A control method and device for driving active short circuit of an electric vehicle

Abstract

The present invention discloses a control method and device for driving active short circuit in an electric vehicle. The control method includes the following steps: the PDU controller synchronously outputs an active short circuit safety state enabling signal and a PDU relay turn-off signal; the motor control system exits the boost charging mode through the PDU relay turn-off signal; after the motor control system exits the boost charging mode, the motor control system enters the active short circuit safety state through the active short circuit safety state enabling signal. The present invention solves the risk that the motor controller accidentally enters the active short circuit safety state due to a fault in the boost charging mode, resulting in damage to the drive module.

Description

Technical Field

[0001] The present invention belongs to the field of electric vehicles, and particularly relates to a control method and device for driving active short circuit of an electric vehicle. Background Art

[0002] With the rapid development of modern electric vehicle technology, 800V pure electric vehicles are the new trend in the current electric vehicle market. Most electric vehicles in the existing market are 400V, and the supporting facilities, charging piles are generally of 400V standard. To promote the market application of the 800V platform, the 800V drive platform is mostly equipped with a Boost (step-up) charging function to solve the battery charging problem. At the same time, to save costs, the drive mode and the Boost charging mode share the controller and the power module, and the motor coil is used as the charging inductor for the Boost charging mode. Under such a premise, there are three working conditions of the vehicle that will affect the control strategy of the controller, namely the drive mode, the step-up charging mode, and the trailer mode. This poses new challenges to how the controller can achieve safe and reliable control in the three modes, especially in the case of a fault, the controller cannot distinguish whether it is in the drive, step-up or trailer mode currently, and still can make an effective response. At the same time, to solve the charging problem, a power distribution unit (PDU) usually needs to be configured. Since this unit is a high-voltage unit, to ensure the reliability and safety of the PDU, a PDU management module is required. Usually, the controller manages several solenoid valves and monitors the voltage of each node of the high-voltage path.

[0003] The 800V platform is still a new technology in the market. The active short circuit control solution on the 400V platform currently cannot take into account the step-up charging mode, and the fault condition cannot solve the problem that the system enters the active short circuit state, that is, enters ASC, in the step-up charging mode, bringing a failure risk to the high-voltage drive module. There is no clear solution in the current market. Summary of the Invention

[0004] In view of the above problems, the technical solution adopted by the present invention is: a control method for driving active short circuit of an electric vehicle, the control method comprising the following steps:

[0005] The PDU controller synchronously outputs an active short circuit safety state enable signal and a PDU relay turn-off signal;

[0006] When a fault occurs while the vehicle is in the step-up charging mode, the motor control system exits the step-up charging mode through the PDU relay turn-off signal;

[0007] After the motor control system exits the step-up charging mode, the motor control system enters the active short circuit safety state through the active short circuit safety state enable signal.

[0008] Optionally, the active short - circuit safety state enabling signal lags behind the PDU relay turn - off signal transmission through a delay circuit.

[0009] Optionally, when the vehicle is in the normal operating condition of the boost charging mode, the control method further includes the following steps: The PDU controller outputs a PDU relay start signal and synchronously outputs it to the motor controller to lock the output of the active short - circuit safety state.

[0010] Optionally, when a fault occurs when the vehicle is in the driving mode, the control method includes the following steps: Trigger the motor control system to enter the active short - circuit safety state according to the functional safety management signal.

[0011] Optionally, when the vehicle is in the driving mode under normal operating conditions, the control method further includes the following steps:

[0012] The PDU relay turn - off signal output by the PDU controller is synchronously output to the motor controller;

[0013] Judge whether the motor control system needs to enter the active short - circuit safety state according to the bus voltage of the motor controller;

[0014] If so, the motor control system enters the active short - circuit safety state according to the active short - circuit safety state enabling signal.

