A normalized least mean logarithmic square based control of SPV grid tied system

Abstract

This study proposes a grid-tied single phase single-stage solar photovoltaic (SPV) system. The standard voltage source converter (VSC) is used as the single-stage power converter. The proposed system consists of an SPV array, the VSC, the single-phase distribution grid and linear/nonlinear loads. The control algorithm includes a maximum power point tracking (MPPT) algorithm to draw the maximum available power from the solar photovoltaic (PV) array. The perturb and observe (P&O) MPPT algorithm is used. Aside from feeding power to the grid, the system mitigates harmonics and also provides power factor correction at the point of common coupling (PCC). The employed VSC control algorithm is the normalized least mean logarithmic square (NLMLS) algorithm. The total harmonic distortion (THD) of the grid supply current and the grid supply voltage at the PCC conform to the IEEE-519 standard. The performance of the system is studied experimentally under a variety of load and insolation conditions, on a prototype developed in the laboratory.