Efficient torque ripple minimization for variable reluctance motors

Addresses the design of current waveforms that minimize torque ripples in variable reluctance (VR) motors at low excitation levels. The general problem of torque ripple reduction has been investigated before by several researchers, but the approach presented here exploits magnetic linearity to derive an efficient excitation that is much easier to calculate. A nonlinear optimal design problem is developed and then converted to a linear representation by a simple transformation. The transformed linear optimization problem is straightforwardly solved by standard numerical methods, and yields the optimal current waveform in a transformed variable. Finally, the optimal current waveform is found by applying an inverse transformation. The analytical result presented in this paper is supplemented by a design example