A Proposed Non-Invasive Rogowski Coil Design for Measuring 3-Phase Currents Through a 3-Core Cable

In this article, a proposed non-invasive design of Rogowski coil to measure 3-phase currents through a 3-core cable is presented. Considering this design, there is no need to remove the insulation layers of a 3-core cable to measure its core currents. The adopted Rogowski coil design uses three separate coils wound at the same circular non-magnetic core with equal spacing between them. When the Rogowski coil is fitted around a 3-core cable, EMF is induced in each coil. The three induced EMFs are used to reconstruct the current passes through each cable core using a proposed current reconstruction technique. In order to validate the presented Rogowski coil design as well as the current reconstruction technique, theoretical verification is carried out using Power Simulation Program (PSIM) software. Hence, a 3-phase source feeds a 3-phase load is simulated. Also, simulation of the designed Rogowski coil as well as the adopted current reconstruction technique is carried out. The obtained theoretical results prove the accurate measurements of the Rogowski coil design and the introduced current reconstruction technique. For more validation, the Rogowski coil design is experimentally implemented. The implemented Rogowski coil is fitted around a 3-core cable that feeds a 3-phase load from a 3-phase source. The current reconstruction technique is implemented using a digital signal processing (DSP) board. The obtained experimental results give another evidence for the validity and efficacy of the proposed Rogowski coil design as well as the current reconstruction technique.