Self-checking device of motor short circuit and application method thereof

Abstract

The invention relates to the field of emergency protective circuit devices which react to overcurrents, in particular to a self-checking device of a motor short circuit and an application method thereof. The self-checking device of the motor short circuit includes current sensors (1) and is characterized by further including a motor controller (2), and a microprocessor (21) outputs a three phase pulse signal to a PWM (Pulse Width Modulation) rectifier (22) through a three phase signal line. The application method of the self-checking device of the motor short circuit is characterized in that when a motor (3) stops working, the following steps are performed sequentially: the microprocessor (21) outputs a three phase pulse detection signal to the PWM rectifier (22) through the three phase signal line; and the microprocessor (21) calculates L according to the formula delta I=U0 / L*delta t, if L<L0-d, the microprocessor (21) judges that the motor is in the state of short circuit and finishes judging. The self-checking device of the motor short circuit is simple in structure, convenient to install, quick in response, safe, reliable and wide in range of application.

Description

technical field [0001] The invention relates to the field of emergency protection circuit devices reacting to overcurrent, in particular to a self-checking device for motor short-circuit and a use method thereof. Background technique [0002] At present, new energy vehicles are being widely used. New energy vehicles are generally driven by synchronous motors. The direct current output by the battery pack is converted into three-phase alternating current by the inverter and then input to the synchronous motor. The synchronous motor drives the car. At the same time, it is equipped with Motor controllers to control the operation of synchronous motors. In actual use, the synchronous motor may cause phase-to-phase short-circuit or inter-turn short-circuit due to installation or design problems, which may cause short-circuit or inductance saturation of the motor controller during output, which will damage the motor controller and bring hidden dangers to safety. The existing outpu...

AI Technical Summary

Problems solved by technology

In actual use, the synchronous motor may cause phase-to-phase short circuit or inter-turn short circuit due to installation or design problems, which may cause short circuit or inductance saturation of the motor controller during output, which will damage the motor controller and bring hidden dangers to safety

The existing output short-circuit protectors are all connected in the output circuit to a device specially used to monitor the output state of the inverter to judge whether there is an output short circuit. Requires higher output voltage detection, resulting in increased cost and difficult installation

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