Remote current sensing on overhead power lines

Power utilities are challenged on several fronts. They have to achieve higher levels of performance, in terms of supply quality and reliability. They have to do so with fewer resources, particularly staff. They have to accommodate more complex connections to the networks, in terms of distributed generators, modern industrial plants, etc. There is a significant movement towards network automation to address these challenges. The major variable in network operation is the current flowing in the networks. The most exposed and problematic network element tends to be the long MV overhead lines. It is difficult to monitor currents in these networks at present due to the difficulty and expense of installing conventional sensors e.g. MV CTs. This paper describes an innovative new technology for sensing currents in medium (MV) and high (HV) voltage power lines at a safe distance from the wires. It is based on measuring magnetic fields of the conductors. Instrumentation can be installed outside the high voltage ´hot zone´ around the wires, e.g. half way up a pole. It measures the current in each individual conductor in real time, like a set of current transformers (CTs), and can feed this information to a range of backend data processing applications. This technology addresses this problem. Electronic instruments to monitor or analyse current behaviour can be installed easily without outages, live working crews, etc. The technique is independent of voltage and can be applied to any type of overhead line. It can of course be used on low voltage (LV) lines, but the needs here are less compelling