Efficient solution of the DC-link hard switching inverter of the PV system

Abstract

Soft switching inverter alleviate and treat the negative impacts resulted from hard switching inverter. It provides many advantages such as low power losses, high efficiency, stress reduction during switching instants, and high reliability and lowering EMI generation. Soft switching is achieved in this paper by adding the LC resonant circuit to the voltage source inverters (VSI). This is the first time to achieve soft switching with the photovoltaic (PV) system. To demonstrate the effectiveness of this technique, the simulation of the PV system is using both switching techniques; the resonant dc-link soft switching inverter and the conventional hard switching inverter; is introduced, analyzed and compared. The total resonant dc-link soft switching losses are reduced dramatically to the half of the total hard switching losses in case of not using soft switching. To validate our work, the detailed comparisons between the proposed topology with another famous one is introduced, analyzed and evaluated. In addition, the resonant dc-link soft switching losses and the hard switching losses of the inverter are estimated. The total resonant dc-link soft switching losses and the total hard switching losses are calculated under similar operating conditions and the conduction losses are kept constant in both switching modes. The simulation results prove the superiority performance of the PV system based on the proposed resonant dc-link soft switching mode compared to the other ones based on the conventional hard switching mode and single transistor resonant dc-link soft switching inverter.