Patent ID: 7288909

Claim:
An electrical vehicle controller for detecting axle speeds of axles corresponding to plural AC electric motors torque-controlled by an inverter and detecting idle running of wheels directly joined to the axles, comprising: high-level priority calculating means for extracting the maximum frequency from frequencies corresponding to the respective axle speeds; low-level priority calculating means for extracting the minimum frequency from the frequencies corresponding to the respective axle speeds; a first subtracter for subtracting the minimum frequency from the maximum frequency to calculate a first frequency deviation; primary delay means to which the first frequency deviation is input as a primary delay system to calculate a second frequency deviation; a second subtracter for subtracting the second frequency deviation from the first frequency deviation to calculate an idle running frequency deviation; idle running detection setting means for outputting an idle running detection set value for judging the idle running of the wheels at the frequency level; idle running detecting means for comparing the idle running frequency deviation and the idle running detection set value with each other and outputting an idle running detection signal when the idle running frequency deviation is larger than the idle running detection set value; and torque instruction correcting means for calculating a torque correction amount of the AC electric motors on the basis of the idle running detection signal and instructing torque correction to the inverter.