Speed sliding control of PMSM drives

The current controlled voltage source inverter fed PMSM has received wide spread interest in high performance vector control and motion control applications. Hysteresis controllers are intrinsically robust to system parameters, exhibit very high dynamics and are suitable for simple implementation. The main drawback of the hysteresis controller is a limited control on switching frequency. Very high switching frequency may be resulted from the use of three independent controllers. In this paper, both the fixed band and the sinusoidal band current controllers are presented and their performances evaluated. In addition, a mixed mode controller of a sinusoidal band added to a fixed band is proposed. For comparison purposes, the harmonics spectra of the phase currents are obtained using the fast Fourier transformer (FFT). This paper presents also a detailed analysis and simulation of speed sliding mode control (SMC). The effectiveness is demonstrated for different operating conditions.