A Novel Low-Cost Smart Current Sensor for Utility Conductors

Grid-wide monitoring of utility assets is essential for maintaining a healthy and reliable power grid. Electric current is an important parameter for grid monitoring. Expensive and large current sensors that require field calibration inhibit utilities from implementing an intelligent monitoring infrastructure. This paper introduces a novel technique and algorithm for current sensing using small, low-cost “stick-on” current sensors that do not require clamping around the utility conductor. Thus, the proposed sensor can be used for monitoring many different utility conductors (not just overhead-conductors). The challenge pertaining to error in current measurement due to the presence of other current carrying assets in proximity has been tackled. The new current sensing technique is shown to discriminate far magnetic fields from the near-field of interest; eliminate expensive calibration requirements for the sensor, and provide accurate current measurements in a noisy magnetic field environment. Simulation and experimental results are presented to validate the proposed concept. The proposed technique for current sensing promises development of low-cost smart sensors that will be an integral part of the future smart grid.