摘要: |
提出一种谐波分析的新方法——同步校正法,该方法采用恒定采样周期进行非同步采样,然后对非同步采样序列加权生成等价同步采样序列。在所关心的频率点上,等价同步采样序列的FFT与同步采样序列的FFT相同。生成等价同步采样序列的权系数来源于同步校正方程的解。该方法在线计算与常规的加窗相似,但后者每次加的是同一组权系数,前者则有许多组权系数供选择,其选择的依据是当前采样时段的信号频率。Matlab仿真和配电变压器监测终端中的应用都验证了所提方法的有效性。 |
关键词: 谐波分析 FFT 加窗 非同步采样 同步校正 |
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基金项目:国家863计划项目(2004AA304050);江苏省高校自然科学基金资助项目(08KJD470002) |
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Synchronizing correction for harmonics analysis of power system |
MEI Yong1,2, WANG Bolin1
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1.Hohai University,Nanjing 210098,China;2.Nanjing University of Information Science & Technology,Nanjing 210044,China
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Abstract: |
Synchronizing correction,a new method for harmonics analysis is proposed,which applies asynchronous sampling with constant sampling period to produce the sample sequence and generates the equivalent synchronous sample sequence according to the weighted asynchronous sample sequence. On the frequency points of interest,the FFT results of the equivalent synchronous sample sequence are the same as those of the synchronous sample sequence. The weights are the solutions of the synchronizing correction equation. Its online calculation is similar to that of conventional windowing method,but the former selects one weight set from different weight sets to fit the signal frequency of present sampling interval while the latter has only one weight set for all intervals. Matlab simulation and application in transformer monitoring terminal verify its effectiveness. |
Key words: harmonics analysis FFT windowing asynchronous sampling synchronizing correction |