A New Nonisolated High-Step-Up DC-DC Converter Topology with High Voltage Gain Using Voltage Multiplier Cell Circuit for Solar Photovoltaic System Applications

摘要

The solar photovoltaic (PV) source is preferred to be functioned at low voltages. The practical systems such as grid-tied systems require a high output voltage causing a reduction in conversion efficiency. To handle this problem, this paper presents a new nonisolated boost DC-DC converter with a single switch suitable for solar PV applications. This converter comprises dual voltage multiplier (VM) cells, leakage energy recovery scheme, and coupled inductor (CI) techniques to get the desired output voltage from the converter. The double-clamp capacitors are connected to the primary side of the CI. The clamp capacitors can share the current through CI, and it ensures that the leakage inductance energy of CI can be recovered, leading to an expansion in the converter voltage gain and conversion efficiency. In addition, the clamp circuit clamps the voltage stress of the MOSFET switch, and the clamp capacitors will discharge at a specific time to increase the converter gain. A high duty cycle is not necessary for getting a high voltage gain, which avoids the diode reverse recovery issues. The converter can be operated in both continuous conduction mode (CCM) and discontinuous conduction mode (DCM). A 500-W experimental prototype is developed for experimental validation, and the supporting simulation results are presented. The maximum efficiency of the converter is 93.94%, and, at full load, the efficiency is 92.55%.