| 引用本文: | 李博,孙建军,王朝亮,许烽,查晓明.考虑高次谐波影响的智能配电合并单元改进采样数据同步方法[J].电力系统保护与控制,2019,47(18):20-27.[点击复制] |
| LI Bo,SUN Jianjun,WANG Chaoliang,XU Feng,ZHA Xiaoming.Improved sampling synchronization method used by merging unit in smart distribution network considering higher harmonic effects[J].Power System Protection and Control,2019,47(18):20-27[点击复制] |
|
| 摘要: |
| 通过合并单元进行不同电子式互感器间的采样数据同步过程中，当信号内存在谐波尤其是高次谐波时，现有方法难以准确地还原采样间隔处的数据，导致同步误差较大。针对这一问题，提出了一种改进采样数据同步方法。基于三样条插值理论，研究了采样数据的整体特征，用连续的分段三次函数描述采样点间的波形，提高了重采样精度。再根据插值算法原理与采样特征，通过归一化处理、矩阵变换、收敛性分析等方法，减小了计算量。最后通过仿真验证，该方法能够保证不高于21次谐波的重采样数据不失真，且计算时间仅为同等精度插值算法的10%左右。改进算法提高了采样数据同步精度，同时又解决了高精度插值运算量大的局限性，具有工程应用价值。 |
| 关键词: 合并单元 采样同步 高次谐波 三样条插值理论 |
| DOI：10.19783/j.cnki.pspc.181247 |
| 投稿时间：2018-10-08修订日期：2018-12-14 |
| 基金项目:国家重点研发计划资助(2017YFB0903100);国家自然基金面上项目资助(5177145);国家电网公司科技项目资助(521104170043) |
|
| Improved sampling synchronization method used by merging unit in smart distribution network considering higher harmonic effects |
| LI Bo,SUN Jianjun,WANG Chaoliang,XU Feng,ZHA Xiaoming |
| (School of Electrical Engineering, Wuhan University, Wuhan 430072, China;State Grid Zhejiang Electric Power Research Institute, Hangzhou 310014, China) |
| Abstract: |
| The sampling signals from different electronic transformers need to be synchronized in the merging unit. However, when harmonics, especially when the higher harmonics, exist in the signal, it’s difficult for the existing methods to restore the original data at the sampling interval accurately, leading to a large error during the synchronization process. To solve this problem, an improved sampling data synchronization method is studied. Based on the cubic spline interpolation theory, the global feature of sampling date is analyzed, and a continuous piecewise cubic function is used to describe the waveforms between the sampling points to improve the re-sampling accuracy. Then, based on the principle of interpolation algorithm and the sampling characteristics, the normalization process, matrix transformation, convergence analysis and other methods are used to reduce the amount of calculations. Finally, through simulation and verification, this method can ensure that the resampling data no higher than the 21th harmonic is not distorted, and the calculation time is only about 10% of the equal precision interpolation algorithm. In summary, this method can not only improve the accuracy of sampling data synchronization with the influence of higher harmonics, but also solve the limitation of high precision interpolation operation. Therefore, it is valuable for engineering applications. This work is supported by National Key Research and Development Program of China (No. 2017YFB0903100), National Natural Science Foundation of China (No. 5177145), and Science and Technology Program of State Grid Corporation of China (No. 521104170043). |
| Key words: merging unit synchronizeddata-sampling higher harmonics cubic spline interpolation |
