This paper presents an adaptive Under Frequency Load Shedding scheme based on Wide Area Measurement System. Due to the lack of enough adaptability to the operation state of the system, the traditional successive appro...This paper presents an adaptive Under Frequency Load Shedding scheme based on Wide Area Measurement System. Due to the lack of enough adaptability to the operation state of the system, the traditional successive approximation under frequency load shedding method will cause excessive cut or undercut problems inevitably. This method consists first in a comprehensive weight index including load characteristics and inertias of generators. Then active-power deficit calculation based on the Low-order Frequency Response Model, concerning the effect of voltage was put forward. Finally, a dynamic correction of the load shedding amount was proposed to modify the scheme. This approach was applied to IEEE-39 system and the simulation results indicated that the proposed method was effective in reducing the load shedding amount as well as the frequency recovery time.展开更多
The UFMylation modification is a novel ubiquitin-like conjugation system,consisting of UBA5(E1),UFC1(E2),UFL1(E3),and the conjugating molecule UFM1.Deficiency in this modification leads to embryonic lethality in mice ...The UFMylation modification is a novel ubiquitin-like conjugation system,consisting of UBA5(E1),UFC1(E2),UFL1(E3),and the conjugating molecule UFM1.Deficiency in this modification leads to embryonic lethality in mice and diseases in humans.However,the function of UFL1 is poorly characterized.Studies on Ufl1 conditional knockout mice have demonstrated that the deletion of Ufl1 in cardiomyocytes and in intestinal epithelial cells causes heart failure and increases susceptibility to experimentally induced colitis,respectively,suggesting an essential role of UFL1 in the maintenance of the homeostasis in these organs.Yet,its physiological function in other tissues and organs remains completely unknown.In this study,we generate the nephron tubules specific Ufl1 knockout mice and find that the absence of Ufl1 in renal tubular results in kidney atrophy and interstitial fibrosis.In addition,Ufl1 deficiency causes the activation of unfolded protein response and cell apoptosis,which may be responsible for the kidney atrophy and interstitial fibrosis.Collectively,our results have demonstrated the crucial role of UFL1 in regulating kidney function and maintenance of endoplasmic reticulum homeostasis,providing another layer of understanding kidney atrophy.展开更多
智能电网环境下,可控负荷参与低频减载（under frequency load shedding,UFLS）协助电力系统辅助调频,成为了新型低频减载研究的重点。新型低频减载策略对于负荷调节的时效性以及准确性要求较高,但负荷的通信状态和用户被控意愿等问题...智能电网环境下,可控负荷参与低频减载（under frequency load shedding,UFLS）协助电力系统辅助调频,成为了新型低频减载研究的重点。新型低频减载策略对于负荷调节的时效性以及准确性要求较高,但负荷的通信状态和用户被控意愿等问题会对调频减载结果造成影响。该文综合考虑上述问题,对负荷通信延迟、丢包进行建模,同时考虑用户被控次数,提出了一种新型集群控制策略。该文首先分析了简化的发电机–负荷模型下的通信状态对调频减载结果的影响,而后基于此提出了考虑通信状态与控制均衡的负荷群参与低频减载的优化控制方案。最后以IEEE3机9节点系统模型为例,对优化控制策略的效果进行验证。仿真结果说明了控制策略对负荷群的控制具有低延时、高准确性的特点,能够保证控制动作的及时性,从而抑制系统频率下降深度,减少频率调节误差,大大降低了系统失稳的风险。展开更多
文摘This paper presents an adaptive Under Frequency Load Shedding scheme based on Wide Area Measurement System. Due to the lack of enough adaptability to the operation state of the system, the traditional successive approximation under frequency load shedding method will cause excessive cut or undercut problems inevitably. This method consists first in a comprehensive weight index including load characteristics and inertias of generators. Then active-power deficit calculation based on the Low-order Frequency Response Model, concerning the effect of voltage was put forward. Finally, a dynamic correction of the load shedding amount was proposed to modify the scheme. This approach was applied to IEEE-39 system and the simulation results indicated that the proposed method was effective in reducing the load shedding amount as well as the frequency recovery time.
基金supported by grants from the National Natural Science Foundation of China(31871416,31730020)the Natural Science Foundation of ZhejiangProvince of China(LY18C070001)the Hangzhou Science and Technology Bureau(20182014B01,20180533B27)。
文摘The UFMylation modification is a novel ubiquitin-like conjugation system,consisting of UBA5(E1),UFC1(E2),UFL1(E3),and the conjugating molecule UFM1.Deficiency in this modification leads to embryonic lethality in mice and diseases in humans.However,the function of UFL1 is poorly characterized.Studies on Ufl1 conditional knockout mice have demonstrated that the deletion of Ufl1 in cardiomyocytes and in intestinal epithelial cells causes heart failure and increases susceptibility to experimentally induced colitis,respectively,suggesting an essential role of UFL1 in the maintenance of the homeostasis in these organs.Yet,its physiological function in other tissues and organs remains completely unknown.In this study,we generate the nephron tubules specific Ufl1 knockout mice and find that the absence of Ufl1 in renal tubular results in kidney atrophy and interstitial fibrosis.In addition,Ufl1 deficiency causes the activation of unfolded protein response and cell apoptosis,which may be responsible for the kidney atrophy and interstitial fibrosis.Collectively,our results have demonstrated the crucial role of UFL1 in regulating kidney function and maintenance of endoplasmic reticulum homeostasis,providing another layer of understanding kidney atrophy.
文摘智能电网环境下,可控负荷参与低频减载（under frequency load shedding,UFLS）协助电力系统辅助调频,成为了新型低频减载研究的重点。新型低频减载策略对于负荷调节的时效性以及准确性要求较高,但负荷的通信状态和用户被控意愿等问题会对调频减载结果造成影响。该文综合考虑上述问题,对负荷通信延迟、丢包进行建模,同时考虑用户被控次数,提出了一种新型集群控制策略。该文首先分析了简化的发电机–负荷模型下的通信状态对调频减载结果的影响,而后基于此提出了考虑通信状态与控制均衡的负荷群参与低频减载的优化控制方案。最后以IEEE3机9节点系统模型为例,对优化控制策略的效果进行验证。仿真结果说明了控制策略对负荷群的控制具有低延时、高准确性的特点,能够保证控制动作的及时性,从而抑制系统频率下降深度,减少频率调节误差,大大降低了系统失稳的风险。
