Transformer Short Circuit Detection Methods and Improvement of Anti-short Circuit Ability Based on Digital Twin Technology: A Survey

Transformer is one of the most important equipments in the power system, and its stability is the basic guarantee for the safe operation of the system. This paper first describes the calculation method of the magnitude of the overcurrent, the leakage magnetic field and the electric power generated by electromagnetic coupling during the short circuit of the transformer. The existing analysis and calculation of the leakage magnetic field and electromagnetic force generally use the finite element integration method to solve the dynamic modeling of the short circuit of the transformer. Secondly, the transformer short-circuit monitoring scheme based on the principle of transformer internal electromagnetic and winding vibration is described: low-voltage pulse method, short-circuit impedance method and frequency response method, and some emerging schemes derived from these three methods, which have high accuracy but are mostly offline monitoring. Finally, the concept of transformer online monitoring based on digital twin (DT) technology is proposed. The DT modeling and monitoring prediction of transformer are carried out by four core technologies of data acquisition, data management, model construction and DT platform constructed with IoT as the carrier of human-computer interaction.