直驱风电场并入弱交流电网次同步振荡(sub-synchronous oscillation,SSO)威胁电力系统安全运行,分析其次同步分量通路能够揭示系统内部次同步交互作用特性,并能够分别针对每条通路进行阻尼特性分析,目前尚无文献开展相关研究。针对上述...直驱风电场并入弱交流电网次同步振荡(sub-synchronous oscillation,SSO)威胁电力系统安全运行,分析其次同步分量通路能够揭示系统内部次同步交互作用特性,并能够分别针对每条通路进行阻尼特性分析,目前尚无文献开展相关研究。针对上述问题,该文首先建立直驱风电场并入弱交流电网系统闭环传递函数框图,并利用阻尼转矩法分析直驱风电机组直流电容主导的振荡模态。然后,基于传递函数框图,分析得到2条次同步分量通路:直驱风电场内部次同步分量通路以及直驱风电场和弱交流系统之间的次同步分量通路。最后,利用通路阻尼分析,结合时域仿真,分别分析直驱风电机组网侧控制器(grid side controller,GSC)参数对2条通路阻尼特性的影响。结果表明:GSC直流电压外环积分系数增大时,2条次同步分量通路的阻尼均减小;直流电压外环比例系数和电流内环比例、积分系数减小会导致直驱风电场内部次同步分量通路的阻尼减小。研究结果对阻尼控制器的设计有一定的指导意义。展开更多
liverrelated morbidity and mortality worldwide.It impacts nearly 300 million people.The current treatment for chronic infection with the hepatitis B virus(HBV)is complex and lacks a durable treatment response,especial...liverrelated morbidity and mortality worldwide.It impacts nearly 300 million people.The current treatment for chronic infection with the hepatitis B virus(HBV)is complex and lacks a durable treatment response,especially hepatitis B surface antigen(HBsAg)loss,necessitating indefinite treatment in most CHB patients due to the persistence of HBV covalently closed circular DNA(cccDNA).New drugs that target distinct steps of the HBV life cycle have been investigated,which comprise inhibiting the entry of HBV into hepatocytes,disrupting or silencing HBV cccDNA,modulating nucleocapsid assembly,interfering HBV transcription,and inhibiting HBsAg release.The achievement of a functional cure or sustained HBsAg loss in CHB patients represents the following approach towards HBV eradication.This review will explore the up-to-date advances in the development of new direct-acting anti-HBV drugs.Hopefully,with the combination of the current antiviral drugs and the newly developed direct-acting antiviral drugs targeting the different steps of the HBV life cycle,the ultimate eradication of CHB infection will soon be achieved.展开更多
文摘直驱风电场并入弱交流电网次同步振荡(sub-synchronous oscillation,SSO)威胁电力系统安全运行,分析其次同步分量通路能够揭示系统内部次同步交互作用特性,并能够分别针对每条通路进行阻尼特性分析,目前尚无文献开展相关研究。针对上述问题,该文首先建立直驱风电场并入弱交流电网系统闭环传递函数框图,并利用阻尼转矩法分析直驱风电机组直流电容主导的振荡模态。然后,基于传递函数框图,分析得到2条次同步分量通路:直驱风电场内部次同步分量通路以及直驱风电场和弱交流系统之间的次同步分量通路。最后,利用通路阻尼分析,结合时域仿真,分别分析直驱风电机组网侧控制器(grid side controller,GSC)参数对2条通路阻尼特性的影响。结果表明:GSC直流电压外环积分系数增大时,2条次同步分量通路的阻尼均减小;直流电压外环比例系数和电流内环比例、积分系数减小会导致直驱风电场内部次同步分量通路的阻尼减小。研究结果对阻尼控制器的设计有一定的指导意义。
文摘liverrelated morbidity and mortality worldwide.It impacts nearly 300 million people.The current treatment for chronic infection with the hepatitis B virus(HBV)is complex and lacks a durable treatment response,especially hepatitis B surface antigen(HBsAg)loss,necessitating indefinite treatment in most CHB patients due to the persistence of HBV covalently closed circular DNA(cccDNA).New drugs that target distinct steps of the HBV life cycle have been investigated,which comprise inhibiting the entry of HBV into hepatocytes,disrupting or silencing HBV cccDNA,modulating nucleocapsid assembly,interfering HBV transcription,and inhibiting HBsAg release.The achievement of a functional cure or sustained HBsAg loss in CHB patients represents the following approach towards HBV eradication.This review will explore the up-to-date advances in the development of new direct-acting anti-HBV drugs.Hopefully,with the combination of the current antiviral drugs and the newly developed direct-acting antiviral drugs targeting the different steps of the HBV life cycle,the ultimate eradication of CHB infection will soon be achieved.
