Voltage Error Analysis of Three-phase Combined Transformer Based on Real Test Platform

The voltage error of three-phase combined transformer is detected according to the single-phase method, but this situation is not consistent with the actual operation state, thus the single-phase method can not accurately detect the actual voltage error characteristics of the three-phase combined transformer. In this paper, the three-phase combined transformer composed by three-column is treated as the object, using the real test platform to simulate the actual operation condition of the three-phase combined transformer, which carries out the test and in-depth analysis of its voltage error under different primary current conditions. The main conclusions are as follows: the three-phase combined transformer qualified in single-phase method may not be qualified in three-phase method, the current makes a linear influence on the voltage error of three-phase combined transformer, with the increase of current, the algebraic sum of error variation of three-phase voltage transformer is approximately equal to zero.