研究因模式谐振引起的统一潮流控制器(unified power flow controller,UPFC)与同步机(synchronous generator,SG)轴系之间的动态相互作用。借鉴复转矩系数法的建模思想,将含UPFC的电力系统区分为独立互联的2部分:SG轴系子系统与含UPFC...研究因模式谐振引起的统一潮流控制器(unified power flow controller,UPFC)与同步机(synchronous generator,SG)轴系之间的动态相互作用。借鉴复转矩系数法的建模思想,将含UPFC的电力系统区分为独立互联的2部分:SG轴系子系统与含UPFC的主系统。详细推导UPFC控制模式的数学表达式,针对含UPFC的IEEE第一基准系统和某实际220kV等值电网,从模式谐振角度分析UPFC与SG轴系的控制交互作用。为量化分析该谐振现象对系统次同步振荡稳定性的影响,基于留数指标提出一种模式谐振估计方法,能够近似估计次同步模式谐振时两闭环模式在复平面的位置。应用所提方法评估实际电网中UPFC对系统次同步稳定性的影响,得出UPFC谐振参数域。时域仿真验证理论分析的正确性。展开更多
In order to explore the precise dynamic response of the maglev train and verify the validity of proposed controller,a maglev guideway-electromagnet-air spring-cabin coupled model is developed in the first step.Based o...In order to explore the precise dynamic response of the maglev train and verify the validity of proposed controller,a maglev guideway-electromagnet-air spring-cabin coupled model is developed in the first step.Based on the coupled model,the stresses of the modules are analyzed,and it is pointed out that the inherent nonlinearity,the inner coupling,misalignments between the sensors and actuators,and external disturbances are the main issues that should be considered for the maglev engineering.Furthermore,a feedback linearization controller based on the mathematical model of a maglev module is derived,in which the nonlinearity,coupling and misalignments are taken into account.Then,to attenuate the effect of external disturbances,a disturbance observer is proposed and the dynamics of the estimation error is analyzed using the input-to-state stability theory.It shows that the error is negligible under a low-frequency disturbance.However,at the high-frequency range,the error is unacceptable and the disturbances can not be compensated in time,which lead to over designed fluctuations of levitation gap,even a clash between the upper surface of electromagnet and lower surface of guideway.To solve this problem,a novel nonlinear acceleration feedback is put forward to enhancing the attenuation ability of fast varying disturbances.Finally,numerical comparisons show that the proposed controller outperforms the traditional feedback linearization controller and maintains good robustness under disturbances.展开更多
文摘研究因模式谐振引起的统一潮流控制器(unified power flow controller,UPFC)与同步机(synchronous generator,SG)轴系之间的动态相互作用。借鉴复转矩系数法的建模思想,将含UPFC的电力系统区分为独立互联的2部分:SG轴系子系统与含UPFC的主系统。详细推导UPFC控制模式的数学表达式,针对含UPFC的IEEE第一基准系统和某实际220kV等值电网,从模式谐振角度分析UPFC与SG轴系的控制交互作用。为量化分析该谐振现象对系统次同步振荡稳定性的影响,基于留数指标提出一种模式谐振估计方法,能够近似估计次同步模式谐振时两闭环模式在复平面的位置。应用所提方法评估实际电网中UPFC对系统次同步稳定性的影响,得出UPFC谐振参数域。时域仿真验证理论分析的正确性。
基金Project(60404003)supported by the National Natural Science Foundation of China
文摘In order to explore the precise dynamic response of the maglev train and verify the validity of proposed controller,a maglev guideway-electromagnet-air spring-cabin coupled model is developed in the first step.Based on the coupled model,the stresses of the modules are analyzed,and it is pointed out that the inherent nonlinearity,the inner coupling,misalignments between the sensors and actuators,and external disturbances are the main issues that should be considered for the maglev engineering.Furthermore,a feedback linearization controller based on the mathematical model of a maglev module is derived,in which the nonlinearity,coupling and misalignments are taken into account.Then,to attenuate the effect of external disturbances,a disturbance observer is proposed and the dynamics of the estimation error is analyzed using the input-to-state stability theory.It shows that the error is negligible under a low-frequency disturbance.However,at the high-frequency range,the error is unacceptable and the disturbances can not be compensated in time,which lead to over designed fluctuations of levitation gap,even a clash between the upper surface of electromagnet and lower surface of guideway.To solve this problem,a novel nonlinear acceleration feedback is put forward to enhancing the attenuation ability of fast varying disturbances.Finally,numerical comparisons show that the proposed controller outperforms the traditional feedback linearization controller and maintains good robustness under disturbances.
