Current ripple minimisation in switched reluctance (SR) machines for aerospace applications

This paper discusses a strategy for tailoring the individual phase current waveforms within an SRM to facilitate the internal circulation of reactive power and significantly reduce the capacitance requirements. There are many converter topologies that could be used for achieving this, but the key to its realisation is the need for the phases to draw constant current. Given the complexity and non-linearity of SR machines, achieving this optimised objective is far from trivial. The methodology described involves the optimisation of the current waveform to meet this constant current objective whilst maximising torque, minimising resistive losses and meeting constraints on achievable dynamic performance. Quantitative comparisons in terms of torque capability are drawn with optimised current waveforms.