The Design and Optimization of Combined Rogowski Coil Based on Printed Circuit Board

Pongchit Saetang,Amnart Suksri,T Deaconescu,A Deaconescu

doi:10.1051/matecconf/20167010014

Abstract

Rogowski coil has been widely used for measurement of small magnitude with fast rise time signal such as partial discharge (PD), but Rogowski coil based on Printed circuit board (PCB Rogowski) has limitation for this application. This paper presents the prototype of Combined Rogowski coil that can overcome the drawback of PCB Rogowski coil. Experimental results showed that the proposed coil was able to measure a simulated of PD signal and its output signal indicated that the coil is suitable for a detection of small magnitude signal when compare with the other coils. The proposed Combined Rogowski coil in this research has upper frequency ( f h ) of 53.59 MHz and mutual inductance ( M )of 0.417 μH , while PCB Rogowski coil has f h of 22.48 MHz and M of 0.026 μH. The oscillation of signal output that caused by non-uniform winding also has diminished. The electrical parameters that affected the performance of coil were controlled by the geometric variables and optimized by multi-objective genetic algorithm to achieve the optimum design of coil.

Highlights

Rogowski coil is a toroidal coil wound on a nonmagnetic core form
We propose a Combined Rogowski coil which is quite similar to the PCB Rogowski coil but the Combined Rogowski coil uses copper wire as a half loop to be connected to the baseboard that has the imprint as half loop for a complete coil
Using a copper wire as a half loop makes the coil has low capacitance because core is an air instead of baseboard material which has a low value of permittivity. (As a result would improve the upper frequency of coil) Lastly, copper wire made coil’s cross-section larger than PCB Rogowski coil, which is a mean of improving the sensitivity of the coil

Summary

Introduction

The coil has been widely used for the detection and measurement of electric currents in many applications [1]. PCB Rogowski coil has a narrow bandwidth and very low sensitivity because inherent defect from its structure [3] meaning PCB Rogowski coil is not suitable for the detection of small and wide bandwidth signal such as partial discharge signal. The design coil was looking into an optimization of the bandwidth and sensitivity of the coil. It is sought by using genetic algorithm for multi-objective optimization technique. Rogowski coil works by sensing the magnetic field in space around the conductor, Ampere’s Law and Faraday’s Law provide the relationship between current in the conductor ݅௣(‫ )ݐ‬and output of Rogowski coil ܸ௖(‫)ݐ‬ as.

Rogowski coil principle

Experimental measurement

Optimization

Conclusion