Time-Frequency Diagnosis and Monitoring: Time-Frequency Analysis of Electric Power Disturbances

Time-frequency analysis (TFA) methods are applicable to the area of machine condition monitoring and diagnosis. They are capable of efficiently and unambiguously characterizing a large number of faults. TFA methods are used for detection, classification, and monitoring the progression of the faults and wear with time. This enables prediction and prevention of catastrophic failures. Time-frequency analysis techniques, in the form of either time-frequency distribution (TFD) or wavelet transforms (WT), are used as visual indicators of the presence of faults and as a feature extractor in a fully automated pattern recognition process. This chapter focuses on applications of time-frequency analysis to transient power quality events. A power system is mainly divided into distribution and transmission levels. The chapter presents an example from the distribution level for power quality assessment and the other from the transmission level for the propagation of disturbance waves.