Wavelet-based EMTR method for fault location of VSC-HVDC transmission lines

Abstract

A wavelet-based electromagnetic time reversal method for locating faults in voltage source converter-high-voltage direct current (VSC-HVDC) transmission lines is proposed in this study. This principle, firstly, is to use wavelet decomposition to filter the 1-mode fault currents, which are recorded at ends of the transmission line. Secondly, the filtered currents are mirrored on time axes, which called time reversal. Thirdly, the time-reversed currents are set as current sources at ends of the lossless mirror lines. Through assuming a fault at each point of line, the assumed fault currents are calculated, and the RMS of fault current at actual fault location is maximal according to a strict scientific proof. Theoretically, the Wavelet-based Electromagnetic Time Reversal (WEMTR) method is robust against fault types and resistance. A multilevel converter-HVDC system is established in Power Systems Computer-Aided Design (PSCAD)/Electromagnetic Transients including DC (EMTDC) to verify the feasibility of the proposed method, and the transmission line is simulated by frequency independent phase model. The results show that, the fault location can be calculated exactly without high sampling rates.

Keywords

• HVDC power transmission
• power transmission faults
• HVDC power convertors
• fault location
• wavelet transforms
• fault currents
• power transmission lines
• power transmission protection
• voltage-source convertors
• wavelet-based EMTR method
• VSC-HVDC transmission lines
• wavelet-based electromagnetic time reversal method
• wavelet decomposition
• 1-mode fault currents
• transmission line
• filtered currents
• time-reversed currents
• current sources
• lossless mirror lines
• fault current
• actual fault location
• WEMTR-based method
• multilevel converter-HVDC system
• voltage source converter-high-voltage direct current transmission lines