The study 500 kV system harmonics in Central China Power Network

This paper studies the harmonics in 500 kV Central China Power Network (CCPN), analyzes the 24 h continuous measurement results of harmonics in several representative substations and gives the variation curve of harmonic voltage rate and harmonic current content with time in 24 h. Based on above results this paper makes the analysis and simulation calculation of harmonic level in 500 kV CCPN. The measurement results accords basically with the calculation results. The measures to reduce the harmonic in 500 kV CCPN have been proposed. The harmonic in 500 kV power system is particular comparing with medium and low voltage power systems. In the past, comprehensive studies and analyses in this subject were lacking. The reason why the harmonic voltage level is higher in 500 kV power systems is analyzed based on the characteristics and magnitudes of harmonic sources, transmission characteristics and harmonic impedance features in 500 kV power systems