contactor, heating contactor and main negative contactor to close.

[0028] Reference below Figure 3-Figure 4 The present invention describes a method, device, vehicle and storage medium for detecting a fault in a heating circuit of a power battery system according to an embodiment of the present invention. It should be noted that the method, device, vehicle and storage medium for detecting a fault in a heating circuit of a power battery system according to an embodiment of the present invention are applicable to Figure 1 and Figure 2 The hardware circuit structure of the power battery system shown.

[0029] Figure 3 FIG. 1 is a flow chart of a method for detecting a fault in a heating circuit of a power battery system according to an embodiment of the present invention. Figure 3 As shown, a method for fault detection of a heating circuit of a power battery system comprises the following steps:

[0030] Step S1: Determine whether the power battery system has completed the high voltage power-up, or respond to the control instruction of the vehicle high voltage power-down.

[0031] Specifically, when the power battery system completes the high voltage application, or responds to the control instruction of the high voltage power-down of the whole vehicle, the main positive contactor and the main negative contactor are in a closed state, and the heating contactor is in a disconnected state. At this time, if the high voltage load on the whole vehicle is in a non-working state and there is current flowing through the DC converter, when there is no fault in the heating branch, the current value detected by the current detection device is the current value flowing through the DC converter, and when the heating branch has a adhesion or short circuit fault, the current value detected by the current detection device will be greater than the current value flowing through the DC converter. Therefore, when the power battery system completes the high voltage application, or responds to the control instruction of the high voltage power-down of the whole vehicle, the heating circuit of the power battery system can be detected for faults.

[0032] Step S2: Control the DC converter to output a preset current for a preset time.

[0033] Specifically, the preset current is the output current requested by the BMS for the DC converter, and its size can be set in advance. The preset time is the duration of the DC converter outputting the preset current. As mentioned above, when the heating branch is stuck or short-circuited, the current value detected by the current detection device will be greater than the preset current. Therefore, the embodiment of the present invention controls the DC converter to output the preset current, and the duration of the DC converter outputting the preset current reaches the preset time to determine whether the heating circuit of the power battery system has a fault. Since the DC converter can output a fixed preset current, the embodiment of the present invention can eliminate the situation of unstable power consumption of the vehicle-related controllers, etc., and improve the reliability of fault diagnosis.

[0034] Step S3: within a preset time, obtaining the current value detected by the current detection device, wherein the current detection device is connected to the DC converter and the heating circuit respectively, and is used to detect the sum of the currents flowing through the DC converter and the heating circuit.

[0035] Specifically, if Figure 1 As shown, when the power battery system completes the high voltage, or responds to the control instruction of the vehicle high voltage power down, and the high voltage load on the vehicle end is in a non-working state, the main positive contactor and the main negative contactor are in a closed state, and the heating contactor is in a disconnected state. During the duration of the DC converter outputting the preset current, the current value detected by the current detection device is obtained. Since the heating circuit is in a disconnected state during the preset time, if the heating circuit does not have adhesion or short circuit fault, the current detected by the current detection device is only the preset current output by the DC converter; if the heating circuit has adhesion or short circuit fault, the current detected by the current detection device is the sum of the currents of the DC converter and the heating circuit.

[0036] Step S4: Determine whether a fault occurs in the heating circuit of the power battery system according to the current value.

[0037] Specifically, the heating circuit may fail due to a sticking fault in the heating contactor, or the heating element may be turned on when not heating, that is, the heating circuit may have a sticking or short circuit fault. As mentioned above, when the heating circuit has a sticking or short circuit fault, the current value detected by the current detection device will be greater than the preset current output by the DC converter. Therefore, the embodiment of the present invention determines whether the heating circuit of the power battery system has failed based on the current value detected by the current detection device. Since the embodiment of the present invention does not require a high-voltage detection circuit when determining whether the heating circuit of the power battery system has failed, it can reduce hardware costs and avoid high-voltage coupling problems caused by high-voltage detection circuits, thereby reducing the cost of subsequent troubleshooting and maintenance.

[0038] In one embodiment of the present invention, the heating circuit includes a heating element for heating the power battery, and determining whether the power battery system heating circuit fails based on the current value includes: when the current value is greater than a first preset current threshold, determining that the heating element has a short circuit failure.

[0039] Specifically, the heating element includes a heating film or a power resistor. When determining whether a power battery system heating circuit fails according to the current value detected by the current detection device, different heating elements correspond to different first preset current thresholds. The embodiment of the present invention is described with a heating film. Specifically, when a short circuit failure occurs in the heating film, the calculation formula of the first preset current threshold is:

[0040]

[0041] Among them, I set1 is the first preset current threshold, I is the preset current output by the DC converter, and I e is the first current error set after comprehensive consideration of various influencing factors, U is the total voltage of the battery pack, R1 is the resistance of the heating film, ΔI is the short-circuit current value of the heating film obtained through theoretical calculation, simulation or test, and The minimum difference between .

