李德文,任旭虎,吕正阳,艾洁.电网畸变下基于改进DSSOGI-FLL同步信号提取方法[J].电测与仪表,2019,56(10):40-46. Li Dewen,Ren Xuhu,Lv Zhengyang,Ai Jie.Synchronization signal extraction method based on Improved DSSOGI-FLL in power grid distortion[J].Electrical Measurement & Instrumentation,2019,56(10):40-46.
电网畸变下基于改进DSSOGI-FLL同步信号提取方法
Synchronization signal extraction method based on Improved DSSOGI-FLL in power grid distortion
With the rapid development of new energy such as wind power and photovoltaic power generation, three-phase grid connected converter has been widely applied. In order to meet the requirement of extracting synchronous signals in the condition of asymmetric, DC-offset and harmonics, the positive and negative sequence components, amplitude and fundamental frequency of the voltage signal need to be extracted accurately. The synchronization signal can be extracted under voltage asymmetry and distortion based on DSOGI-FLL. But when the unbalanced three-phase voltage is large, the DC component and the multiple harmonics are influenced by the DSOGI-FLL method, the accurate extraction of the synchronous signal can not be realized, and the waveform of the tracking is relatively large and the tracking speed is reduced. In this paper, the structure of SOGI is improved, and the difference node and adaptive filter are added on the basis of SOGI, and the method of synchronous signal extraction based on improved DSSOGI-FLL is proposed. In the case of large imbalance, DC-offet and multiple harmonics, this method can eliminate these effects well, and can accurately and quickly extract the positive and negative sequence components, phase and frequency information. The accuracy and effectiveness of the improved DSSOGI-FLL method is verified by simulation analysis.
