APPARATUS FOR ANALYZING OPERATION CAUSE OF EARTH LEAKAGE BREAKER

摘要

PROBLEM TO BE SOLVED: To determine whether an earth leakage breaker normally operates because of electric leakage or it performs an oversensitive operation (unnecessary operation) because of a high-frequency leakage current by serge or an inverter.

SOLUTION: A time-frequency analysis part 8 frequency-analyzes a leakage current (zero-phase current) at a breaking operation of a leakage breaker 2 and analyzes temporal changes of frequency components to grasp transitive leakage current changes in the breaking operation of the breaker 2 from both time and frequency. Furthermore, an operation cause analysis part 10 evaluates the leakage current by considering a threshold of ventricular fibrillation to a frequency described in IEC479-2 to determine whether the breaker 2 operates normally because of the electrical leakage or it performs the oversensitive operation (unnecessary operation) because of the high-frequency leakage current by the serge or the inverter.

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