| 摘要 |
PROBLEM TO BE SOLVED: To inhibit flowing in of higher harmonics near fifth harmonic component so as to prevent the occurrence of overloads by forming a parallel resonance circuit which uses a frequency near that of a fifth harmonic component as a resonance frequency by connecting a capacitor for resonance in parallel with a series reactor for reducing harmonics connected to a phase advancing capacitor section. SOLUTION: A parallel resonance circuit 2 becomes an indefinite impedance against a harmonic component (near fifth harmonic component) of a resonance frequency in the harmonic voltage distortion remaining in a power distribution system. Consequently, all harmonic voltage distortion Vn is added to the circuit 2 in the harmonic component and electric currents IL and Ib corresponding to the distortion Vn do not flow to a phase advancing capacitor C (Ia=0), but to a series reactor L and capacitor Cb for resonance. Therefore, a harmonic current near the resonance frequency is inhibited by the circuit 2 and the overload and burning of the reactor L can be prevented. |
