Apparatus for starting a switched reluctance motor

A switched reluctance motor providing rotor position detection without a rotor shaft position sensor, said motor comprising:

• a rotor mounted for rotation about an axis and including a plurality of rotor poles;
• a stator surrounding said rotor and including at least three stator phases;
• energizing means for selectively energizing said phases in succession to rotate said rotor, said energizing means including,
• an electrical energy source,
• a plurality of phase switches connected between said phases and said energy source for selectively electrically connecting said energy source to said phases,
• switch operating means connected to said phase switches for selectively operating said phase switches;
• and
• starting means for determining which of said phases to energize first for rotating said rotor, said starting means including pulse means connected to said switch operating means for operating all of said switches for a limited time to connect said energy source to said phases without causing rotation of said rotor so as to simultaneously generate a seek current in each of said phases, current sensing means for sensing the amount of seek current in each of said phases, timing means connected to said current sensing means and to said switch operating means for measuring the amount of time for said seek current in each of said phases to reach a predetermined current level threshold and for establishing a seek current rise time for each of said phases, and comparing means connected to said timing means for determining the lowest, intermediate and highest seek current rise times;
• and
• said energizing means energizing a selected phase of said motor based upon said priority sequence so as to cause rotation of said rotor.