次/超同步间谐波影响下PMU基波频率测量误差机理分析及抑制OA北大核心CSTPCD

The high proportion of renewable energy and power electronic equipment has generated a large number of sub-/super-synchronous interharmonics in the power grid,resulting in significant deviations in the fundamental frequency measurement of synchrophasor measurement unit(PMU),which affects the effectiveness of various frequency applications.Therefore,the paper proposes a mechanism analysis and suppression method for fundamental frequency measurement error under the influence of sub-/super-synchronous interharmonics.Firstly,a frequency domain characteristic model of the frequency measurement algorithm is established,and based on this,a mathematical model of fundamental frequency oscillation under the influence of a single interharmonic and symmetrical sub-/super-synchronous interharmonics is derived,revealing the mechanism of fundamental frequency measurement error under interharmonic interference.Secondly,based on the oscillation behavior of frequency,a fitting model of multi-component superposition is established,and a short-time window frequency oscillation component suppression method based on Fourier transform and least squares method is proposed,which significantly reduces the fundamental frequency deviation.Finally,simulation and on-site recorded data test verify that the proposed method reduces frequency measurement errors greatly.