To enable a drive controller for electric rolling stock which performs vector control on an electric rolling stock, without using speed sensors for preventing the occurrence of overcurrent and, at the same time, to quicken the start of torque control, when the rolling stock is restarted.
This drive controller for electric rolling stock comprises an induction motor 5 which drives the electric rolling stock, a power converter 4 which outputs an alternating current; a converting means 7, which converts the alternating current into the d- and q-axis currents of a rotating magnetic field coordinate system; a speed- estimating means 9, which estimates the rotational frequency of the motor 5 from the q-axis current and a means, which controls the drive of the motor based on an estimated speed value; an initial value setting means 13, which decides the travel speed range of the electric rolling stock based on the information on the advancing direction of the rolling stock and sets a value at or near the center of the traveling speed range as the initial value of the estimated speed, when the power converter is actuated from the stopping or coasting state of the rolling stock, where the power converter is stopped; and a current pattern computing means 14 which delays the start of the rising of a d-axis current pattern, by suppressing the d-axis current pattern to a prescribed value or lower.
NAGATA KOICHIRO
ISHIDA SEIJI
NAKADA KIYOSHI
