DESIGN OF FLYBACK MICRO-INVERTER FOR GRID CONNECTED PHOTOVOLTAIC SYSTEMS

The flyback micro-inverters operating at discontinuous conduction mode are very attractive due to the operation in open loop and working without current sensor. in this paper, the working characteristics of a grid-connected photovoltaic micro-inverter based on flyback converter are investigated and design details are presented. “perturbation and observation” method is used for maximum power point tracking. a micro-inverter prototype of 80 wp is designed and produced. all the inverter functions, such as maximum power point tracking, islanding protection, serial communication, power control etc., are implemented by pic24fj64ga002 microcontroller. the measurements taken from protyped micro-inverter are compatible with design values. the highest efficiency of the converter was found as 80% and the loss mechanisms are discussed.