Overvoltage Challenges & Solutions in Solar PV-Enriched Power Distribution Networks

The rapid adoption of distributed solar photovoltaic (PV) generation, particularly rooftop solar, is transforming traditional-unidirectional power distribution networks into bidirectional systems. While this transition supports India’s renewable energy targets and decarbonisation goals, it has also introduced critical power quality challenges, notably overvoltage (OV) events. High rooftop PV penetration in low-tension (LT) networks, especially during periods of low load and peak-solar generation, often results in voltage rise at distribution transformer (DT) tail-ends, leading to equipment stress, power-losses, and potential consumer complaints. This paper presents a comprehensive study of overvoltage phenomena-in solar PV-enriched distribution networks, using real case studies from GUVNL (Gujarat, India), and analyses foreign studies from countries with high PV penetration like Germany, Australia, and the USA. It identifies root causes, evaluates-existing mitigation practices, and proposes multi-level solutions—from consumer and LT line interventions to feeder, transformer, and substation-level enhancements.