Method and apparatus for implementing sensorless control of a switched reluctance machine

DETAILED DESCRIPTION In accordance with one embodiment of the present invention a "sensorless" method of controlling a switched reluctance machine having a plurality of phase windings is provided that eliminates the need for a rotor position transducer.
In general, this embodiment involves the acts of, over a given rotor interval, energizing at least two of the phase windings; monitoring the voltage on an un-energized phase winding over the given rotor interval; and controlling the energization of the phase windings in response to the monitored voltage changing from a voltage level of one polarity to a voltage level of the opposite polarity.
In one exemplary embodiment the act of controlling the energization of the phase windings in response to the change in the monitored voltage involved a switching act to energize the previously un-energized phase winding in response to the monitored voltage changing from a voltage level of one polarity to a voltage level of the opposite polarity.
In alternate embodiments, the act of controlling the energization involves using the detected voltage polarity change to implement an angle control scheme.
The present invention also extends to a switched reluctance machine system that generally includes a switched reluctance machine including a stator, a plurality of phase windings positioned within the stator, and a rotor positioned to rotate relative to the stator; a voltage detection circuit coupled to the phase windings for detecting the voltage on a given phase winding and for generating a control signal in response to the voltage on the phase winding changing from a voltage of one polarity to a voltage of opposite polarity to generate at least one switching signal; and a power inverter responsive to the at least one switching signal for controlling the application of electric power to the phase windings.
Alternate constructions of the power inverter and the voltage detection circuitry are contemplated by the present invention.
Other exemplary embodiments of the present invention and other features of the present invention will be apparent to one of ordinary skill in the art having the benefit of this disclosure