Study on Surge Voltage Mitigation of Evolving Close-in Fault in HV Substations

Voltage surges are sudden and short-term increases in voltage that can potentially damage electrical equipment, cause data loss, or disrupt operation. Surge voltage mitigation is crucial for the reliability of power systems and the protection of sensitive electronic equipment. By implementing effective surge protection strategies, power system operators can minimize the risk of damage and improve the overall stability of the electrical infrastructure. In this paper, the surge voltage caused by an evolving close-in fault in the 20 kV busbar of a sub transmission station is investigated. According to the results of the measurements made by recorders at the location of the substation, the reason for happening of the incident is elaborated. Using a simulation by PowerFactory software (DIgSILENT/2022 version), the occurred disturbances and relevant cases are investigated. Focusing on the role of shunt capacitor banks, the necessary solutions to mitigate the surge voltage are presented and their effectiveness are analyzed with the help of simulation.

Close-in Fault, Evolving Fault, Opening Surge, Damper Resistance, Snubber Filter, Surge Suppressing Technique