Power quality analysis of low voltage grid-tied network with PV system

Abstract

Power quality analysis (PQA) in power systems has become important to consider since there has been an increase in distributed energy resources installed on the existing grid, particularly in the area of renewable energy generation. South Africa is primarily depending on generating electricity from fossil fuel, as a result, the shortage of fossil fuel in the country has influenced the increase in electricity tariff. On the other hand, market price for installing photovoltaic (PV) system is decreasing, hence low voltage (LV) customers are beginning to utilise the advantage. Concerns have been raised about the power quality of grid-tied PV system because PV systems incorporate devices such as inverters for power conversion. Inverters have been regarded as a possible source of power quality problems according to many previous studies published. PQA of a low voltage South African network connected with PV system will be addressed in the paper. This paper analyses the level of harmonic distortions measured in the low voltage grid network the presence of PV system and compares the measured Total Harmonics Distortion on current (THDI) with the NRS 097 standard to verify if the network with PV system meets the requirements.