Design of Optimal Integrator Control Algorithm for Single-Stage Grid Connected Solar Array System

Abstract

This paper presents an optimal integrator control algorithm for a three-phase single-stage grid connected solar array system for improving the power quality of the distribution system under variation of solar irradiance and unbalanced grid conditions. The P&O based maximum power point tracking (MPPT) technique is used to acquire maximum power from solar array under different environmental conditions. The load stabilization, harmonic mitigation unitpowerfactor operation and reactive power mitigation is also improved using the proposed control algorithm The optimal integrator control algorithm delivers DC offset rejection in Voltage Source Converter (VSC) input voltage and reduces voltage fluctuation in the DC link voltage under varying solar irradiance. In this proposed control scheme, the main aim is to extract positive sequence of per unit phase voltage values and also to function under unbalanced grid voltages and weak grid scenarios. The results of the MATLAB show the behaviour of the system under steady and dynamic situations such as unbalanced loading and changes in solar irradiation. It is analysed from the results that the THD of source current and voltage as defined in IEEE 519 standards are achieved.