The Study Of An Adaptive Distanc Protection Approach Based On Artificial Neural Network

In this paper, the application of artificial neural network (ANN) to distance protection of transmission lines in power system is presented in simulation and its practical possibility is also discussed.Although distance protection is the main protection in the protection of transmission lines in complex power network for it is not affected by the structure of the power network and the changing network conditions, its performance is not perfect and not appropriate to high voltage transmission lines. Some problems exist in the traditional protection method. In order to solve these problems, many researchers are working hard all the times. In this paper, ANN is introduced into this field to deal with the fault resistance problem. To resolve the capability problem in traditional device, this paper investigates how to identify the fault according to a different model of combining the various parameters in system. The estimation of the state of power system is finished after analyzing the combine model in terms of ANN. This research reflects all characteristics mentioned above andcomprehensively evaluates the state of power system. When the signals reflecting the state of power system is stored in the weights of ANN after training a great deal of samples, the output of ANN can exactly identify each state of the power system; and it can also adjust the starting impedance of the relay adaptively at the same time.Finally, this paper reports the simulative result of this new model of ANN. Numerous samples firstly acquired from simulating an actual transmission line -line Bailongtan to Etan of Guangxi power network with PSCAD/MTDC, and trained the ANN model established by the Matlab neural network toolboxes. According to these samples, the reliability of ANN model is verified. The satisfactory result of simulation shows that the adaptive distance protection based on ANN is promising and the research developing value of application will also make greater progress in the future. With the development of ANN technology, the scheme will be brought to center stage and make greater progress in the coming years.