Closed Loop Residential Photovoltaic Power System with Soft-Switching Push-Pull Front-End Converter

Abstract

Renewable energy has experienced impressive growth over the past decade due to the fast depletion of fossil fuels, concern of energy security and green gas emission. Hence nowadays Photovoltaic (PV) cells play an important role in residential power system.  In this paper, a novel soft-switching current-fed push-pull front-end converter with closed loop control is proposed. Push-pull converter has only two primary devices with common ground to supply and results in simple and reduced gating requirement. The device voltage is clamped naturally by secondary modulation without active clamping circuit or passive snubbers. Closed loop control is provided using PID controller which provides the gating signal to the switches. Hence provide a constant output voltage even if there is a variation in the source voltage. The proposed system is suitable for PV based power systems which provide a constant output voltage, maximum power transfer capacity and high efficiency. A 250W prototype of the converter has been built, and simulation results are provided to verify the theoretical analysis. Open loop and closed loop controlled photovoltaic power system with soft-switching push-pull front-end converter systems are modeled and simulated. The results of open loop and closed loop systems are presented and also analysed for different input voltages