Ground fault protection circuit breaker and ground fault protection method

Abstract

The invention relates to a ground fault protection circuit breaker and a ground fault protection method. The ground fault protection circuit breaker comprises a circuit breaker, which comprises a plurality of sampling circuits, wherein the plurality of sampling circuits respectively comprise a phase detection circuit, and the phase detection circuits of the plurality of sampling circuits are respectively connected with a single-chip microcomputer. According to the invention, when the single-chip microcomputer samples current signals of the plurality of sampling circuits through a signal processing circuit at a fixed frequency, phases corresponding to the current signals at the moment can be acquired through the phase detection circuit, the grounding current values of the current signals ofthe plurality of sampling circuits at the moment are calculated according to the corresponding phases, whether a grounding fault occurs is judged according to the grounding current values at multiplemoments, and the single-chip microcomputer obtains the phase according to a hardware and software algorithm instead of depending on direct calculation of hardware, so that the structure is simpler, and the efficiency is higher.

Description

technical field [0001] The invention relates to the field of low-voltage electrical appliances, in particular to a ground fault protection circuit breaker and a ground fault protection method. Background technique [0002] Ground fault refers to the conductive part of the external leakage relative to the ground or related to the ground, such as the direct contact short circuit of the equipment shell, pipeline and structure. Compared with the general short circuit form, the effective value of the short circuit current is not very large, but the ground fault Indirect contact electric shock accidents caused by ground faults are the most common electric shock accidents, and ground-to-ground arcs and electric sparks caused by ground faults are the most common electrical short-circuit ignition sources. [0003] In the event of a ground fault, the existing circuit breaker can protect the circuit through differential type (T) and ground current type (W) to prevent accidents such as ...

AI Technical Summary

Problems solved by technology

[0004] The existing ground current type (W) protection method needs to be realized by adding a special current transformer, which is not only large in size, but also the specifications of the transformers cannot be used for different rated currents, and more specifications of the transformers are required

However, although the existing differential type (T) protection method can protect according to the vector sum of the currents of each phase, it needs an external grounding current transformer for protection for ground fault protection, so for the circuit breaker, the volume increases and the components increase, unable to meet the needs of users

Not very accurate

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