基于高精度测频的修正DFT相量及功率测量算法  

A modified DFT of phasor and power measurement algorithm based on high precision frequency measurement

作　　者：谢运华[1] 赵庆生[1] 郭贺宏 张学军[3] 

机构地区：[1]太原理工大学电力系统运行与控制山西省重点实验室,山西太原030024 [2]国网临汾供电公司,山西临汾041000 [3]山西大学,山西太原030006

出　　处：《电力系统保护与控制》2016年第12期23-28,共6页Power System Protection and Control

基　　金：国家自然科学青年基金项目(51505317);山西省自然科学基金项目(2015011057)~~

摘　　要：为了提高频率偏移时电力系统相量及功率测量精度,提出了一种基于改进扩展卡尔曼滤波(IEKF)频率测量的修正离散傅里叶变换(DFT)相量及功率测量算法。分析了频率发生偏移时非同步采样下DFT的测量误差,建立了相角、幅值与频率偏移量和初相角之间的函数关系式。由IEKF得到频率偏移量,然后对DFT计算结果进行修正即可得到输入信号的真实相量和功率。仿真结果表明:该算法相比较于传统自适应DFT算法能有效消除或减弱谐波、噪声以及频率偏移对相量同步测量的影响,提高了相量及功率测量精度。In order to improve the power system phase and power measurement accuracy when frequency offset, this paper presents a modified DFT of phasor and power algorithm based on improved expansion Kalman filter（IEKF） frequency measurement, the measurement error of DFT under nonsynchronous sampling caused by frequency offset is analyzed, and the function relationship between the phase, amplitude and frequency offset and initial phase angle is established. The frequency offset is obtained by IEKF, and then the DFT calculation results can be corrected to obtain the real phase and power of the signal. The simulation results show that the proposed method compared with the traditional adaptive DFT algorithm can effectively eliminate or weaken the influence of harmonics, noise and frequency offset on the synchronized phasor measurement, and improve the precision of phasor and power measurement.

关 键 词：离散傅里叶变换(DFT) IEKF 非同步采样 相量测量 功率测量 

分 类 号：TM933.3[电气工程—电力电子与电力传动]