The optimized adaptive space vector pulse width modulation for four switch three phase inverter under DC - link voltage ripple condition

This paper proposes a new space vector PWM technique for four-switch three-phase inverters (FSTPI) under DC-link voltage ripple condition with the optimization of the amplitude of first harmonic output voltage. The proposed algorithm is based on the establishment of quasi-space-vectors with their maximum length and modulation technique, which is simulated the technique for six-switch three-phase inverters. This approach has a very important sense to solve these problems for FSTPI under DC-link voltage ripple conditions, for example ensuring the required voltage for under modulation mode and over modulation mode 1 and 2, extended to six-step mode with the possibility of increasing the modulation index. The compensated technique also allows reduce the size of DC-link capacitors and the cost of the inverter. Matlab/Simulink is used for the simulation of the proposed dynamic SVPWM algorithm under DC-link voltage unbalance condition. This modified SVPWM technique is also implemented using DSP TMS320LF2407a. The effectiveness of this optimized adaptive SVPWM method and the output quality of the inverter are verified.