Circuit and method for control three-phase active short circuit of electric vehicle motor system

Abstract

The invention discloses a control circuit and a control method for a three-phase active short circuit of an electric vehicle motor system. A three-phase full-bridge inverter circuit is divided into two groups, namely a high side and a low side. The low side and the high side are respectively controlled during ASC. When a high-side power device is damaged or a driving power supply of the high-sidepower device is lost, switching control from the high-side ASC state to the low-side ASC state is carried out through the obtained specific fault information state signal; or when a low-side power device is damaged or a driving power supply of the low-side power device is lost, switching control from the low-side ASC state to the high-side ASC state is carried out through the obtained specific fault information state signal. When the occurrence of a potential fault that may lead to torque safety risks is detected, the case that the damage of the power device or the loss of the driving power supply of the power device or the unexpected open circuit of a 12 V power supply makes the system unable to enter or maintain a three-phase short circuit state will be avoided; and the inverter circuitcan be maintained in the ASC state to ensure the safety of electric vehicles to the greatest extent.

Description

technical field [0001] The invention relates to the field of new energy passenger vehicles, in particular to a control circuit and a control method for switching an electric vehicle motor system to a three-phase active short-circuit state (ASC state). Background technique [0002] In recent years, China has actively promoted the development of new energy vehicles, especially electric vehicles, in order to reduce the use of petroleum, reduce vehicle exhaust emissions, and realize green energy consumption for vehicles. As the core component of the electric vehicle motor system, the motor controller is capable of realizing mutual conversion between DC and AC. When the electric vehicle is running normally, it can invert the DC power of the power battery into three-phase AC power to provide power for the drive motor and control the output of the motor. Torque drives the vehicle to drive; the motor controller can control the driving motor to run in the feed mode during the coastin...

AI Technical Summary

Problems solved by technology

[0006] However, when the power device of the motor controller is damaged or the driving power of the power device is lost, the power device that should be turned on is turned off unexpectedly, or the power device that needs to be turned off is turned on unexpectedly, so that the motor controller It is impossible to maintain the motor in the ASC state. If the motor controller detects a potential fault that may cause a torque safety risk and sends a control signal to allow the motor to enter and maintain the ASC state, because the three-phase power device composed of power devices at this time The full-bridge inverter circuit can no longer be turned on or off according to the control command signal. At this time, the motor cannot be guaranteed to be in a three-phase short-circuit state, which will still cause torque and high-voltage safety risks in the vehicle; another serious situation is , since the driving power of the high-side power device and the low-side power device comes from the 12V low-voltage battery of the vehicle, when the 12V power supply entering the motor controller is unexpectedly disconnected, the power device will enter the power supply due to the complete loss of the driving power. A completely off state, which in different motor applications may result in unacceptable braking conditions or unintended residual high voltage energy in the vehicle that may lead to a hazardous event

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