Influence of traction transformer with different connection forms on power quality of the grid

In this paper, a large amount of data is collected and sorted out and a regional power grid was selected as the analysis object. Using MATLAB to build a typical model of public power grid, we analyzed the harmonic and negative sequence effects of different connection traction transformer under different operation modes. If the traction substation adopts the appropriate connection mode, as far as possible to ensure that the traction substation two power supply arm load balance, then the negative sequence generated by the current is very small and three-phase voltage balance. Comparing the harmonic and negative sequence effects of several connection modes of traction transformer on system bus, the conclusion that Scott connection has the best comprehensive performance is obtained. Therefore, in the actual operation, we should consider the characteristics of various connection modes of traction transformer in different operation modes, and reasonably dispatch, in order to reduce the negative sequence impact on the power grid.