Abstract: A sensor and associated circuits are provided for on-line monitoring of the state of the high-voltage insulation in electrical equipment with capacitance tap. In this arrangement, both the power frequency signal and the radio frequency signals associated with partial discharge activity are sensed. These signals are transmitted from the sensor to remote monitoring instrumentation via one connecting cable. The sensor contains a surge arrester in parallel with a capacitor shunt, a radio frequency current transformer and a connecting circuit. The polarity terminal of the primary winding of the radio frequency current transformer is connected to the tap output. The non-polarity terminal is connected to the common connection point of the surge arrester and the capacitor shunt while the second terminals of these components are connected to the local ground.

Abstract: A sensor and associated circuits are provided for on-line monitoring of the state of the high-voltage insulation in electrical equipment with capacitance tap. In this arrangement, both the power frequency signal and the radio frequency signals associated with partial discharge activity are sensed. These signals are transmitted from the sensor to remote monitoring instrumentation via one connecting cable. The sensor contains a surge arrester in parallel with a capacitor shunt, a radio frequency current transformer and a connecting circuit. The polarity terminal of the primary winding of the radio frequency current transformer is connected to the tap output. The non-polarity terminal is connected to the common connection point of the surge arrester and the capacitor shunt while the second terminals of these components are connected to the local ground.