Four-quadrant brushless reluctance motor drive

Commutation of the SR motor is as simple as that of the brushless PM motor, using a similar shaft position sensor and gating logic. Speed and torque can be modulated by commutation angle control over a wide range. Combined with voltage p.w.m., sufficient flexibility is obtained by switching between a small number of modes or commutation angle combinations to at least double the speed and torque control ranges compared to those possible with fixed angles. Four-quadrant symmetrical operation is easily achieved, with extremely rapid reversing. The entire control is readily implemented using any of the normal methods (gate array, programmable logic array, custom LSI, or microprocessor)