| 摘要 |
PURPOSE:To sustain effective function of generative brake even in low speed region by increasing the resistance of a brake resistor when the running speed makes a transition from high speed region to low speed region through genera tive brake operation. CONSTITUTION:Generative brake resistors R1, R2 consume DC power fed from an inverter 7 side and produce brake force. Generative brake functions upon closure of an electromagnetic contactor 15. When the running speed of an elec tric rolling stock exceeds a predetermined level, an electromagnetic contactor 15 short-circuits the resistor R2. Consequently, brake resistance is decreaced for a high running speed whereas it is increased for a low running speed. By such arrangement, the inverter 7 can be operated upto the low rotation region of an induction motor 9. |
