Research on the coupling and superposition mechanism of high-frequency zero sequence harmonics in the substation area based on PSCAD

In the macro context of promoting the green and low-carbon transformation of energy to achieve carbon peak and carbon neutrality goals, a large number of new elements such as distributed photovoltaics, electric vehicle charging facilities, and energy storage equipment are integrated into the distribution network substation, which has a complex and far-reaching impact on the harmonic environment of the substation. This article mainly analyses the harmonic characteristics of common power electronic converters in the substation. The substation is modelled using PSCAD software, and complex harmonics in the substation are simulated using single-phase uncontrolled rectification capacitive load. The harmonic current content of the neutral line is analyzed, and the conclusion that the high-frequency zero sequence current on the neutral line is three times the zero-sequence current of each phase is verified.