Electric vehicle and power battery pack for realizing fault isolation

Abstract

The utility model provides an electric vehicle and a power battery pack for realizing fault isolation. The electric vehicle comprises the power battery pack, a power assembly and at least one direct current protection switch. Wherein the power battery pack comprises a battery shell, a battery cell and a direct current bus, the battery shell is used for accommodating the battery cell, and the battery cell is used for supplying power to the direct current bus. The battery shell is provided with a direct current output interface, and the direct current output interface is used for receiving power supplied by the direct current bus and supplying power to at least one power assembly. Each power assembly is used for receiving power supplied by the direct-current bus through one direct-current protection switch and driving wheels of the electric vehicle, and the direct-current protection switches are used for connecting or disconnecting the power assemblies and the direct-current bus. In the electric vehicle, when any electric component has a short-circuit fault, only the direct-current protection switch in front of the electric component is switched off, so that fault isolation can be realized, normal work of other electric components is ensured, and the problem of safety throwing of the vehicle is avoided.

Description

Technical Field

[0001] The present application relates to the field of new energy vehicles, and more specifically, to an electric vehicle and a power battery pack for achieving fault isolation. Background Art

[0002] With increasing environmental awareness and the continuous development of electric vehicle technology, the market demand for dual-drive electric vehicles is growing. However, to ensure the safety of both passengers and the electric vehicle, it is necessary to be able to disconnect the power battery when a high-voltage circuit short circuits. Otherwise, the drive motor may burn out or even cause the vehicle to spontaneously combust.

[0003] The current common solution is to install a master protection device at the output of the vehicle's DC bus distribution architecture from the power battery pack, and then power the various loads mounted on the DC bus. At this time, if a load mounted on the high-voltage bus short-circuits, the master protection device will be disconnected, and the entire vehicle's high-voltage bus will lose power, thereby ensuring the safety of the vehicle and passengers. However, if the master protection device is disconnected, the short circuit of one load will cause all loads mounted on the high-voltage bus to lose power, resulting in power loss.

[0004] Therefore, how to isolate the short-circuit fault when a load is short-circuited is an urgent problem to be solved. Utility Model Content

[0005] The present application provides an electric vehicle and a power battery pack for achieving fault isolation. By adding an independent DC protection switch between each high-voltage power supply component of the electric vehicle, such as the powertrain and the power battery, and only disconnecting the DC protection switch in front of any electrical component when a short circuit fault occurs in the electrical component, fault isolation can be achieved to ensure the normal operation of other electrical components and avoid vehicle abandonment problems.

[0006] In a first aspect, an electric vehicle for achieving fault isolation is provided, characterized in that the electric vehicle includes a power battery pack, a powertrain, and at least one DC protection switch. The power battery pack includes a battery housing, battery cells, and a DC busbar. The battery housing is used to accommodate the battery cells, and the battery cells are used to supply power to the DC busbar. The battery housing is provided with a DC output interface, and the DC output interface is used to receive power from the DC busbar and supply power to the at least one powertrain. Each powertrain is used to receive power from the DC busbar through one of the DC protection switches and to drive the wheels of the electric vehicle. The DC protection switch is used to connect or disconnect the connection between the powertrain and the DC busbar.

[0007] It can be understood that in order to supply power to multiple high-voltage electrical components connected to the DC bus, the power battery pack can include multiple DC output ports, each DC output port is used to connect a high-voltage electrical component, so that each high-voltage electrical component can receive power from the power battery through an independent DC protection switch and DC output port.

[0008] It can be understood that the DC bus includes a positive DC bus and a negative DC bus. The positive DC bus connects to the positive pole of the battery cell, and the negative DC bus connects to the negative pole of the battery cell. Each DC output interface includes a positive output terminal and a negative output terminal. The positive output terminal is used to connect to the positive DC bus, and the negative output terminal is used to connect to the negative DC bus.

[0009] It is understood that the powertrain can receive power from the positive DC bus through the DC protection switch, or receive power from the negative DC bus through the DC protection switch, or receive power from the positive DC bus and the negative DC bus through the two sub-switches in the DC protection switch. Among them, the above-mentioned DC protection switch can be a controlled switching device such as a switch tube, a relay, etc., or it can be a device that automatically detects overcurrent and blows, such as a fuse, a fuse, etc., and this application does not limit this. If the DC protection switch is a controlled switching device, it can be connected to the control circuit in the motor controller and be controlled by the control circuit, or it can be connected to the controller in the battery management system (BMS) in the power battery and be controlled by the battery management system.

[0010] Furthermore, when a short circuit occurs within the powertrain, the DC protection switch disconnects the powertrain from the DC bus. This prevents the fault from spreading through the DC bus to the power battery pack and other high-voltage electrical equipment connected to the DC bus, regardless of whether the short circuit occurs in the powertrain's motor controller, motor, or wiring harness. This prevents the entire vehicle from being powered down and potentially abandoned.

[0011] It is understandable that there may be a variety of scenarios for the type and location of a powertrain failure. For example, a short circuit occurs in the motor controller of the powertrain. Specifically, the short circuit may occur inside the motor controller, such as in the power device or other electrical components, or it may occur outside the motor controller, such as in the motor controller housing, the motor controller wiring harness, or the connection between the motor controller and the power battery. For another example, a short circuit occurs in the drive motor of the powertrain. For example, the short circuit may occur in the winding coil of the drive motor, or it may be a failure in the wiring harness connecting the winding of the drive motor and the motor controller.

[0012] According to the solution of the present application, by adding an independent DC protection switch between each high-voltage power supply component of the electric vehicle, such as the powertrain and the power battery, and only disconnecting the DC protection switch in front of any electrical component when a short circuit fault occurs in the electrical component, fault isolation can be achieved to ensure the normal operation of other electrical components and avoid vehicle abandonment problems.

[0013] In conjunction with the first aspect, in certain implementations of the first aspect, the at least one DC protection switch is housed in the battery housing, each DC output interface is configured to connect to the DC bus via a DC protection switch, and the DC protection switch is configured to connect or disconnect the DC bus and the corresponding DC output interface. Each powertrain is configured to receive power from the DC bus via the DC output interface and the DC protection switch.

[0014] That is, the DC protection switch can be installed inside the battery housing of the power battery pack. Specifically, the DC protection switch can be connected in series between the positive DC output interface and the positive DC bus, or the DC protection switch can be connected in series between the negative DC output interface and the negative DC bus, or one sub-switch in the DC protection switch can be connected in series between the positive DC output interface and the positive DC bus, and the other sub-switch can be connected in series between the negative DC output interface and the negative DC bus.

[0015] Moreover, when a short circuit fault occurs inside the power battery pack, the DC protection switch can quickly detect and disconnect the high-voltage electrical components from the DC output interface, preventing the fault on the power battery side from spreading to the high-voltage electrical components and protecting the high-voltage electrical components.

[0016] According to the solution of the present application, by adding an independent DC protection switch to each high-voltage electrical component on the power battery side of the electric vehicle, the DC protection switch can be uniformly assembled on the power battery side without the need for structural adjustments to the powertrain, thereby achieving stronger compatibility while achieving fault isolation.

[0017] In conjunction with the first aspect, in certain implementations of the first aspect, the powertrain includes a motor controller, a motor, and a motor controller housing. The motor controller is configured to receive power from the DC bus through the DC output interface and drive the motor. The motor controller housing is configured to accommodate the DC protection switch and an inverter circuit of the motor controller. The housing also includes a DC input port and an AC output port. The inverter circuit is configured to connect to the DC input interface through the DC protection switch to receive DC power from the DC bus and output three-phase AC power to the three-phase windings of the motor through the AC output port.

[0018] That is, the DC protection switch can be assembled inside the housing of the motor controller. The DC input port includes a positive DC input port and a negative DC input port. Specifically, the DC protection switch can be connected in series between the positive DC output interface and the positive DC input port, or the DC protection switch can be connected in series between the negative DC output interface and the negative DC input port, or one sub-switch in the DC protection switch can be connected in series between the positive DC output interface and the positive DC input port, and another sub-switch can be connected in series between the negative DC output interface and the negative DC input port.

[0019] Furthermore, when a short circuit fault occurs inside the powertrain, the DC protection switch disconnects the connection between the inverter circuit in the motor controller and the DC output port, thereby disconnecting the connection between the inverter circuit of the motor controller and the DC bus, preventing the fault inside the powertrain from spreading through the DC bus.

[0020] According to the solution of the present application, the DC protection switch is integrated inside the motor controller, which has a higher degree of integration and is conducive to improving the reliability of the motor controller.

[0021] In conjunction with the first aspect, in certain implementations of the first aspect, the powertrain includes a motor controller, a motor, and a motor controller housing. The motor controller is configured to receive power from the DC bus through the DC output interface and drive the motor. The motor controller housing includes a DC input port. The DC input port is configured to connect to a DC output port of the power battery pack through the DC protection switch. The DC protection switch is configured to open or close the connection between the DC input port and the corresponding DC output port.

[0022] In other words, the DC protection switch can also be connected in series between the DC input port of the motor controller and the DC output port of the power battery pack, so that the DC bus can be connected to the DC input port of the motor controller through the DC output port and the DC protection switch. Specifically, the DC protection switch can be installed on the battery housing of the power battery or the housing of the motor controller, or installed on the high-voltage wiring harness between the powertrain and the power battery pack, which is not limited in this application.

[0023] According to the present application solution, the specific assembly position between the power battery pack and the motor controller can be selected according to actual implementation, which is highly flexible. In addition, the DC protection switch is easy to repair and replace later.

[0024] In combination with the first aspect, in certain implementations of the first aspect, when a current value passing through the DC protection switch is greater than a first threshold, the DC protection switch is disconnected.

[0025] It is understood that the first threshold value can be understood as a relatively large current value. A portion of the DC current output by the power battery pack is input into the powertrain through the DC protection switch. When a short circuit occurs in the powertrain, the DC current passing through the DC protection switch suddenly increases. When the current passing through the DC protection switch exceeds the first threshold value, it indicates that a short circuit has occurred in the powertrain. At this time, to protect other electrical components, the DC protection switch must be disconnected, thereby disconnecting the powertrain from the DC bus. This isolates the powertrain short circuit and does not affect other electrical components mounted on the DC bus.

[0026] Optionally, when the voltage of the current passing through the DC protection switch is less than a fifth threshold, the DC protection switch disconnects the DC bus from the motor controller. Alternatively, when the rate of change of the voltage of the current passing through the DC protection switch is greater than a sixth threshold, the DC protection switch disconnects the DC bus from the motor controller. Alternatively, when the magnitude of the current passing through the DC protection switch is greater than a first threshold and / or the voltage of the current passing through the DC protection switch is less than a fifth threshold and / or the rate of change of the voltage of the current passing through the DC protection switch is greater than a sixth threshold, the DC protection switch disconnects the DC bus from the powertrain.

[0027] According to the solution of the present application, it is possible to determine whether a short circuit occurs in the powertrain or the DC bus by detecting the current and / or voltage, thereby controlling whether the DC protection switch is disconnected. The control method is simple and reliable.

[0028] In combination with the first aspect, in certain implementations of the first aspect, the power battery pack further includes a DC bus switch, the battery cell is used to supply power to the DC bus through the DC bus switch, and the current value passing through the DC bus switch is greater than or equal to the current value passing through the DC protection switch.

[0029] It can be understood that the power battery pack supplies power to the powertrain via the DC bus. When the power battery supplies power to multiple powertrains simultaneously via the DC bus, the multiple powertrains are connected in parallel. At this point, the current received by the DC bus from the power battery is greater than the current passing through the DC protection switch. Alternatively, it can be understood that the current passing through the DC bus is greater than the current passing through the DC protection switch. For example, when the vehicle is a front-wheel drive vehicle with both front-wheel drive powertrains operating simultaneously, the current passing through the DC bus is greater than the current passing through the DC protection switch.

[0030] It can be understood that if the power battery pack only supplies power to a single powertrain via the DC bus, the current received by the DC bus from the power battery is equal to the current passing through the DC protection switch. Alternatively, it can be understood that the current passing through the DC bus is equal to the current passing through the DC protection switch. For example, if the vehicle is a single-wheel drive vehicle and the power battery only supplies power to a single powertrain via the DC bus, the current passing through the DC bus is greater than the current passing through the DC protection switch.

[0031] It's understood that when an overcurrent occurs on the DC bus, the DC bus switch will fuse after a certain period of time, thereby protecting the power battery and electrical components. To prevent the DC bus switch from tripping when a single electrical component short-circuits, thereby affecting other normal electrical components, a DC-side disconnect device is provided that trips before the protective device in the event of an overcurrent.

[0032] Therefore, when selecting the DC bus switch and the DC protection switch, it is necessary to ensure that the device disconnection delay time of the DC protection switch is shorter than the device disconnection delay time of the DC bus switch.

[0033] In combination with the first aspect, in certain implementations of the first aspect, a disconnection current of the DC bus switch is greater than a disconnection current of the DC protection switch.

[0034] In this way, since the disconnection current of the DC bus switch is greater than the disconnection current of the DC protection switch, it can be ensured that the DC protection switch is disconnected before the DC bus switch when a high-voltage electrical component fails, which can prevent the DC bus switch from disconnecting when the fault is controllable and affecting other normal electrical components.

[0035] According to the present application, a DC bus switch is installed on the DC bus of an electric vehicle. This can be disconnected in the event of a power battery pack failure, preventing damage to high-voltage electrical components. Furthermore, by ensuring that the DC protection switch has a shorter disconnection delay and current than the DC bus switch, the DC bus switch will not disconnect in the event of a short circuit in a single electrical component, preventing the normal operation of other electrical components.

[0036] In conjunction with the first aspect, in certain implementations of the first aspect, the powertrain includes a motor controller and a motor. The motor controller is configured to receive power from the DC bus via a DC output interface of the power battery pack and drive the motor. The motor controller includes a three-phase bridge arm and three AC protection switches. The midpoint of each phase of the three-phase bridge arm is configured to be connected to a phase winding of the motor via one of the AC protection switches.

[0037] It is understood that each phase bridge arm of the motor controller can be divided into an upper bridge arm and a lower bridge arm at the bridge arm midpoint. Both the upper bridge arm and the lower bridge arm include power modules. The power module located in the upper bridge arm includes an upper bridge arm switching tube, and the power module located in the lower bridge arm includes a lower bridge arm switching tube. In addition to the upper bridge arm switching tube or the lower bridge arm switching tube, the power module may also include a detection module, such as a temperature detection module, a short-circuit detection module, etc.

[0038] In combination with the first aspect, in certain implementations of the first aspect, when the current value passing through any one of the AC protection switches is greater than a second threshold, the any one of the AC protection switches is disconnected.

[0039] It is understandable that the powertrain can also include an AC protection switch, which can be a controlled switching device such as a relay, a switching tube, etc. The AC protection switch can be a plurality of switch devices set separately or an integral switch device. The AC protection switch is used to connect the three-phase bridge arm of the motor controller and the three-phase winding of the drive motor. When the current of any phase bridge arm in the three-phase bridge arm is greater than the second threshold, a short circuit fault may occur in any phase bridge arm in the three-phase bridge arm. At this time, the fault of the phase bridge arm needs to be isolated. The AC protection switch disconnects the phase bridge arm, thereby isolating the short circuit fault. The remaining phase bridge arms can still continue to output current, thereby achieving phase-loss operation for a short period of time.

[0040] According to the solution of this application, adding an AC protection switch to the power line between the motor controller and the motor can isolate the short-circuit fault on the inverter circuit. When a single module fails, the motor can be operated in a short-term phase-loss state, which can prevent the vehicle from completely losing power and improve the vehicle's driving safety and operational reliability.

