| 摘要 |
PURPOSE:To make an induction motor type electric railway car to enable to perform starting surely on a grade by a method wherein output frequency of an electric power transducer to be supplied to induction motors is fixed when the electric railway car is retreating. CONSTITUTION:Slip frequency fS is added to speed frequency fIM to be made as inverter frequency fINV when the electric railway car is advancing. When the electric railway car retreats in spite of the car is intending to advance, a change-over relay 3 operates to fix inverter frequency fINV to frequency (starting frequency) fO to be generated at starting time. Accordingly because actual slip frequency fSR at retreating time is not enlarged so much, torque is not reduced so much also, and starting on the grade can be attained. |
