New space vector control approach for four switch three phase inverter under DC - link voltage ripple

This paper is to present a new space vector PWM algorithm for four- switch three-phase inverters (FSTPI) under DC-link voltage imbalance in Photovoltaic or Fuel cell - inverter technology. By using reasonable mathematical transform, Space Vector PWM technique for FSTPI under DC-link voltage imbalance or ripples have been solved, which is based on the establishment of basic space vectors and modulation technique in similarity with six-switch three-phase inverters. This approach has a very important sense to solve hard problems for FSTPI under DC-link voltage imbalance, for example ensuring the required referenced voltage for undermodulation mode and overmodulation mode 1, 2 to six-step mode. 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 DSP TMS320LF2407a.