Fast S-Transform for Time-Varying Voltage Flicker Analysis

Voltage flicker analysis is one of the elementary tools of power quality assessment in power systems. A new algorithm, fast S-transform (FST) is proposed and is used to analyze the time-varying voltage flicker in this paper. A voltage flicker waveform envelope, which captures the main flicker characteristic, is obtained by Teager-Kaiser energy operator instantaneously. FST achieves much lower computational complexity in comparison to the S-transform. FST is used to extract both the time and the frequency domain information of each flicker component. The proposed algorithm can be easily implemented with hardware multipliers, making the method a good choice for real-time applications for the time-frequency analysis of flicker. The implementation of the proposed algorithm in the dual-core processor-digital signal processor and advanced RISC machines-based voltage flickermeter is also introduced. The simulation and application results validate the accuracy and efficiency of the proposed algorithm.