The algorithm by weighted for three points of Fourier transformed series alleviated spectral leakage, accuracy of dielectric loss angle calculation in asynchronous sampling was improved, realization of algorithm was easy, and in the meantime, the calculation quantity was only a little more than FFT algorithm.

The main factor of spectral leakage is conducted when the sampling would be non-synchronous.

The kind of windows has advantages of simple structure, lower attenuation and good inhibition of spectral leakage.

An improved algorithm for reducing spectrum leakage based on equal angle-interval sampling principle;

Simulation of software sampling frequency adaptive algorithm for reducing spectrum leakage;

Reduce spectrum leakage based on frequency pursuit;

By means of the discrete frequency spectrum, the frequency spectrum leakages of the conventional DFT and the DFT with a Hanning window are comparatively analyzed in this paper.

Three factors affecting the performance of the proposed algorithm are analyzed,including signal-noise ratio (SNR),frequency spectrum leakage and group-delay.

The restrain method of DFT frequency spectrum leakage base on signal symmetry extension is proposed in this paper, experimental results show that this method is effective.

There are difficulties in performing synchronized sampling and integral period truncation in the harmonic analysis of power system with the Fourier transform technique, and the measuring results will be disturbed by the frequency leakage.

The simulation results show that the proposed algorithms can reduce the frequency leakage,decrease the measurement error and improve the harmonic measurement precision.