Intelligent load-limiting universal circuit breaker

Abstract

The invention discloses an intelligent load-limiting universal circuit breaker, which comprises a current transformer, a rectification filter circuit, a step-down circuit, a single-chip microcomputer, a single-port tripping module, a digital signal type current detection circuit, a voltage detection circuit, and a residual current detection circuit , signal preprocessor, A / D converter, and an analog signal current detection circuit. Compared with the prior art, the present invention has the following remarkable effects: (1) Since the present invention adds an analog signal type current detection circuit to realize a short-circuit fault fast protection scheme, the response time of the analog circuit is extremely short, and its power-on time is 5 microseconds (2) The power supply part adopts the current power supply mode of the frame circuit breaker itself, which improves the safety and reliability of the circuit in operation, and especially important is to greatly reduce various strong interferences from the low-voltage power grid when the high-voltage power supply is used; (3 ) The present invention uses a four-port trip module, which can greatly improve its anti-interference ability.

Description

technical field [0001] The invention relates to the technical field of circuit breakers, in particular to an intelligent load-limiting universal circuit breaker. Background technique [0002] The existing circuit breaker consists of a current transformer, a rectification filter circuit, a step-down circuit, a single-chip microcomputer, a single-port tripping module, a digital signal current detection circuit, a voltage detection circuit, a residual current detection circuit, a signal preprocessor, A / D Converter composition. When working, the current transformer winding passing through the phase line outputs the induced current, which is rectified and filtered by the rectifier filter circuit and stepped down by the step-down circuit, and then input to the single chip microcomputer, and the signals of the digital signal current detection circuit, voltage detection circuit, and residual current detection circuit are respectively The input signal is pre-processed and converted ...

AI Technical Summary

Problems solved by technology

[0004] ① It cannot meet the requirements of fast power-on action time. To ensure that the working conditions of the single-chip circuit are not fully established after power-on reset and the chip cannot run normally when power-on, it is necessary to set a certain delay time (for example: The power-on reset delay timer PWRT of Microchip's single-chip microcomputer has a delay time of 72 milliseconds); in addition, in order to configure the functions and status of each port of the chip, there must be a period of initialization time after the single-chip microcomputer is put into operation; with a quartz crystal frequency stabilization The single-chip microcomputer also needs to have a stabilization time of 1024 oscillation waveforms, etc.; this requires a fast (<0.1 second) trip trip response for the frame circuit breaker in certain fault conditions (for example: power on in the presence of a short-circuit fault) more difficult

[0005] ② When using AC power supply, it will be subject to various strong interference from the power grid

[0006] ③The action of the tripping module is generally only controlled by one port, and this circuit is susceptible to interference

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