考虑UPFC控制模式的N-1安全约束最优潮流及应用

N-1 Security Constrained Optimal Power Flow Considering Control Modes of Unified Power Flow Controller and Its Application

统一潮流控制器(UPFC)能有效解决电网潮流分布不均引起的一系列问题,近年来受到广泛关注。为进一步挖掘UPFC控制潜力、提高电网运行的安全性,提出了一种考虑UPFC控制模式的N-1安全约束最优潮流模型。首先,建立了考虑UPFC双回线结构的等效功率注入模型;其次,结合中国苏州南部500 kV实际电网算例,分析了UPFC控制模式对静态安全性的影响,指出了在潮流优化过程中考虑UPFC控制模式的必要性;最终,构建以静态安全裕度为目标的优化模型,并在优化的过程中充分计及UPFC控制模式对系统N-1故障后潮流分布的影响,实现系统运行参数与UPFC控制模式的共同择优。基于苏州南部电网的仿真算例表明,所提的潮流优化方法能够充分挖掘UPFC的静态控制潜力,显著提高系统的静态安全水平。

The unified power flow controller(UPFC) can effectively solve a series of problems caused by unbalanced power flow distribution, which has received extensive attention in recent years. In order to further explore the control potential of UPFC and enhance the safety of power grids, this paper proposes an N-1 security constrained optimal power flow model considering control modes of UPFC. Firstly, the equivalent power injection model considering the double-circuit structure of UPFC is established.Secondly, combined with the actual example of 500 kV power grid in southern Suzhou of China, the effect of UPFC control mode on static security is analyzed. The necessity of considering UPFC control mode in the process of power flow optimization is also indicated. Finally, the optimization model of the system aiming at minimizing static security margin is constructed. In the optimization process, the effect of UPFC control modes on the power flow distribution after the N-1 fault is fully taken into account to make the optimal selection of both system operation parameters and control modes of UPFC. The results of the simulation case of the power grid in southern Suzhou of China show that the proposed power flow optimization method can fully exploit the static control potential of UPFC and significantly improve the static security of the system.