[0015] Optionally, when the connector connection between the motor controller and the PDU controller is unreliable, the control method further includes the following steps:

[0016] Judge whether the motor control system needs to enter the active short - circuit safety state according to the bus voltage of the motor controller and the current vehicle mode;

[0017] If so, the motor control system enters the active short - circuit safety state according to the active short - circuit safety state enabling signal.

[0018] Optionally, when the vehicle is in the trailer mode, the control method further includes the following steps:

[0019] The PDU relay turn - off signal output by the PDU controller is synchronously output to the motor controller;

[0020] Judge whether the motor control system needs to enter the active short - circuit safety state according to the bus voltage of the motor controller;

[0021] If so, the motor control system enters the active short - circuit safety state according to the active short - circuit safety state enabling signal.

[0022] And, a control device for driving active short - circuit of an electric vehicle, the control device includes:

[0023] The PDU management unit is used to synchronously output an active short - circuit safety state enabling signal and a PDU relay turn - off signal, where the PDU relay turn - off signal is synchronously output to the motor controller;

[0024] The motor control unit is used to make the motor control system exit the boost charging mode according to the PDU relay turn - off signal;

[0025] The active short - circuit safety state triggering unit is used to make the motor control system enter the active short - circuit safety state according to the active short - circuit safety state enabling signal after the motor control system exits the boost charging mode.

[0026] Optionally, the control device further includes:

[0027] The signal delay unit is used to make the active short - circuit safety state enabling signal lag behind the transmission of the PDU relay turn - off signal, so that after the motor control system exits the boost charging mode, the motor control system enters the active short - circuit safety state according to the active short - circuit safety state enabling signal.

[0028] Optionally, the control device further includes:

[0029] The active short - circuit safety state locking unit is used to lock the output of the active short - circuit safety state when the PDU management unit outputs a PDU relay start signal.

[0030] Optionally, the control device further includes:

[0031] The functional safety management unit is used to issue a functional safety management signal when a fault occurs when the vehicle is in the driving mode;

[0032] The active short - circuit safety state triggering unit is also used to trigger the motor control system to enter the active short - circuit safety state according to the functional safety management signal.

[0033] Optionally, the control device further includes:

[0034] The judgment unit is used to judge whether the motor control system needs to enter the active short - circuit safety state according to the bus voltage of the motor controller when the vehicle is in the driving mode or the trailer mode under normal working conditions.

[0035] Optionally, the judgment unit is further used to judge whether the motor control system needs to enter the active short - circuit safety state according to the bus voltage of the motor controller and the current vehicle mode when the connection of the connector between the motor controller and the PDU controller is unreliable.

[0036] An electric vehicle, which includes the above - mentioned control device for driving active short - circuit.

[0037] Due to the adoption of the above technical solution, the present invention has the following beneficial effects: it solves the risk that the motor controller accidentally enters the active short - circuit safety state (ASC) due to a fault in the boost charging mode, resulting in damage to the drive module; it differentiates overvoltage in the trailer mode and overvoltage in the boost charging mode, so that the hardware enters the corresponding correct protection mode; the implementation method is simple, avoiding the logic risk brought by complex circuit design and having a relatively low cost.

[0038] Other features and advantages of the present invention will be described in the following specification, and part of them will become obvious from the specification or be understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the structures pointed out in the specification, claims and drawings. Brief Description of the Drawings

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following - described drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0040] Figure 1 Shows a schematic diagram of the logic circuit according to an embodiment of the present invention;

[0041] Figure 2 Shows a schematic diagram of the signal output circuit according to an embodiment of the present invention. Detailed Embodiment

[0042] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0043] The control method for active short - circuit of the drive for an electric vehicle in the embodiment of the present invention includes the steps: the PDU controller synchronously outputs an active short - circuit safety state enable signal and a PDU relay turn - off signal, and the PDU relay turn - off signal output by the PDU controller is synchronously output to the motor controller.

