Real time power quality analysis for industrial power systems based on fast S-transform

Power Quality (PQ) is a key issue for power systems measurement, operation, protection, security, planning and economy since it will lead to relay malfunction, aging, higher electricity costs and other disadvantages. This problem must necessarily be quickly monitored, investigated, and mitigated for security power systems operation. Therefore, real-time PQ analysis is an interesting research to be developed. One method for analyze this problem is Stockwell Transform (ST) widespread application in signal analysis. However, the high computational complexity of ST is a challenge that needs to be solved. Fast Stockwell Transform (FST) has lower computational complexity compared to ST. This paper proposes Power Quality Analysis (PQA) using the FST method and its implemented in industrial power systems. The FST is used to extract the PQ signal from the time-frequency domain. The implementation of FST using STM32F407VGT6 microcontroller is introduced. The simulation and application result is compared to the several common methods to validate the accuracy and efficiency of the proposed algorithm. The simulation results demonstrate that this algorithm can accurately detect the harmonic, voltage sag, voltage flicker, oscillatory transient, notch and spike. The experiment results of the harmonic are compared with the well known commercial product, showing a good agreement.