A combined current voltage sensor for metering and protection in high voltage power systems

This paper describes a patented Poynting-vector transducer for the simultaneous measurement of both current and voltage in a high voltage power system. It also describes its application for protective relaying, high voltage metering, and measurement of losses in large transformers and shunt reactors. The principle of operation is based on the measurement of the Poynting vector from its constituent electric and magnetic fields in a very well-defined region of space around the high voltage conductor. The signals from the current and voltage sensors are processed by simple electronic circuits to bring them to the form and level required by the computers, meters, and relays. The new transducer is also ideally suitable for integration as a module in gas-insulated busbar duct system