Electric vehicle control system using speed sensorless control

摘要

PROBLEM TO BE SOLVED: To stably and surely restart an induction motor when coasting. SOLUTION: This electric rolling stock controller has a main circuit composed of a VVVF inverter 5, a filter capacitor 4 provided on its DC side, and an induction motor 6 provided on its AC side, is composed of a current command computing means 10 for computing a current command value, output voltage command computing means 11, 12 for computing an output voltage command value so as to obtain a current coinciding with the current command value, an output frequency command computing means 14 for computing an output frequency command value, and a gate control means 13 which performs gate control of the VVVF inverter 5 from the output voltage command value and output frequency command value, is provided with a means for gradually increasing/decreasing the output frequency command from a first specified value to a second prescribed value on the occasion of restarting the induction motor from its coasting state, since the output frequency command computing means 14, and is provided with a current detecting means 9 for detecting the current of the induction motor, and a rotor rotation frequency sensing means 15 for estimating the rotor rotation frequency of the induction motor from at least one of this detected current value, the current command value, and output voltage command value.