An AC motor controller is provided that utilizes a direct torque controller and primary and secondary control loops. The primary control loop operates in a relatively conventional manner, determining a voltage vector that sets the inverter switching variables for the motor's power inverter, where the voltage vector is based on the motor's torque and flux as estimated from the measured voltage and current of the motor. The voltage vector determined by the primary loop is selected and applied immediately upon completion of the corresponding primary control loop computational cycle. The secondary loop, utilizing a faster sampling rate than that of the primary loop, compares the measured phase current to a preset current limit. If the secondary loop determines that the measured phase current has exceeded the preset current limit, it sets a null voltage vector, thereby limiting transient over currents.