SUPPRESSION OF HIGHER HARMONIC INFLOW FOR PWM CURRENT TYPE POWER CONVERTER

摘要

PROBLEM TO BE SOLVED: To provide suppression of higher harmonic inflow the capable of restraining higher harmonic inflow by inserting an LC filter into AC side and properly selecting resonance frequency. SOLUTION: A serial LC filter, consisting of a reactor L1 and a capacitor C1, is inserted between AC power supply lines. Two or more serial resonance frequencies of the LC filter are made to exist, when the filter is seen from the AC side, so that the frequency of the higher harmonics degree with a large voltage distortion on AC side exists between the two serial resonance frequencies. It is thus possible to increase the combined impedance of the LC filter, thereby restraining higher harmonic voltage inflow.