Research on magnetic balance differential protection based on single-core phase-shifting transformer

As an efficient method for managing power flow, phase-shifting transformers have gained widespread applications in the operation of power systems. The protection of phase-shifting transformers is crucial. This paper focuses on the research of a 35kV single-core symmetric phase shifting transformer in a demonstration project. Utilizing the electromagnetic induction law, the operational characteristics of the transformer are analyzed, and the placement of the protection current transformer is determined to design a magnetic balance differential protection scheme. This scheme effectively covers interphase faults, winding lead faults, and interturn faults in the single-core phase-shifting transformer. Furthermore, a model of the single-core phase-shifting transformer is developed using the MATLAB/Simulink platform to verify the effectiveness of the proposed differential protection configuration scheme by simulating typical faults.