Speed Regulated Continuous DTC Induction Motor Drive in Field Weakening

The paper describes sensorless speed controlled continuous Direct Torque Control (DTC) Induction Motor (IM) drive in the field weakening regime. Drive comprises an inner torque loop and an outer speed loop. Torque control is based on Proportional - Integral (PI) controller with adaptive Gain Scheduling (GS) parameters. The GS PI control provides full DC link voltage utilization and a robust disturbance rejection along with a fast torque response. Outer speed loop has a PI regulator with the gains selected so as to obtain a fast and strictly aperiodic response. Proposed drive fully utilizes the available DC bus voltage. The paper comprises analytical considerations, simulation results, and detailed description of the implementation steps. Experimental verification of the proposed solution is conducted on a fixed point Digital Signal Processor (DSP) platform.