[0044] The control methods for different working conditions are as follows:

[0045] I. When a fault occurs (in an over - voltage state) when the vehicle is in the boost charging mode:

[0046] The motor control system exits the boost charging mode through the PDU relay off signal;

[0047] After the motor control system exits the boost charging mode, the motor control system enters the active short - circuit safety state through the active short - circuit safety state enable signal.

[0048] II. When the vehicle is in the normal condition of the boost charging mode:

[0049] The PDU controller outputs the PDU relay start signal and synchronously outputs it to the motor controller to lock the output of the active short - circuit safety state.

[0050] III. When a fault occurs in the vehicle during the drive mode and an over - voltage state is generated:

[0051] The motor control system is triggered to enter the active short - circuit safety state according to the functional safety management signal.

[0052] IV. When the vehicle is in the drive mode under normal conditions:

[0053] It is judged whether the motor control system needs to enter the active short - circuit safety state according to the bus voltage of the motor controller;

[0054] If so, the motor control system enters the active short - circuit safety state according to the active short - circuit safety state enable signal.

[0055] V. When the connection of the plug - in connector between the motor controller and the PDU controller is unreliable:

[0056] It is judged whether the motor control system needs to enter the active short - circuit safety state according to the bus voltage of the motor controller and the current vehicle mode;

[0057] If so, the motor control system enters the active short - circuit safety state according to the active short - circuit safety state enable signal.

[0058] VI. When the vehicle is in the trailer mode:

[0059] It is judged whether the motor control system needs to enter the active short - circuit safety state according to the bus voltage of the motor controller;

[0060] If so, the motor control system enters the active short - circuit safety state according to the active short - circuit safety state enable signal.

[0061] Such as Figure 1The schematic diagram of the logic circuit shown includes two circuits for implementing the active short - circuit installation state. In the first circuit, when a fault signal, i.e., the function fault signal, is issued, after passing through the isolation units S1 and S2, it directly triggers the active short - circuit safety state execution signal, i.e., the ASC_LS_EM signal. In the second circuit, the ASC_LS_EM signal is triggered by selecting through the logic tri - state gate IC1. Since the output results of the above two circuits are the same, the first logic OR gate is used to reduce the circuit complexity.

[0062] As Figure 2 shown in the schematic diagram of the signal output circuit, the PDU management MCU (PDU management chip) of the PDU controller controls the circuit to output the active short - circuit safety state enable signal, i.e., the PDU_ASC_EN signal, through the ASC enable signal, and at the same time outputs the PDU relay turn - off signal of the charging control relay CB1 through the PDU charging control relay interface circuit, so as to synchronously output the PDU_ASC_EN and the PDU relay turn - off signal.

[0063] Combined with Figure 1 the schematic diagram of the logic circuit shown, the specific logic of the above - mentioned multiple working conditions is as follows:

[0064] In the above - mentioned working condition three, when a fault occurs in the driving mode and an over - voltage state is generated, the motor control system is triggered to enter the active short - circuit safety state through the functional safety management signal, and the functional safety management signal is the SAFE STATE signal. Since the logic of the PDU_ASC_EN signal is the same as that of the SAFE STATE signal, the second logic OR gate is used to reduce the circuit complexity.

[0065] In the above - mentioned working condition two, the PDU controller outputs the PDU relay start signal, where the PDU relay start signal is a logic high level, and the logic high level is synchronously output to the motor controller. The motor controller works normally. At this time, the PDU_ASC_EN signal and the SAFE STATE signal are not output, and the logic tri - state gate IC1 is in the cut - off state, thus locking the output of the active short - circuit safety state.

[0066] In the above - mentioned working condition one, when a fault occurs when the vehicle is in the boost charging mode, the PDU controller synchronously outputs the PDU_ASC_EN signal and the PDU relay turn - off signal. The PDU relay turn - off signal is a logic low level and is synchronously output to the motor controller to make the motor control system exit the boost charging mode. The PDU_ASC_EN signal is transmitted with a delay behind the PDU relay turn - off signal. After passing through the isolation unit S1, the logic tri - state gate conducts, so as to trigger the ASC gating under over - voltage in the boost charging mode, that is, to trigger the ASC_LS_EM signal. Thus, it is ensured that the motor control system will not enter the ASC state in the boost charging mode.

