Output overload and fault tolerant commutation method for a switched reluctance generator and an electric power generating system employing same

A method of commutation of a switched reluctance machine to allow operation in a generate mode, the switched reluctance machine having wound stator poles and a rotor with salient poles rotatable therein, the method comprising the steps of:

• exciting the stator winding during a first phase;
• generating current during a second phase;
• and
• freewheeling the stator winding during a third phase.

An electric power generating system, comprising:

• a switched reluctance machine having a wound stator and a salient pole rotor rotatably mounted therein, said rotor drivably coupled to a source of rotational energy, said stator having a plurality of poles wound with a winding to form pole pairs;
• a power bus having a positive feeder and a return;
• first switching means switchably coupling a first end of said winding to said positive feeder of said power bus;
• second switching means switchably coupling a second end of said winding to said return of said power bus;
• a first commutation means coupled between said second end of said winding and said positive feeder of said power bus;
• a second commutation means coupled between said first end of said winding and said return of said power bus;
• voltage sensing means in sensor communication with said positive feeder of said power bus for monitoring a voltage level thereon, said voltage sensing means generating a monitored voltage signal indicative of said monitored voltage;
• current sensing means in sensory communication with said winding for monitoring a flow of current therethrough, said current sensing means generating a monitored current signal indicative of said monitored current;
• rotor position sensing means for monitoring an angular position of said rotor, said rotor position means generating a monitored angle signal indicative of said rotor angular position;
• and
• a controller responsive to said monitored voltage, current, and angle signals for commutating said switched reluctance machine in a generate mode, said controller commanding said first and said second switching means closed at a fixed angle prior to alignment of said rotor and said stator pole, said controller thereafter commanding said first and said second switching means open at a fixed angle after alignment of said rotor and said stator poles, said controller thereafter commanding one of said first and said second switching means closed at a fixed angle of non-alignment of the rotor and stator poles for substantially a whole period of non-alignment of the rotor and stator poles.