| 摘要 |
PROBLEM TO BE SOLVED: To provide an inexpensive filter device capable of adjusting a tuning lag in the resonance frequency of a higher harmonic filter by a simple means regardless of fluctuations in the system frequency of a power system. SOLUTION: In this filter device eliminates higher harmonic by attaching the higher harmonic filter 13 consisting of a resonance circuit of a reactor 11 and a capacitor 12 to a power system and controlling the resonance frequency of the higher harmonic filter 13 so as to be tuned to the higher harmonic frequency of the power system, a control circuit is provided which takes the device temperature of the capacitor 12 detected by a temperature sensor 18 as a control input, converts the capacitor device temperature into capacitor capacitance from the capacitance - temperature characteristics, and tunes the resonance frequency of the higher harmonic filter 13 to the higher harmonic frequency of the power system based on the capacitor capacitance. |
