| 摘要 |
PURPOSE: A load harmonic current reducing device is provided to reduce the circulation of a harmonic current from a load system to a power side by installing an LC filter in series to a secondary power line. CONSTITUTION: One or more LC filters(10) are installed at each power line of a three phase or single phase load of a power system. The LC filter prevents a zero phase harmonic current from flowing in a power system. A bypass contactor(20) bypasses the current flowing in the power line. A current sensor(30) senses the current flowing in the power line. A first amplification unit(41) amplifies a harmonic current flowing in the power line. A second amplification unit(42) amplifies unbalance current flowing in the power line. A first comparator(43) compares the amplified harmonic current with a reference value. A second comparator(44) compares the amplified unbalance current with the reference value. A driving relay(45) drives a bypass contactor if an excessive signal is received.
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