Clarification and measurements of high frequency harmonic resonance by a voltage sourced converter

This work presents the clarification and measurements of a high-order harmonic resonance phenomenon for voltage sourced converters. When a voltage sourced converter is connected to a power system through a cable, there is a possibility that small, high frequency, harmonic voltages due to the converter are magnified by series and parallel resonances. The cause of the high-order harmonic resonance is investigated and clarified in this paper by analysis using EMTP. It is shown that this high frequency phenomenon can be strongly attenuated and will not cause any problems in a field installation if measures are taken a priori to avoid its impacts. Additionally, the phenomenon is verified by field tests of an actual installation showing that high-order harmonic resonance can occur and is a practical matter to be dealt with. The measurements for the resonance phenomenon are included in this paper. Furthermore, it is shown that this high-order harmonic resonance can be predicted by power system analysis in advance. The procedure of the analysis is investigated and presented here.