[0041] In combination with the first aspect, in certain implementations of the first aspect, when the current passing through any one of the AC protection switches is greater than the second threshold for a duration greater than the first duration, the DC protection switch and at least two of the AC protection switches are disconnected.

[0042] Since the overcurrent signal will only appear briefly when a single module fails, the duration can be less than or equal to 10 microseconds. When the overcurrent signal exceeds the first duration, it indicates that there is a short circuit in the entire circuit.

[0043] It can be understood that when the overcurrent signal on the motor controller remains at a low level, that is, the current is greater than the second threshold for a duration greater than the first duration, it indicates that the upper and lower bridge arm switch modules in one-phase bridge arm may have both experienced a short circuit. At this time, it is necessary not only to disconnect the DC protection switch to prevent the DC bus from being affected and causing power loss to the entire vehicle, but also to disconnect at least two AC protection switches so that the current in the motor controller does not form a loop, thereby avoiding the short-circuit current that causes the motor to generate a large braking torque and thus affect driving safety.

[0044] According to the solution of the present application, when multiple modules of the motor controller fail, disconnecting at least two AC protection switches can avoid causing the drive motor to generate braking torque, so that the vehicle will not suddenly decelerate even when power is lost, effectively improving driving safety.

[0045] In conjunction with the first aspect, in certain implementations of the first aspect, the powertrain includes a motor controller and a motor. The motor controller is configured to receive power from the DC bus via a DC output interface of the power battery pack and drive the motor. The motor controller includes a three-phase bridge arm, each phase of the three-phase bridge arm including an isolating switch, the isolating switch being configured to connect or disconnect the corresponding phase of the bridge arm from the positive DC bus or the negative DC bus.

[0046] In combination with the first aspect, in certain implementations of the first aspect, the isolating switch is used to turn on or off the connection between the upper bridge arm switch tube of the corresponding single-phase bridge arm and the midpoint of the bridge arm; or, the isolating switch is used to turn on or off the connection between the upper bridge arm switch tube of the corresponding single-phase bridge arm and the positive DC bus.

[0047] In combination with the first aspect, in certain implementations of the first aspect, the isolating switch is used to turn on or off the connection between the lower bridge arm switch tube of the corresponding single-phase bridge arm and the midpoint of the bridge arm; or, the isolating switch is used to turn on or off the connection between the lower bridge arm switch tube of the corresponding single-phase bridge arm and the negative DC bus.

[0048] In conjunction with the first aspect, in certain implementations of the first aspect, the isolating switch of each phase arm of the three-phase bridge arm includes an upper isolating switch and a lower isolating switch. The upper isolating switch is used to connect or disconnect the connection between the upper bridge arm switching tube of the corresponding phase bridge arm and the midpoint of the bridge arm, or the connection between the upper bridge arm switching tube of the corresponding phase bridge arm and the positive DC bus. The lower isolating switch is used to connect or disconnect the connection between the lower bridge arm switching tube of the corresponding phase bridge arm and the midpoint of the bridge arm, or the connection between the lower bridge arm switching tube of the corresponding phase bridge arm and the negative DC bus.

[0049] According to the solution of the present application, the isolating switch can be set at different positions of each bridge arm according to actual implementation, which has high flexibility and strong applicability.

[0050] In combination with the first aspect, in certain implementations of the first aspect, when the upper arm switch tube or the lower arm switch tube of any phase arm in the three-phase bridge arm is short-circuited, the isolating switch corresponding to the phase arm is disconnected.

[0051] Exemplarily, when the current passing through any isolating switch is greater than a third threshold, the isolating switch is disconnected. Exemplarily, when the voltage between an arm of any bridge and the positive DC bus or the negative DC bus is lower than a preset voltage value, or the rate of voltage drop is greater than a preset rate, the isolating switch on the bridge arm is disconnected.

[0052] According to the present application, when a short-circuit fault occurs in any of the three-phase bridge arms, causing the bridge arm's current to be excessive, the upper bridge arm's isolating switch can be used to disconnect the upper bridge arm's switch tube from the bridge arm's midpoint, thereby disconnecting the corresponding phase bridge arm from the positive DC bus or the negative DC bus, thereby avoiding a direct fault in the positive DC bus and the negative DC bus, and preventing the vehicle from experiencing a bus voltage loss problem. In addition, because only the short-circuit faulty phase bridge arm is disconnected, the other two phase bridge arms can still output two-phase AC power to the motor windings, allowing the drive motor to operate in a phase-missing state, thereby preventing the vehicle from completely losing power and improving the vehicle's driving safety and operational reliability.

[0053] In conjunction with the first aspect, in certain implementations of the first aspect, the motor controller includes a control circuit configured to: when the current value passing through the DC protection switch is greater than a first threshold, control the DC protection switch to be disconnected; or, when the current value passing through any of the AC protection switches is greater than a second threshold, control the disconnection of any of the AC protection switches; or, when the current value passing through an upper or lower switching tube of any of the three-phase bridge arms is greater than a third threshold, control the disconnection of the corresponding isolation switch of any of the three-phase bridge arms to be disconnected.

[0054] According to the solution of the present application, the motor controller can control the on and off of at least one of the DC protection switch, AC protection switch or isolation switch by detecting the current value control circuit. The control method is simple and reliable.

[0055] In conjunction with the first aspect, in certain implementations of the first aspect, the second threshold is less than or equal to the third threshold. The second threshold and the third threshold may be effective values ​​or average values ​​of the three-phase currents.

[0056] In other words, the disconnect current of the AC protection switch is less than the cut-off current of the isolation switch. Thus, if a power module or motor winding in a phase bridge arm short-circuits, the AC protection switch between the midpoint of that phase bridge arm and the motor winding will open first, followed by the isolation switch in that phase bridge arm. This prevents the motor winding from forming a loop with a power module in that phase bridge arm, further improving fault isolation speed.

[0057] In combination with the first aspect, in certain implementations of the first aspect, the control circuit is specifically used to control any one of the AC protection switches to turn off and the isolating switch corresponding to any one of the phase bridge arms to disconnect, and then control the midpoints of the other two phase bridge arms to output two-phase AC power when the current value passing through any one of the AC protection switches is greater than the second threshold, or the current value passing through the upper bridge arm switch tube or the lower bridge arm switch tube of any one of the phase bridge arms of the three-phase bridge arm is greater than the third threshold.

[0058] According to the present invention, when a short circuit occurs in one phase bridge arm or one phase winding, the control circuit can control the AC protection switch and isolating switch corresponding to that phase bridge arm to open. After the connecting switch and isolating switch corresponding to that phase bridge arm open, the midpoints of the other two phase bridge arms are controlled to output two-phase AC power. This two-phase AC power can be used to drive the motor to output torque, ensuring that the vehicle does not lose power.

[0059] In combination with the first aspect, in certain implementations of the first aspect, in the process of controlling the midpoints of the other two-phase bridge arms to output two-phase AC power, the control circuit is also used to first control the DC protection switch to disconnect, and then control the AC protection switch and the isolating switch corresponding to the one-phase bridge arm to disconnect, when the current value passing through one of the other two AC protection switches is greater than a second threshold, or the current passing through the upper bridge arm switch tube or the lower bridge arm switch tube of one of the other two-phase bridge arms is greater than a third threshold.

[0060] According to the solution of the present application, during the process of the motor controller outputting two-phase AC power to the motor, if one of the two-phase bridge arms outputting two-phase AC power has a short-circuit fault again or the winding connected to the midpoint of the bridge arm of one phase bridge arm has a short-circuit fault, the motor cannot output torque at this time. The DC protection switch can be controlled to disconnect first to avoid the spread of the fault, and then the AC protection switch and the isolating switch corresponding to the bridge arm with the short-circuit fault can be controlled to disconnect, so that the short-circuit three-phase current of the phase bridge arm will not flow to the winding of the motor, which can protect the motor.

[0061] In conjunction with the first aspect, in certain implementations of the first aspect, the battery cell includes a first battery module and a second battery module, and the power battery pack further includes three switches housed in the battery housing. The first switch is configured to connect the positive electrode of the first battery module to the negative electrode of the second battery module, the second switch is configured to connect the positive electrode of the first battery module to the positive electrode of the second battery module, and the third switch is configured to connect the negative electrode of the first battery module to the negative electrode of the second battery module.

[0062] That is, the connection mode between the first battery module and the second battery module can be switched by controlling the on and off of the first switch, the second switch and the third switch.

[0063] In conjunction with the first aspect, in certain implementations of the first aspect, while the electric vehicle is traveling, the first switch is open, and the second and third switches are closed. While the power battery pack is charging, the first switch is closed, and the second and third switches are open.

[0064] Specifically, during the driving process of the electric vehicle, the first switching switch and the second switching switch can be controlled to close, so that the first battery module and the second battery module are connected in parallel, so that the first motor controller receives power from the first battery module and the second battery module in parallel, and outputs three-phase AC power to the first motor to drive the wheels to rotate.

[0065] Specifically, during the high-voltage charging process of the electric vehicle, the third switching switch can be controlled to close so that the first battery module and the second battery module are connected in series, so that the first motor controller receives power from the first battery module and outputs three-phase AC power to the first motor to heat the three-phase winding of the first motor, and heats the first battery module through a heat-conducting component (not shown in the figure). At the same time, since the first battery module and the second battery module are connected in series, the charging power is large at this time, which can increase the charging rate of the first battery module and the second battery module. Among them, high-voltage charging refers to the process of charging the power battery pack using a charging pile with an output voltage higher than the voltage of a single battery module (such as the first battery module). For example, the voltage of the first battery module is 400V. If a charging pile that can output 800V voltage is used for charging, the third switching switch can be controlled to close so that the first battery module and the second battery module are connected in series, thereby increasing the charging rate of the power battery pack.

[0066] According to the solution of the present application, the connection mode of the first battery module and the second battery module in the power battery pack can be switched by the switch module, which has strong flexibility and can increase the charging rate of the power battery pack during high-voltage charging.

[0067] In conjunction with the first aspect, in certain implementations of the first aspect, the electric vehicle includes two powertrains, the battery cell includes a first battery module and a second battery module, one of the two powertrains is configured to receive power from the first battery module via a DC protection switch, and the other of the two powertrains is configured to receive power from the second battery module via another DC protection switch, and the power battery pack further includes two redundant switches housed in the battery housing. The powertrain is further configured to connect to the positive electrode of the second battery module via one redundant switch, and the powertrain is further configured to connect to the negative electrode of the second battery module via another redundant switch.

[0068] In combination with the first aspect, in certain implementations of the first aspect, when the first battery module fails, the DC protection switch is disconnected, and a redundant switch and another redundant switch are closed, so that the first motor controller receives power from the second battery module, thereby avoiding the first powertrain from losing power due to the failure of the first battery module, and thus realizing the function of redundant power supply.

[0069] According to the solution of the present application, when a battery module fails, the one redundant switch and the other redundant switch are closed, so that the motor controller can receive power from another battery module in the power battery pack, thereby avoiding the motor controller losing power due to the failure of the battery module, and thus realizing the redundant power supply function.

[0070] In conjunction with the first aspect, in certain implementations of the first aspect, the electric vehicle includes a hybrid powertrain, comprising a dual-motor controller, an electric motor, and a generator. The dual-motor controller is configured to receive power from the power battery pack to drive the electric vehicle's drive motor or to transmit power generated by the generator to the power battery to charge the power battery pack. The dual-motor controller includes a dual-motor controller housing, a motor power circuit, and a generator power circuit. The dual-motor controller housing is configured to accommodate the generator power circuit, the motor power circuit, and at least one DC protection switch. The dual-motor controller housing includes a high-voltage DC port. The dual-motor controller is configured to receive power from the power battery or charge the power battery through the high-voltage DC port. The motor power circuit is configured to receive direct current (DC) from the high-voltage DC port via the DC protection switch. The generator power circuit is configured to receive alternating current (AC) generated by the generator and output DC power to the high-voltage DC port via the DC protection switch. The DC protection switch is configured to connect or disconnect the motor power circuit, the generator power circuit, and the high-voltage DC port.

[0071] According to the present application, a DC protection switch is added to the front end of the dual-motor controller connected to the DC bus. This DC protection switch prevents faults in other loads connected to the DC bus from spreading to the dual-motor controller, protecting the power devices within the dual-motor controller. Furthermore, the DC protection switch can be installed within the dual-motor controller housing, resulting in a highly integrated dual-motor controller and easy installation and use.

[0072] In conjunction with the first aspect, in certain implementations of the first aspect, the electric vehicle further includes a DC conversion circuit, and the housing further includes another high-voltage DC port, the another high-voltage DC port being configured to be connected to the one high-voltage DC port via the DC protection switch. The DC conversion circuit is configured to receive DC power from the one high-voltage DC port via the another high-voltage DC port and the DC protection switch, and to step down the DC power from the one high-voltage DC port for output.

[0073] It can be understood that the DC conversion circuit is connected to the power battery pack through the other high-voltage DC port, the DC protection switch and the high-voltage DC port in sequence to receive DC power from the power battery pack and perform voltage reduction conversion.

[0074] In conjunction with the first aspect, in certain implementations of the first aspect, the dual-motor controller further includes a DC conversion circuit housed in the housing, and the housing further includes a low-voltage DC port. The DC conversion circuit is configured to receive DC power from the high-voltage DC port via the DC protection switch, perform voltage reduction conversion on the DC power from the high-voltage DC port, and output the DC power through the low-voltage DC port.

[0075] It is understood that one end of the DC conversion circuit is connected to the DC protection switch, and the other end of the DC conversion circuit is connected to the low-voltage DC port. The DC conversion circuit can receive a first DC power provided by the power battery through the DC protection switch and the high-voltage DC port, and output a second DC power to the low-voltage DC port. The voltage of the first DC power is higher than the voltage of the second DC power. That is, the DC conversion circuit is used to reduce the voltage of the first DC power to generate and output the second DC power.

[0076] It can be understood that the DC conversion circuit can be connected to the low-voltage electrical equipment of the electric vehicle, or connected to the low-voltage battery of the electric vehicle through the low-voltage DC port, and the embodiments of the present application are not limited to this.

[0077] According to the solution of the present application, the DC conversion circuit can be integrated into the housing of the dual-motor controller, and the dual-motor controller has a high degree of integration and a wider range of applications.

[0078] In combination with the first aspect, in certain implementations of the first aspect, after the DC protection switch is disconnected, the DC conversion circuit is further used to receive power from the generator power circuit and perform step-down conversion on the DC power output by the generator power circuit before outputting it.

[0079] It is understood that when the DC protection switch is in the on state, the DC conversion circuit can receive the DC power provided by the power battery, perform step-down conversion, and output it through the low-voltage DC port. When the DC protection switch is in the off state, the DC conversion circuit can receive the DC power provided by the generator power circuit, perform step-down conversion, and output it through the low-voltage DC port. In other words, the low-voltage DC port can reuse the DC conversion circuit to receive power from the DC bus or the generator power circuit.

[0080] According to the application scheme, after the DC protection switch is disconnected, the hybrid powertrain can generate electricity from the generator and output low-voltage DC power through the DC conversion circuit and the low-voltage DC port, thereby ensuring uninterrupted vehicle power while further improving the user's driving experience and driving safety.

[0081] In combination with the first aspect, in certain implementations of the first aspect, the dual-motor controller also includes a control circuit, which is also used to: in the process of the generator power circuit being used to receive the alternating current generated by the generator and supply power to the motor power circuit, control the output power of the generator power circuit to increase with the increase of the accelerator pedal opening and decrease with the decrease of the accelerator pedal opening.