[0067] Among them, as Figure 1 shown, the delay circuit is an RC circuit, which provides delay for the signal while filtering. The RC circuit includes a resistor R1, a resistor R2, and a capacitor C1. The two ends of R1 are connected between the PDU_ASC_EN signal and the second logic OR gate. The first end of R2 is connected between R1 and the PDU_ASC_EN signal, and the second end of R2 is grounded. The first end of C1 is connected between R1 and the second logic OR gate, and the second end of C1 is connected to the second end of R2.

[0068] In the above working conditions IV and VI, when the vehicle is in the driving mode or the towing mode under normal working conditions, the PDU controller outputs a PDU relay turn-off signal, that is, a logic low level, and synchronously outputs it to the motor controller. Then, according to the bus voltage of the motor controller, it is judged whether the motor control system needs to enter the active short-circuit safety state.

[0069] In the above working condition V, when the connector connection between the motor controller and the PDU controller is unreliable, the control port is configured as a low level at this time. Since the voltage threshold for entering the active short-circuit safety state is different when the vehicle is in different modes, whether the motor control system needs to enter the active short-circuit safety state is controlled by the bus voltage of the motor controller and the current vehicle mode.

[0070] In the above working conditions IV, V, and VI, it is judged whether the motor control system needs to enter the active short-circuit safety state according to the bus voltage of the motor controller. Specifically: when the bus voltage of the motor controller exceeds the first threshold voltage in the driving mode, the motor control system is triggered to enter the active short-circuit safety state; when the bus voltage of the motor controller is higher than the set second threshold voltage in the towing mode, the motor control system is triggered to enter the active short-circuit safety state.

[0071] As Figure 1 shown, VDC_S is the bus voltage of the motor controller. Under normal working conditions, the logic tri-state gate is turned off, and VDC_S cannot affect the ASC logic. After the low-voltage side loses power in the towing working condition, because the high-voltage side is powered (in the control system of the on-vehicle drive motor, the low voltage refers to the electronic unit or circuit powered by the vehicle's 12V or 24V battery, and the high voltage is the power battery, usually the electronic module and unit powered by 380V - 800V. Since there cannot be a physical path between the two power supply systems, the isolation units S1 and S2 realize the high-low voltage connection through magnetic field coupling), when VDC_S is higher than the threshold, ASC can be triggered, that is, high-speed towing can trigger ASC to avoid the failure of the power module in the towing mode.

[0072] The embodiment of the present invention also provides a control device for driving active short-circuit of an electric vehicle, and the control device includes:

[0073] A PDU management unit, configured to synchronously output an active short - circuit safety state enabling signal and a PDU relay turn - off signal;

[0074] A motor control unit, configured to cause the motor control system to exit the boost charging mode according to the PDU relay turn - off signal;

[0075] An active short - circuit safety state triggering unit, configured to cause the motor control system to enter the active short - circuit safety state according to the active short - circuit safety state enabling signal after the motor control system exits the boost charging mode;

[0076] A signal delay unit, configured to make the active short - circuit safety state enabling signal lag behind the PDU relay turn - off signal in transmission, so that after the motor control system exits the boost charging mode, the motor control system enters the active short - circuit safety state according to the active short - circuit safety state enabling signal;

[0077] An active short - circuit safety state locking unit, configured to lock the output of the active short - circuit safety state when the PDU management unit outputs a PDU relay start signal;

[0078] A functional safety management unit, configured to issue a functional safety management signal when a fault occurs when the vehicle is in the driving mode; the active short - circuit safety state triggering unit is further configured to trigger the motor control system to enter the active short - circuit safety state according to the functional safety management signal output by the functional safety management unit;

[0079] A judgment unit, configured to judge whether the motor control system needs to enter the active short - circuit safety state according to the bus voltage of the motor controller when the vehicle is in the driving mode or the trailer mode under normal working conditions; the judgment unit is further configured to judge whether the motor control system needs to enter the active short - circuit safety state according to the bus voltage of the motor controller and the current vehicle mode when the connector connection between the motor controller and the PDU controller is unreliable.

