Impacts of distributed generators on utility grid — An experimental and simulation analysis

This paper investigates the impacts of distributed generator such as solar PV and energy storage on the utility grid. Initially experiment was conducted by increasing PV penetration into the grid and analysed the voltage fluctuation at PCC and harmonic emission on the network. Later, a software model was developed and same impacts were investigated with increased penetration of solar PV. The model was further extended and energy storage was integrated into the network to investigate the voltage fluctuation and harmonic emission in the network. From both experimental investigation and model simulation (load flow and load profile analysis), it was found that, increased PV penetration increases node voltage and harmonic current in the network. Energy storage improves voltage fluctuation by supporting load demand and storing excess energy from PV but storage adds additional harmonic current into the network. By minimizing fluctuating power in the network due to the fluctuating nature of PV output, energy storage improves the loading condition of the distribution transformer which eventually improves the capacity of the distribution transformer. Thus this investigation provides the strategic information of the impacts due to the integration of distributed generators in the utility grid.