Short-circuit protection circuit for motor controller

Abstract

The invention relates to a short-circuit protection circuit for a motor controller, which is used for judging a three-phase circuit signal input from a drive circuit. The short-circuit protection circuit for the motor controller comprises a voltage limiting circuit, a reference circuit, a load comparison circuit, a short-circuit judgment circuit and a misinformation signal eliminating circuit, wherein the voltage limiting circuit limits a voltage value of the three-phase circuit signal input from the drive circuit; the reference circuit provides a judgment reference voltage; the load comparison circuit judges whether a three-phase voltage is within a normal range or not by comparing the output of the reference circuit serving as the reference with the output of the voltage limiting circuit; the short-circuit judgment circuit judges whether the drive circuit causes a short-circuit and outputs a short-circuit signal or not; and the misinformation signal eliminating circuit is arranged between the load comparison circuit and the short-circuit judgment circuit, receives a signal from the load comparison circuit, and ensures that the short-circuit judgment circuit compares the input phase current only. The short-circuit protection circuit for the motor controller has the advantages that the overall circuit is low in cost and convenient to maintain and replace due to the adoption of common circuit components, can be applicable for a large-power controller because the sampling function of the drive circuit is realized without relying on resistors, and has a phase current identification function and high reliability in short-circuit situation judgement.

Description

technical field [0001] The invention relates to a short-circuit protection circuit of a motor controller, in particular to a short-circuit protection circuit of a motor controller of a high-power electric bicycle. Background technique [0002] The electric bicycle that uses electric energy as the driving force is widely used because of its light shape and no exhaust pollution. As a means of transportation, electric bicycles have high requirements for driving safety and reliability, which requires the motor controller to have a strong self-protection ability under abnormal conditions. For motor controllers, the biggest security threat comes from damage to the controller caused by a short circuit in the three-phase wires of the motor. The traditional short-circuit protection method needs to connect current sampling resistors in series on the bus, which is only suitable for low-power controllers and cannot keep up with the trend of high-power electric bicycles; although the hi...

AI Technical Summary

Problems solved by technology

The traditional short-circuit protection method needs to connect current sampling resistors in series on the bus, which is only suitable for low-power controllers and cannot keep up with the trend of high-power electric bicycles; although the high-speed response current transformer can realize the short-circuit protection function, but Its cost is too high to be economical

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