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The significance of detection and classification of power quality events that disturb the voltage and/or current waveforms in the electrical power distribution networks is well known. Consequently, in spite of a large number of research reports in this area, a research on the selection of proper parameter for specific classifiers was so far not explored. The parameter selection is very important for successful modelling of input-output relationship in a function approximation model. In this study, probabilistic neural network (PNN) has been used as a function approximation tool for power disturbance classification and genetic algorithm (GA) is utilised for optimisation of the smoothing parameter of the PNN. The important features extracted from raw power disturbance signal using S-Transform are given to the PNN for effective classification. The choice of smoothing parameter for PNN classifier will significantly impact the classification accuracy. Hence, GA based parameter optimization is done to ensure good classification accuracy by selecting suitable parameter of the PNN classifier. Testing results show that the proposed S-Transform based GA-PNN model has better classification ability than classifiers based on conventional grid search method for parameter selection. The noisy and practical signals are considered for the classification process to show the effectiveness of the proposed method in comparison with existing methods.

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& The significance of detection and classification of power quality (PQ) events that disturb the voltage and=or current waveforms in electrical power distribution networks is well known. Consequently, in spite of a large number of research reports in this area, research on the selection of useful features from the existing feature set and the parameter selection for specific classifiers has thus far not been explored. The choice of a smoothing parameter for a probabilistic neural network classifier (PNN) in the training process, together with feature selection, will significantly impact the classification accuracy. In this work, a thorough analysis is carried out, using two wrapper-based optimization techniques-the genetic algorithm and simulated annealing-for identifying the ensemble of celebrated features obtained using discrete wavelet transform together with the smoothing parameter selection of the PNN classifier. As a result of these analyses, the proper smoothing parameter together with a more useful feature set from among a wider set of features for the PNN classifier is obtained with improved classification accuracy. Furthermore, the results show that the performance of simulated annealing is better than the genetic algorithm for feature selection and parameter optimization in Power Quality Data Mining.

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Recognition of the presence of any disturbance and classifying any existing disturbance into a particular type is the first step in combating the power quality problem. Support Vector Machines (SVMs) have gained wide acceptance because of the high generalization ability for a wide range of classification applications. Although SVMs have shown potential and promising performance in power disturbances classification, they have been limited by speed particularly when the training data set is large. The hyper plane constructed by SVM is dependent on only a portion of the training samples called support vectors that lie close to the decision boundary (hyper plane). Thus, removing any training samples that are not relevant to support vectors might have no effect on building the proper decision function. We propose the use of clustering techniques such as K-mean to find initial clusters that are further altered to identify non-relevant samples in deciding the decision boundary for SVM. This will help to reduce the number of training samples for SVM without degrading the classification result and classification time can be significantly reduced.