摘要
准确估计系统谐波阻抗是开展谐波溯源的关键。现有方法大多基于背景谐波保持不变或平滑波动的前提,但在新型电力系统中,背景谐波电压或系统谐波阻抗通常呈现非平滑波动特征,甚至在某些时间断面发生突变,导致现有方法产生较大的计算误差。针对此,提出1种计及背景谐波时变特征的系统谐波阻抗估计方法。首先,利用二分滑动T极大值,辨识出背景谐波的多个突变点,据此将公共连接点PCC(pointofcommon coupling)处谐波监测数据划分为若干连续非平滑波动的区间;然后,在每个数据区间内,考虑相邻采样点背景谐波波动较小的特征,基于综合最小波动量原理开展系统谐波阻抗估计,并引入矩阵稀疏技术降低计算时间复杂度;最后,利用仿真和实际工程案例数据开展对比分析,结果表明,所提方法相比现有方法可以更加准确地估计系统谐波阻抗,且具有更高的计算效率。
An accurate estimation of utility harmonic impedance is the key to harmonic source determination.Most of the existing methods are based on the premise that the background harmonics keep constant or fluctuate smoothly.However,the background harmonic voltage or utility harmonic impedance generally exhibits unsmooth fluctuation patterns in the novel power system,and there are even abrupt changes in some time sections,which leads to large calculation errors in the existing methods.To solve this problem,an estimation method for utility harmonic impedance considering the time-varying characteristics of background harmonics is proposed.First,this method identifies multiple abrupt change points of background harmonics by means of the binary sliding T maximum,and the measured harmonic data at a point of common coupling(PCC)is divided into several intervals of continuous unsmooth fluctuation accordingly.Then,with the consideration of the small var-iation of background harmonics between adjacent sampling points,utility harmonic impedance estimation is carried out based on the principle of comprehensive minimum fluctuation within each data interval,and the matrix sparse technique is introduced to reduce the computational time complexity.Finally,simulations and field data are adopted to conduct a comparative analysis,and results indicate that compared with the existing methods,the proposed method can more accurately estimate the utility harmonic impedance and demonstrate a higher computational efficiency.
作者
王小明
郑浩
赵文广
文一
朱明星
丁同
WANG Xiaoming;ZHENG Hao;ZHAO Wenguang;WEN Yi;ZHU Mingxing;DING Tong(Electric Power Research Institute,State Grid Anhui Electric Power Co.,Ltd.,Hefei 230601,China;State Grid Anhui Electric Power Co.,Ltd.,Hefei 230022,China;School of Electrical Engineering and Automation,Anhui University,Hefei 230601,China)
出处
《电源学报》
北大核心
2025年第3期36-46,共11页
Journal of Power Supply
基金
国家电网有限公司科技资助项目(52120524000X)。
关键词
系统谐波阻抗
背景谐波突变
连续非平滑波动
二分滑动T极大值
综合最小波动量
Utility harmonic impedance
abrupt change in background harmonics
continuous unsmooth fluctuation
binary sliding T maximum
comprehensive minimum fluctuation
