Faults and unbalance forces in the switched reluctance machine

The author identifies and analyzes a number of severe fault conditions that can arise in the switched reluctance machine from the electrical and mechanical points of view. It is shown how the currents, torques, and forces may be estimated, and examples are included showing the possibility of large lateral forces on the rotor. The methods used for analysis include finite element analysis, magnetic circuit models, and experiments on a small machine specially modified for the measurement of forces and magnetization characteristics when the rotor is off-centered. The author also describes a computer program (PC-SRD Dynamic) which is used for simulating operation under fault, as well as normal, conditions. The author discusses various electrical configurations of windings and controller circuits, along with methods of fault detection and protective relaying