摘要
IEC61000-4-7:2002标准推荐的谐波间谐波测量新方法在同步采样下对非平稳信号具有良好的测量精度,但在非同步采样下测量精度较差,在各次谐波和间谐波相对相位变化下测量值会不同。为提高IEC新方法测量精度并保持测量值恒定,提出基于IEC新方法与全相位谱分析相结合的改进方法。该方法利用全相位谱分析具有优良的抑制频谱泄漏和相位不变性特点,实现在非同步采样下对多种典型非平稳信号谐波间谐波的精确测量,并与IEC新方法和传统加二阶余弦窗IEC新方法对比。仿真结果表明,所提出的改进方法非常适用于在非同步采样下谐波间谐波测量,即使各次谐波和间谐波相对相位出现变化,测量值仍然具有较高的精度并能保持恒定。
The new harmonic and interharmonic measurement method with good measuring accuracy for non-stationary signals under synchronous sampling is recommended by IEC 61000-4-7：2002 standard, but it shows poor measuring accuracy under asynchronous sampling, and the results are variable when relative phase of harmonic and interharmonic changes. To make up the deficiency above, this paper presents an advanced method which combines IEC standard framework with all-phase FFT. The method has the excellent property of inhibiting spectral leakage and the feature of phase invariance of all-phase FFT for detecting various typical non-stationary signals, and then is compared with the IEC method and IEC order cosine window method. Simulation results demonstrate that the advanced method is suitable for harmonic and interharmonic measurement for asynchronous sampling, even though the relative phase of harmonic and interharmonic changes, the measurement results are still with high accuracy and keep constant.
出处
《电力系统保护与控制》
EI
CSCD
北大核心
2013年第11期51-59,共9页
Power System Protection and Control
基金
重庆市自然科学基金(cstcjjA90001)~~
关键词
非同步采样
非平稳信号
全相位谱分析
IEC标准
谐波间谐波检测
asynchronous sampling
nonstationary signals
all-phase spectrum analysis
IEC standard
harmonic and interharmonicdetection
