Measurement of Transformer Transfer Voltage and a Study of its Modelling

Abstract

This paper proposed an improved model to simulate the transfer voltage of a power transformer. This model consists of the EMTP TRANSFORMER model with some capacitances, and is used as a component of EMTP. Conventionally, the power frequency EMTP TRANSFORMER model can not be used for high frequency transfer voltage study. In high frequency transfer voltage study, transformers are simulated as capacitances only. This representation is very simple and less accurate. Recently, the high frequency transformer models have been reported. these models are based on the numerical calculations for a wide range of frequency response of the transformer. However, the users have to deal with the model as a black box, the physical meaning of which is unknown.
In this paper, the measurement of transfer voltages for an actual transformer(11/154kV, 68.3MVA) was performed in various conditions. The value of various parameters of the proposed model are calculated from the actual measurements entailing no numerical calculations and help in understanding their physical relevance. The accuracy of the proposed model is confirmed by comparing the simulated results with the actual measurements.