Sidestay lock mechanism is an important part of landing gear system,and the locking performance can be analyzed based on changes in its stability.However,during numerical continuation analysis of fully-rigid dual-side...Sidestay lock mechanism is an important part of landing gear system,and the locking performance can be analyzed based on changes in its stability.However,during numerical continuation analysis of fully-rigid dual-sidestay landing gear without clearance,it has been found that the appearance of bifurcation points does not necessarily imply that both sidestay links can be locked synchronously.This problem reveals the limitations of fully-rigid model with ideally-articulated in solving dual-sidestay mechanisms with extremely high motion sensitivity.Therefore,this study proposes a bifurcation analysis method for synchronous locking of dual-sidestay landing gears,which takes into consideration the joint clearance.For in-depth analysis of this problem,we initially build kinematic and mechanical models of a landing gear mechanism that consider joint clearance.Then,the models are solved based on continuation.The fundamental causes of synchronous locking are discussed in detail,and the number of bifurcation points is found to be closely related to whether the landing gear is completely locked.Finally,the effects of structural parameters on the synchronous locking are analyzed,and the feasible region of parameters satisfying synchronous locking condition is given,which agrees well with the test results.展开更多
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
基金financially supported by the National Natural Science Foundation of China(51805249)the Natural Science Foundation of Jiangsu Province(BK20180436)+1 种基金the Fundamental Research Funds for the Central Universities(NF2018001)the Priority Academic Program Development of Jiangsu Higher Education Institutes。
文摘Sidestay lock mechanism is an important part of landing gear system,and the locking performance can be analyzed based on changes in its stability.However,during numerical continuation analysis of fully-rigid dual-sidestay landing gear without clearance,it has been found that the appearance of bifurcation points does not necessarily imply that both sidestay links can be locked synchronously.This problem reveals the limitations of fully-rigid model with ideally-articulated in solving dual-sidestay mechanisms with extremely high motion sensitivity.Therefore,this study proposes a bifurcation analysis method for synchronous locking of dual-sidestay landing gears,which takes into consideration the joint clearance.For in-depth analysis of this problem,we initially build kinematic and mechanical models of a landing gear mechanism that consider joint clearance.Then,the models are solved based on continuation.The fundamental causes of synchronous locking are discussed in detail,and the number of bifurcation points is found to be closely related to whether the landing gear is completely locked.Finally,the effects of structural parameters on the synchronous locking are analyzed,and the feasible region of parameters satisfying synchronous locking condition is given,which agrees well with the test results.
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.
