A PV interface system based on high-gain high-frequency link converter

Abstract

this paper presents a PV interface system based on an isolated high-gain high-frequency dc/dc converter. The PV array is connected to a square pulse high-frequency H-bridge. The Pulse Width (PW) of the output square voltage from the H-bridge inverter is controlled to extract the maximum power from the PV array using any of the Maximum Power Point Tracking (MPPT) schemes. The output of the H-bridge inverter is connected to the primary winding of a multi-secondary high-frequency transformer where each secondary winding is connected to a bridge rectifier. The bridge rectifiers are connected in series to boost the output dc-link voltage which is interfaced with the grid using a Voltage Source Inverter (VSI). During normal operating conditions, the VSI is controlled to regulate the dc-link voltage to transfer the harvested maximum power from the PV array to the grid at unity power factor. Moreover, the paper presents a Low Voltage Ride Through (LVRT) controller to meet the grid-code requirements and simultaneously protecting the proposed interface system from overvoltage. Simulation results based on PSCAD/EMTDC software are provided to assess the proposed PV interface system during different modes of operations.