Spatial Deadbeat Torque Control for Six-Step Operation

This paper presents a methodology for implementing a spatially triggered, deadbeat torque control for permanent magnet synchronous machines in six-step operation using deadbeat flux vector control. At every sampling instant, the flux vector is controlled on a hexagonal trajectory, and hence, the flux trajectory is manipulated for torque control while maintaining six-step operation. Six-step operation allows control of the flux angle, and therefore the torque, only at sixty electrical degree intervals, limiting dynamic operation. Consequently, this work proposes a deadbeat torque controller that achieves the commanded average torque as fast as possible, i.e., every sixty electrical degrees. The advantages of this approach are very fast and smooth torque and flux dynamics. Step and sinusoidal torque trajectories are evaluated using simulations and experiments to show the deadbeat response and the smoothness of the proposed controller.