Development of low cost, efficient residential utility interface for modular PV system with improved power quality

This paper presents a high performance residential utility interface for photovoltaic (PV) system with DSP based control. The system is designed to realize high utilization efficiency and stability. The utilization efficiency is improved by using a new MPPT algorithm namely, three-point weight comparison method with dP/dD control. The overall efficiency is improved by using soft switching converters. The output power quality is improved by using unipolar sinusoidal pulse width modulation (SPWM) switching strategy. It reduces total harmonic distortion (THD) at the output and thereby improves the power quality. A 1Φ, 230 V, 200 W system was designed and implemented on a low cost DSP (TMS320C240). Maximum power point (MPP) tracking efficiency of 98% and THD of around 6% under full load conditions was achieved. The effectiveness of the proposed system has been confirmed by experimental results. Due to its simplified power stage and control stage, this system presents a better efficiency, lower cost and high reliability.