[0082] Specifically, in the process of controlling the generator power circuit to receive the AC power generated by the generator and supply power to the motor power circuit, in response to an increase in the accelerator pedal opening of the electric vehicle, the control circuit is configured to control the generator power circuit and the motor power circuit to increase output power. In response to a decrease in the accelerator pedal opening of the electric vehicle, or in response to an increase in the brake pedal opening of the electric vehicle, the control circuit is configured to control the generator power circuit and the motor power circuit to decrease output power.

[0083] It will be understood that the present application does not limit the specific manner in which the control circuit adjusts the generator power circuit and the motor power circuit.

[0084] According to the solution of this application, the control circuit in the dual-motor controller can adjust the power of the power circuit, generator and drive motor in response to the opening of the accelerator pedal or the brake pedal, ensuring that the power output can be adjusted according to user needs, which is more practical.

[0085] In conjunction with the first aspect, in certain implementations of the first aspect, during travel of the electric vehicle, in response to the DC protection switch being in an on state and the accelerator pedal opening of the electric vehicle decreasing or the brake pedal opening of the electric vehicle increasing, the motor power circuit is configured to output DC power through the high-voltage DC port. In response to the DC protection switch being in an off state and the accelerator pedal opening decreasing or the brake pedal opening increasing, the motor power circuit ceases to output the DC power through the high-voltage DC input terminal.

[0086] It is understood that when the electric vehicle operates in single-pedal mode and the accelerator pedal is opened less, or the brake pedal is opened more, the electric vehicle is in a braking state. Furthermore, when the electric vehicle is in the braking state, the vehicle controller of the electric vehicle receives a braking signal and sends an energy recovery signal to the dual-motor controller. In response to the energy recovery signal, the dual-motor controller controls the drive motor to operate in a power generation state. At this time, the drive motor converts the kinetic energy of the electric vehicle's wheels into electrical energy and outputs a counter-torque to the electric vehicle's wheels to provide braking force to the electric vehicle.

[0087] According to the solution of the present application, after the DC protection switch is disconnected, the dual-motor controller stops energy recovery, avoiding overvoltage failure of the wiring harness between the internal power circuits, and further improving the safety and reliability of the dual-motor controller.

[0088] In conjunction with the first aspect, in certain implementations of the first aspect, the electric vehicle includes a distributed powertrain, the distributed powertrain comprising a dual-motor controller, two motors, and two DC protection switches, the distributed powertrain being configured to drive the two front wheels or the two rear wheels of the electric vehicle. The dual-motor controller includes a first inverter circuit and a second inverter circuit. The first inverter circuit is configured to receive power from the DC bus through one of the DC protection switches and output three-phase AC power to one of the motors. The second inverter circuit is configured to receive power from the DC bus through the other DC protection switch and output three-phase AC power to the other motor.

[0089] In conjunction with the first aspect, in certain implementations of the first aspect, when the magnitude of the current passing through the one DC protection switch is greater than a first threshold, the one DC protection switch disconnects the DC bus from the first inverter circuit. When the magnitude of the current passing through the other DC protection switch is greater than the first threshold, the other DC protection switch disconnects the DC bus from the second inverter circuit.

[0090] In combination with the first aspect, in certain implementations of the first aspect, when the current passing through one of the two DC protection switches is greater than a first threshold, the one DC protection switch disconnects the connection between the DC bus and the first inverter circuit and the other DC protection switch disconnects the connection between the DC bus and the second inverter circuit.

[0091] It is understood that a vehicle can have a distributed drive motor architecture, with two drive motors driving either the front or rear wheels, controlled by a motor controller. The motor controller includes two inverter circuits, each for outputting current to the two drive motors. These two inverter circuits are connected to the DC bus via two DC-side disconnect devices. If a short circuit or overcurrent condition occurs in either inverter circuit, only the corresponding DC-side disconnect device is disconnected, isolating the fault without affecting the current output of the remaining inverter circuit to the drive motor.

[0092] According to the solution of the present application, for the motor controller of the distributed drive motor, the DC bus and the inverter circuit are connected through the DC side disconnect device respectively, and only the connection between the faulty inverter circuit and the DC bus can be disconnected, thereby not affecting the normal operation of the drive motor and realizing power redundancy.

[0093] In conjunction with the first aspect, in certain implementations of the first aspect, the electric vehicle includes a front drive power assembly and a rear drive power assembly. The front drive power assembly includes a front drive motor controller and a front drive motor, wherein the front drive motor controller is configured to receive power from the DC bus through a DC protection switch and output a first three-phase AC power to drive the front drive motor. The rear drive power assembly includes a rear drive motor controller and a rear drive motor, wherein the rear drive motor controller is configured to receive power from the DC bus through another DC protection switch and output a second three-phase AC power to drive the rear drive motor.

[0094] In conjunction with the first aspect, in certain implementations of the first aspect, when the front-drive motor controller fails, the front-drive motor controller outputs a first fault signal and stops supplying the first three-phase AC power to the front-drive motor, the first fault signal being used to instruct a rear-drive motor controller of the vehicle to control the rear-drive motor to increase torque output. When the rear-drive motor controller fails, the rear-drive motor controller outputs a second fault signal and stops supplying the second three-phase AC power to the rear-drive motor, the second fault signal being used to instruct the front-drive motor controller of the vehicle to control the front motor to increase torque output.

[0095] It is understood that the first motor controller and the second motor controller can send a fault signal to the vehicle controller of the electric vehicle, so that the vehicle controller can adjust the torque output by the other motor in response to the fault signal. Alternatively, the first motor controller and the second motor controller can directly transmit the fault signal and / or torque signal to each other and adjust the torque output by the motor after receiving the fault signal.

[0096] According to this application solution, fault signals from each motor controller are detected. When a single motor controller fails, the fault is isolated for the bus load. After the fault is isolated, a torque demand signal is issued, requesting the remaining functioning motor controllers to start and control the corresponding drive motors to compensate for the torque required by the vehicle. The operating status of each motor controller can be coordinated uniformly through the vehicle controller, or torque demand signals can be transmitted between motor controllers to request driving capacity compensation.

[0097] In conjunction with the first aspect, in certain implementations of the first aspect, the electric vehicle includes four wheel-side powertrains. A first wheel-side powertrain is configured to receive DC bus power through a first DC protection switch to drive the left front wheel of the electric vehicle, a second wheel-side powertrain is configured to receive DC bus power through a second DC protection switch to drive the right front wheel of the electric vehicle, a third wheel-side powertrain is configured to receive DC bus power through a third DC protection switch to drive the left rear wheel of the electric vehicle, and a fourth wheel-side powertrain is configured to receive DC bus power through a fourth DC protection switch to drive the right rear wheel of the electric vehicle.

[0098] In combination with the first aspect, in certain implementations of the first aspect, when the current passing through the first DC protection switch is greater than a first threshold, the first DC protection switch is disconnected, the second wheel-side powertrain reduces torque output, and the third wheel-side powertrain and the fourth wheel-side powertrain increase torque output.

[0099] It is understood that when a short circuit occurs in any wheel-side powertrain of an electric vehicle, the corresponding DC protection switch will disconnect the powertrain from the DC bus, and the powertrain will stop outputting torque to the wheels. At this time, to avoid the vehicle body from tilting due to unbalanced forces on the left and right wheels, the other powertrain will reduce the torque output to the other wheel coaxial with the wheel driven by the faulty powertrain. Furthermore, the other two wheel-side powertrains can also increase torque output, thereby compensating for the power loss caused by the failure of one wheel-side powertrain and improving the safety of the electric vehicle.

[0100] According to the solution of this application, while achieving fault isolation of a single wheel-side powertrain through an independent DC protection switch, the wheel-side powertrain driving the coaxial wheel is controlled to reduce torque output and the other two wheel-side powertrains are controlled to increase power output, thereby reducing the power loss of the entire vehicle while ensuring the stability of the vehicle body.

[0101] In combination with the first aspect, in certain implementations of the first aspect, when the current passing through the first DC protection switch is greater than a first threshold, the first DC protection switch is disconnected, the third wheel-side powertrain reduces torque output, and the second wheel-side powertrain and the fourth wheel-side powertrain increase torque output.

[0102] It is understood that when a short circuit occurs in any wheel-side powertrain of an electric vehicle, the corresponding DC protection switch will disconnect the powertrain from the DC bus, and the powertrain will stop outputting torque to the wheels. At this time, to avoid the vehicle body from tilting due to unbalanced forces on the left and right wheels, the other powertrain will reduce the torque output to the other wheel diagonally opposite the wheel driven by the faulty powertrain. Furthermore, the other two wheel-side powertrains can also increase torque output, thereby compensating for the power loss caused by the failure of one wheel-side powertrain and improving the safety of the electric vehicle.

[0103] According to the solution of this application, while achieving fault isolation of a single wheel-side powertrain through an independent DC protection switch, the wheel-side powertrain driving the diagonal wheel is controlled to reduce torque output and the other two wheel-side powertrains are controlled to increase power output, thereby reducing the power loss of the entire vehicle while ensuring the stability of the vehicle body.

[0104] In a second aspect, a power battery pack is provided, comprising a battery housing, battery cells, a DC protection switch, and a DC busbar. The battery housing is configured to house the battery cells and the DC protection switch, and the battery cells are configured to supply power to the DC busbar. The battery housing is provided with a DC output interface, which is configured to connect to the DC busbar via the DC protection switch, and the DC protection switch is configured to open or close the connection between the DC busbar and the DC output interface.

[0105] According to the present application, by providing an independent DC protection switch on the DC output interface of the power battery pack and disconnecting the corresponding DC protection switch when a connected electrical component fails, the fault can be prevented from spreading to the DC bus and affecting the cells and other electrical components of the power battery pack. Furthermore, the DC protection switch is uniformly installed on the power battery pack side, eliminating the need for structural adjustments to the powertrain, thereby achieving both fault isolation and enhanced compatibility.

[0106] In combination with the second aspect, in certain implementations of the second aspect, when the current value passing through the DC protection switch is greater than a first threshold, the DC protection switch is disconnected.

[0107] In conjunction with the second aspect, in certain implementations of the second aspect, the power battery pack further includes a DC bus switch, the battery cell is configured to supply power to the DC bus via the DC bus switch. During the process of the power battery pack outputting DC power, a current value passing through the DC bus switch is greater than a current value passing through the DC protection switch.

[0108] In combination with the second aspect, in certain implementations of the second aspect, a disconnection current of the DC bus switch is greater than a disconnection current of the DC protection switch.

[0109] In combination with the second aspect, in certain implementations of the second aspect, the power battery pack includes a battery management system, which is configured to control the DC protection switch to disconnect when the current value passing through the DC protection switch is greater than a first threshold.

[0110] In conjunction with the second aspect, in certain implementations of the second aspect, the power battery pack includes a battery management system configured to: control the DC protection switch to be disconnected when the current value passing through the DC protection switch is greater than a first threshold; and control the DC bus switch to be disconnected when the current value passing through the DC bus switch is greater than a fourth threshold, wherein the fourth threshold is greater than the first threshold.

[0111] For the supplementary and technical effects of the solution provided in the second aspect above, please refer to the corresponding description of the first aspect and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0112] Figure 1 It is a schematic diagram of a DC bus protection device;

[0113] Figure 2 Schematic diagrams of several possible electric vehicle 01 architectures proposed in the embodiments of the present application;

[0114] Figure 3 This is a schematic diagram of a partial structure of the electric vehicle 01 provided in an embodiment of the present application;

[0115] Figure 4 This is another partial structural diagram of the electric vehicle 01 provided in an embodiment of the present application;

[0116] Figure 5 This is another partial structural diagram of the electric vehicle 01 provided in the embodiment of the present application.

[0117] Figure 6 is a schematic diagram of a powertrain provided in an embodiment of the present application;

[0118] Figure 7 This is a circuit diagram of a dual powertrain provided in an embodiment of the present application;

[0119] Figure 8 is a circuit diagram of another dual powertrain provided in an embodiment of the present application;

[0120] Figure 9 Schematic diagrams of two control architectures provided in embodiments of the present application;

[0121] Figure 10 is a circuit diagram of a hybrid powertrain provided in an embodiment of the present application;

[0122] Figure 11This is a circuit diagram of a centralized distributed powertrain provided in an embodiment of the present application. DETAILED DESCRIPTION

[0123] The technical solution in this application will be described below with reference to the accompanying drawings.

[0124] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; “and / or” in this article is merely a way to describe the association relationship of associated objects, indicating that three relationships can exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone.

[0125] In the embodiments of the present application, prefixes such as "first" and "second" are used only to distinguish different description objects and have no limiting effect on the position, order, priority, quantity or content of the described objects. The use of prefixes such as ordinal numbers to distinguish description objects in the embodiments of the present application does not constitute a restriction on the described objects. For the statement of the described objects, please refer to the description in the context of the claims or embodiments, and the use of such prefixes should not constitute an unnecessary restriction. In addition, in the description of this embodiment, unless otherwise specified, the meaning of "plurality" is two or more.

[0126] References to "some embodiments" and the like in this specification mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in one or more embodiments of the present application. Thus, phrases such as "in some embodiments" and the like that appear in different places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "including," "comprising," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0127] With increasing environmental awareness and the continuous development of vehicle technology, the market demand for dual-motor and multi-motor vehicles is growing. However, in the event of a high-voltage short circuit in an electric vehicle, it is necessary to be able to disconnect the power battery to ensure the safety of both passengers and the vehicle. Failure to do so could damage the vehicle's electrical components and even cause the vehicle to spontaneously combust.

[0128] In one possible implementation, Figure 1As shown, a master protection device is installed at the power battery output, and power is supplied to various loads, such as the powertrain, via a high-voltage DC bus. For example, in a dual-motor vehicle, the front and rear drivetrains share a common high-voltage DC bus, receiving power from the power battery. If a short circuit occurs in one of the powertrains, the master protection device on the high-voltage DC bus will fuse, causing the power battery to stop outputting current, thus ensuring the safety of the vehicle and its passengers.

[0129] It should be noted that the type and location of a powertrain failure may vary. For example, a short circuit may occur in the motor controller of the powertrain. Specifically, the short circuit may occur inside the motor controller, such as in power devices or other electrical components, or it may occur outside the motor controller, such as in the motor controller housing, the motor controller wiring harness, or the connection between the motor controller and the power battery. For another example, a short circuit may occur in the drive motor of the powertrain. For example, the short circuit may occur in the winding coil of the drive motor, or it may be a fault in the wiring harness connecting the winding of the drive motor and the motor controller.

[0130] However, since the power battery no longer outputs current after the main circuit fuse blows, normal electrical components that have not failed will also be unable to work normally due to the loss of power supply, causing the entire vehicle to lose power and then break down.

[0131] In view of this, the present application provides an electric vehicle for achieving fault isolation. By adding an independent DC protection switch between each high-voltage power supply component of the electric vehicle, such as the powertrain and the power battery, and only disconnecting the DC protection switch in front of any electrical component when a short circuit fault occurs in the electrical component, fault isolation can be achieved to ensure the normal operation of other electrical components and avoid vehicle abandonment problems.

[0132] Figure 2 It is a schematic diagram of several possible electric vehicle 01 architectures provided in this application.

[0133] like Figure 2 As shown in (a), the electric vehicle 01 can be a single electric drive vehicle, and the electric vehicle 01 can include a power battery pack, a powertrain 10 and four wheels. Among them, the powertrain 10 includes a motor 101 and a motor controller 102. The motor controller 102 is used to receive power from the power battery pack and output AC power to the motor 101 to drive the motor 101. It can be understood that the electric vehicle 01 can be a front-wheel drive vehicle, in which case the powertrain 10 is used to drive the two front wheels of the electric vehicle. Alternatively, the electric vehicle 01 can also be a rear-wheel drive vehicle, in which case the powertrain 10 is used to drive the two rear wheels of the electric vehicle.