[0042] It should be noted that the first current error is the maximum sampling deviation of the current detection device when detecting the current, and the maximum sampling deviation may be caused by factors such as the measurement error of the current detection device and the current error caused by the heating film being affected by the temperature. Since the embodiment of the present invention can accurately determine the first preset current threshold, it has a higher accuracy when judging whether the heating element has a short circuit fault according to the current value detected by the current detection device.

[0043] In a specific embodiment, after determining that the power battery system has completed the high voltage, or when the power battery system responds to the control instruction of the vehicle high voltage power down, the DC converter is controlled to output a preset current I and lasts for a preset time. During the preset time, the high voltage load at the vehicle end is in a non-working state, and the current value detected by the current detection device is obtained. The current value is the sum of the current flowing through the DC converter and the heating circuit, for example, I j1 , if I j1 >I set1 , it is determined that the heating film has a short circuit failure.

[0044] In one embodiment of the present invention, after determining that a short circuit fault occurs in the heating element, the method further includes: controlling a main positive contactor and a main negative contactor of the power battery system to be disconnected, and controlling an output current of the DC converter to be zero.

[0045] Specifically, the main positive contactor is a contactor connected to the positive electrode of the battery on the main circuit of the power battery system, and the main negative contactor is a contactor connected to the negative electrode of the battery on the main circuit of the power battery system. After determining that a short circuit fault has occurred in the heating element, in order to protect the circuit of the power battery system, it is necessary to control the main positive contactor and the main negative contactor of the power battery system to be disconnected, so as to cut off the current in the heating circuit by disconnecting the main positive contactor and the main negative contactor, so as to avoid circuit damage and fire in the case of a short circuit in the heating element. At the same time, controlling the output current of the DC converter to zero can quickly cut off the connection between the DC converter and other circuits, reducing the risk of equipment damage.

[0046] In one embodiment of the present invention, after determining that a short circuit fault occurs in the heating element, the method further includes: issuing a first alarm signal for indicating a short circuit fault in the heating element.

[0047] Specifically, after determining that a short circuit fault occurs in the heating element, it is believed that the safety of the entire vehicle has been greatly affected. If the fault is not handled in time, an accident may occur. Therefore, after determining that a short circuit fault occurs in the heating element, a first alarm signal is issued to warn the user in advance and remind the user to repair it in time, thereby avoiding driving risks during driving and improving driving safety. Specifically, the first alarm information includes: at least one of text prompt information, image prompt information, sound prompt information, optical prompt information and vibration prompt information. Exemplarily, after determining that a short circuit fault occurs in the heating element, the user can be prompted in the form of a text message on the central control screen that a short circuit fault occurs in the heating element, and a prompt message of "The heating element is short-circuited, please handle it in time" is issued through the vehicle audio.

[0048] In one embodiment of the present invention, the heating circuit also includes: a heating contactor connected to the heating element, the heating contactor is used to control the start and stop of the heating element, and the method also includes: when the current value is greater than a second preset current threshold, determining that the heating contactor has a adhesion fault; wherein the first preset current threshold is greater than the second preset current threshold.

[0049] Specifically, the adhesion fault of the heating contactor is a fault in which the heating contactor is closed due to adhesion without controlling the heating contactor to close. Specifically, the calculation formula of the second preset current threshold is:

[0050]

[0051] Among them, I set2 is the second preset current threshold, I is the preset current output by the DC converter, and I e1 It is the second current error set after comprehensively considering various influencing factors. U is the total voltage of the battery pack, and R1 is the resistance of the heating film.

[0052] It should be noted that the second current error is the maximum sampling deviation of the current detection device when detecting the current, and the maximum sampling deviation may be caused by factors such as the measurement error of the current detection device and the current error caused by the temperature of the heating film. Since the embodiment of the present invention can accurately determine the second preset current threshold, it has a high accuracy when judging whether the heating contactor has a adhesion fault according to the current value detected by the current detection device.

[0053] In a specific embodiment, after determining that the power battery system has completed the high voltage, or when the power battery system responds to the control instruction of the vehicle high voltage power down, the DC converter is controlled to output a preset current I and last for a preset time. During the preset time, the high voltage load at the vehicle end is in a non-working state, and the current value detected by the current detection device is obtained. The current value is the sum of the current flowing through the DC converter and the heating circuit Ij2 , if I j2 >I set2 , determine that the heating contactor has a sticking failure.

