A Novel Non-Intrusive Self-Powered Current Sensor With Time-Division Operation

With the development of power electronics converters in power grid, real-time current monitoring, covering both AC current and high frequency harmonics, is important. Non-intrusive current sensing has become a promising solution due to its advantages of portable installation and non-interference with equipment operation. However, current sensors rely on external power supplies, limiting their large-scale application. Non-intrusive, compact and self-powered current sensor becomes a future trend for flexible sensor deployment within the constrained space of power converters. The principle of electromagnetic induction can be employed both for current sensing and energy harvesting. This article proposes a novel dual-coil-single-magnetic core module to realize a self-powered non-intrusive current sensor. Due to different energy and bandwidth requirements for energy harvesting and signal sensing, dual coils with time-division operation strategy are adopted. The designed prototype achieved an output power of 8.18mW under magnetic field of 50Hz/300μT. Wideband current sensing is verified from 50Hz to 500kHz with sensitivity of 0.996mV/A, which is comparable with commercial product. The proposed dual-coil-single-magnetic core module achieves self-powering and wideband current sensing in non-intrusive applications.