الفهرس | Only 14 pages are availabe for public view |
Abstract Faults on senes compensated transmission lines need to be detected, classified, and located accurately for being cleared as fast as possible. This research presents an adaptive protection directional scheme by using artificial neural networks for the series compensated transmission system. The scheme is designed to detect the faults, classify the fault type and identify the faulted phase for all types of faults. The proposed topology of this scheme is composed of two levels of neural networks. In level-I a neural network (ANNF) is used to detect the fault, while in level-2, four networks (ANNA, ANNa, ANNe and ANNG) are used to identify faulted phase(s). The output of ANNF activates (ANNA. ANNa. ANNe and ANNG) if there is a fault. Therefore. the proposed topology determines both the fault type and the faulted phase(s) selection. The proposed scheme is trained and tested using 10caJ measurements of three phase voltage and current samples. These samples are generated using EMTDC package. All ten possible fault .types are simulated. The sampling rate is 16 samples per cycle of power frequency. ANNs are trained by different methods until getting the proper number of samples per input pattern and proper design of ANN. The proper design for all ANNs used in this research consists of three layers; an input layer having 24 input nodes (four recursive samples of three phase voltages and currents), a hidden layer of 10 neurons, and an output layer of one neuron. The ANN approach is compared with a travelling wave-based relaying technique for similar case studies. ANN shows higher resolution regarding selecting faulted phases.Testing results proved that the proposed scheme is accurate, reliable and more efficient. |