An online measurement method for power grid fundamental frequency based on adaptive window length chirp Z-transform
WANG Binwu1, LIU Guangjun1, DONG Rui2
1. School of Electrical and Electronic Engineering, Hubei University of Technology, Wuhan 430068; 2. Motor Soft-Start Hubei Provincial Key Laboratory, Xiangyang, Hubei 441022
Abstract：The online measurement of power grid fundamental frequency is of great significance for power quality analysis, relay protection and fault diagnosis. To solve the problem that traditional methods such as fast Fourier transform (FFT) and chirp Z-transform (CZT) are difficult to balance measurement accuracy and response speed, an online measurement method for power grid fundamental frequency based on adaptive window length CZT is proposed. It utilizes the ability of CZT to achieve high-resolution spectrum analysis in any frequency range and introduces an adaptive window length adjustment mechanism to dynamically adjust the analysis window length according to the frequency change rate, seeking a balance between measurement accuracy and response speed and achieving the optimal allocation of measurement resources. Simulation results show that the proposed method can adaptively adjust the window length according to the frequency change rate for power frequency signals with a frequency fluctuation range within ±0.5 Hz, meeting the design expectations.
王斌武, 刘光军, 董睿. 自适应窗长线性调频Z变换的电网工频在线测量方法[J]. 电气技术, 2026, 27(9): 28-33.
WANG Binwu, LIU Guangjun, DONG Rui. An online measurement method for power grid fundamental frequency based on adaptive window length chirp Z-transform. Electrical Engineering, 2026, 27(9): 28-33.
2026, Vol. 27 
