Drive controller and control method for electric vehicle

Abstract

In an electric vehicle drive controller, a drive controller has a controlling means which incorporates means for calculating a magnetic flux command from a basic torque command, for calculating a torque current command, exciting current command and slip frequency, and for operating vector calculation, and drives the motor. Voltage or power density of the power source is input to a correction coefficient calculating means and then input to a magnetic flux generating means by a correction coefficient to correct a magnetic flux. A magnetic flux generating means calculates the magnetic flux command by limiting and correcting the magnetic flux command according to the basic torque command and rotating speed, and determines a control variable for the magnetic flux command in correspondence to the motor rotating speed and torque command. By controlling the voltage to be applied to the motor in correspondence to the quantity of state of power source, it is possible to operate a drive unit on the most efficient point and reduce the size of electric power converter.