DSP based random discontinuous space vector PWM for variable speed electrical drives

Space Vector Modulation (SVM) approaches that decrease current ripples and switching losses of voltage source inverters for automotive applications and their DSP implementation are presented in this paper. To improve the quality of the energy delivered by the voltage source inverter (VSI), we combine two modulation strategies; Random Space Vector Modulation (RSVM) and Discontinuous Space Vector Modulation (DSVM). Randomisation is achieved by varying the switching frequency randomly from one switching interval to another, discontinuities are introduced by clamping the inverter´s leg either to the positive or negative rail with the capacity to auto-adjust to the load characteristics with a Scalable DSVM (SDSVM). This ensure the reduction of switching losses and the effective switching frequency of the inverters. These algorithms are successfully implemented on the TMS320F28335 DSP platform for two levels voltage source inverter feeding a permanent magnet synchronous motor (PMSM) and experimental results are presented.