High Performance Torque-Controlled Induction Motor Drives

The way in which a practical control method using derived torque feedback signal has made it possible to obtain the same high bandwidth torque control with standard cage induction motors as can be achieved with dc motors is demonstrated. In contrast with previous torque control systems, this method does not require the angular position of a motor field vector to be determined for control purposes. The versatility of this torque controller is illustrated with measured torque responses obtained from a transitorized servo drive, a cycloconvertor, and a current source inverter.