Comprehensive Analysis of Different Space Vector PWM Techniques for the Speed Control of Two-Level Traction Inverter

The popular methods to generate PWM (Pulse width modulation) are triangle comparison method and space vector method. The work evaluates the performance of continuous and discontinuous space vector pulse width modulation techniques based on the switching losses and harmonic distortion. The flexibility in the placement of null vectors and active vectors gives generality in SVPWM (Space Vector PWM) techniques. Continuous SVPWM employs the conventional switching sequences which are equally divided the null vectors and active vectors. Discontinuous PWM are derived based on the different combinations of null and active switching vectors. The discontinuous PWM techniques clamps each phase for either 300 or 600 in each half cycle. Majority of the discontinuous SVPWM uses any one of the null vectors and effectively to reduce the average switching loss in a cycle and the total harmonic distortion.The study brings out the optimum SVPWM sequences for the control of PMSM(PERMENANT MAGNET SYNCHRONOUS MACHINE). Influence of the switching sequences on the line current distortion is investigated. The performance of inverter based on switching loss and harmonic distortion are studied based on the switching frequency of the inverter over the linear modulation range. The results are analyzed using MATLAB/SIMULINK environment.