Voronoi Multi-Phase Predictive Current Control With Variable Application Times

Predictive Stator Current Control (PSCC) is a flexible technique for drives of different types. For the multi-phase case, PSCC must deal with an increased number of available control options (the voltage vectors) and cope with the different current spaces: torque producing (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\alpha -\beta$</tex-math></inline-formula>) and harmonic planes (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$x-y$</tex-math></inline-formula>). In this paper, a Voronoi region based scheme is designed to cope with both issues while maintaining an affordable commutation frequency. The proposal is enhanced by using variable application times with fine resolution. The method is compared with state of the art dead-beat multi-vector approach. The comparison is made using a real, laboratory setup designed for experimentation based on a five-phase induction machine. The comparison shows enhanced control results together with a reduction in harmonic content, without compromising the switching frequency limits of the power converters and maintaining flexibility due to the cost function.