Phase advance control of commutation in a switched reluctance machine is a well known expedient in the motor control art. In a particularly advantageous application of phase advance control, the commutation is advanced with increasing motor speed so that the build up of current in the phase windings tracks the peak inductance of the machine's magnetic circuit, thereby optimizing operating efficiency over a wide speed range. However, achieving precise control of the commutation phase angle using conventional control methods typically requires high resolution position encoders and/or substantial processing capability, both of which add significant cost to the system.
USPTO Backgrounds
USPTO Backgrounds