Sensorless control of five-phase induction machine supplied by the VSI with output filter

In this paper, a novel sensorless control structure based on multi-scalar variables is proposed. The static feedback control law is obtained by using the multi-scalar variables transformation, where the multi-scalar variables approach allows a full linearization of the nonlinear system. The control system could be described as “optimized” because of the minimized number of controllers. Furthermore, control system is divided into two independent control systems which are synchronized by additional controllers. The first control system is responsible for the generation of the 1st fundamental harmonic, while the second control system is responsible for the generation of the 3rd harmonic. Both control systems are synchronized and ensure a trapezoidal shape of air gap induction waveform regardless of the machine operation point. In order to ensure a sensorless control system the rotor angular speed and the state variables are estimated by a speed observer. This speed observer is based on the backstepping approach. All analytical proposed assumptions are confirmed by simulations and experimental results.