[0134] like Figure 2As shown in (b), the electric vehicle 01 can be a front and rear dual-electric drive vehicle. The electric vehicle 01 can include a power battery pack, a first powertrain 20, a second powertrain 21, and four wheels. The first powertrain 20 is used to drive the two front wheels of the vehicle 01, and the second powertrain 21 is used to drive the two rear wheels of the vehicle 01. The first powertrain 20 includes a first motor 201 and a first motor controller 202. The first motor controller 202 is used to receive power from the power battery pack and output AC power to the first motor 201 to drive the first motor 201. The second powertrain 21 includes a second motor 204 and a second motor controller 203. The second motor controller 203 is used to receive power from the power battery pack and output AC power to the second motor 204 to drive the second motor 204.

[0135] like Figure 2 As shown in (c), the electric vehicle 01 can be a hybrid vehicle, and the electric vehicle 01 can include a power battery pack, a hybrid powertrain 30 and four wheels. The hybrid powertrain 30 includes a motor 301, a generator 302 and a dual-motor controller 303. The dual-motor controller 303 is used to receive the electric energy output by the generator 302 and charge the power battery pack, or the dual-motor controller 303 is used to receive the output electric energy and supply power to the motor 301 to drive the motor 301, or the dual-motor controller 303 is used to receive the electric energy output by the generator 302 and the electric energy output by the power battery and supply power to the motor 301 to drive the motor 301. It can be understood that the dual-motor controller 303 can also be split into a generator controller and a motor controller, which are used to control the generator 302 and the motor 301 respectively.

[0136] like Figure 2 As shown in (d) of FIG, electric vehicle 01 can be a centrally distributed electric vehicle, comprising a power battery pack, a distributed powertrain 40, and four wheels. Distributed powertrain 40 includes a first motor 401, a second motor 402, and a dual-motor controller 403. First motor 401 and second motor 402 are used to drive the two front wheels or the two rear wheels. Motor controller 403 receives power from the power battery pack and outputs AC power to first motor 401 and second motor 402 to drive the two motors.

[0137] like Figure 2As shown in (e), the electric vehicle 01 can be a wheel-side distributed electric vehicle, and the electric vehicle 01 includes four power assemblies and four wheels. Specifically, the motor controller 502 is used to receive power from the power battery pack and output AC power to the motor 501 to drive the motor 501, the motor controller 504 is used to receive power from the power battery pack and output AC power to the motor 503 to drive the motor 503, the motor controller 506 is used to receive power from the power battery pack and output AC power to the motor 505 to drive the motor 505, and the motor controller 508 is used to receive power from the power battery pack and output AC power to the motor 507 to drive the motor 507. Each power assembly can be a hub motor power assembly or a wheel-side motor power assembly. The hub motor power assembly is to directly set the motor and the reducer in the wheel hub, eliminating the transmission components such as the half shaft, universal joint, differential, and transmission; the wheel-side motor power assembly is to set the motor on the subframe.

[0138] It is understandable that the above Figure 2 (a) to Figure 2 The electric vehicles shown in (e) in FIG. 1 and FIG. 2 each include at least one powertrain. The powertrain 10 is used as an example to describe the specific embodiments below.

[0139] In some embodiments, the electric vehicle 01 includes a power battery pack, a powertrain 10, and a DC protection switch. The power battery pack includes a battery housing, battery cells, and a DC busbar. The battery housing is used to house the battery cells, which are used to supply power to the DC busbar. The battery housing is provided with a DC output interface, which is used to receive power from the DC busbar and supply power to the powertrain 10. The powertrain 10 is used to receive power from the DC busbar via the DC protection switch and is used to drive the wheels of the electric vehicle. The DC protection switch is used to connect or disconnect the connection between the powertrain and the DC busbar.

[0140] It can be understood that in order to supply power to multiple high-voltage electrical components connected to the DC bus, the power battery pack can include multiple DC output ports, each DC output port is used to connect a high-voltage electrical component, so that each high-voltage electrical component can receive power from the power battery through an independent DC protection switch and DC output port.

[0141] It can be understood that the DC bus includes a positive DC bus and a negative DC bus. The positive DC bus connects to the positive pole of the battery cell, and the negative DC bus connects to the negative pole of the battery cell. Each DC output interface includes a positive output terminal and a negative output terminal. The positive output terminal is used to connect to the positive DC bus, and the negative output terminal is used to connect to the negative DC bus.

[0142] It can be understood that the DC protection switch can be connected in series between the positive DC bus and the positive DC input terminal of the powertrain 10, that is, the powertrain 10 can receive power from the positive DC bus through the DC protection switch. Alternatively, the DC protection switch can be connected in series between the negative DC bus and the negative DC input terminal of the powertrain, that is, the powertrain 10 can receive power from the negative DC bus through the DC protection switch. Alternatively, a DC protection switch can be understood as a switch group including two sub-switches, one sub-switch is connected in series between the positive DC bus and the positive DC input terminal of the powertrain, and the other sub-switch is connected in series between the negative DC bus and the negative DC input terminal of the powertrain, that is, the powertrain 10 can receive power from the positive DC bus and the negative DC bus through the two sub-switches.

[0143] Furthermore, when a short circuit occurs within the powertrain 10, the DC protection switch disconnects the powertrain 10 from the DC bus. This prevents the fault from spreading through the DC bus to the power battery pack and other high-voltage electrical equipment connected to the DC bus, regardless of whether the short circuit occurs within the powertrain 10's motor controller, motor, or wiring harness. This prevents the entire vehicle from being powered down and potentially abandoned.

[0144] According to an embodiment of the present application, by adding an independent DC protection switch between each high-voltage power supply component of an electric vehicle, such as the powertrain and the power battery, and only disconnecting the DC protection switch in front of any electrical component when a short circuit fault occurs in the electrical component, fault isolation can be achieved to ensure the normal operation of other electrical components and avoid vehicle abandonment problems.

[0145] It is understood that the embodiment of the present application does not limit the location of the DC protection switch. Figure 3 and Figure 4 Provide explanation.

[0146] In some embodiments, as Figure 3 As shown, the DC protection switch is housed in the battery housing. Each DC output interface is used to connect to the DC bus through a DC protection switch, and the DC protection switch is used to connect or disconnect the DC bus and the corresponding DC output interface. Each powertrain is used to receive power from the DC bus through the DC output interface and the DC protection switch.

[0147] That is, the DC protection switch can be installed inside the battery housing of the power battery pack. Specifically, the DC protection switch can be connected in series between the positive DC output interface and the positive DC bus, or the DC protection switch can be connected in series between the negative DC output interface and the negative DC bus, or one sub-switch in the DC protection switch can be connected in series between the positive DC output interface and the positive DC bus, and the other sub-switch can be connected in series between the negative DC output interface and the negative DC bus.

[0148] It is understandable that the battery housing can be formed with one or more accommodating cavities. For example, when the battery housing is formed with multiple accommodating cavities, the battery cells in the power battery pack can be assembled in different accommodating cavities from the DC protection switch. During the subsequent maintenance and replacement of the DC protection switch, there is no need to disassemble the accommodating cavity for accommodating the battery cells, thereby improving the convenience of maintenance. In other words, the DC protection switch can be assembled in the same accommodating cavity with the battery cells in a centralized manner, or it can be assembled in different accommodating cavities with the battery cells in a distributed manner, and the embodiments of the present application are not limited thereto.

[0149] Moreover, when a short circuit fault occurs inside the power battery pack, the DC protection switch can quickly detect and disconnect the high-voltage electrical components from the DC output interface, preventing the fault on the power battery side from spreading to the high-voltage electrical components and protecting the high-voltage electrical components.

[0150] According to an embodiment of the present application, by adding an independent DC protection switch to each high-voltage electrical component on the power battery side of the electric vehicle, the DC protection switch can be uniformly assembled on the power battery side without the need for structural adjustments to the powertrain, thereby achieving stronger compatibility while achieving fault isolation.

[0151] In some embodiments, as Figure 4 As shown, the powertrain 10 includes a motor controller 102, a motor 101, and a motor controller housing. The motor controller 102 is configured to receive power from the DC bus through the DC output interface and drive the motor 101. The motor controller housing is configured to accommodate the DC protection switch and the inverter circuit of the motor controller 102. The housing also includes a DC input port and an AC output port. The inverter circuit is configured to connect to the DC input port through the DC protection switch to receive DC power from the DC bus and output three-phase AC power to the three-phase windings of the motor 101 through the AC output port.

[0152] That is, the DC protection switch can be assembled inside the housing of the motor controller. The DC input port includes a positive DC input port and a negative DC input port. Specifically, the DC protection switch can be connected in series between the positive DC output interface and the positive DC input port, or the DC protection switch can be connected in series between the negative DC output interface and the negative DC input port, or one sub-switch in the DC protection switch can be connected in series between the positive DC output interface and the positive DC input port, and another sub-switch can be connected in series between the negative DC output interface and the negative DC input port.

[0153] Furthermore, when a short circuit fault occurs inside the powertrain 10, the DC protection switch disconnects the connection between the inverter circuit in the motor controller and the DC output port, thereby disconnecting the connection between the inverter circuit of the motor controller and the DC bus, preventing the fault inside the powertrain 10 from spreading through the DC bus.

[0154] According to the embodiment of the present application, the DC protection switch is integrated into the motor controller, which has a higher degree of integration and is conducive to improving the reliability of the motor controller.

[0155] In some embodiments, the DC protection switch can also be connected in series between the DC input port of the motor controller and the DC output port of the power battery pack. Specifically, the DC protection switch can be assembled on the battery housing of the power battery or the housing of the motor controller. The DC protection switch can be welded on the battery housing of the power battery pack or the housing of the motor controller, or fixed on the battery housing of the power battery pack or the housing of the motor controller by means of bolts, slide rails, etc. Or as Figure 5 As shown, the DC protection switch can also be installed on the high-voltage wiring harness between the powertrain 10 and the power battery pack, so that the power battery pack can be connected to the DC input terminal of the motor controller through the DC output terminal and the DC protection switch in sequence. Figure 5 As shown, the DC protection switch can be a fuse.

[0156] According to the embodiment of the present application, the specific assembly position between the power battery pack and the motor controller can be selected according to actual implementation, which is highly flexible. In addition, the DC protection switch is easy to repair and replace later.

[0157] It should be noted that the DC protection switch can be a controlled switching device such as a switching tube, relay, etc., or a device that automatically detects overcurrent and blows, such as a fuse, etc., and this application does not limit this. If the DC protection switch is a controlled switching device, it can be connected to the control circuit in the motor controller and controlled by the control circuit, or it can be connected to the controller in the battery management system (BMS) in the power battery and controlled by the battery management system.

[0158] In some embodiments, the DC protection switch can be a quick disconnect switch (HiFuse). The DC protection switch includes a conductor a, an actuator b, a drive circuit c, and a controller d. It is understood that during normal operation of the motor controller 102, the cells in the power battery pack can supply power to the motor controller 102 through the DC bus and the conductor a of the DC protection switch. Furthermore, in response to a short circuit fault in the power assembly 10, the controller d sends a drive signal to the drive circuit c, thereby controlling the actuator b to quickly cut off the conductor a, so that the power battery stops supplying power to the power assembly 10.

[0159] In some embodiments, the conductor a can be designed as a structure that can be quickly cut off. For example, the conductor a can be designed as a copper busbar with a weak point, and the actuator b can quickly cut off the weak point of the copper busbar in response to the driving signal sent by the driving circuit c.

[0160] In some embodiments, when the current value passing through the DC protection switch is greater than a first threshold, the DC protection switch is disconnected.

[0161] It is understood that the first threshold value can be understood as a relatively large current value. A portion of the DC current output by the power battery pack is input into the powertrain 10 through the DC protection switch. When a short circuit occurs in the powertrain 10, the DC current passing through the DC protection switch suddenly increases. When the current passing through the DC protection switch exceeds the first threshold value, it indicates that a short circuit has occurred in the powertrain. At this time, to protect other electrical components, the DC protection switch must be disconnected, thereby disconnecting the powertrain 10 from the DC bus. This isolates the short circuit in the powertrain 10 and does not affect other electrical components mounted on the DC bus.

[0162] According to the embodiment of the present application, it is possible to determine whether a short circuit fault occurs in the corresponding high-voltage electrical component based on the current passing through the DC protection switch, and the control method is simple and highly reliable.

[0163] In some embodiments, when the voltage of the current passing through the DC protection switch is less than a fifth threshold, the DC protection switch disconnects the DC bus from the motor controller. Alternatively, when the rate of change of the voltage of the current passing through the DC protection switch is greater than a sixth threshold, the DC protection switch disconnects the DC bus from the motor controller. Alternatively, when the magnitude of the current passing through the DC protection switch is greater than a first threshold and / or the voltage of the current passing through the DC protection switch is less than a fifth threshold and / or the rate of change of the voltage of the current passing through the DC protection switch is greater than a sixth threshold, the DC protection switch disconnects the DC bus from the powertrain.

[0164] It is understandable that whether a short circuit occurs in the powertrain or the DC bus can be determined by detecting the current and / or voltage, thereby controlling whether the DC protection switch is disconnected.

[0165] In some embodiments, the motor controller 102 further includes a temperature sensor, and when the temperature indicated by the temperature sensor is greater than a preset temperature value, the DC protection switch is disconnected. The temperature sensor here can be arranged on the shell surface of the motor controller 102, the heat dissipation water channel inside the motor controller 102, or the power device and other electrical components of the motor controller 102. When the temperature indicated by the temperature sensor is too high, it means that the motor controller 102 may have a fault, and the control device promptly controls the DC protection switch to disconnect to avoid overheating of the motor controller 102. In the embodiment of the present application, one temperature sensor can be set, and multiple temperature sensors can also be set.

[0166] In some embodiments, a first temperature sensor is provided on the surface of the circuit board of the motor controller 102, and a second temperature sensor is provided on the inner surface of the housing of the motor controller 102. When the temperature indicated by the first temperature sensor is greater than a first preset temperature value or when the temperature indicated by the second temperature sensor is greater than a second preset temperature value, the DC protection switch is disconnected. The first preset temperature value is greater than the second temperature value. Since the over-temperature location of the motor controller 102 is generally on the circuit component, when the motor controller 102 is over-temperature, the temperature at the circuit board is greater than the temperature at the housing. Therefore, when determining whether the motor controller 102 is over-temperature, the first preset temperature value is greater than the second temperature value.

[0167] In some embodiments, when the average of the temperature indicated by the first temperature sensor and the temperature indicated by the second temperature sensor is greater than a third preset temperature value, the DC protection switch is disconnected. Simultaneously considering the temperature values ​​collected by multiple temperature sensors when making an over-temperature determination can avoid inaccurate determinations caused by failure of a single temperature sensor.

[0168] Continue to refer Figure 3 or Figure 4In some embodiments, the power battery pack further includes a DC bus switch, through which the cells in the power battery pack are used to supply power to the DC bus. During operation of the electric vehicle 01, the current passing through the DC bus switch is greater than the current passing through the DC protection switch.

[0169] It can be understood that the power battery pack supplies power to the powertrain via the DC bus. When the power battery supplies power to multiple powertrains simultaneously via the DC bus, the multiple powertrains are connected in parallel. At this point, the current received by the DC bus from the power battery is greater than the current passing through the DC protection switch. Alternatively, it can be understood that the current passing through the DC bus is greater than the current passing through the DC protection switch. For example, when the vehicle is a front-wheel drive vehicle with both front-wheel drive powertrains operating simultaneously, the current passing through the DC bus is greater than the current passing through the DC protection switch.

