基于UPFC的电力系统低频振荡控制策略研究

发布时间：2018-04-27 22:04

本文选题：统一潮流控制器 + 附加阻尼控制器　；参考：《山东科技大学》2017年硕士论文

【摘要】：统一潮流控制器(Unified Power Flow Controller, UPFC)作为电力电子技术与自动控制技术相融合的产物,依托其先进的电网控制特性在电力系统中的应用日益增多。本文针对UPFC用于抑制电力系统低频振荡的机理进行了研究,设计了用于抑制电力系统低频振荡的UPFC主控制器和附加阻尼控制器。本文首先详细分析了统一潮流控制器的基本结构和工作原理,总结了 UPFC的运行方式,建立了 UPFC的基频动态模型和高频数学模型,探讨了在未加入附加阻尼控制器状态下统一潮流控制器对提高电力系统稳定水平的作用。而后,基于UPFC的基频动态模型和高频数学模型,分别设计了 UPFC的系统级控制器和装置级控制器。UPFC的系统级控制器采用基于两相旋转坐标系下的非线性解耦控制方案,该控制方案在UPFC的精确控制下具有快速跟踪给定值的优点,且在dq坐标下可以实现对有功和无功功率的独立控制。同时,本文采用了基于SPWM控制的UPFC开关函数分析方法,分析了的UPFC装置级控制器的工作原理和UPFC装置级控制器的控制参数对电力系统稳定性的影响。其次,为提高UPFC抑制电力系统低频振荡的效果,建立了装有UPFC的电力系统Phillips-Heffron模型,并通过对该模型的分析,设计了以发电机轴的机械功率作为反馈信号的附加阻尼控制器。最后,借助MATLAB/Simulink平台,搭建了双回线路中的系统主电路仿真模型、UPFC主控制器模型及附加阻尼控制器模型,并通过仿真验证了所设计的UPFC主控制器及附加阻尼控制器均具有抑制电力系统低频振荡的效果,电力系统在加入附加阻尼控制器后,系统的动态响应时间可进一步缩短,并可以更快的恢复稳定状态。
[Abstract]:Unified Power Flow Controller (UPFC), as a product of the integration of power electronics and automatic control technology, is increasingly used in power system based on its advanced power network control characteristics. In this paper, the mechanism of UPFC used to suppress low frequency oscillation of power system is studied. The main controller of UPFC and the additional damping controller are designed to suppress the low frequency oscillation of power system. In this paper, the basic structure and working principle of the unified power flow controller are analyzed in detail, the operation mode of UPFC is summarized, and the fundamental frequency dynamic model and high frequency mathematical model of UPFC are established. The effect of unified power flow controller on the stability of power system without additional damping controller is discussed. Then, based on the fundamental frequency dynamic model and the high frequency mathematical model of UPFC, the system-level controller and the system-level controller of UPFC are designed respectively. The system level controller of UPFC adopts a nonlinear decoupling control scheme based on two-phase rotating coordinate system. This control scheme has the advantage of fast tracking the given value under the accurate control of UPFC, and can realize the independent control of active and reactive power in dq coordinates. At the same time, the UPFC switching function analysis method based on SPWM control is used to analyze the working principle of the UPFC device level controller and the influence of the control parameters of the UPFC device level controller on the power system stability. Secondly, in order to improve the effect of UPFC to suppress the low frequency oscillation of power system, the Phillips-Heffron model of power system with UPFC is established, and through the analysis of this model, the additional damping controller with mechanical power of generator shaft as feedback signal is designed. Finally, with the help of MATLAB/Simulink platform, the main circuit simulation model and the additional damping controller model of dual circuit are built. The simulation results show that both the UPFC main controller and the additional damping controller can suppress the low frequency oscillation of the power system. The dynamic response time of the power system can be further shortened when the additional damping controller is added to the power system. And can return to stable state more quickly.
【学位授予单位】：山东科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM712

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