Global MPPT of grid connected solar PV inverter under partially shaded condition

Abstract

The power generated by a solar photovoltaic (SPV) system depends upon the solar radiation level and cell temperature. A suitable maximum power point tracking (MPPT) algorithm is required to extract the maximum power from the SPV. However at a partial shading condition (PSC) the conventional MPPT techniques may lead to the operation at a local maximum power point (LMPP) instead of global maximum power point (GMPP). This paper used a GMPPT algorithm to extract maximum power from the solar PV system, and a DC/AC inverter is used to convert extracted solar DC power into AC power to inject into the grid. A three-leg intelligent power module (IPM) is used for implementation of both DC-DC converter and DC-AC inverter. A hysteresis current control (HCC) is used to track the inverter current. All the simulation studies have been done using PSCAD (4.5.1 ver.) simulation software. An experimental setup is developed which consists of IPM, capable of MPPT with DC/DC converter and generates AC output using DC/AC inverter. A solar array simulator (E4260A) is used for laboratory generation of the solar power. In this paper FPGA controller has been used to implement the GMPPT and HCC algorithms using LabVIEW platform.