[0170] It can be understood that if the power battery pack only supplies power to one powertrain through the DC bus, the current received by the DC bus from the power battery is equal to the current passing through the DC protection switch, or it can be understood that the current passing through the DC bus is equal to the current passing through the DC protection switch. For example, when the vehicle is a single-wheel drive vehicle, the power battery only supplies power to one powertrain through the DC bus, and the current passing through the DC bus is greater than the current passing through the DC protection switch. For example, Figure 3 As shown, the current received by the DC bus from the battery cell is I1, and the current passing through the DC protection switch is I2, and I1 is greater than I2.

[0171] It is understood that when an overcurrent occurs on the DC bus, the DC bus switch will disconnect after a certain period of time, thereby protecting the power battery and electrical components. To prevent the DC bus switch from disconnecting when a single electrical component short-circuits, thereby affecting other normal electrical components, a DC-side disconnect device is provided to disconnect before the protective device in the event of an overcurrent.

[0172] Therefore, when selecting the DC bus switch and the DC protection switch, it is necessary to ensure that the device disconnection delay time of the DC protection switch is shorter than the device disconnection delay time of the DC bus switch.

[0173] In some embodiments, the DC bus switch has a greater disconnect current than the DC protection switch. This ensures that the DC protection switch disconnects before the DC bus switch when a high-voltage electrical component fails, preventing the DC bus switch from disconnecting under controllable fault conditions and affecting other normal electrical components.

[0174] According to an embodiment of the present application, a DC bus switch is installed on the DC bus of an electric vehicle. This can be disconnected in the event of a power battery pack failure, preventing damage to high-voltage electrical components. Furthermore, by ensuring that the DC protection switch has a shorter disconnection delay and current than the DC bus switch, the DC bus switch will not disconnect in the event of a short circuit in a single electrical component, thus preventing the normal operation of other electrical components.

[0175] Continue to refer Figure 3 or Figure 4 The powertrain 10 may also be provided with an AC protection switch. Specifically, the powertrain 10 includes a motor controller 102 and a motor 101. The motor controller 102 is configured to receive power from the DC bus via the DC output interface and drive the motor 101. The motor controller 102 includes a three-phase bridge arm and three AC protection switches. The midpoint of each phase of the three-phase bridge arm is connected to a phase winding of the motor via one of the AC protection switches.

[0176] It is understood that each phase bridge arm of the motor controller can be divided into an upper bridge arm and a lower bridge arm at the bridge arm midpoint. Both the upper bridge arm and the lower bridge arm include power modules. The power module located in the upper bridge arm includes an upper bridge arm switching tube, and the power module located in the lower bridge arm includes a lower bridge arm switching tube. In addition to the upper bridge arm switching tube or the lower bridge arm switching tube, the power module may also include a detection module, such as a temperature detection module, a short-circuit detection module, etc.

[0177] It is understood that the motor controller may also include an N-phase bridge arm connected to the N-phase winding of the motor 101, where N is a positive integer greater than 2. This application is described with N being 3, and similar methods can be used when N is other values, which will not be repeated here.

[0178] The present application does not limit the installation location of the AC protection switch. The AC protection switch can be inside the housing of the motor controller or can be a separately added device.

[0179] In some embodiments, the AC protection switch can be a device that automatically detects overcurrent and trips, such as a fuse. When the current passing through any of the AC protection switches exceeds a second threshold, the AC protection switch is disconnected. In other words, when the current in any phase bridge arm exceeds the second threshold, the AC protection switch connected to that phase bridge arm is disconnected.

[0180] In some embodiments, the AC protection switch may be a controlled switch device such as a switch tube, a relay, etc., and the overcurrent signal detected by the detection device in the motor controller 102 is used as a trigger source.

[0181] Specifically, such as Figure 6As shown, each circuit in powertrain 10 includes a detection device. This detection device is used to detect overcurrent signals within the circuit. The detection device transmits the overcurrent signals to the motor controller, allowing the motor controller to detect overcurrent signals within each circuit. For example, overcurrent signals can be detected at any of the overcurrent points 1-7 shown in the figure. The AC protection switch is a controlled disconnect device, triggered by the overcurrent signal detected by the detection device in motor controller 102.

[0182] For example, when a short overcurrent signal appears at any one of overcurrent point 5, overcurrent point 6 or overcurrent point 7, that is, the current of any one of the three-phase bridge arms is greater than the second threshold, the AC protection switch will disconnect the connection between the phase bridge arm where the overcurrent signal appears and the motor, and at the same time control the first drive motor 101 to reduce the output torque.

[0183] It is easy to understand that when a single switch tube module in a phase bridge arm is short-circuited, the current on the phase bridge arm will only overcurrent when the switch tube module is closed. Therefore, the overcurrent signal in the motor controller will be detected to be instantaneous low level and then return to normal. At this time, it is only necessary to disconnect the AC protection switch corresponding to the phase bridge arm of the module.

[0184] According to the embodiments of the present application, adding an AC protection switch to the power line between the motor controller and the motor can isolate the short-circuit fault on the inverter circuit. When a single module fails, the motor can be operated in a short-term phase-loss state, which can prevent the vehicle from completely losing power and improve the vehicle's driving safety and operational reliability.

[0185] In some embodiments, when the current value passing through any one of the AC protection switches is greater than a second threshold, the upper bridge arm switch tube or the lower bridge arm switch tube that is not short-circuited in at least one phase bridge arm is first controlled to disconnect, and then the corresponding AC protection switch of at least one phase bridge arm is controlled to disconnect.

[0186] According to an embodiment of the present application, when a single switching tube module in a phase bridge arm short-circuits, the remaining switching tubes in that phase bridge arm can be turned off first to prevent both the upper and lower switching tubes in that phase bridge arm from being turned on, which could short-circuit the drive motor. The corresponding AC protection switch in at least one phase bridge arm is then controlled to open, preventing the short-circuited three-phase current in that phase bridge arm from flowing into the drive motor windings, thereby protecting the drive motor.

[0187] In some embodiments, when the current passing through the upper arm switch tube or the lower arm switch tube of any one of the three-phase bridge arms is greater than the current threshold, the three-phase bridge arm is controlled to be in a safety protection state. The safety protection state includes an active short-circuit state or a full-off state. Then, when the control circuit controls the three-phase bridge arm to be in the safety protection state for a preset time, the upper arm switch tube and the lower arm switch tube of the three-phase bridge arm can be controlled to be turned off. Finally, when the output current of the midpoint of the bridge arm of the at least one phase bridge arm is greater than the set current value, the connection switch corresponding to the at least one phase bridge arm is controlled to be disconnected.

[0188] The safety protection states include the active short circuit (ASC) state and the switching pulse off (SPO) state. The active short circuit (ASC) state refers to the state where all upper bridge arm switches of each phase arm of the three-phase bridge arm are turned on or all lower bridge arm switches are turned on, and the three-phase winding of the motor and the three upper bridge arm switches or three lower bridge arm switches in the turned-on state and the three-phase winding form a closed loop. When the motor controller enters the active short circuit protection (ASC) state, it can isolate the motor controller, the motor, and the power battery to ensure the high voltage safety of the entire vehicle. It can also cause the motor to generate reverse torque to slowly brake the vehicle. At the same time, when the motor controller enters the active short circuit (ASC) state, it can prevent the motor from generating excessive back electromotive force that may damage the power battery, bus capacitors, and other components.

[0189] The fully off SPO state means that the upper and lower arm switching tubes of each phase of the three-phase bridge arm are all turned off, thereby isolating the motor controller, the motor and the power battery.

[0190] According to an embodiment of the present application, after determining that the current of the upper bridge arm switch tube or the lower bridge arm switch tube of at least one phase bridge arm is greater than the current threshold, it is possible to further verify whether the upper bridge arm switch tube or the lower bridge arm switch tube of at least one phase bridge arm is short-circuited. Before verification, controlling the motor to enter the safety protection state for a preset time can reduce the back electromotive force generated by the motor to protect the components in the inverter circuit. After turning off the upper bridge arm switch tube and the lower bridge arm switch tube in the three-phase bridge arm, if there is a three-phase current at the midpoint of at least one phase bridge arm that is greater than zero or greater than the current threshold, it can be determined that the upper bridge arm switch tube or the lower bridge arm switch tube of the at least one phase bridge arm is short-circuited, and then the AC protection switch corresponding to the at least one phase bridge arm can be disconnected to prevent the short-circuited three-phase current of the phase bridge arm from flowing to the winding of the motor, which can protect the motor.

[0191] In some embodiments, in response to the current value of the upper bridge arm switch tube or the lower bridge arm switch tube of at least one phase bridge arm of the three-phase bridge arm being greater than a second threshold and the speed of the driving motor being greater than a preset speed, the motor is controlled to enter a safety protection state.

[0192] According to an embodiment of the present application, before re-verifying whether there is a short circuit in the upper arm switch tube or the lower arm switch tube of at least one phase bridge arm, if the speed of the drive motor is greater than the preset speed, it is necessary to control the inverter circuit to be in a safety protection state to reduce the back electromotive force generated by the motor and protect the components in the inverter circuit.

[0193] In some embodiments, while controlling the other two bridge arms that are not experiencing short-circuit faults to output two-phase AC power to motor 101, the speed of motor 101 can be controlled to be less than a preset speed value, thereby ensuring normal rotation of motor 101 and preventing motor 101 from malfunctioning. This preset speed value can be set by a technician based on the performance of motor 101. When the speed of motor 101 is less than the preset speed value, it can safely output torque to the vehicle under the drive of two-phase AC power.

[0194] In some embodiments, when the duration of the current passing through any one of the two AC protection switches is greater than the second threshold value is greater than the first duration, at least two of the AC protection switches are disconnected.

[0195] Since the overcurrent signal will only appear briefly when a single module fails, the duration can be less than or equal to 10 microseconds. When the overcurrent signal exceeds the first duration, it indicates that there is a short circuit in the entire circuit.

[0196] It can be understood that when the overcurrent signal on the motor controller remains at a low level, that is, the current is greater than the second threshold for a duration greater than the first duration, it indicates that the upper and lower bridge arm switch modules in one-phase bridge arm may have both experienced a short circuit. At this time, it is necessary not only to disconnect the DC protection switch to prevent the DC bus from being affected and causing power loss to the entire vehicle, but also to disconnect at least two AC protection switches so that the current in the motor controller does not form a loop, thereby avoiding the short-circuit current that causes the motor to generate a large braking torque and thus affect driving safety.

[0197] According to an embodiment of the present application, when multiple modules of the motor controller fail, disconnecting at least two AC protection switches can avoid causing the drive motor to generate braking torque, so that the vehicle will not suddenly decelerate even when power is lost, effectively improving driving safety.

[0198] In some embodiments, continue to refer to Figure 3 or Figure 4 The motor controller 102 includes a three-phase bridge arm, and each phase bridge arm of the three-phase bridge arm includes an isolating switch, which is used to connect or disconnect the corresponding phase bridge arm and the positive DC bus or the negative DC bus.

[0199] Specifically, the isolating switch in each phase bridge arm can be set between the upper bridge arm switch tube of each bridge arm and the positive DC bus, or the isolating switch in each phase bridge arm can be set between the upper bridge arm switch tube of each bridge arm and the midpoint of the bridge arm. Similarly, the isolating switch can also be independently set on the lower bridge arm of each phase bridge arm according to the above-mentioned setting method, and the embodiments of the present application are not described in detail here. The isolating switch in each phase bridge arm can also include an upper isolating switch and a lower isolating switch. The upper isolating switch can be independently set on the upper bridge arm of each phase bridge arm according to the above-mentioned setting method, and the lower isolating switch can be independently set on the lower bridge arm of each phase bridge arm according to the above-mentioned setting method.

[0200] It can be understood that when the motor controller operates normally, the isolation switch is closed, so that the motor controller can output three-phase AC power to the motor 101 by controlling the on and off of the upper bridge arm switch tube and the lower bridge arm switch tube.

[0201] In some embodiments, when the upper or lower switching tube of any phase arm in the three-phase bridge arm is short-circuited, the isolating switch corresponding to that phase arm is disconnected. Exemplarily, when the current passing through any isolating switch is greater than a third threshold, the isolating switch is disconnected. Exemplarily, when the voltage between the bridge arm and the positive DC bus or the negative DC bus in any bridge arm is lower than a preset voltage value, or the rate of voltage drop is greater than a preset rate, the isolating switch on that bridge arm is disconnected.

[0202] According to an embodiment of the present application, when a short-circuit fault occurs in any of the three-phase bridge arms, causing the current in the bridge arm to be excessive, the upper bridge arm switch can be disconnected from the bridge arm midpoint by the upper bridge arm isolating switch, thereby disconnecting the corresponding one-phase bridge arm from the positive DC bus or the negative DC bus, thereby avoiding a direct fault in the positive DC bus and the negative DC bus, and preventing the vehicle from experiencing a bus voltage loss problem. In addition, because only the one-phase bridge arm with the short-circuit fault is disconnected, the other two-phase bridge arms can still output two-phase AC power to the windings of the motor 101, so as to drive the motor 101 to operate in a phase-missing state, thereby avoiding a complete loss of power for the vehicle and improving the vehicle's driving safety and operational reliability.

[0203] It is understood that when the isolating switch includes two sub-switches, when one sub-switch is disconnected, the other sub-switch can be automatically disconnected. Based on this, in addition to preventing direct faults in the positive DC bus and the negative DC bus, the drive motor 101 can also be protected when the drive motor 101 operates in a phase-loss state, thereby ensuring more stable operation of the drive motor 101.

[0204] In some embodiments, the motor controller includes a control circuit (not shown) configured to control the DC protection switch to disconnect when the current value passing through the DC protection switch exceeds a first threshold. Alternatively, when the current value passing through any of the AC protection switches exceeds a second threshold, the AC protection switch is disconnected; or when the current value passing through the upper or lower switching transistor of any phase arm of the three-phase bridge arm exceeds a third threshold, the isolating switch corresponding to the phase arm is disconnected.

[0205] According to an embodiment of the present application, the motor controller can control the on and off of at least one of the DC protection switch, AC protection switch or isolation switch by detecting the current value control circuit. The control method is simple and reliable.

[0206] In some embodiments, the second threshold is less than or equal to the third threshold. The second threshold and the third threshold may be effective values ​​or average values ​​of the three-phase current.

[0207] In other words, the disconnect current of the AC protection switch is less than the cut-off current of the isolation switch. Thus, if a power module or motor winding in a phase bridge arm short-circuits, the AC protection switch between the midpoint of that phase bridge arm and the motor winding will open first, followed by the isolation switch in that phase bridge arm. This prevents the motor winding from forming a loop with a power module in that phase bridge arm, further improving fault isolation speed.

[0208] In some embodiments, the control circuit is specifically used to control any one of the AC protection switches to turn off and the isolating switch corresponding to any one of the phase bridge arms to disconnect, and then control the midpoints of the other two phase bridge arms to output two-phase AC power when the current value passing through any one of the AC protection switches is greater than a second threshold, or the current value passing through the upper bridge arm switch tube or the lower bridge arm switch tube of any one of the phase bridge arms of the three-phase bridge arm is greater than a third threshold.

[0209] According to the present invention, when a short circuit occurs in one phase bridge arm or one phase winding, the control circuit can control the AC protection switch and isolating switch corresponding to that phase bridge arm to open. After the connecting switch and isolating switch corresponding to that phase bridge arm open, the midpoints of the other two phase bridge arms are controlled to output two-phase AC power. This two-phase AC power can be used to drive the motor to output torque, ensuring that the vehicle does not lose power.

