Circuit breaker - Mitsubishi Electric Corporation

Title:

Circuit breaker

Document Type and Number:

Japanese Patent JP6138353

Kind Code:

B2

Abstract:

A circuit breaker 30 includes a current transformer 14 that outputs a current signal in accordance with an AC current flowing along an electric path 1; a reference waveform storage part 15 that has stored, in advance, reference waveforms of reference frequencies that are stored in association with a plurality of reference frequencies, one of which is equal to the frequency of the AC current; a multiplication circuit 8 that multiplies a current waveform output from the current transformer 14 by each of the reference waveforms stored in the reference waveform storage part 15; an FFT circuit 7 that performs fast Fourier transformation on each piece of multiplication data obtained by multiplication in the multiplication circuit 8 and that thereby converts the multiplication data into frequency components; and a comparison determination circuit 10 that determines whether a DC component is included in each piece of multiplication data converted into frequency components by the FFT circuit 7 and that detects a reference frequency corresponding to multiplication data including a largest DC component, as the frequency of the AC current flowing along the electric path 1.

Inventors:

Hiroaki Ohashi
Takeshi Itakura

Application Number:

JP2016513528A

Publication Date:

May 31, 2017

Filing Date:

April 15, 2014

Export Citation:

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