Fractional-order control(FOC)has gained significant attention in power system applications due to their ability to enhance performance and increase stability margins.In grid-connected converter(GCC)systems,the synchro...Fractional-order control(FOC)has gained significant attention in power system applications due to their ability to enhance performance and increase stability margins.In grid-connected converter(GCC)systems,the synchronous reference frame phase-locked loop(SRF-PLL)plays a critical role in grid synchronization for renewable power generation.However,there is a notable research gap regarding the application of FOC to the SRF-PLL.This paper proposes a fractional-order SRF-PLL(FO-SRF-PLL)that incorporates FOC to accurately track the phase angle of the terminal voltage,thereby improving the efficiency of grid-connected control.The dynamic performance of the proposed FO-SRF-PLL is evaluated under varying grid conditions.A comprehensive analysis of the small-signal stability of the GCC system employing the FO-SRF-PLL is also presented,including derived small-signal stability conditions.The results demonstrate that the FO-SRF-PLL significantly enhances robustness against disturbances compared with the conventional SRF-PLL.Furthermore,the GCC system with the FO-SRF-PLL maintains stability even under weak grid conditions,showing superior stability performance over the SRF-PLL.Finally,both simulation and experimental results are provided to validate the analysis and conclusions presented in this paper.展开更多
Integration of inverter-based resources(IBRs)reshapes conventional power swing patterns,challenging the operation of legacy power swing protec-tion schemes.This paper highlights the significant con-sequences of the di...Integration of inverter-based resources(IBRs)reshapes conventional power swing patterns,challenging the operation of legacy power swing protec-tion schemes.This paper highlights the significant con-sequences of the distinctive power swing patterns exhib-ited by grid-forming IBRs(GFM-IBRs).The swing mechanism involving GFM-IBRs is elucidated using an-alytical modeling of GFM-IBRs with various power syn-chronization loops(PSLs).With varying GFM-IBR pen-etration levels and different generator scenarios,the per-formance of power swing protection functions is examined,including power swing blocking(PSB)and out-of-step tripping(OST).Additionally,the IEEE PSRC D29 test system is employed to present power swing protection results in a large-scale power system integrated with synchronous generators(SGs)and IBRs.The results in-dicate that,GFM-IBRs with sufficient voltage support capability can provide positive impact on power swing dynamics,and power swing protection performance can be enhanced by emulating the inertia and droop mecha-nism of SGs and rapidly adjusting the active power output.However,with high penetration levels of GFM-IBRs,OST maloperation may occur in scenarios with inadequate voltage support capability.展开更多
基金supported in part by the Natural Science Foundation of China(No.52077144)the Youth Innovative Research Team of Science and Technology Scheme,Sichuan Province,China(No.22CXTD0066).
文摘Fractional-order control(FOC)has gained significant attention in power system applications due to their ability to enhance performance and increase stability margins.In grid-connected converter(GCC)systems,the synchronous reference frame phase-locked loop(SRF-PLL)plays a critical role in grid synchronization for renewable power generation.However,there is a notable research gap regarding the application of FOC to the SRF-PLL.This paper proposes a fractional-order SRF-PLL(FO-SRF-PLL)that incorporates FOC to accurately track the phase angle of the terminal voltage,thereby improving the efficiency of grid-connected control.The dynamic performance of the proposed FO-SRF-PLL is evaluated under varying grid conditions.A comprehensive analysis of the small-signal stability of the GCC system employing the FO-SRF-PLL is also presented,including derived small-signal stability conditions.The results demonstrate that the FO-SRF-PLL significantly enhances robustness against disturbances compared with the conventional SRF-PLL.Furthermore,the GCC system with the FO-SRF-PLL maintains stability even under weak grid conditions,showing superior stability performance over the SRF-PLL.Finally,both simulation and experimental results are provided to validate the analysis and conclusions presented in this paper.
基金supported by the Hong Kong Research Grant Council for the Research Project(No.15229421)the PolyU Presidential PhD Fellowship Scheme。
文摘Integration of inverter-based resources(IBRs)reshapes conventional power swing patterns,challenging the operation of legacy power swing protec-tion schemes.This paper highlights the significant con-sequences of the distinctive power swing patterns exhib-ited by grid-forming IBRs(GFM-IBRs).The swing mechanism involving GFM-IBRs is elucidated using an-alytical modeling of GFM-IBRs with various power syn-chronization loops(PSLs).With varying GFM-IBR pen-etration levels and different generator scenarios,the per-formance of power swing protection functions is examined,including power swing blocking(PSB)and out-of-step tripping(OST).Additionally,the IEEE PSRC D29 test system is employed to present power swing protection results in a large-scale power system integrated with synchronous generators(SGs)and IBRs.The results in-dicate that,GFM-IBRs with sufficient voltage support capability can provide positive impact on power swing dynamics,and power swing protection performance can be enhanced by emulating the inertia and droop mecha-nism of SGs and rapidly adjusting the active power output.However,with high penetration levels of GFM-IBRs,OST maloperation may occur in scenarios with inadequate voltage support capability.
