【作者】 陈芝奔；

【导师】 康积涛；

【作者基本信息】 西南交通大学 ， 电力系统及其自动化， 2012， 硕士

【摘要】 目前统一潮流控制器(UPFC)是FACTS器件家族中功能最为强大,综合了控制各种电力系统基本参数的能力。论文分别从统一潮流控制器的工作原理,模型,对电力系统的影响以及控制策略上进行了初步的研究。首先论文对统一潮流控制器的研究现状及其工作原理进行了介绍。引入简单双机模型用于解释UPFC的工作原理。通过对UPFC的基本结构的描述,分析其并联侧和串联侧的运行机理,并介绍了UPFC的运行模式。介绍电力系统仿真软件PSAT (Power System Analysis Toolbox)及其仿真原理和动态仿真模型,搭建含统一潮流控制器的三机九节点系统和四机两区域模型。仿真分析UPFC对三机九节点系统的静态影响。最后仿真单台和双台UPFC在短路故障下对四机两区域系统的暂态影响,可以给出初步结论UPFC能够改善系统的稳态和暂态性能,同时多台UPFC也会促进系统性能的稳定。接着论文介绍了统一潮流控制器系统的参数设计,给出UPFC容量的定义,以及UPFC的直流电容和变压器在选取容量大小时需要注意的关键因素。总结前人的经验和方法,分别引入UPFC的串联侧模型和并联侧模型,单独对并联侧和串联侧作解耦控制设计,并仿真验证了并联侧的解耦控制的良好性能。采用PSCAD对UPFC进行搭建模型。为了对比模糊控制和常规PI控制在UPFC的控制效果,在UPFC的整体建模中采用的控制策略主要是常规的PI控制。通过大量仿真给出较好的PI参数,最后通过仿真验证了UPFC在稳态下能够控制母线电压和线路潮流,在暂态下能够改善系统的稳定性,提升故障点电压,抑制短路电流和功率波动。最后,采用模糊控制理论,设计UPFC的控制器。首先介绍了模糊控制的概念,接着对UPFC的串联侧作模糊控制设计,将有功和无功的功率差作为模糊控制的输入量,详细介绍了模糊PI控制的设计步骤和参数的选取过程,给出了模糊PI控制的控制器参数。通过系统仿真分析了模糊PI控制和常规PI控制在UPFC的优劣,验证了模糊PI相比常规PI在响应时间和超调上都有改善,提高了UPFC的稳态性能和暂态性能。更多还原

【Abstract】 Nowadays,the Unified Power Flow Controller(UPFC) is the most powerful device in the FACTS family, which have the ability of controlling kings of power system’s fundamental parameters. The paper primarily do some studies on operation mechanism, model and control strategy of UPFC for getting deep insight into the impacts of UPFC on power system performance.Firstly, the UPFC’s current research situation and working principle is introduced. The simple two machines model is adopted to explain UPFC’s working principle. The basic structure of UPFC is described and the UPFC’s parallel and series parts’operation mechanism are respectively analyzed. We have introduced kinds of UPFC’s working modes.We do some introduction of PSAT (Power System Analysis Toolbox) software and its simulation principle and simulation models.The PAST software is adopted to set up multi-machine systems with UPFC model,which include WSCC three machines nine nodes system and four machine two area system. The WSCC three machines nine nodes system including UPFC is simulated to analyze its steady state performance.We have simulated four machine two area system including UPFC in the short-circuit fault and have preliminary conclusions that UPFC can improve the steady state and transient performance of the system and multiple UPFCs will promote power system’s stability.Then the paper describes the unified power flow controller’s system parameters and the definition of the UPFC capacity. And we should notice some key factors when UPFC DC’s and transformer’s capacitors are selected. The paper adopted UPFC’s series part and parallel part models and decoupled control strategy to designe two parts controllers.Then we have simulated parallel part and verifed that the control strategy is feasible for the systems. In orde to compare fuzzy control strategy and PI (Proportional-Integral) control strategy, the PI control is adopted to design the series and parallel part controllers in the whole UPFC model.The UPFC model is set up by PSCAD software,which is simulated to analysis the steady-state and transient-state performance. Through large numbers of simulation,we get the good PI parameters and find that UPFC with PI control is able to imrove the the steady-state and transient-state performanceFinally, the Fuzzy control is applied to UPFC controllers. Firstly,we have introduced the concept of Fuzzy control and designed UPFC’s series part with Fuzzy-PI control.The active and reactive power difference are the fuzzy control input.We have introduced the Fuzzy-PI control design process and the selection of parameters in detail.The simulation shows that the Fuzzy-PI control have improved response time and overshoot and improve steady state and transient state performance of UPFC than the conventional PI control.更多还原