{"title":"Sliding-Mode Observer-Based Grid Voltage-Observation Method with Frequency-Fixed Dual SOGI and Cross-Compensated Phase-Locked Loop","authors":"Leilei Guo;Qingyang Ye;Nan Jin;Zhenkun Liu;Zhenjun Wu","doi":"10.23919/CJEE.2024.000090","DOIUrl":null,"url":null,"abstract":"Conventional sliding-mode observer (SMO)-based grid-voltage observation methods often require a low-pass filter (LPF) to remove high-frequency sliding-mode noise. However, a complicated phase- and amplitude-compensation method, which is highly sensitive to the DC-offset, is required. A frequency-adaptive dual second-order generalized integrator (SOGI) can be used to replace the LPF, eliminating the compensation link and the effects of the DC-offset; however, strong coupling is introduced between the front-end SOGI block and back-end phase-locked loop (PLL) block, thereby reducing the dynamic performance. To solve this problem, this study proposes an SMO-based grid-voltage observation method with a frequency-fixed dual SOGI and cross-compensated PLL that can eliminate the frequency coupling between the front-end SOGI block and back-end PLL blocks, thereby increasing its dynamic performance. In this study, the phase and amplitude are compensated simultaneously using the proposed cross-compensation method, achieving an accurate observation of the grid voltage under off-nominal frequencies. An analysis of the small-signal model theoretically verified that the proposed method has good dynamic performance. Finally, the superiority of the proposed method is verified through comparative experiments.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10707126","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Chinese Journal of Electrical Engineering","FirstCategoryId":"1087","ListUrlMain":"https://ieeexplore.ieee.org/document/10707126/","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"Engineering","Score":null,"Total":0}
引用次数: 0
Abstract
Conventional sliding-mode observer (SMO)-based grid-voltage observation methods often require a low-pass filter (LPF) to remove high-frequency sliding-mode noise. However, a complicated phase- and amplitude-compensation method, which is highly sensitive to the DC-offset, is required. A frequency-adaptive dual second-order generalized integrator (SOGI) can be used to replace the LPF, eliminating the compensation link and the effects of the DC-offset; however, strong coupling is introduced between the front-end SOGI block and back-end phase-locked loop (PLL) block, thereby reducing the dynamic performance. To solve this problem, this study proposes an SMO-based grid-voltage observation method with a frequency-fixed dual SOGI and cross-compensated PLL that can eliminate the frequency coupling between the front-end SOGI block and back-end PLL blocks, thereby increasing its dynamic performance. In this study, the phase and amplitude are compensated simultaneously using the proposed cross-compensation method, achieving an accurate observation of the grid voltage under off-nominal frequencies. An analysis of the small-signal model theoretically verified that the proposed method has good dynamic performance. Finally, the superiority of the proposed method is verified through comparative experiments.