Estimation of Influence of External Magnetic Field on New Technology Current-to-Voltage Transducers Operating in Protection System of AC Power Networks

High accuracy is required from devices operating in the measuring and protection systems of transmission lines during the transformation of signals. Their immunity to external fields is very important because it has a direct influence on the proper functioning of the protection system. In this paper, the electromagnetic current-to-voltage transducers, with coils designed and manufactured using a multilayer high-density interconnect printed-circuit board technology, are presented. The analysis of the influence of the external magnetic field caused by other devices on the proper functioning of the current-to-voltage transducer has been presented. The analysis of the electromagnetic-field distributions has been carried out using the 3-D field-circuit method based on the finite-element numerical method. The magnetic-field distributions and the induced secondary voltages for several different applications have been presented. The results have been compared with tests of real-life models.