Electric Field Immunity Test on Epoxy-Resin Capacitive Voltage Sensor in Smart Bushing

With the development of Smart Grids, unconventional voltage transformers known as Low Power are being widely deployed in medium voltage power networks for measurement and protection functions. Low power voltage transformers, referred to as voltage sensors, are prone to the parasitic coupling of electric fields which may disturb the voltage measurement. In this work, an electrical equivalent model of the voltage sensor embedded in Smart Bushing is suggested for estimating the immunity versus electric fields present in Gas Insulated Switchgears. In addition, a setup is designed to test the immunity under different scenarios.