[0054] It should be noted that when the heating film is short-circuited, its current will be greater than the working current. Therefore, the first preset current threshold is greater than the second preset current threshold. Thus, the first preset current threshold and the second preset current threshold can be used to determine whether a heating film short circuit fault or a heating contactor adhesion fault occurs in the battery system heating circuit.

[0055] In one embodiment of the present invention, after determining that the heating contactor has an adhesion fault, the method further includes: controlling a main positive contactor and a main negative contactor of the power battery system to be disconnected, and controlling an output current of the DC converter to be zero.

[0056] Specifically, the main positive contactor is a contactor connected to the positive electrode of the battery on the main circuit of the power battery system, and the main negative contactor is a contactor connected to the negative electrode of the battery on the main circuit of the power battery system. After determining that the heating contactor has an adhesion failure, in order to protect the circuit of the power battery system, it is necessary to control the main positive contactor and the main negative contactor of the power battery system to disconnect, so that the current in the heating circuit can be cut off by disconnecting the main positive contactor and the main negative contactor, avoiding circuit damage and fire in the event of a short circuit in the heating contactor. At the same time, controlling the output current of the DC converter to zero can quickly cut off the connection between the DC converter and other circuits, reducing the risk of equipment damage.

[0057] In one embodiment of the present invention, after determining that the heating contactor has an adhesion failure, the method further includes: issuing a second alarm signal for indicating the adhesion failure of the heating contactor.

[0058] Specifically, after determining that the heating contactor has an adhesion failure, it is believed that the safety of the entire vehicle has been greatly affected. If the failure is not handled in time, an accident may occur. Therefore, after determining that the heating contactor has an adhesion failure, a second alarm signal is issued to warn the user in advance and remind the user to repair it in time, thereby avoiding driving risks during driving and improving driving safety. Specifically, the second alarm information includes: at least one of text prompt information, image prompt information, sound prompt information, optical prompt information and vibration prompt information. Exemplarily, after determining that the heating contactor has an adhesion failure, the user can be prompted in the form of a text message on the central control screen that the heating contactor has an adhesion failure, and a prompt message of "The heating contactor is sticking, please handle it in time" can be issued through the vehicle audio.

[0059] In a specific embodiment of the present invention, it also includes: when it is determined that the power battery system has completed high voltage and it is determined that the heating circuit of the power battery system has not failed, the power battery system is controlled to discharge normally, or, when the power battery system responds to the control instruction of the whole vehicle high voltage power-down and it is determined that the heating circuit of the power battery system has not failed, the main positive contactor and the main negative contactor of the power battery system are controlled to be disconnected.

[0060] Specifically, when it is determined that the power battery system has completed high voltage and that the power battery system heating circuit has not failed, it is considered that the vehicle is powered on and can be discharged normally, that is, the power battery system can be controlled to discharge normally. When the power battery system responds to the control instruction of the vehicle high voltage power-off and it is determined that the power battery system heating circuit has not failed, it is considered that the power-off process can continue, that is, the main positive contactor and the main negative contactor are controlled to be disconnected to complete the power-off process and disconnect the power battery system from the main circuit of the vehicle.

[0061] According to the fault detection method of the heating circuit of the power battery system of the embodiment of the present invention, by determining that the power battery system has completed the high voltage, or, in response to the control instruction of the high voltage power-down of the whole vehicle, the DC converter is controlled to output a preset current and continue for a preset time. Within the preset time, the current value detected by the current detection device is obtained, wherein the current detection device is respectively connected to the DC converter and the heating circuit, and is used to detect the sum of the currents flowing through the DC converter and the heating circuit. Whether the heating circuit of the power battery system fails is determined according to the current value, which can reduce hardware costs and avoid high-voltage coupling problems caused by high-voltage detection circuits, thereby reducing subsequent troubleshooting and maintenance costs; further, by outputting a fixed preset current through the DC converter, unstable power consumption of relevant controllers of the whole vehicle can be eliminated, thereby improving the reliability of fault diagnosis; further, by accurately setting the first preset current threshold and the second preset current threshold, the accuracy of heating circuit fault detection can be improved.

