| 摘要 |
PURPOSE:To restrain a rise in d.c. voltage when load fluctuates by disposing d.c. chopper between a rectifier for converting a.c. power source output to d.c. output and a d.c. bus bar, whereby d.c. bus bar voltage is kept constant by on- off controlling the d.c. chopper. CONSTITUTION:A.C. lowered by a transformer 1 for a rectifier for lowering three-phase a.c. voltage is changed into d.c. voltage by a silicon rectifier 2 to be output, and the terminal on the negative pole side is connected to one electric car line N. The terminal on the positive pole side is connected to an input terminal of a d.c. chopper 3, and an output terminal thereof is connected to a d.c. bus bar 4. The d.c. bus bar 4 is connected to the other electric car line P through a feeder breaker 5. When d.c. voltage is input to the d.c. chopper 3, a semiconductor switch S is on-off controlled according to a control signal from a gate control device at the d.c. chopper 3 to output constant d.c. voltage to the d.c. bus bar 4. At a light load, a rise in d.c. voltage of the d.c. bus bar 4 is restrained. |
