一种用于分析电网谐波的多谱线插值算法

以矩形窗为例,尝试在一定条件下以积分求和来求解离散傅里叶变换,所得表达式可直观反映非同步采样条件下频谱分析中的长、短范围泄漏效应。据此,不同于以往应用性能较好的窗函数来减小长范围泄漏效应的作法,提出一种能同时修正长、短范围泄漏的多谱线插值新算法。针对长范围泄漏效应可被忽略和应被计及两种情况,将所提出新算法与已有加窗插值算法进行比较,发现已有算法是新算法的特例,而新算法具有更广泛的应用范围。以三种不同算法计算含有间谐波的信号参数,通过比较发现,新算法具有较高的准确度;利用新算法对含有高斯噪声的信号做仿真分析,结果表明其具有良好的抗干扰能力。

An Algorithm of MICA for Analyzing Harmonics in Power System

Taking the rectangular window as an example, the summation in the expression of discrete Fourier transform (DFT) is solved out by the integral operation. The obtained expression is used to interpret directly the long-range leakage and short-range leakage effects in the spectrum analysis under the asynchronous sampling. Being different from applying the window with better spectrum characteristic to reduce the long-range leakage, a new method, named multi-spectrum-line interpolation correction algorithm (MICA), is presented to correct both kinds of leakage. Under the conditions that the long-range leakage effect is neglected or considered, the differences between MICA and the existing windowed interpolation algorithm are analyzed, which indicates the existing algorithm is a special case of MICA and MICA has a wider application. Using three different kinds of algorithm to calculate the parameters of a signal with inter-harmonic, the simulation results show that the accuracy of MICA is very high. For the signal with Guassian noise, MICA has a good anti-interference capacity.