[0210] In some embodiments, in the process of controlling the midpoint of the other two-phase bridge arms to output two-phase AC power, the control circuit is also used to control the DC protection switch to disconnect first, and then control the AC protection switch and the isolating switch corresponding to the one-phase bridge arm to disconnect when the current value passing through one of the other two AC protection switches is greater than a second threshold, or the current passing through the upper bridge arm switch tube or the lower bridge arm switch tube of one of the other two-phase bridge arms is greater than a third threshold.

[0211] According to the solution of the present application, during the process of the motor controller outputting two-phase AC power to the motor, if one of the two-phase bridge arms outputting two-phase AC power has a short-circuit fault again or the winding connected to the midpoint of the bridge arm of one phase bridge arm has a short-circuit fault, the motor cannot output torque at this time. The DC protection switch can be controlled to disconnect first to avoid the spread of the fault, and then the AC protection switch and the isolating switch corresponding to the bridge arm with the short-circuit fault can be controlled to disconnect, so that the short-circuit three-phase current of the phase bridge arm will not flow to the winding of the motor, which can protect the motor.

[0212] It should be emphasized that the above Figures 3 to 5 In an actual powertrain, one or more of the DC protection switch, AC protection switch, DC bus switch, and isolating switch described above may be selected based on actual implementation, and the present application does not limit this.

[0213] The above Figure 2 The following describes different types of powertrains that may be included in an electric vehicle in conjunction with the embodiments.

[0214] like Figure 7 As shown, in some embodiments, for Figure 2 For the front-to-rear dual-drive electric vehicle shown in (b), the power battery pack includes a first battery module and a second battery module. The first powertrain 20 is used to receive power from the first battery module through a DC protection switch to drive the two front wheels of the electric vehicle. The second powertrain 21 is used to receive power from the second battery module through another DC protection switch to drive the two rear wheels of the electric vehicle. The operating modes of the two DC protection switches can be found in the relevant content above and are not detailed here.

[0215] Continue to refer Figure 7The power battery pack also includes a switch module for switching the connection mode between the first battery module and the second battery module. Exemplarily, the switch module includes a first switch S3, a second switch S1, and a third switch S2. The first switch S3 is used to connect the positive electrode of the first battery module to the negative electrode of the second battery module. The second switch S1 is used to connect the positive electrode of the first battery module to the positive electrode of the second battery module. The third switch S2 is used to connect the negative electrode of the first battery module to the negative electrode of the second battery module.

[0216] In some embodiments, when the electric vehicle is driving, the first switch S3 is open, and the second switch S1 and the third switch S2 are closed. When the electric vehicle is charging, the first switch S3 is closed, and the second switch S1 and the third switch S2 are open.

[0217] Specifically, during the driving process of the electric vehicle 01, the second switching switch S1 and the third switching switch S2 can be controlled to close, so that the first battery module and the second battery module are connected in parallel, so that the first motor controller 202 receives power from the first battery module and the second battery module in parallel, and outputs three-phase AC power to the first motor 201 to drive the wheels to rotate.

[0218] Specifically, during the high-voltage charging process of the electric vehicle 01, the third switch S3 can be controlled to close so that the first battery module and the second battery module are connected in series, so that the first motor controller 202 receives power from the first battery module and outputs three-phase AC power to the first motor 201 to heat the three-phase winding of the first motor 201, and heats the first battery module through a heat-conducting component (not shown in the figure). At the same time, since the first battery module and the second battery module are connected in series, the charging power is large at this time, which can increase the charging rate of the first battery module and the second battery module. Among them, high-voltage charging refers to the process of charging the power battery pack using a charging pile with an output voltage higher than the voltage of a single battery module (such as the first battery module). For example, the voltage of the first battery module is 400V. If a charging pile that can output 800V voltage is used for charging, the third switch can be controlled to close so that the first battery module and the second battery module are connected in series, thereby increasing the charging rate of the power battery pack.

[0219] Based on the above solution, the connection mode of the first battery module and the second battery module in the power battery pack can be switched by the switch module, which has strong flexibility and can increase the charging rate of the power battery pack during high-voltage charging.

[0220] In some embodiments, the first powertrain 20 is further configured to connect to the positive electrode of the second battery module via a redundant switch, and the powertrain 20 is further configured to connect to the negative electrode of the second battery module via another redundant switch. When the first battery module fails, the DC protection switch opens, and the redundant switches close, allowing the first motor controller 202 to receive power from the second battery module. This prevents the first powertrain 20 from losing power due to a first battery module failure, thereby achieving a redundant power supply function.

[0221] In some embodiments, when one powertrain in the electric vehicle 01 fails, the motor controller in the other powertrain can also increase the current of the three-phase AC power output to the corresponding drive motor and the output power of the motor controller, thereby increasing the torque output by the drive motor and / or the output power of the drive motor, thereby reducing the power loss of the electric vehicle 01 caused by the powertrain failure and improving the safety of the electric vehicle 01. Among them, the current is an active current, which is used to increase the torque output by the drive motor, and the output power of the motor controller is an active power. Taking the failure of the first powertrain 20 as an example, the second motor controller 203 in the second powertrain 21 can increase the current of the three-phase AC power output to the second motor 204 and the output power of the second motor controller 203, thereby increasing the torque output by the second motor 204 and / or the power of the second motor 204, thereby reducing the power loss of the electric vehicle 01 caused by the failure of the first powertrain 20.

[0222] like Figure 8 As shown, in some embodiments, for Figure 2 For the front-to-rear dual-drive electric vehicle shown in (b) of FIG, the electric vehicle includes a first powertrain 20 and a second powertrain 21. The first motor controller 202 is configured to receive power from the DC bus via a DC protection switch and output a first three-phase AC power to drive the first motor 201. The second motor controller 203 is configured to receive power from the DC bus via another DC protection switch and output a second three-phase AC power to drive the second motor 204. The operating modes of the two DC protection switches can be found in the relevant sections above and are not described here in detail.

[0223] It can be understood that for a front and rear dual-drive electric vehicle, the two DC protection switches can be respectively arranged in the housing of the corresponding motor controller, that is, Figure 8As shown in (a), one DC protection switch is provided between the inverter circuit in the first motor controller and the DC input port on the housing of the first motor controller, and the other DC protection switch is provided between the inverter circuit in the second motor controller and the DC input port on the housing of the second motor controller. Alternatively, the two DC protection switches can be provided in the housing of the power battery pack, that is, Figure 8 As shown in (b), one DC protection switch is arranged between the DC bus and the first DC output port, and the other DC protection switch is arranged between the DC bus and the second DC output port, wherein the first DC output port is used to connect to the DC input port of the first motor controller, and the second DC output port is used to connect to the DC input port of the second motor controller.

[0224] In some embodiments, as Figure 8 As shown in (b), the DC busbar of the power battery pack does not need to be equipped with a main fuse. Instead, the fault isolation of each powertrain is completed through a DC protection switch, which is beneficial to reducing the internal space and assembly complexity of the power battery pack.

[0225] In some embodiments, when the first motor controller 202 fails, the first motor controller 202 outputs a first fault signal and stops supplying the first three-phase AC power to the front-drive motor. The first fault signal is used to instruct the second motor controller 203 of the vehicle to control the rear-drive motor to increase torque output. When the second motor controller 203 fails, the second motor controller 203 outputs a second fault signal and stops supplying the second three-phase AC power to the rear-drive motor. The second fault signal is used to instruct the first motor controller 202 of the vehicle to control the front-drive motor to increase torque output.

[0226] It is understandable that Figure 9As shown in (a) of FIG, the first motor controller 202 and the second motor controller 203 can send a fault signal to the vehicle controller of the electric vehicle, so that the vehicle controller can adjust the torque output by the other motor in response to the fault signal. For example, during the process of the first motor controller 202 outputting current, in response to a fault in the first motor controller 202, the first motor controller 202 is configured to output a first fault signal to the vehicle controller of the vehicle and stop outputting current to the first motor 201. The vehicle controller is configured to send a first torque signal to another motor controller, namely the second motor controller 203, in response to the first fault signal. The first torque signal is configured to instruct the second motor controller 203 to output current to another motor, namely the second motor 204, so that the second motor 204 outputs the torque indicated by the first torque signal. Similarly, when the second motor controller 203 fails, the second motor controller 203 sends a second fault signal to the vehicle controller, indicating that the second motor controller 203 has failed. In response to the second fault signal sent by the second motor controller 203, the vehicle controller of the vehicle sends a third torque signal to the first motor controller 202. The first motor controller 202 is configured to output current to the first motor 201 in response to the third torque signal so that the first motor 201 outputs the torque indicated by the third torque signal.

[0227] It is understandable that Figure 9 As shown in (b) of FIG, first motor controller 202 and second motor controller 203 can directly transmit fault signals and / or torque signals between them, and adjust the torque output by the motors upon receiving the fault signals. While first motor controller 202 is outputting current, in response to first motor controller 202, first motor controller 202 is configured to output a first fault signal and a second torque signal and stop outputting current to first motor 201. The first fault signal is configured to instruct second motor controller 203 to receive power from the power battery and output current to second motor 204, so that second motor 204 outputs the torque indicated by the second torque signal. Similarly, when second motor controller 203 fails, second motor controller 203 sends a second fault signal and / or a third torque signal to first motor controller 202, indicating a fault in second motor controller 203. In response to the second fault signal and / or the third torque signal, first motor controller 202 is configured to receive power from the power battery and output current to first motor 201, so that first motor 201 outputs the torque indicated by the third torque signal.

[0228] According to an embodiment of the present application, fault signals from each motor controller are detected. When a single motor controller fails, the fault is isolated for the bus load. After the fault is isolated, a torque demand signal is issued, requesting the remaining functioning motor controllers to start and control the corresponding drive motors to compensate for the torque required by the vehicle. The operating status of each motor controller can be coordinated uniformly through the vehicle controller, or torque demand signals can be transmitted between motor controllers to request driving capacity compensation.

[0229] like Figure 10 As shown, in some embodiments, for Figure 2 For the hybrid vehicle shown in (c) of FIG, the dual-motor controller 303 is used to receive power from the power battery pack to drive the electric vehicle's drive motor or to transmit power generated by the generator to the power battery to charge the power battery pack. The dual-motor controller 303 includes a dual-motor controller housing, a generator power circuit 303a, and a motor power circuit 303b. The dual-motor controller housing is used to accommodate the generator power circuit 303a, the motor power circuit 303b, and the at least one DC protection switch. The dual-motor controller housing includes a high-voltage DC port. The dual-motor controller 303 is used to receive power from the power battery or charge the power battery through the high-voltage DC port. The motor power circuit 303b is used to receive DC power from the high-voltage DC port through the DC protection switch. The generator power circuit 303a is used to receive AC power generated by the generator and output DC power to the high-voltage DC port through the DC protection switch. The DC protection switch is used to connect or disconnect the motor power circuit 303b and the generator power circuit 303a from the high-voltage DC port. The specific operation mode of the DC protection switch can be referred to the relevant content above and will not be described here in detail.

[0230] It is understandable that the at least one DC protection switch mentioned above can also be arranged inside the battery housing of the power battery pack. For the specific implementation, please refer to the relevant content in the powertrain 10, which will not be described in detail here.

[0231] According to an embodiment of the present application, a DC protection switch is added to the front end of the dual-motor controller connected to the DC bus. This DC protection switch can prevent faults in other loads connected to the DC bus from spreading to the interior of the dual-motor controller 303, thereby protecting the power devices in the dual-motor controller 303. Furthermore, the DC protection switch can be assembled in the housing of the dual-motor controller 303, making the dual-motor controller 303 highly integrated and easy to install and use.

[0232] In these embodiments, the generator power circuit 303a is also used to receive the AC power generated by the generator 302 and supply power to the motor power circuit 303b during the driving of the electric vehicle 01, after the DC protection switch disconnects the connection between the motor power circuit 303b and the generator power circuit 303a and a high-voltage DC port, so that the motor power circuit 303b is used to drive the motor 301.

[0233] It is understood that after the DC protection switch is disconnected, the motor power circuit 303b cannot receive power from the power battery through the high-voltage DC port. At the same time, the generator power circuit 303a can receive power from the generator 302 and supply power to the motor power circuit 303b, so that the power of the motor 301 is not interrupted.

[0234] According to an embodiment of the present application, after the DC protection switch in the dual-motor controller disconnects the power circuit in the dual-motor controller from the DC bus, the generator power circuit can be controlled to supply power to the motor power circuit, thereby preventing the drive motor from losing power supply, thereby ensuring uninterrupted power to the entire vehicle.

[0235] In some embodiments, in response to the power battery stopping supplying power to the dual-motor controller 303 during the driving of the electric vehicle 01, the generator power circuit 303a is also used to receive the AC power generated by the generator 302 and supply power to the motor power circuit 303b so that the motor power circuit 303b is used to drive the motor 301.

[0236] Among them, the power battery stops supplying power to the dual-motor controller 303, which can be understood as insufficient power of the power battery, or a failure of the battery pack in the power battery, or a break or short circuit failure of the wiring harness between the power battery and the dual-motor controller 303. This application does not limit this.

[0237] According to an embodiment of the present application, the dual-motor controller can receive power from the generator and supply power to the drive motor after losing power from the power battery, thereby ensuring uninterrupted power for the entire vehicle and further improving the safety of the electric vehicle.

[0238] In some embodiments, the electric vehicle 01 further includes a DC conversion circuit, and the housing further includes another high-voltage DC port (not shown in the figure), the other high-voltage DC port being configured to connect to the one high-voltage DC port via the DC protection switch. The DC conversion circuit is configured to receive DC power from the one high-voltage DC port via the other high-voltage DC port and the DC protection switch, and to step down the DC power from the one high-voltage DC port for output.

[0239] It can be understood that the DC conversion circuit is connected to the power battery pack through the other high-voltage DC port, the DC protection switch and the high-voltage DC port in sequence to receive DC power from the power battery pack and perform voltage reduction conversion.

[0240] It can be understood that one end of the DC conversion circuit is connected to the other high-voltage DC port, and the other end can be connected to the low-voltage electrical equipment of the electric vehicle 01, or connected to the low-voltage battery of the electric vehicle 01. This embodiment of the present application does not limit this.

[0241] In some embodiments, the dual-motor controller 303 further includes a DC conversion circuit housed in a housing, which also includes a low-voltage DC port. The DC conversion circuit is configured to receive DC power from a high-voltage DC port via a DC protection switch, perform step-down conversion on the DC power from the high-voltage DC port, and output the power through a low-voltage DC port.

[0242] It is understood that one end of the DC conversion circuit is used to connect to the DC protection switch, and the other end of the DC conversion circuit is used to connect to the low-voltage DC port. The DC conversion circuit can receive a first DC power provided by the power battery pack through the DC protection switch and the high-voltage DC port, and output a second DC power to the low-voltage DC port. The voltage of the first DC power is higher than the voltage of the second DC power. That is, the DC conversion circuit is used to reduce the voltage of the first DC power to generate and output the second DC power.

[0243] It can be understood that the DC conversion circuit can be connected to the low-voltage electrical equipment of the electric vehicle 01 or the low-voltage battery of the electric vehicle 01 through the low-voltage DC port, and this embodiment of the application does not limit this.

[0244] According to an embodiment of the present application, the DC conversion circuit can be integrated into the housing of the dual-motor controller, and the dual-motor controller has a high degree of integration and a wider range of applications.

[0245] In some embodiments, after the DC protection switch is disconnected, the DC conversion circuit is further configured to receive power from the generator power circuit and perform voltage reduction conversion on the DC power output by the generator power circuit before outputting the DC power through a low-voltage DC port.

