Robust control of high-speed synchronous reluctance machines

High-speed regimes allow to increase the power density of electrical drives, which is a necessary characteristic in aeronautical applications. In such a context, together with the typical non-linearity of low speed drives, such as core saturation, phenomena related to high fundamental to sampling frequency ratios appear increasingly significant. This paper applies methodologies based on modern robust control to high-speed synchronous reluctance machines. The proposed method is based on a reformulation of the motor model as a linear parameter varying system. This allows transforming the current controller design in a multivariable optimization problem, which is solved with efficient numeric tools. Two digital controllers are developed, one designed in the continuous time domain and discretized for the implementation, and another directly designed in discrete time domain. Their performances are compared with standard decoupled current control using PI regulators. Both numerical simulations and experiments on a laboratory bench are presented.