Circuit breaker and short-circuit protection method

Abstract

The invention relates to a circuit breaker and a short-circuit protection method. The circuit breaker comprises a power circuit, a sampling circuit, a micro-processing unit and a driving circuit, wherein the power circuit is connected to an IGBT circuit between an input power grid end and an output load end, the sampling circuit is used for obtaining a first sampling voltage and a second samplingvoltage, the micro-processing unit is used for comparing the first sampling voltage or the second sampling voltage with a preset reference voltage value and outputting a control signal when the sampling voltage is larger than the preset reference voltage value, the driving circuit is used for controlling the power circuit to be disconnected according to the control signal. The sampling circuit isused for sampling a voltage in a power grid, and the micro-processing unit is used for comparing the sampling voltage with the preset reference voltage value and generating the control signal to control the IGBT circuit to be switched off so as to achieve an effect of short-circuit protection when short circuit occurs; and since the whole control process is synergically achieved by sampling, control and IGBT, the response is more rapid, and the probability of a safety accident is reduced.

Description

technical field [0001] The invention relates to the technical field of circuit breakers, more specifically, it relates to a circuit breaker and a short-circuit protection method. Background technique [0002] In the power distribution system, the circuit breaker can not only connect and break the normal load current, but also disconnect the short-circuit fault current, which can timely and effectively remove the short-circuit fault and ensure the safe and stable operation of the power system. [0003] When a traditional circuit breaker is short-circuited, the mechanical switch automatically trips to disconnect the power supply system. Due to the inherent characteristics of its internal mechanical switch, it takes a long time to cut off the power supply system, usually between tens of milliseconds and hundreds of milliseconds. Due to the small contact resistance at the short circuit, it is easy to cause a sharp increase in the current of the power supply circuit, a sharp rise...

AI Technical Summary

Problems solved by technology

[0003] When a traditional circuit breaker is short-circuited, the mechanical switch automatically trips to disconnect the power supply system. Due to the inherent characteristics of its internal mechanical switch, it takes a long time to cut off the power supply system, usually between tens of milliseconds to hundreds of milliseconds. Due to the small contact resistance at the short circuit, it is easy to cause a sharp increase in the current of the power supply circuit, a sharp rise in the temperature of the conductor of the power supply circuit, and a strong dangerous arc spark at the short circuit point. The high temperature and arc generated by it can easily cause safety accidents such as fire or electric shock.

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