【作者】 黄崇鑫；

【导师】 王奔；

【作者基本信息】 西南交通大学 ， 电力系统及其自动化， 2009， 硕士

【摘要】 统一潮流控制器(UPFC)是由串、并联双变流器构成的FACTS设备。它在FACTS家族中,功能最齐全、最具有吸引力。它既可以把并联变流器作为静止同步补偿器单独运行来补偿系统无功和维持母线电压稳定,也可以把串联变流器作为静止同步串联补偿器单独运行来补偿输电线路电抗,而且它还可以通过联合串、并联变流器一起运行,实现母线端电压调节和输电线路有功、无功潮流控制。因此,针对UPFC的研究有其特殊的意义。控制系统是UPFC的核心,它的控制策略决定着整个UPFC系统的性能。因此,本文的研究重点是设计UPFC控制系统的控制策略。考虑到UPFC在dq坐标系下,表现为一个多变量、强耦合、非线性系统,本文把并联变流器和串联变流器分开,分别设计其各自的控制系统,来降低控制系统设计的难度。针对UPFC在dq坐标系下的数学模型,本文用两种控制策略设计出UPFC的控制器。第一种控制策略,通过引用状态反馈解耦附加PI控制策略和双环解耦附加PI控制策略来分别设计并联变流器和串联变流器的控制系统。这种控制策略的设计原理成熟,理论简单。但是,在设计控制系统过程中,运用的PI调节器较多,且PI调节器的比例和积分参数不易确定。另一种控制策略,是逆系统方法解耦附加变结构控制的控制策略。这种控制策略,首先采用逆系统方法,将并联变流器和串联变流器系统线性化解耦成伪线性系统,再运用变结构控制理论来设计出伪线性系统的控制律,最终构造出并、串联变流器的控制系统。这种方法的设计思路清晰,控制器参数稳定范围宽,确定容易。但是,它所运用的理论相对复杂,而且不够成熟。在设计好UPFC的控制系统之后,本文运用MATLAB软件,建立UPFC的系统仿真实验模型以进行仿真研究。仿真结果表明,本文所设计的控制策略能够使UPFC实现其各项功能,而且与引用的控制策略相比,控制系统具有相近的响应性能,可为设计UPFC控制系统提供一种新的思路。更多还原

【Abstract】 Unified power flow controller (UPFC) is a Flexible AC Transmission System (FACTS) device that is composed of a shunt converter and a series converter. It is the most versatile and attractive member in the FACTS family for the reason that it not only can use shunt converter as a Static Synchronous Compensator (STATCOM) to compensate the power system for reactive power and keep the bus voltage stability, and series converter as a Static Synchronous Series Compensator (SSSC) to compensate transmission line for the reactance independently, but also can be applied to regulating the bus voltage and controlling the active and reactive power flow on the transmission lines through combining the shunt converter with the series converter. Therefore, the researches on UPFC are proved significative.The control system whose control strategy determines the performance of the system is the heart of UPFC. Designing the control method for the UPFC control system is mainly focused to in this thesis. Considering the UPFC system in the rotating coordinate system (dq coordinate system) being a multi-variable, seriously coupling and nonlinear system, UPFC is separated into a shunt converter and a series converter to design the control systems for them independently so as to reduce the difficulty of designing.According to the mathematical model of UPFC in the dq coordinates system, two control strategies are employed to design its controllers in this thesis. The first control strategy is quoted in the paper that it takes the PI control based on state feedback decoupling method to design the shunt converter system and the PI control based on dual-loop decoupling method to devise the series converter system. The design principle of the first control strategy is simple and its theory is mature. However, it involves much difficulty that too many PI regulators of which the proportional and integral parameters are hard to be fixed are used during the whole designing process. So, the other control strategy that Inverse-System Method(ISM) and Variable Structure Control (VSC) theory are adopted to devise the UPFC control system is proposed in this thesis. In this method, first of all, the shunt converter and series converter are decoupled and linearized to be a pseudo-linear system by ISM. Then, the VSC control laws for the pseudo-linear system are laid out with the VSC control theory. Finally the control systems of the shunt converter and series converter are built by this strategy. Not only does the control strategy proposed in this thesis show a clear idea in the whole design process, but also the parameters of VSC controllers have wide stable scopes. However, the used theories are relatively complex and not mature enough.After finished designing the control system of UPFC, the models of UPFC are established to make simulations under the support of the Simpowersystem packages in the MATLAB software. It is indicated by the simulation results that the control strategy presented in this thesis can make UPFC achieve all its functions and its response performances be similar to the control system which is designed by citing the control methods. In this way, a novel idea can be provided in this paper when one designs the control strategies for UPFC control system.更多还原