Analysis of high-frequency interference characteristics of UHVDC converters

Abstract

The converter is the main component of the converter station and the main noise source of the PLC interference. The accurate modelling of the high-frequency characteristics of the converter is the foundation for the design of the ± 1100 kV UHVDC PLC filter. Based on deep analysis of the high-frequency characteristics of the converter valve, this paper first proposes three high-frequency models of the converter valve. Compared with a real converter valve used in similar HVDC project, model two is chosen to analyse the high-frequency characteristics. Second, the model of Zhundong–Wannan UHVDC transmission project is established in the PSCAD simulation platform to determine the actual high-frequency characteristics of the converter valve. The voltage before the smoothing reactor is calculated, and the high-frequency noise level is obtained by Fourier transform. Considering the practical application of the high-frequency model of the converter valve, this paper finally proposes a formula to express the measured noise level. The noise source expressed by the formula is more practical for research on high-frequency characteristics of the converter station.

Keywords

• HVDC power convertors
• valves
• HVDC power transmission
• substations
• reactors (electric)
• Fourier transforms
• UHVDC converters
• converter station
• converter valve
• high-frequency noise level
• high-frequency interference characteristics
• UHVDC PLC filter
• PSCAD simulation platform
• Zhundong–Wannan UHVDC transmission project
• smoothing reactor
• Fourier transform
• voltage 1100.0 kV