Grid connected photovoltaic system with data-based MPPT and fuzzy controlled DVR

This paper presents the impact of a fuzzy logic controlled dynamic voltage restorer on a transformer-less single-stage grid-connected solar photovoltaic system controlled by a data based maximum power point tracking technique. The solar photovoltaic system uses a data based maximum power point technique to derive maximum power from solar photovoltaic array and maintains constant DC voltage by changing modulation index of voltage source converter. A dynamic voltage restorer with pulse width modulated control is introduced to mitigate unbalanced sag in grid voltage and current during fault conditions. Fuzzy logic control (FLC) has been implemented to maintain voltage at grid side for normal as well as for faulted conditions. Simulation results show that distortion in active and reactive power exchange among solar photovoltaic converter, load and grid is reduced during fault conditions. A reduction in total harmonic distortion for all temperature conditions, low and high solar radiation is observed in grid voltage and current. Apart from these, it has been observed that distortion in DC link voltage while deriving maximum power from photovoltaic array is considerably reduced by introducing fuzzy logic controlled dynamic voltage restorer in proposed system.