Research Of Fault Location Method For HVDC Transmission Line

High-voltage direct current transmission plays a more and more important role in long distance, large capacity transmission system. Because the high voltage direct current transmission system has long transmission lines, the geographical environment is complex for transmission lines, the failure probability occurs; Once the failure take places, it is not easy to find out the failure for the staff, therefore, it is urgent to develop high-voltage direct current transmission line fault location techniques. When the transmission line is broken down, the transmission line produces the travelling wave, we can use the traveling wave to complete the fault location. Traveling wave fault location method can locate fault accurately and reliably, because it is not influenced by the transition resistance and system operation mode, thus, it can timely repair line, improve the economy and reliability of the power system operation.Independent component method is a blind source processing technology, which has been developed in recent years, has high order statistics. The method hardly relies on the objective factors such as the environment, but it can separate the original mixed signals that are independent. When the high-voltage direct current transmission line fault, the voltage and current is independent signal, the improved fast independent component method of single channel can be applied to the high-voltage direct current transmission line fault location, the improved FastICA algorithm can improve the convergence speed of FastICA algorithm; Using single channel fault location algorithm is applied to the fault location can avoid the ranging error because of the more channels of different sample point, and can improve the accuracy of fault location; Due to the traveling wave speed is variable on the propagation, the single-ended fault location algorithms is proposed in this paper, which is not affected by the wave velocity, the corresponding moment Bob is used in the transmission lines can only calculate the fault distance, we don’t need to know wave velocity.PSCAD simulation software is used in the paper is to verify the simulation model of HVDC transmission lines, the collected current signal is separated by FastICA algorithm of single channel and single channel improved FastICA algorithm, a large number of simulation test are proceeded in the paper for current signal in different fault location, and a large number of simulation test are proceeded for the current signal in different transition resistance. Simulation results show that the improved Fast ICA algorithm separation effect is more clearly and ranging accuracy is higher.