Active short circuit control method, motor controller and motor control system

Abstract

The invention provides an active short circuit control method, a motor controller and a motor control system. The method is suitable for a T-type three-level inverter. The T-type three-level inverter comprises three-phase circuits connected in parallel, one phase circuit comprises a vertical bridge and a transverse bridge, an upper bridge arm and a lower bridge arm of the vertical bridge are connected in series and then connected to the two ends of a direct-current power source in parallel, one end of a bridge arm of the transverse bridge is connected with a reference ground, and the other end of the bridge arm of the transverse bridge is connected with a series connection point of the upper bridge arm and the lower bridge arm of the vertical bridge. The anode / cathode of the DC power supply is connected with the reference ground through a capacitor. The series connection point of the upper and lower bridge arms of each vertical bridge is connected with the motor. The method comprises the following steps: controlling on-off of switching tubes in a vertical bridge and a transverse bridge of a three-phase circuit so as to convert direct current into three-phase alternating current to be supplied to a motor for use; and when the T-type three-level inverter enters an active short-circuit working mode, the switch tube of the same bridge arm of each phase of circuit is switched on, and the switch tubes of other bridge arms of each phase of circuit are switched off to short-circuit the motor. According to the invention, the safety and reliability of the T-type three-level inverter can be improved.

Description

technical field [0001] The present application relates to the technical field of motor control, in particular to an active short circuit control method, a motor controller and a motor control system. Background technique [0002] In recent years, more and more attention has been paid to the environmental problems caused by automobiles. In order to solve the environmental pressure caused by automobile exhaust emissions, automobile manufacturers have spared no effort to develop new energy vehicles, especially electric vehicles. Among them, the motor controller, as the core component of the electric vehicle motor system, has the function of realizing the mutual conversion between direct current and alternating current. Specifically, the motor controller can invert the DC power of the power battery into three-phase AC power when the electric vehicle is running normally, provide power for the motor and control the output torque of the motor to drive the vehicle. During the coast...

AI Technical Summary

Problems solved by technology

[0003] Among them, due to the characteristics of back EMF during the operation of the motor, if the motor speed is abnormal and the control is poor during the driving of the new energy vehicle, it is very likely that the back EMF of the motor is higher than the input voltage of the motor, thus causing the back EMF to pass through T Type three-level inverter pours back into the power battery, causing damage to the power battery and related high-voltage devices

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