Time–Frequency Analysis of Power Quality Signals: A Novel Amplitude-Preserving Adaptive Synchrosqueezed S-Transform

With the widespread deployment of renewable energy and power electronic devices, the incidence of power quality disturbances (PQDs) has risen significantly. This paper presents a novel approach for accurately detecting the parameters of PQDs: an amplitude-preserving adaptive synchrosqueezed S-transform. Firstly, to mitigate computational burden, a fast calculation method for the instantaneous frequency (IF) is introduced. This method efficiently separates the real and imaginary parts of complex numbers, reducing unnecessary computations and preserving information integrity at the edges of the IF matrix. Secondly, to counter the impact of changes in window width on the accuracy of PQDs amplitude detection, a synchrosqueezed S-transform framework with amplitude preservation is proposed. Furthermore, to accommodate the detection requirements of various signal components within PQDs signals, an amplitude-preserving adaptive synchrosqueezed S-transform (APASST) is introduced. This method ensures amplitude accuracy post-synchrosqueezing through normalization windows in the frequency domain, facilitating the accurate detection of multiple PQDs signal components via adaptive adjustment. Finally, the simulation and experimental results prove the efficacy of the proposed method.