Simple starting sequence for variable reluctance motors without rotor position sensor

Abstract

Abstract A rotor position sensing system (10) for a variable reluctance motor having a plurality of phases Φ 1 -Φ 3 with each phase having a phase winding wound on stator poles (18, 20 and 22) and first and second switches (Q 1 and Q 2 , Q 3 and Q 4 , and Q 5 and Q 6 ) each having a first terminal, a control terminal and a second terminal, the control terminal of each switch having a control signal applied thereto to switch the switch between on and off states, the first terminal of the switch being coupled to a first power supply potential (30), the second terminal of the first switch being coupled to the phase winding, the first terminal of the second switch being coupled to a second power supply potential (32) and the second terminal being coupled to the phase winding which senses rotor position prior to activation of the phase windings to starting rotation of the rotor in accordance with the invention that includes a current sensor (34), coupled to each phase winding, for producing an output signal of a magnitude of current flowing in the windings; and a controller (26), coupled to each current sensor and to each control terminal of the switches, for applying control signals to the switches to cause current to flow between the power supply potentials through the phase windings and in response to the sensed magnitude of the current flow through the phase windings determining the position of the rotor with respect to the stator by determination of relative magnitude of the current flow through the phase windings.

Inventors

• 👤 David J. Belanger

Bibliographic Details