| 摘要 |
PURPOSE: A harmonic filter with a reverse phase detection function and an absent phase detection function is provided to efficiently reduce harmonic, thereby safely protecting a power system. CONSTITUTION: A temperature detection unit detects a temperature state of a zigzag wiring transformer. The zigzag wiring transformer is connected to a three phase line and a neutral line of a power system. A voltage detection unit (130) detects the voltage of the three phase line and the neutral line of the power system. A current detection unit (140) detects the current of the three phase line and the neutral line of the power system. A phase detection unit (150) senses the phase state of the three phase line of the power system. [Reference numerals] (11) Power supply unit; (12) Load terminal; (160) Control unit; (170) Harmonic wave tracking unit; (180) State displaying unit |
