Fan Chunju

An Adaptive Fault Location Technique Based on PMU for Transmission Line

A new adaptive fault location technique based on Phasor Measurement Unit (PMU) for transmission line is presented in this paper. Voltage and current phasors of both terminals of the transmission line are obtained through PMU. The online parameter-calculation algorithm is adopted to obtain the practical operating parameters when fault occurs, solving the problems that parameters provided by electric power company is different from the practical parameters because of the running environment and the operation history. The suddenly changed voltage and current are utilized to obtain suddenly changed positive voltage and current components to solve the systems impedance at the fault time. The on-line calculated systems impedance and parameters of the line are employed in the fault location equation and the fault location accuracy is high. The proposed fault location method is applied in single transmission line, parallel transmission line as well as teed transmission line. Extensive EMTP simulations as well as practical system data testing results have shown that the proposed technique accurately locate the fault point adaptively, not influenced by factors such as operation mode, fault resistance at fault point, fault type, prefault load and fault distance.

Power system fault data compression based on wavelet packet transform and vector quantization

According to the characteristics of fault transient signal of a power system, some principles of fault signal compression are proposed. That is keeping some waveband lossless compression and other waveband lossy compression. An integrated signal compression algorithm based on wavelet packet transform, Huffman coding and vector quantization is proposed. Programming software is also given. The simulation result shows this algorithm can precisely meet the requirements of signal compression in a power system and have great application potential.