Abstract
Due to environmental impacts of traditional energy production, the integration of renewable energy in high volume has become more favorable. A series of analytical studies are required prior to integration of windfarms into the transmission system. For instance, equipment sizing and high voltage analysis are some of the crucial assessments. Equipment sizing in high voltage substation is done considering Transient Over Voltage (TOV) quantity that any device may tolerate due to experiencing surge and/or switching. The high elevation levels that windfarms are installed, make them more susceptible to TOVs related to lightning strikes. This paper focuses on sizing the required protecting devices in a windfarm interconnected to transmission system through a high voltage substation. The study methodology is suitable for fast transient analysis such as lightning analysis.