| 摘要 |
PROBLEM TO BE SOLVED: To provide a DC filter for electric railway in which the size and the cost can be reduced, while sufficiently suppressing harmonic components on the feeder line. SOLUTION: The DC filter is employed in a DC substation for electric railway, in order to smooth the waveform of a DC voltage formed through a 12 phase rectifier 22. Leakage impedance of a transformer 20 is utilized as a DC reactor. A first filter branch 11 for absorbing a harmonic component having frequency 12 times that of an AC power supply frequency, and a second branch 12 for absorbing a harmonic component having frequency 24 times that of the AC power supply frequency are provided, while being formed of resonance capacitors 4, 5 and resonance reactors 7, 8. |
