PROJECT TITLE :

Modulation With Sinusoidal Third-Harmonic Injection for Active Split DC-Bus Four-Leg Inverters

ABSTRACT:

Three-part four-leg inverters are commonly employed to produce unbalanced hundreds avoiding the utilization of a transformer. A appropriate output filter is necessary to boost the harmonic content of the output voltage and current waveforms. To the current aim, completely different reasonably filters, presenting each symmetrical and asymmetrical section-to-section and part-to-neutral behavior, will be used. The paper discusses and analyzes the consequences of different carrier-based modulation techniques, primarily based on the freelance control of the fourth leg from that of the opposite phases, with regards to the various filter topologies. The comparison, performed through extensive simulations and experimental tests, have demonstrated that in case of the asymmetrical filter utilization, like the active split dc-bus (also referred to as split-link), the standard continuous and discontinuous space-vector modulations manufacture a significant harmonic content within the output voltages even at no-load condition. Moreover, the analysis is extended considering the interaction between the modulation strategy and load characteristics as linear, nonlinear, balanced and unbalanced loads. The matter is discussed intimately and a selected style procedure for the active split dc-bus is presented.