A DC-DC converter with high-voltage step-up ratio and reduced-voltage stress for renewable energy generation systems

Abstract

This research work presents a high gain direct current-direct current (DC-DC) converter which is derived from a traditional boost converter. Electrical power systems are changing from a centralized generation model to a hybrid model with distributed generation. Distributed renewable energy sources such as photovoltaic (PV) modules, wind and fuel cells are becoming possible alternatives. However, to connect these systems to the grid, reliable DC-DC boost converters with high voltage gain is becoming a requirement. Firstly, a new open-loop DC-DC boost converter with superior performance in terms of voltage step-up ratio and reduced voltage stress on the switches, compared to other existing high gain DC-DC boost converter counterparts is proposed. Along with analyzing the operation principle of the proposed converter, design procedure and component selection procedures are presented in this report. Experimental results along with simulation results are provided to validate the fundamentals of the open-loop proposed converter. This converter can easily achieve a gain of 20 while benefiting from the continuous input current. Secondly, to effectively maintain the voltage output at the required level, closed loop dc-dc converter with Proportional-Integral-Differential (PID) controller was proposed and simulated. Thirdly a multi-loop with Proportional-Integral (PI) was proposed and simulated. Later, a charge controller was designed and operated along with closed loop dc-dc converter to supply load with two different voltage requirements. Simulation results are presented and analyzed to validate the theoretical results of the closed loop converter. Based on the simulation results the proposed controller can maintain the output voltage at the required level with respect to the changes in load.