| 摘要 |
PROBLEM TO BE SOLVED: To prevent generation of induction damages by reducing the level of direct noise to a signal transmission line of a protective control device for a rail way. SOLUTION: An LC filter is formed of a reactor 4 and a capacitor 5 and is used in common by four inverter circuits INVA-INVD. Although higher harmonics exist between the reactor 4 and the inverter circuits INVA-INVD, the number of circuits through which the higher harmonic flows practically is one. In conventional cases, from the fact that the number of circuits through which the higher harmonic flow is used to be four, the direct noise level can be markedly reduced, so that malfunctions of a protective control device for a rail way can be prevented. |
