Control techniques for improved high-speed performance of interior PM synchronous motor drives

A description is given of two control techniques to enhance the performance of the interior permanent magnet (IPM) drive over an extended speed range. The first technique is a feedforward compensation algorithm that improves the performance of current regulators operating in the stationary reference frame. Speed-dependent back-EMF (electromotive force) and inductive voltage drops are compensated, so that steady-state current errors are nulled at all speeds until current regulator saturation limits are encountered. The second technique is a flux-weakening control algorithm which uses stator current components to prevent premature current regulator saturation, thereby improving the machine's torque production capabilities at high speeds. Neither algorithms requires additional feedback signals from the motor beyond those already used in the preexisting controls, and they are relatively insensitive to variations in the machine parameters, despite their feedforward characteristics.<>