Design and performance analysis of a switched reluctance motor for low duty cycle operation

A design methodology is presented for a low duty cycle switched reluctance (SR) motor. A low duty cycle motor can withstand higher current density, since winding temperature cannot rise instantaneously to the steady-state value due to the gradual heating of the thermal masses. The relationship between the current density and stack length can be utilized to reduce the stack length for intermittently operating motors. A lumped-parameter (LP) thermal model is used to predict the transient thermal behavior, which is necessary for the resizing of the motor. Finite-element analysis (FEA) and laboratory experiments are done to validate the proposed method.