IMPACT OF SOLAR POWER PLANTS ON THE POWER QUALITY OF THE DISTRIBUTION NETWORK

Abstract

The development of the solar energy network provides an opportunity for photovoltaic energy to connect to national distribution networks. This important technology optimizes the balance of electricity supply, increases the cost-effectiveness of the photovoltaic system, reduces operating costs and provides added value to the consumer and the distribution network operator. The increasing share of renewable energy that needs to be integrated into electricity systems causes engineering challenges, such as changes in electricity quality, capacity limitations, safety measures, synchronization processes, system inertia, etc. In this work, the quality of electricity in a 0.4 kV distribution network with integrated solar power plants was studied. A 409 m long 0.4 kV overhead line was selected for the study, to which 35 electricity consumers and 8 solar power plants are connected. The permissible usable power of the electricity consumers connected to the line is 305 kW, and the permissible generating power of the solar power plants is 72 kW. This study determined voltage deviations at the input of consumers as the loads on the line and the power generated by solar power plants varied. The paper presents an analysis of changes in the consumption and generation of electricity and voltage deviations of consumers connected to the line under study for one week. During the week, generating consumers supplied 6919 kWh to the operator's networks, of which they consumed about 3553 kWh of electricity. Voltage deviations at the transformer station during the study period were small. The most significant change in phase voltages was observed during the day, when the power generated by generating consumers was at its highest. The asymmetry of phase voltages at the input of the transformer station and the generating consumer is almost independent of the solar power plant's operating schedule.