[0062] A further embodiment of the present invention also discloses a fault detection device for a heating circuit of a power battery system. Figure 4 FIG. 1 is a schematic diagram of a structure of a fault detection device for a power battery system heating circuit according to an embodiment of the present invention. Figure 4As shown, the device 10 includes: a first determination module 11, a control module 12, an acquisition module 13, and a second determination module 14. The first determination module 11 is used to determine whether the power battery system has completed the high voltage, or responds to the control instruction of the vehicle high voltage power down; the control module 12 is used to control the DC converter to output a preset current and last for a preset time; the acquisition module 13 is used to obtain the current value detected by the current detection device within the preset time, wherein the current detection device is respectively connected to the DC converter and the heating circuit, and is used to detect the sum of the current flowing through the DC converter and the heating circuit; the second determination module 14 is used to determine whether the heating circuit of the power battery system fails according to the current value.

[0063] In one embodiment of the present invention, the heating circuit includes a heating element for heating the power battery, and the second determination module 14 determines whether a fault occurs in the heating circuit of the power battery system according to the current value, including: when the current value is greater than a first preset current threshold, determining that a short circuit fault occurs in the heating element.

[0064] In one embodiment of the present invention, after determining that a short circuit fault occurs in the heating element, the control module 12 is further used to: control the main positive contactor and the main negative contactor of the power battery system to be disconnected, and control the output current of the DC converter to be zero.

[0065] In one embodiment of the present invention, after determining that a short circuit fault occurs in the heating element, the control module 12 is further configured to: issue a first alarm signal indicating a short circuit fault in the heating element.

[0066] In one embodiment of the present invention, after determining that the heating contactor has an adhesion fault, the control module 12 is further used to: control the main positive contactor and the main negative contactor of the power battery system to be disconnected, and control the output current of the DC converter to be zero.

[0067] In one embodiment of the present invention, after determining that the heating contactor has an adhesion fault, the control module 12 is further configured to: issue a second alarm signal indicating the heating contactor has an adhesion fault.

[0068] In one embodiment of the present invention, the control module 12 is also used to: when it is determined that the power battery system has completed high voltage and that the heating circuit of the power battery system has not failed, control the power battery system to discharge normally; or, when the power battery system responds to the control instruction of the vehicle high voltage power-down and it is determined that the heating circuit of the power battery system has not failed, control the main positive contactor and the main negative contactor of the power battery system to be disconnected.

[0069] It should be noted that when the fault detection device 10 of the heating circuit of the power battery system of the embodiment of the present invention performs fault detection of the heating circuit, its specific implementation method is similar to the specific implementation method of the fault detection method of the heating circuit of the power battery system of the embodiment of the present invention. Please refer to the description of the method part for details. In order to reduce redundancy, it will not be repeated here.

[0070] According to the fault detection device 10 of the heating circuit of the power battery system of the embodiment of the present invention, by determining that the power battery system has completed the high voltage, or, in response to the control instruction of the high voltage power-down of the whole vehicle, controlling the DC converter to output a preset current for a preset time, obtaining the current value detected by the current detection device within the preset time, and determining whether the heating circuit of the power battery system has a fault according to the current value, it can reduce the hardware cost and avoid the high voltage coupling problem caused by the high voltage detection circuit, thereby reducing the cost of subsequent troubleshooting and maintenance; further, by outputting a fixed preset current through the DC converter, it can eliminate the situation of unstable power consumption of the relevant controller of the whole vehicle, and improve the reliability of fault diagnosis; further, by accurately setting the first preset current threshold and the second preset current threshold, it can improve the accuracy of heating circuit fault detection.

[0071] A further embodiment of the present invention also discloses a vehicle, which includes a fault detection device for a heating circuit of a power battery system as described in any of the above embodiments.

[0072] It should be noted that when the vehicle of the embodiment of the present invention performs heating circuit fault detection, its specific implementation method is similar to the specific implementation method of the power battery system heating circuit fault detection method of the embodiment of the present invention. Please refer to the description of the method part for details. In order to reduce redundancy, it will not be repeated here.

[0073] According to the vehicle of the embodiment of the present invention, by determining that the power battery system has completed the high voltage, or, in response to the control instruction of the whole vehicle to power off the high voltage, controlling the DC converter to output a preset current and continuing for a preset time, obtaining the current value detected by the current detection device within the preset time, and determining whether the heating circuit of the power battery system has failed based on the current value, the hardware cost can be reduced, and the high voltage coupling problem caused by the high voltage detection circuit can be avoided, thereby reducing the cost of subsequent troubleshooting and maintenance; further, by outputting a fixed preset current through the DC converter, the unstable power consumption of the whole vehicle-related controllers can be eliminated, thereby improving the reliability of fault diagnosis; further, by accurately setting the first preset current threshold and the second preset current threshold, the accuracy of heating circuit fault detection can be improved.

[0074] A further embodiment of the present invention also discloses a computer-readable storage medium, on which a fault detection program for a heating circuit of a power battery system is stored. When the fault detection program for the heating circuit of a power battery system is executed by a processor, a fault detection method for a heating circuit of a power battery system as in any of the above embodiments is implemented.

