New Space Vector Control Approach for Four Switch Three Phase Inverter (FSTPI)

This paper is to present a space vector PWM algorithm for four switch three phase inverters (B4, FSTPI) based on the one for six switch three phase inverters (B6, SSTPI) (principle of similarity) where the alphabeta plan is divided into 6 sectors and the formation of the required reference voltage space vector is done in the same way as for B6 by using effective (mean) vectors. This facilitates the calculation for B4 and some studies on B6 can be applied for B4 as well through this proposed similarity, e.g. the problem with PWM in the overmodulation zone due to the complicated non-linear character there. Matlab/ Simulink is used for the simulation of the proposed SVPWM algorithm for undermodulation, overmodulation mode 1 and 2. This SVPWM approach is also validated experimentally using control board TMS eZDSP2812 (Texas Instrument Co.).