A Review of Voltage Stability Issues in Distribution System Influenced by High PV Penetration and Its Mitigation Techniques

Abstract

The installation of the photovoltaic system across the world is dramatically increasing to meet the increase in electrical energy demand. But the higher penetration of PV will lead to severe impacts on the distribution system such as instability in power balancing, over-voltage, under-voltage, etc. Voltage fluctuations may cause recurrent disturbances in voltage-controlled devices connected to the feeder which will reduce their estimated lifetimes and necessitate more maintenance. Typically, voltage stability is achieved using conventional and emerging mitigation technologies. The inconsistent nature of the output with SPV power generation systems, which is brought on by changes in their input sources, such as solar intensity and extensive use of electric vehicles along with solar power plants has an adverse influence on the grid's reliability. It is necessary to understand and investigate the stability aspects of the distribution system and provide necessary control mechanisms. This paper provides two field studies for the purpose of understanding the voltage stability issues in the distribution system due to high penetration of SPV generation and EVs. A field study on variation in PV power generation was carried out at a 10 kWp solar power plant in Umayanalloor, Kollam, Kerala, and a study on the charging pattern of a TATA Nexon EV car having a 30-kWh power bank from the same 10 kWp PV plant at Umayanallor, Kollam. This paper attempts to provide a comprehensive survey of related literatures, giving emphasis on the high penetration of SPV generation and EVs in the distribution systems, their effects, and suitable mitigating techniques.