针对UPFC内部多个SISO控制器单独运行效果良好，但联合运行时各控制器间存在负交互影响的问题，对UPFC各控制器间的工作关系进行了详细分析。结果表明，无功潮流控制引起的负交互影响程度与有功、无功控制器间的耦合程度有关。根据负交互影响存在的原因，应用分层结构设计了潮流解耦控制器，其中外层控制为内层控制提供参考信号，内层控制应用解耦控制策略来实现有功、无功解耦的功能。利用 PSCAD 建立了 UPFC的动态模型，比较分别采用以有功、无功电压为控制目标的常规潮流控制器及潮流解耦控制器时的仿真结果。验证了潮流解耦控制器的优越性，可有效解决无功潮流调节时与其他控制器间的负交互影响问题。%Unified Power Flow Controller (UPFC) contains multiple SISO controllers. These controllers run separately to good effect. When they jointly run, there are negative interactions between each controller. This paper analyzes working relations between each controller of UPFC. The results show that negative interactions, caused by reactive power flow control, relative to the degree of coupling between active and reactive power controllers. Then, depending on the cause of negative interaction, we design current decoupling controllerusing hierarchical structure. The outer controller provides reference signal for inner controller. The inner controller applies decoupling control strategy to realize the decoupling function. Finally, this paper establishes dynamic model of UPFC in PSCAD, and compares the simulation results of conventional power flow controller and trend decoupling controller. The results verify the superiority of trend decoupling controller, whichcan effectively solvenegative interaction problems caused by reactive power regulation.
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