| 摘要 |
PURPOSE: To reduce the generated torque to smaller value in the same slip frequency and to eliminate the slip or glide of an axle by increasing the rotor resistance of one of a plurality of induction main motors which are energized from the same PWM-controlled inverter from that of the other motor. CONSTITUTION: An electric railcar main circuit system fetches power from an electric overhead line, converts it to AC power by a PWM-controlled inverter 4, and supplies it to a plurality of induction main motors 5a to 5c, 5d'. The secondary resistor R'2 of at least one of the energized motors 5a to 5c, 5d' such as, for example, 5d' is increased larger than that R2 of the other motors 5a to 5c. Thus, since the motor 5d' can decrease the torque in the same slip as those of the other motors 5a to 5c, large slip or glide is suppressed without adding any other unit, thereby improving the acceleration or deceleration of the railcar. |
