Modeling of 10 kV Distribution Transformer Excited by Three-Phase Common Mode Transients

A 10-kV distribution transformer is exposed to the three-phase common mode transients due to the coupling between the three-phase transmission lines and transient electromagnetic disturbances. In this case, the multiconductor transmission line theory for a single winding is not sufficient to analyze the response of the transformer. In this article, a model of a 10-kV distribution transformer excited by three-phase common mode transients is proposed. The circuit diagram of the model is put forward based on the real scenario of the 10-kV distribution system excited by transient electromagnetic disturbances. The model takes into account the boundary conditions of the transformer windings, which enables the calculation of the responses of three phases simultaneously. The derivations are verified by an equivalent simulation method using PSpice. The test platform is built up and a 10-kV distribution transformer is studied for further verification. The model calculation results are compared with the test results, which is satisfactory.