Comparative Study of Power Losses in Single and Parallel High-Power Photovoltaic Inverter Systems

In this paper, a comparative study of power losses in single and parallel photovoltaic inverter systems is presented. The voltage source inverters (VSI) use power semiconductor as a switch. The insulated-gate bipolar transistor (IGBT) is the most used. These semiconductor devices generate significant power losses thus reducing the efficiency in high-power grid-connected photovoltaic (PV) systems. In this case, paralleling several PV inverters to share the load could improve the efficiency of the system. Using the polynomial approximation method, the losses in the IGBT module have been calculated. A theoretical comparative study in terms of power losses is first carried out and then, it would be validated by simulation using Matlab / Simulink software. The results show that, the parallel inverter structure in high power PV systems improves the efficiency of the system by reducing the power losses generated by the IGBT modules.