A novel traveling-wave-based protection scheme for LCC-HVDC systems using Teager Energy Operator

Line Commutated Converter (LCC) based High-Voltage Direct Current (HVDC) technology has been in operation with a high level reliability and little maintenance requirements for more than thirty years. The current-source based or classical LCC-HVDC systems are being considered for buried cable transmission as well as overhead transmission. The fault analysis and protection of LCC-HVDC system is a very important aspect in terms of power system stability. This paper proposes a novel protection scheme for LCC-HVDC systems, in which the difference between propagation processes of traveling wave under internal and external faults is used as a criterion for detection of fault incidents in HVDC transmission lines. In order to quantify and intensify this difference, Teager Energy Operator (TEO) is used which has the ability to reflect the instantaneous energy of a signal. The main feature of the proposed scheme in comparison with the existing ones is that it operates faster, since it does not require to extract any harmonic or high frequency component; moreover, a 2-ms sampling window is sufficient for its algorithm which only deals with simple calculations. In order to validate the effectiveness of the proposed protection scheme, several fault events under different fault resistances and fault locations were simulated on a test network using PSCAD/EMTDC software. Also, the performance of the proposed scheme under real fault events was tested using four field data cases. Both simulation data and field data test results indicated that the proposed protection strategy has the ability to accurately discriminate between internal and external faults and detect the faulted pole in the bipolar systems even under high-impedance fault conditions.