| 摘要 |
PURPOSE: To perform the optimum harmonic control by a method wherein a zero-cross signal from one of a plurality of sets of the respective voltage detectors is used as a common zero-cross signal and used as the timing reference of a plurality of respective control logic units. CONSTITUTION: Three main converters 12a-12c are provided in one formation of vehicles. Pantographs 2a-2c, PT's 9a-9c and main transformers 3a-3c are provided to drive respective induction motors 8a-8c. Zero-cross signals Sa-Sc which are once inputted to control logic units 11a-11c from ACPT's 10a-10c are inputted to a synchronous signal selector 13 which selects one common zero-cross signal S1 among the signals Sa-Sc in accordance with a predetermined priority order and supplies the signal S1 to the respective control logic units 11a-11c as a timing reference. With this constitution, the optimum phase-shift conditions which suppress the harmonics can be always realized as a whole vehicle formation accurately and a high harmonic suppression effect can be realized even if the error characteristics of the respective PT's 9a-9c and the ACPT's 10a-10c have variations. |
