Hybrid distance protection relay with rotating magnetic field

The paper presents a new hybrid distance protective relay based on single-phase transformers with rotating magnetic field for distribution system applications. Both theoretical aspects and a method for the practical implementation of the distance protection element with predetermined impedance operating characteristic is shown. The paper also provides recommendations for the choice of its parameters to obtain the desired characteristics for the distance relay operation implemented as a circle in the complex plane. An experimental prototype distance relay based on converters with rotating magnetic field has been created and the laboratory tests confirmed adequate performance compared to commercial state-of-the-art technology.