A Voltage Phasor Based Fault Classification Method for PMU Only State Estimator Output

This paper presents a fault classification method for transmission lines based on voltage phasors using classification and regression trees (CART). The proposed method is intended to aid system operators in understanding the outputs of a PMU only state estimator. Faults are classified into four categories when the estimator is positive sequence and into ten categories when the estimator is three phase. The fault data is generated in PowerWorld and DSA Tools. The pre-fault state consists of a variety of operating conditions and loading angles of faulted lines. The fault condition comprises of different fault types, fault locations, fault impedances, and fault incidence angles. The fault classification is done using MATLAB. The approach is successfully tested on the IEEE-118 bus system. The results demonstrate that the technique developed here is effective and robust, irrespective of the pre-fault and fault conditions. Keywords— Classification and Regression Tree (CART), Fault Classification, Fault Type, Fault Voltage, Phasor Measurement Units (PMUs), State Estimation, Voltage Phasors.