含多端柔性直流的交直流电力系统静态电压稳定域构建方法

A Predictor-Corrector Algorithm for Forming Voltage Stability Region of Hybrid AC/DC Power Grid with Inclusion of VSC-MTDC

针对高比例可再生能源并网给交直流电力系统静态电压稳定评估带来的挑战,提出一种含多端柔性直流(VSC-MTDC)的交直流电力系统静态电压稳定域(SVSR)构建方法。该方法根据含VSC-MTDC的交直流电力系统静态电压稳定域边界(SVSRB)的拓扑特性,计及SVSRB搜索过程中换流站控制策略的转换,构建含VSC-MTDC的交直流电力系统SVSRB快速求解的预测-校正模型。首先,该模型借助连续潮流求取出交直流电力系统SVSRB上的初始临界点;然后,根据交直流系统SVSRB上相邻临界点之间的关联,以上一个已求SVSRB临界点为初值,通过所提预测-校正算法求解下一个SVSRB临界点,在此过程中,计及换流站运行参数越限带来的控制策略转换问题,实现SVSRB临界点的准确求解,以提升SVSR的构建精度和效率,增强交直流电力系统的电压稳定态势感知能力;最后,将所提方法应用于含VSC-MTDC的IEEE 5节点测试系统和IEEE 118节点测试系统中进行分析。结果表明,所提方法可实现交直流电力系统SVSR的准确、高效构建。

To address the voltage stability assessment of hybrid AC/DC power grid with high permeation of renewable energy,a voltage stability region(SVSR)of the hybrid AC/DC power grid with inclusion of voltage sourced converter based multi-terminal high voltage direct current(VSC-MTDC)is developed in this work.In the light of the topological characteristics of SVSR boundary(SVSRB),a predictor-corrector model is proposed to explore the SVSRB points with regarding the control strategy switching of the VSC-MTDC converter station.The continuation power flow(CPF)is employed to explore the first SVSRB point on the SVSRB,then rest SVSRB points on the SVSRB are explored by the proposed predictor-corrector model with the adjacent explored SVSRB point as the initial point.During this procedure,if the operational parameters of the converter station violate their limits,the control strategy switching of the converter station is switched following the proposed switching condition,which significantly enhance the computational accuracy and efficiency of the SVSRB.The performance of the developed approach is evaluated by the modified IEEE 5 and IEEE 118 test systems with the VSCMTDC.The results confirm that the proposed predictor-corrector approach exhibits a great performance in the computational accuracy and efficiency for forming the SVSR of the hybrid AC/DC power grid.