Switched Reluctance Machine And Method Of Operation Thereof

A switched reluctance (SR) machine supporting a phase comprising a hollow and substantially cylindrical stator having a plurality of inwardly extending stator poles positioned substantially equidistant from each other, two adjacent stator poles defining a recess therebetween;

• a substantially cylindrical rotor positioned in the stator and having a plurality of outwardly extending rotor poles formed on the outer surface thereof, each of the stator pole and the rotor pole subtending an angle having a value less than 0.5 electrical pole pitches at a center of rotation;
• a means for supporting the rotor for rotation about the axis;
• coils provided on stator poles in proportion to the number of the poles wound thereon and occupying the recess between adjacent stator poles;
• the rotor being rotated in a desired direction of motion by a reluctance torque generated between the rotor and the stator, the reluctance torque being generated by energizing the phase in a current controlled manner, the energizing concluding upon the rotation of the rotor through a minimum commutation angle required to maintain motion, de-energizing the phase by freewheeling the phase, a freewheeling current being maintained by energy stored in the phase.

A switched reluctance (SR) machine supporting one or more phases distributed along the axis of rotation, each phase whereof comprising a hollow and substantially cylindrical rotor having a plurality of inwardly extending rotor poles positioned substantially equidistant from each other, a substantially cylindrical stator positioned in the rotor and having a plurality of outwardly extending stator poles formed on the outer surface thereof, two adjacent stator poles defining a recess therebetween, each of the stator pole and the rotor pole subtending an angle having a value less than 0.5 electrical pole pitches at the center of rotation;

• a means for supporting the rotor for rotation about the axis;
• coils provided on stator poles in proportion to the number of poles, wound thereon and occupying the recess between adjacent stator poles;
• the rotor being rotated in a desired direction of motion by a reluctance torque generated between the rotor and the stator, the reluctance torque being generated by energizing a phase in a current controlled manner, the energizing concluding upon the rotation of the rotor through a minimum commutation angle required to maintain motion, de-energizing the phase by freewheeling the phase, a freewheeling current being maintained by energy stored in the phase, and energizing a second sequential phase, the steps of de-energizing the phase and energizing a second sequentially adjacent phase being performed substantially simultaneously.

A method of operating a switched reluctance (SR) machine supporting one or more phases distributed along the axis of rotation, each phase whereof comprising a hollow and substantially cylindrical stator having a plurality of inwardly extending stator poles positioned substantially equidistant from each other, two adjacent stator poles defining a recess therebetween;

• a substantially cylindrical rotor positioned in the stator and having a plurality of outwardly extending rotor poles formed on the outer surface thereof, each of the stator pole and the rotor pole subtending an angle having a value less than 0.5 electrical pole pitches at the center of rotation;
• a means for supporting the rotor for rotation about the axis;
• coils provided on stator poles in proportion to the number of the poles and wound thereon, the coils occupying the recess between adjacent stator poles;
• the method comprising the step of:
• rotating the rotor in a desired direction of motion by a reluctance torque generated between the rotor and the stator, the reluctance torque being generated by continuously and repeatedly performing the steps of:
• energizing a first phase in a current controlled manner for a first period of time, the first period of time being a time in which the rotor rotates through a minimum commutation angle required to maintain motion;
• de-energizing the phase by freewheeling the phase, a freewheeling current being maintained by energy stored in the phase;
• energizing a second sequential phase;
• the steps of de-energizing the phase and energizing a second sequential adjacent phase being performed substantially simultaneously.