Method for preventing malfunction of residual current circuit breaker and residual current circuit breaker

Abstract

The invention discloses a method for preventing the misoperation of an RCCB (residual current circuit-breaker). The method comprises the steps: obtaining the ratio K of an actual current in a line toa rated current of the RCCB in real time, and carrying out the real-time adjustment of a residual current operation value when the ratio K is greater than or equal to one: determining that the residual current operation value is greater when K is greater when K is not less than one and is less than Kmax, and the residual current operation value is less than a maximum residual current operation value allowed by the RCCB; determining that the residual current operation value is the maximum residual current operation value allowed by the RCCB when K is not less than Kmax, wherein Kmax is a presetvalue greater than one. The invention also discloses the RCCB. The method prevents the misoperation, caused by the overloading, of the RCCB in a software mode, and does not need to increase the volume of an iron core in a mutual inductor while effectively improving the safety and reliability of the RCCB.

Description

technical field [0001] The invention relates to a residual current circuit breaker, in particular to a method for preventing the residual current circuit breaker from malfunctioning. Background technique [0002] A residual current circuit-breaker is a mechanical switch that is used to connect, carry and break current under normal working conditions and to disconnect the contacts when the residual current reaches a specified value under specified conditions. electrical appliances. Residual current circuit breakers have been used more and more widely. They can be used to provide indirect contact protection for people, and can also be used to prevent fire hazards caused by ground fault currents caused by equipment insulation damage. They can also be used to distribute electrical energy and protect circuits and The overload and short circuit of the power supply equipment can also be used for the infrequent switching of the line and the infrequent starting of the motor. [000...

AI Technical Summary

Problems solved by technology

However, on the one hand, the iron core of the zero-sequence current transformer product is made of permalloy material, and the finished product cost of permalloy is expensive, which causes a great increase in cost to a certain extent; on the other hand, due to the continuous miniaturization of circuit breaker products, The increase in the volume of the current transformer core will inevitably lead to an increase in the volume of the zero-sequence current transformer, which cannot meet the needs of miniaturization of the circuit breaker

[0005] On the one hand, it is necessary to miniaturize the zero-sequence current transformer, reduce the volume of the transformer, and meet the needs of miniaturization of the circuit breaker; Create a dilemma, otherwise the performance requirements of residual current circuit breakers cannot be met

Images