[0080] For the implementation process of the functions and actions of the above - mentioned module units, refer to the implementation process of the corresponding steps in the control method for driving active short - circuit of the electric vehicle in the above - mentioned embodiment of the present invention, which will not be elaborated here.

[0081] An embodiment of the present invention further provides an electric vehicle, including the control device for driving active short - circuit in the above - mentioned embodiment.

[0082] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments by using the disclosed technical content within the scope of the technical solution of the present invention. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A control method for driving active short circuit of an electric vehicle, applicable to an electric vehicle that uses a motor drive module to boost charge a power battery, characterized in that The control method includes the following steps: The PDU controller synchronously outputs an active short - circuit safety state enabling signal and a PDU relay turn - off signal; When the vehicle is in the normal condition of the boost charging mode, the PDU controller outputs a PDU relay start signal and synchronously outputs it to the motor control system to lock the output of the active short - circuit safety state; When a fault occurs when the vehicle is in the boost charging mode, the motor control system exits the boost charging mode through the PDU relay turn - off signal; after the motor control system exits the boost charging mode, it enters the active short - circuit safety state through the active short - circuit safety state enabling signal.

2. The control method for driving active short circuit of an electric vehicle according to claim 1, characterized in that, The active short - circuit safety state enabling signal is transmitted with a delay behind the PDU relay turn - off signal through a delay circuit.

3. The control method for driving active short - circuit of an electric vehicle according to claim 1, characterized in that When a fault occurs when the vehicle is in the driving mode, the motor control system is triggered to enter the active short - circuit safety state according to the functional safety management signal.

4. The control method for driving active short circuit of an electric vehicle according to claim 1, wherein When the vehicle is in the driving mode under normal conditions, the control method further includes the following steps: The PDU relay turn - off signal output by the PDU controller is synchronously output to the motor control system; Judge whether the motor control system needs to enter the active short - circuit safety state according to the bus voltage of the motor control system; If so, the motor control system enters the active short - circuit safety state according to the active short - circuit safety state enabling signal.

5. The control method for driving active short circuit of an electric vehicle according to claim 1, characterized in that, When the connection of the plug - in connector between the motor control system and the PDU controller is unreliable, the control method further includes the following steps: Judge whether the motor control system needs to enter the active short - circuit safety state according to the bus voltage of the motor control system and the current vehicle mode; If so, the motor control system enters the active short - circuit safety state according to the active short - circuit safety state enabling signal.

6. The control method for driving active short circuit of an electric vehicle according to claim 1, characterized in that When the vehicle is in the trailer mode, the control method further includes the following steps: The PDU relay turn - off signal output by the PDU controller is synchronously output to the motor control system; Judge whether the motor control system needs to enter the active short - circuit safety state according to the bus voltage of the motor control system; If so, the motor control system enters the active short - circuit safety state according to the active short - circuit safety state enabling signal.

7. A control device for driving active short circuit of an electric vehicle, applicable to an electric vehicle that uses a motor power module to boost charge a power battery, characterized in that The control device includes: A PDU management unit for synchronously outputting an active short - circuit safety state enabling signal and a PDU relay turn - off signal, wherein the PDU relay turn - off signal is synchronously output to the motor control system; A logic circuit connected to the output terminal of the active short - circuit safety state enabling signal of the PDU management unit, for controlling the output of the active short - circuit safety state enabling signal according to the functional safety management signal, the fault signal, and the bus voltage signal of the motor control system; The motor control system exits the boost charging mode according to the PDU relay turn - off signal; after the motor control system exits the boost charging mode, it enters the active short - circuit safety state according to the active short - circuit safety state enabling signal.

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