Method for inhibiting wheel slip in an electric alternating current induction motor powered vehicle

A method for inhibiting wheel slip in an electric alternating current induction motor powered vehicle including electric power control means comprising the steps of:

• determining a vehicle speed:
• converting the vehicle speed to a torque command signal;
• estimating relatively positive and negative torque command limits using the vehicle speed and a maximum allowable vehicle speed:
• comparing the torque command signal to the positive and negative torque command limits to develop a torque reference signal limited to a maximum value corresponding to a respective one of the positive and negative torque command limits;
• subtracting the magnitude of the signal corresponding to actual motor torque from the magnitude of the torque reference signal to develop a torque error signal;
• converting the torque error signal to a corresponding torque regulator signal;
• summing the torque regulator signal with the torque reference signal to develop a motor torque signal;
• converting the motor torque signal to a corresponding frequency command signal:
• and
• obtaining, from the electric power control means, an excitation frequency for the induction motor corresponding to the frequency command signal.