یک ساختار جدید برای بهبود بازدهی اینورترهای متصل‌شده به شبکه فتوولتائیک بدون ترانسفورماتور

Transformerless topologies are widely preferred to use in the grid connected photovoltaic (PV) generation system due to higher efficiency, lower cost and lower weight in comparison with other topologies employing transformer. In this paper, switching losses is minimized by incorporating Zero Voltage Switching (ZVS) in a full-bridge topology, at switch turn-on and an adaptive Variable dead-time Control at switch turn-off. To reach this aim, a full-bridge inverter is presented in detail by considering the effect of capacitors connected to switches on the efficiency. Furthermore, the system efficiency is significantly improved byzero voltage switching and stabilize input voltage by capacitor. Under this circumstance, inverter can be physically smaller with higher efficiency due to the low inverter switching frequency. To provide more investigation, the proposed topology is also compared with other transformerless topologies from frequency point of view. Simulation results show the effectiveness of the proposed topology under soft-switching condition