Method for quickly discharging for automobile high-voltage DC bus

Abstract

The invention discloses a method for quickly discharging for an automobile high-voltage DC bus, comprising a main motor system and a plurality of electro-subsystems, wherein the main motor system is connected with the DC bus, the electro-subsystems are also connected with the DC bus and are connected with the main motor system in parallel, and each subsystem is driven by the motor. The invention also comprises a discharge resistor connected with the DC bus in parallel. The method comprises the following steps: (1) when the DC bus is in outage, the main motor serves as a first motor for controlling; a first motor controller sends a signal to the first motor; the first motor generates current to cause a motor winding to heat to dissipate capacitor voltage on the DC bus; and (2) when the first motor can not normally operate, the discharge resistor dissipates the capacitor voltage on the DC bus. On the premise of not influencing the automobile running state, the invention only uses motor winding loss to quickly dissipate electricity energy stored in each subsystem filter capacitor on the high-voltage DC bus; and no discharge resistor is required to be connected in parallel in each subsystem controller, thus improving system efficiency and lowering part cost. The invention can quickly discharge to capacitors connected on the high-voltage DC bus in parallel after cutting off high voltage; then, strong electricity and week electricity are almost synchronous during parking so as to simplify finished automobile control algorithm; and specially, passenger safety can be effectively ensured during emergency failure.

Description

technical field [0001] The present invention relates to a control method of an automobile, in particular to a method for rapidly discharging a high-voltage direct-current busbar in a fuel cell vehicle or other electric-powered vehicles when the vehicle stops or breaks down. Background technique [0002] The fuel cell vehicle power system adopts electric drive, and is mainly composed of fuel cell engine system, drive system, body chassis, hydrogen supply system, battery system and accessory system (electric air conditioner, electric steering, electric water pump, electric cooling fan), etc. The system The moving parts must be driven by a controllable motor, and the motor is connected in parallel on the high-voltage DC bus to achieve controllable adjustment of speed or torque. When the vehicle stops and needs to turn off the weak current system (+12V weak current) or the vehicle breaks down, it is necessary to cut off the high voltage power first, and ensure that the high volt...

AI Technical Summary

Problems solved by technology

This will bring the following disadvantages: (1) The discharge resistor will increase the size of the controller and the difficulty of layout, and bring some cost problems; (2) The normal operation of the vehicle will cause certain losses, reduce the efficiency of the power system, and bring continuous heat Problem; (3) The discharge time is long. Within this time frame, the vehicle's weak current (+12V) cannot be cut off, and the vehicle cannot be inspected and repaired. In case of an emergency such as a traffic accident, the safety of passengers cannot be effectively and timely guaranteed

(4) Due to the serious asynchrony of the high-voltage bus voltage and the weak (+12V) power-down sequence, the complexity of the vehicle control strategy

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