[0246] It will be appreciated that when the DC protection switch is in the on state, the DC conversion circuit can receive the DC power provided by the power battery, perform step-down conversion, and output it through the low-voltage DC port. When the DC protection switch is in the off state, the DC conversion circuit can receive the DC power provided by the generator power circuit 303a, perform step-down conversion, and output it through the low-voltage DC port. In other words, the low-voltage DC port can reuse the DC conversion circuit to receive power from the DC bus or the generator power circuit 303a.

[0247] According to an embodiment of the present application, after the DC protection switch is disconnected, the hybrid powertrain can generate electricity from the generator and output low-voltage DC power through the DC conversion circuit and the low-voltage DC port, thereby ensuring uninterrupted vehicle power while further improving the user's driving experience and driving safety.

[0248] In some embodiments, when the generator power circuit 303a is used to receive the alternating current generated by the generator 302 to power the motor power circuit 303b, the control circuit is used to control the output power of the generator power circuit 303a to be greater than the output power of the motor power circuit 303b and to control the difference between the output power of the generator power circuit 303a and the output power of the motor power circuit 303b to be less than a preset threshold.

[0249] The embodiment of the present application does not limit the specific value of the preset threshold. For example, the preset threshold may be 10%.

[0250] It is understood that the power output by generator 302 via generator power circuit 303a should be greater than the power output by motor power circuit 303b to ensure that the torque output by motor 301 reaches the torque indicated by the torque signal. Furthermore, by controlling the output power of generator 302 to be slightly greater than the output power of motor 301, it is possible to avoid excessive voltage in the wiring harness between generator power circuit 303a and motor power circuit 303b due to the inability to consume the power generated by generator 302.

[0251] According to an embodiment of the present application, after the DC protection switch is disconnected, by controlling the output power of the generator power circuit to be slightly greater than the output power of the motor power circuit, the energy utilization rate can be effectively improved and overvoltage faults can be prevented, thereby improving the safety and cruising range of the electric vehicle.

[0252] In some embodiments, in the process of the generator power circuit 303a being used to receive the alternating current generated by the generator 302 to power the motor power circuit 303b, the control circuit is used to control the output power of the generator power circuit 303a to increase as the accelerator pedal opening increases and to decrease as the accelerator pedal opening decreases.

[0253] It can be understood that when the generator power circuit 303a receives the AC power generated by the generator 302 and supplies power to the motor power circuit 303b, in response to an increase in the accelerator pedal opening of the electric vehicle, the generator power circuit 303a and the motor power circuit 303b increase their output power. In response to a decrease in the accelerator pedal opening of the electric vehicle 01, or in response to an increase in the brake pedal opening of the electric vehicle 01, the generator power circuit 303a and the motor power circuit 303b decrease their output power.

[0254] It is understandable that because the response cycle of the generator 302 and the generator power circuit 303a is slower than the response cycle of the motor power circuit 303b, when the generator power circuit 303a receives power from the generator 302, it is necessary to control the generator power circuit 303a and the generator 302 to operate at a lower power. When the vehicle needs to accelerate or decelerate, it is necessary to adjust the power of the power circuit in the dual-motor controller 303, the generator 302, and the motor 301 according to a certain strategy.

[0255] In some embodiments, in response to changes in the accelerator pedal opening or brake pedal opening of the electric vehicle 01, the output power of the generator power circuit 303a and the generator 302 is adjusted first, and then the output power of the motor power circuit 303b and the motor 301 is adjusted. Specifically, in response to an increase in the accelerator pedal opening of the electric vehicle, the generator power circuit 303a is controlled to increase its output power first, and then the motor power circuit 303b is controlled to increase its output power. Alternatively, in response to a decrease in the accelerator pedal opening of the electric vehicle, or an increase in the brake pedal opening of the electric vehicle, the generator power circuit 303a is controlled to decrease its output power first, and then the motor power circuit 303b is controlled to decrease its output power.

[0256] In some embodiments, in response to changes in the accelerator pedal opening or brake pedal opening of electric vehicle 01, the output power of generator power circuit 303a, generator 302, motor power circuit 303b, and motor 301 are simultaneously adjusted, and the rate of change of the output power of generator power circuit 303a and generator 302 is controlled to be greater than the rate of change of the output power of motor power circuit 303b and motor 301. Specifically, in response to an increase in the accelerator pedal opening of the electric vehicle, generator power circuit 303a is controlled to increase a first power within a preset time period, and motor power circuit 303b is controlled to increase a second power within the same preset time period. Alternatively, in response to a decrease in the accelerator pedal opening of the electric vehicle, or an increase in the brake pedal opening of the electric vehicle, generator power circuit 303a is controlled to decrease a first power within a preset time period, and motor power circuit 303b is controlled to decrease a second power within a preset time period. The first power is greater than the second power.

[0257] According to an embodiment of the present application, the control circuit in the dual-motor controller can adjust the power of the power circuit, generator and drive motor in response to the opening of the accelerator pedal or the brake pedal, ensuring that the power output can be adjusted according to user needs, which is more practical.

[0258] In some embodiments, during the driving of the electric vehicle 01, in response to the DC protection switch being in the on state and the accelerator pedal opening of the electric vehicle 01 decreasing or the brake pedal opening of the electric vehicle 01 increasing, the motor power circuit 303b is configured to output DC power through the high-voltage DC port. In response to the DC protection switch being in the off state and the accelerator pedal opening decreasing or the brake pedal opening increasing, the motor power circuit 303b stops outputting DC power through the high-voltage DC port.

[0259] It is understood that when the electric vehicle 01 is in a braking state, the vehicle controller of the electric vehicle 01 will receive a braking signal and send an energy recovery signal to the dual-motor controller 303. In response to the energy recovery signal, the dual-motor controller 303 will control the drive motor 113 to operate in a power generation state. At this time, the drive motor 113 converts the kinetic energy of the wheels of the electric vehicle into electrical energy and outputs a counter-torque to the wheels of the electric vehicle 01 to provide braking force to the electric vehicle 01. In other words, when the electric vehicle 01 is operating in a braking state, the motor power circuit 303b can output DC power to the DC bus through the DC port of the dual-motor controller 303 to charge the power battery, thereby improving the energy utilization efficiency of the electric vehicle 01 and extending the cruising range of the electric vehicle.

[0260] As an example and not a limitation, when the opening of the brake pedal of the electric vehicle 01 increases, the vehicle controller will receive the above-mentioned braking signal, and the electric vehicle 01 is in a braking state.

[0261] As an example and not a limitation, the electric vehicle 01 provided in the embodiment of the present application can operate in a single-pedal mode. The single-pedal mode means that the accelerator pedal of the electric vehicle 01 integrates both the acceleration function and the braking function. When the driver steps on the accelerator pedal, that is, the stroke of the accelerator pedal increases, the electric vehicle 01 operates in a driving state, and at this time the dual-motor controller 303 controls the drive motor 113 to output positive torque. When the driver releases the accelerator pedal, the electric vehicle operates in a braking state, and at this time the dual-motor controller 303 controls the drive motor 113 to operate in a power generation state and outputs negative torque to provide braking force for the electric vehicle 01. In other words, when the electric vehicle 01 operates in a single-pedal mode and the opening of the accelerator pedal of the electric vehicle decreases, the electric vehicle 01 is in a braking state.

[0262] It can be understood that in order to avoid overvoltage failure caused by overcharging the voltage of the positive wiring harness and the negative wiring harness between the generator power circuit 303a and the motor power circuit 303a when the motor power circuit 303b recovers energy, the motor power circuit 303b provided in the embodiment of the present application stops outputting DC power through the DC output terminal when receiving power from the generator power circuit 303a.

[0263] In these embodiments, when the DC protection switch is in the disconnected state, the electric braking capacity fed back by the dual-motor controller 303 to the vehicle controller of the electric vehicle 01 is 0.

[0264] According to an embodiment of the present application, when the DC protection switch is disconnected, the dual-motor controller stops energy recovery, avoiding overvoltage failure of the wiring harness between the internal power circuits of the dual-motor controller, and further improving the safety and reliability of the dual-motor controller.

[0265] like Figure 11 As shown, in some embodiments, for Figure 2 For the central distributed electric vehicle shown in (d) of FIG, the electric vehicle includes a distributed powertrain 40, which includes a dual-motor controller 403, two motors, and two DC protection switches. The distributed powertrain is used to drive the two front wheels or the two rear wheels of the electric vehicle. The dual-motor controller 403 includes a first inverter circuit and a second inverter circuit. The first inverter circuit is used to receive power from the DC bus through one DC protection switch and output three-phase AC power to one of the motors. The second inverter circuit is used to receive power from the DC bus through another DC protection switch and output three-phase AC power to the other motor.

[0266] In some embodiments, when the current passing through the one DC protection switch is greater than a first threshold, the one DC protection switch disconnects the DC bus from the first inverter circuit. When the current passing through the other DC protection switch is greater than the first threshold, the other DC protection switch disconnects the DC bus from the second inverter circuit.

[0267] In some embodiments, when the current passing through one of the two DC protection switches is greater than a first threshold, the one DC protection switch disconnects the DC bus from the first inverter circuit and the other DC protection switch disconnects the DC bus from the second inverter circuit.

[0268] In some embodiments, the housing of the motor controller is used to accommodate a first inverter circuit, a second inverter circuit and two DC side protection switches, and the housing includes two DC input ports and two AC output ports; wherein, the first inverter circuit is connected to a DC input port through a DC side protection switch and receives DC bus power through a DC input port; the first inverter circuit is used to output AC power through an AC output port; the second inverter circuit is connected to another DC input port through another DC side protection switch and receives DC bus power through another DC input port; the second inverter circuit is used to output AC power through another AC output port.

[0269] In some embodiments, the housing of the motor controller is formed with two accommodating cavities, and the first inverter circuit and the second inverter circuit are assembled in different accommodating cavities. At this time, a DC side disconnect device and the first inverter circuit are assembled in the same accommodating cavity, and the other DC side disconnect device and the second inverter circuit are assembled in the same accommodating cavity.

[0270] In some embodiments, when one inverter circuit in the distributed power assembly 40 fails, another inverter circuit can increase the current of the three-phase AC power output to the corresponding motor and the output power of the inverter circuit, thereby increasing the torque output by the motor and / or the output power of the motor, thereby reducing the power loss of the distributed power assembly 40 caused by the inverter circuit failure and improving the safety of the distributed power assembly 40.

[0271] It can be understood that the current of the three-phase alternating current is an active current, which is used to increase the torque output by the drive motor. Increasing the current of the three-phase alternating current can be understood as increasing the effective value of the current of the three-phase alternating current.

[0272] It can be understood that the aforementioned powers are all active powers. When the torque output by the drive motor is large, the motor controller can increase the active power output by the drive motor by increasing the active power.

[0273] According to an embodiment of the present application, when one inverter circuit in a distributed power assembly fails, another inverter circuit can increase the current of the three-phase AC power output to the corresponding drive motor and the output power of the motor controller, thereby increasing the torque output by the drive motor and the output power of the drive motor, thereby reducing the power loss of the distributed power assembly caused by the inverter circuit failure and improving the safety of the distributed power assembly.

[0274] In some embodiments, for Figure 2 For the wheel-side distributed electric vehicle shown in (e), the electric vehicle 01 includes four powertrains. Among them, the first wheel-side powertrain is used to receive DC bus power through the first DC protection switch to drive the left front wheel of the electric vehicle, the second wheel-side powertrain is used to receive DC bus power through the second DC protection switch to drive the right front wheel of the electric vehicle, the third wheel-side powertrain is used to receive DC bus power through the third DC protection switch to drive the left rear wheel of the electric vehicle, and the fourth wheel-side powertrain is used to receive DC bus power through the fourth DC protection switch to drive the right rear wheel of the electric vehicle. Among them, the specific operating modes of the four DC protection switches can be referred to the relevant content above and will not be repeated here.

[0275] In some embodiments, when the current passing through the first DC protection switch is greater than a first threshold, the first DC protection switch is disconnected, the second wheel-side powertrain reduces torque output, and the third wheel-side powertrain and the fourth wheel-side powertrain increase torque output.

[0276] It is understood that when a short circuit occurs in any wheel-side powertrain of electric vehicle 01, the corresponding DC protection switch disconnects the powertrain from the DC bus, causing the powertrain to stop delivering torque to the wheels. To prevent the vehicle from tilting due to unbalanced force on the left and right wheels, the other powertrain reduces the torque delivered to the other wheel coaxial with the wheel driven by the failed powertrain.

[0277] Furthermore, the other two wheel-side powertrains can also increase torque output, thereby compensating for power loss caused by failure of one wheel-side powertrain and improving the safety of the electric vehicle.

[0278] In some embodiments, when the current passing through the first DC protection switch is greater than a first threshold, the first DC protection switch is disconnected, the second wheel-side powertrain reduces torque output, and the third wheel-side powertrain and the fourth wheel-side powertrain increase torque output.

[0279] It is understood that if a short circuit occurs in any wheel-side powertrain of electric vehicle 01, the corresponding DC protection switch disconnects the powertrain from the DC bus, causing the powertrain to stop delivering torque to the wheels. To prevent the vehicle from tilting due to unbalanced force on the left and right wheels, the other powertrain reduces the torque delivered to the wheel diagonally opposite the wheel driven by the failed powertrain.

[0280] Furthermore, the other two wheel-side powertrains can also increase torque output, thereby compensating for power loss caused by failure of one wheel-side powertrain and improving the safety of the electric vehicle.

[0281] The present application also provides a power battery pack comprising a battery housing, battery cells, a DC protection switch, and a DC busbar. The battery housing is configured to house the battery cells and the DC protection switch, and the battery cells are configured to supply power to the DC busbar. The battery housing is provided with a DC output interface, which is configured to connect to the DC busbar via the DC protection switch, and the DC protection switch is configured to open or close the connection between the DC busbar and the DC output interface.

[0282] According to the embodiments of the present application, by providing an independent DC protection switch on the DC output interface of the power battery pack and disconnecting the corresponding DC protection switch when a connected electrical component fails, the fault can be prevented from spreading to the DC bus and affecting the cells and other electrical components of the power battery pack. Furthermore, the DC protection switch is uniformly installed on the power battery pack side, eliminating the need for structural adjustments to the powertrain, thereby achieving fault isolation while enhancing compatibility.

[0283] In some embodiments, when the current value passing through the DC protection switch is greater than a first threshold, the DC protection switch is disconnected.

[0284] In some embodiments, the power battery pack further includes a DC bus switch, and the battery cell is configured to supply power to the DC bus via the DC bus switch. During the process of the power battery pack outputting DC power, the current value passing through the DC bus switch is greater than the current value passing through the DC protection switch.

[0285] In some embodiments, the disconnect current of the DC bus switch is greater than the disconnect current of the DC protection switch.

[0286] In some embodiments, the power battery pack includes a battery management system, which is configured to control the DC protection switch to disconnect when the current value passing through the DC protection switch is greater than a first threshold.

[0287] In some embodiments, the power battery pack includes a battery management system configured to: control the DC protection switch to disconnect when the current value passing through the DC protection switch exceeds a first threshold; and control the DC bus switch to disconnect when the current value passing through the DC bus switch exceeds a fourth threshold, wherein the fourth threshold is greater than the first threshold.

[0288] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. An electric vehicle for achieving fault isolation, characterized in that: The electric vehicle includes a power battery pack, at least one powertrain, and at least one DC protection switch, wherein: The power battery pack includes a battery housing, battery cells, and a DC busbar, wherein the battery housing is used to accommodate the battery cells, and the battery cells are used to supply power to the DC busbar; The battery housing is provided with a DC output interface, the DC output interface is used to receive power from the DC bus and supply power to the at least one powertrain; Each of the power assemblies is used to receive power from the DC bus through a DC protection switch and to drive the wheels of the electric vehicle. The DC protection switch is used to connect or disconnect the connection between the power assembly and the DC bus.