[0075] According to the computer-readable storage medium of an embodiment of the present invention, when the fault detection program of the heating circuit of the power battery system stored thereon is executed by the processor, by determining that the power battery system has completed the high voltage, or, in response to the control instruction of the high voltage power-down of the whole vehicle, the DC converter is controlled to output a preset current and continue for a preset time. Within the preset time, the current value detected by the current detection device is obtained, and whether the heating circuit of the power battery system has a fault is determined according to the current value. This can reduce hardware costs and avoid high-voltage coupling problems caused by high-voltage detection circuits, thereby reducing subsequent troubleshooting and maintenance costs; further, by outputting a fixed preset current through the DC converter, unstable power consumption of relevant controllers of the whole vehicle can be eliminated, thereby improving the reliability of fault diagnosis; further, by accurately setting the first preset current threshold and the second preset current threshold, the accuracy of heating circuit fault detection can be improved.

[0076] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0077] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A method for detecting a fault in a heating circuit of a power battery system, characterized in that: include: Determine that the power battery system has completed the high voltage, or respond to the control instruction of the vehicle high voltage power down; Controlling the DC converter to output a preset current for a preset period of time; Within the preset time, obtaining a current value detected by a current detection device, wherein the current detection device is connected to the DC converter and the heating circuit respectively, and is used to detect the sum of the currents flowing through the DC converter and the heating circuit; Determine whether a fault occurs in the power battery system heating circuit according to the current value.

2. The method for detecting a fault in a heating circuit of a power battery system according to claim 1, characterized in that The heating circuit includes a heating element for heating the power battery, and determining whether the power battery system heating circuit fails according to the current value includes: When the current value is greater than a first preset current threshold, it is determined that a short circuit fault occurs in the heating element.

3. The method for detecting a fault in a heating circuit of a power battery system according to claim 2, characterized in that: After determining that the heating element has a short circuit fault, it also includes: The main positive contactor and the main negative contactor of the power battery system are controlled to be disconnected, and the output current of the DC converter is controlled to be zero.

4. The method for detecting a fault in a heating circuit of a power battery system according to claim 2, characterized in that: After determining that the heating element has a short circuit fault, it also includes: A first alarm signal is issued to indicate a short circuit fault of the heating element.

5. The method for detecting a fault in a heating circuit of a power battery system according to claim 2, characterized in that: The heating circuit further includes: a heating contactor connected to the heating element, the heating contactor being used to control the start and stop of the heating element, and the method further includes: When the current value is greater than a second preset current threshold, it is determined that a sticking fault occurs in the heating contactor; wherein the first preset current threshold is greater than the second preset current threshold.

6. The method for detecting a fault in a heating circuit of a power battery system according to claim 5, characterized in that: After determining that the heating contactor has a sticking fault, it also includes: The main positive contactor and the main negative contactor of the power battery system are controlled to be disconnected, and the output current of the DC converter is controlled to be zero.

7. The method for detecting a fault in a heating circuit of a power battery system according to claim 5, characterized in that: After determining that the heating contactor has a sticking fault, it also includes: A second alarm signal is issued to indicate a sticking fault of the heating contactor.

8. The method for detecting a fault in a heating circuit of a power battery system according to claim 1, characterized in that: Also includes: When it is determined that the power battery system has completed the high voltage application and it is determined that the heating circuit of the power battery system has not failed, the power battery system is controlled to discharge normally, or, When the power battery system responds to the control instruction of the vehicle high voltage power-down and determines that the heating circuit of the power battery system has not failed, the main positive contactor and the main negative contactor of the power battery system are controlled to be disconnected.

9. A fault detection device for a power battery system heating circuit, characterized in that: include: A first determination module is used to determine whether the power battery system has completed the high voltage, or respond to the control instruction of the vehicle high voltage power down; A control module, used to control the DC converter to output a preset current for a preset period of time; an acquisition module, used for acquiring a current value detected by a current detection device within the preset time, wherein the current detection device is connected to the DC converter and the heating circuit respectively, and is used for detecting the sum of the currents flowing through the DC converter and the heating circuit; The second determination module is used to determine whether a fault occurs in the heating circuit of the power battery system according to the current value.

10. A vehicle, characterized in that: include: A fault detection device for a power battery system heating circuit as claimed in claim 9.

11. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a fault detection program for a heating circuit of a power battery system. When the fault detection program for a heating circuit of a power battery system is executed by a processor, the fault detection method for a heating circuit of a power battery system according to any one of claims 1 to 8 is implemented.

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