基于改进S变换的非稳态信号的电能计量方法研究

Research on electric energy measurement method based onimproved S-transform for unsteady signal

随着智能电网的不断发展,非线性负荷大量接入电网,产生的非稳态信号对电能计量造成了影响。为了提高非稳态信号的时频分辨率,文中在S变换的基础上,针对电网非稳态信号的特征并根据窗函数设计原则改进了高斯窗尺度因子σ。此外,为保证非稳态信号下计量的精确性和合理性,应实现基波电能和畸变电能的分开计量,为此本文提出基于改进S变换的电能计量方法,利用改进S变换优秀的时频分辨率实现基波电能和畸变电能的分解重构。通过对几个典型的非线性负荷信号的仿真验证了改进S变换算法在电能计量上的优越性和有效性。

With the development of smart grid,nonlinear load is connected to the grid in large numbers,and the unsteady signal has an impact on the measurement of electric energy.In order to improve the time-frequency resolution of the unsteady signal,this paper improves the Gaussian window scale factorσaccording to the characteristics of the unsteady signal and the design principle of the window function.In addition,in order to ensure the accuracy and rationality of the measurement under the unsteady signal,the fundamental energy and the distorted energy should be measured separately.Therefore,this paper proposes an electric energy measurement method based on the improved S-transform,which uses the excellent time-frequency resolution of the improved S-transform to realize the decomposition and reconstruction of the fundamental energy and the distorted energy.Through the simulation of several typical nonlinear load signals,the superiority and effectiveness of the improved S-transform algorithm in electric energy measurement are verified.