Earth leakage breaker operation cause analyzer

摘要

PPROBLEM 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. PSOLUTION: 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. PCOPYRIGHT: (C)2006,JPO&NCIPI