2. The electric vehicle according to claim 1, characterized in that The at least one DC protection switch is accommodated in the battery housing, each DC output interface is used to connect to the DC bus through the DC protection switch, and the DC protection switch is used to connect or disconnect the connection between the DC bus and the corresponding DC output interface; Each of the power assemblies is configured to receive power from the DC bus through the DC output interface and the DC protection switch.

3. The electric vehicle according to claim 1, wherein: The powertrain includes a motor controller, a motor, and a motor controller housing. The motor controller is used to receive power from the DC bus through the DC output interface and drive the motor. The motor controller housing is used to accommodate the DC protection switch and the inverter circuit of the motor controller. The shell also includes a DC input port and an AC output port. The inverter circuit is used to connect the DC input port through the DC protection switch to receive DC power from the DC bus and output three-phase AC power to the three-phase winding of the motor through the AC output port.

4. The electric vehicle according to claim 1, wherein: The powertrain includes a motor controller, a motor, and a motor controller housing. The motor controller is configured to receive power from the DC bus through the DC output interface and drive the motor. The motor controller housing includes a DC input port, wherein: The DC input port is used to connect to the DC output port of the power battery pack through the DC protection switch, and the DC protection switch is used to connect or disconnect the connection between the DC input port and the corresponding DC output port.

5. The electric vehicle according to any one of claims 1 to 4, characterized in that: When the current value passing through the DC protection switch is greater than a first threshold, the DC protection switch is disconnected.

6. The electric vehicle according to claim 5, characterized in that The power battery pack further includes a DC bus switch, and the battery cell is used to supply power to the DC bus through the DC bus switch. The current value passing through the DC bus switch is greater than or equal to the current value passing through the DC protection switch.

7. The electric vehicle according to claim 6, characterized in that The disconnect current of the DC bus switch is greater than the disconnect current of the DC protection switch.

8. The electric vehicle according to claim 1, wherein: The powertrain includes a motor controller and a motor, wherein the motor controller is configured to receive power from the DC bus through the DC output interface and drive the motor; The motor controller includes a three-phase bridge arm and three AC protection switches. The midpoint of each phase bridge arm of the three-phase bridge arm is used to connect a phase winding of the motor through one of the AC protection switches.

9. The electric vehicle according to claim 8, characterized in that When the current value passing through any one of the AC protection switches is greater than a second threshold, the AC protection switch is disconnected.

10. The electric vehicle according to claim 8, characterized in that When the current passing through any one of the AC protection switches is greater than the second threshold for a duration greater than the first duration, the DC protection switch and at least two of the AC protection switches are disconnected.

11. The electric vehicle according to claim 1, wherein: The powertrain includes a motor controller and a motor, wherein the motor controller is configured to receive power from the DC bus through the DC output interface of the power battery pack and drive the motor, wherein the DC bus includes a positive DC bus and a negative DC bus; The motor controller includes a three-phase bridge arm, each phase bridge arm of the three-phase bridge arm includes an isolating switch, and the isolating switch is used to connect or disconnect the corresponding phase bridge arm and the positive DC bus or the negative DC bus.

12. The electric vehicle according to claim 11, characterized in that The isolating switch is used to connect or disconnect the connection between the upper bridge arm switch tube of the corresponding one-phase bridge arm and the midpoint of the bridge arm; or The isolating switch is used to connect or disconnect the connection between the upper bridge arm switch tube of the corresponding one-phase bridge arm and the positive DC bus.

13. The electric vehicle according to claim 11, characterized in that The isolating switch is used to connect or disconnect the connection between the lower bridge arm switch tube of the corresponding one-phase bridge arm and the midpoint of the bridge arm; or The isolating switch is used to connect or disconnect the connection between the lower bridge arm switch tube of the corresponding one-phase bridge arm and the negative DC bus.

14. The electric vehicle according to claim 11, characterized in that The isolating switch of each phase bridge arm of the three-phase bridge arm includes an upper isolating switch and a lower isolating switch; in; The upper isolating switch is used to connect or disconnect the connection between the upper bridge arm switch tube of the corresponding one-phase bridge arm and the midpoint of the bridge arm, or the connection between the upper bridge arm switch tube of the corresponding one-phase bridge arm and the positive DC bus; The lower isolating switch is used to connect or disconnect the connection between the lower bridge arm switch tube of the corresponding one-phase bridge arm and the midpoint of the bridge arm, or the connection between the lower bridge arm switch tube of the corresponding one-phase bridge arm and the negative DC bus.

15. The electric vehicle according to any one of claims 11 to 14, characterized in that: When the upper bridge arm switch tube or the lower bridge arm switch tube of any phase bridge arm of the three-phase bridge arm is short-circuited, the isolating switch corresponding to the any phase bridge arm is disconnected.

16. The electric vehicle according to claim 3, 8 or 11, characterized in that: The motor controller includes a control circuit, which is configured to: When the current value passing through the DC protection switch is greater than a first threshold, the DC protection switch is controlled to be disconnected; or, When the current value passing through any one of the AC protection switches is greater than a second threshold, any one of the AC protection switches is disconnected; or, When the current value of the upper bridge arm switch tube or the lower bridge arm switch tube of any phase bridge arm of the three-phase bridge arm in the motor controller is greater than a third threshold, the isolation switch corresponding to any phase bridge arm is controlled to be disconnected.

17. The electric vehicle according to claim 16, characterized in that The second threshold is less than or equal to the third threshold.

18. The electric vehicle according to claim 16, wherein: The control circuit is specifically used for: When the current value passing through any one of the AC protection switches is greater than the second threshold, or the current value passing through the upper arm switch tube or the lower arm switch tube of any phase bridge arm of the three-phase bridge arm is greater than the third threshold, first control any one of the AC protection switches to turn off and the isolating switch corresponding to any one of the phase bridge arms to disconnect, and then control the midpoints of the other two phase bridge arms to output two-phase AC power.

19. The electric vehicle according to claim 18, characterized in that In the process of controlling the midpoints of the other two-phase bridge arms to output two-phase alternating current, the control circuit is further used to: When the current value passing through one of the other two AC protection switches is greater than the second threshold, or the current passing through the upper arm switch tube or the lower arm switch tube of one of the other two-phase bridge arms is greater than the third threshold, the DC protection switch is first controlled to disconnect, and then the one AC protection switch and the isolating switch corresponding to the one-phase bridge arm are controlled to disconnect.

20. The electric vehicle according to claim 1, wherein The battery cell includes a first battery module and a second battery module, and the power battery pack further includes three switching switches accommodated in the battery housing, wherein: The first switching switch is used to connect the positive electrode of the first battery module and the negative electrode of the second battery module; The second switching switch is used to connect the positive electrode of the first battery module and the positive electrode of the second battery module; The third switch is used to connect the negative electrode of the first battery module and the negative electrode of the second battery module.

21. The electric vehicle according to claim 20, characterized in that During the driving of the electric vehicle, the first switch is opened, and the second switch and the third switch are closed; During the charging process of the power battery pack, the first switch is closed, and the second switch and the third switch are opened.

22. The electric vehicle according to claim 1, wherein: The electric vehicle includes two powertrains, the battery cell includes a first battery module and a second battery module, one of the two powertrains is used to receive power from the first battery module through one of the DC protection switches, and the other of the two powertrains is used to receive power from the second battery module through another of the DC protection switches, and the power battery pack further includes two redundant switches housed in the battery housing; wherein, The powertrain is further configured to connect the positive electrode of the second battery module via a redundant switch, and the powertrain is further configured to connect the negative electrode of the second battery module via another redundant switch.

23. The electric vehicle according to claim 22, characterized in that When the first battery module is normal, the one redundant switch and the other redundant switch are disconnected; When the first battery module fails, the one DC protection switch is disconnected and the one redundant switch and the other redundant switch are closed, so that the one powertrain is used to receive power from the second battery module.

24. The electric vehicle according to claim 1, wherein The electric vehicle includes a hybrid powertrain, the hybrid powertrain including a dual-motor controller, an electric motor, and a generator; The dual-motor controller is used to receive power from the power battery pack to drive the motor of the electric vehicle or transmit the power generated by the generator to the power battery pack to charge the power battery pack. The dual-motor controller includes a dual-motor controller housing, a motor power circuit, and a generator power circuit; The dual-motor controller housing is used to accommodate the generator power circuit, the motor power circuit and the at least one DC protection switch. The dual-motor controller housing includes a high-voltage DC port. The dual-motor controller is used to receive power from the power battery pack or charge the power battery pack through the high-voltage DC port. The motor power circuit is used to receive direct current from the one high-voltage direct current port through the direct current protection switch; The generator power circuit is used to receive the alternating current generated by the generator and output direct current to the one high-voltage direct current port through the direct current protection switch; The DC protection switch is used to connect or disconnect the connection between the motor power circuit and the generator power circuit and the one high-voltage DC port.

25. The electric vehicle according to claim 24, characterized in that The electric vehicle further includes a DC conversion circuit, and the housing further includes another high-voltage DC port, wherein the another high-voltage DC port is used to connect to the one high-voltage DC port through the DC protection switch; The DC conversion circuit is used to receive DC power from the one high-voltage DC port through the other high-voltage DC port and the DC protection switch, and output the DC power from the one high-voltage DC port after performing voltage reduction conversion.

26. The electric vehicle according to claim 24, characterized in that The dual-motor controller further includes a DC conversion circuit housed in the housing, and the housing further includes a low-voltage DC port; The DC conversion circuit is used to receive DC power from the one high-voltage DC port through the DC protection switch, perform voltage reduction conversion on the DC power from the one high-voltage DC port, and output the DC power through the one low-voltage DC port.

27. The electric vehicle according to claim 25 or 26, characterized in that: After the DC protection switch is disconnected, the DC conversion circuit is further configured to receive power from the generator power circuit and perform voltage reduction conversion on the DC power output by the generator power circuit before outputting the power.

28. The electric vehicle according to claim 24, characterized in that The dual-motor controller further includes a control circuit, which is further configured to: When the generator power circuit receives the AC power generated by the generator and supplies power to the motor power circuit, the output power of the generator power circuit is controlled to increase with the increase of the accelerator pedal opening and decrease with the decrease of the accelerator pedal opening.

29. The electric vehicle according to claim 24, wherein: During the driving of the electric vehicle, In response to the DC protection switch being in the on state and the accelerator pedal opening of the electric vehicle decreasing or the brake pedal opening of the electric vehicle increasing, the motor power circuit is configured to output DC power through the high-voltage DC port; In response to the DC protection switch being in an off state and the accelerator pedal opening decreasing or the brake pedal opening increasing, the motor power circuit stops outputting the DC power through the high-voltage DC port.

30. The electric vehicle according to claim 1, wherein The electric vehicle includes a distributed powertrain, which includes a dual-motor controller, two motors, and two DC protection switches. The distributed powertrain is used to drive two front wheels or two rear wheels of the electric vehicle. The dual-motor controller includes a first inverter circuit and a second inverter circuit. The first inverter circuit is used to receive power from the DC bus through one DC protection switch and output three-phase AC power to one of the motors. The second inverter circuit is used to receive power from the DC bus through another DC protection switch and output three-phase AC power to the other motor.

31. The electric vehicle according to claim 30, characterized in that When the current passing through the one DC protection switch is greater than a first threshold, the one DC protection switch disconnects the DC bus and the first inverter circuit; When the current passing through the other DC protection switch is greater than the first threshold, the other DC protection switch disconnects the DC bus and the second inverter circuit.

32. The electric vehicle according to claim 30, characterized in that When the current passing through one of the two DC protection switches is greater than a first threshold, the one DC protection switch disconnects the DC bus from the first inverter circuit, and the other DC protection switch disconnects the DC bus from the second inverter circuit.

33. The electric vehicle according to claim 1, wherein: The electric vehicle includes a front driving force assembly and a rear driving force assembly, wherein: The front drive power assembly includes a front drive motor controller and a front drive motor, wherein the front drive motor controller is configured to receive power from the DC bus through a DC protection switch and output a first three-phase AC power to drive the front drive motor; The rear drive power assembly includes a rear drive motor controller and a rear drive motor. The rear drive motor controller is used to receive power from the DC bus through another DC protection switch and output a second three-phase AC power to drive the rear drive motor.

34. The electric vehicle according to claim 33, characterized in that When the front-wheel drive motor controller fails, the front-wheel drive motor controller outputs a first fault signal and stops outputting the first three-phase AC power to the front-wheel drive motor, wherein the first fault signal is used to instruct the rear-wheel drive motor controller of the vehicle to control the rear-wheel drive motor to increase torque output; When the rear-wheel drive motor controller fails, the rear-wheel drive motor controller outputs a second fault signal and stops outputting the second three-phase AC power to the rear-wheel drive motor. The second fault signal is used to instruct the front-wheel drive motor controller of the vehicle to control the front-wheel drive motor to increase torque output.

35. The electric vehicle according to claim 1, wherein: The electric vehicle includes four wheel-side power assemblies, wherein: The first wheel-side power assembly is used to receive DC bus power through the first DC protection switch to drive the left front wheel of the electric vehicle; The second wheel-side power assembly is used to receive DC bus power through the second DC protection switch to drive the right front wheel of the electric vehicle; The third wheel-side power assembly is used to receive DC bus power through a third DC protection switch to drive the left rear wheel of the electric vehicle; The fourth wheel-side powertrain is used to receive DC bus power through a fourth DC protection switch to drive the right rear wheel of the electric vehicle.

36. The electric vehicle according to claim 35, characterized in that When the current passing through the first DC protection switch is greater than a first threshold, the first DC protection switch is disconnected, the second wheel-side powertrain reduces torque output, and the third wheel-side powertrain and the fourth wheel-side powertrain increase torque output.

37. The electric vehicle according to claim 35, characterized in that When the current passing through the first DC protection switch is greater than a first threshold, the first DC protection switch is disconnected, the third wheel-side powertrain reduces torque output, and the second wheel-side powertrain and the fourth wheel-side powertrain increase torque output.

38. A power battery pack, characterized in that: The power battery pack includes a battery housing, battery cells, a DC protection switch, and a DC bus, wherein: The battery housing is used to accommodate the battery core and the DC protection switch, and the battery core is used to supply power to the DC bus; The battery housing is provided with a DC output interface, which is used to connect to the DC bus through the DC protection switch, and the DC protection switch is used to connect or disconnect the connection between the DC bus and the DC output interface.

39. The power battery pack according to claim 38, characterized in that: When the current value passing through the DC protection switch is greater than a first threshold, the DC protection switch is disconnected.

40. The power battery pack according to claim 38 or 39, characterized in that: The power battery pack further includes a DC bus switch, and the battery cell is used to supply power to the DC bus through the DC bus switch; During the process of the power battery pack outputting direct current, the current value passing through the direct current bus switch is greater than the current value passing through the direct current protection switch.

41. The power battery pack according to claim 40, characterized in that: The disconnect current of the DC bus switch is greater than the disconnect current of the DC protection switch.

42. The power battery pack according to claim 38, characterized in that: The power battery pack includes a battery management system, which is used to: When the current value passing through the DC protection switch is greater than a first threshold, the DC protection switch is controlled to be disconnected.

43. The power battery pack according to claim 40, characterized in that: The power battery pack includes a battery management system, which is used to: When the current value passing through the DC protection switch is greater than a first threshold, controlling the DC protection switch to be disconnected; When the current value passing through the DC bus switch is greater than a fourth threshold, controlling the DC bus switch to be disconnected; The fourth threshold is greater than the first threshold.

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