提高暂态电压安全性的快投电容器组控制定值优化（英文）

Optimization of Control Settings for Fast Switching of Capacitor Banks to Enhance Transient Voltage Security

快投电容器组是工程上应对暂态电压安全的一种经济有效的紧急控制手段,然而其控制定值通常由试凑仿真进行整定。将快投电容器组控制定值的整定问题描述为多故障联立的混合整数动态优化问题,先求得各故障下的最优电容投入量,然后通过反推的方式得到相应的控制定值最优设定范围。对于混合整数动态优化问题的求解,先借助凸松弛方法将其转变为连续动态优化问题,并引入罚函数对松弛的整数变量在优化过程中进行逐步归整,然后采用多重打靶法将连续动态优化问题转化为非线性规划问题,最后采用简化空间序列二次规划算法对其进行求解。针对多重打靶法与简化空间序列二次规划算法中呈现的故障解耦与时间解耦特性,设计了两层并行框架以提高计算效率。以10机39节点系统和某省级165机1003节点系统验证了所提方法的有效性。

Fast switching of capacitor banks is an economical and effective emergency control means to deal with transient voltage security problem in engineering. But its control settings are usually set based on trial-and-error simulation. This paper establishes amixed-integer dynamic optimization model considering multiple contingencies to depict the problem of tuning control settings, and the optimal range of these control settings are obtained by inverse derivation from the optimal capacitors’ outputs corresponding to each contingency. To solve this mixed-integer dynamic optimization problem, the convex relaxation method is applied to transform it into a continuous dynamic optimization problem, meantime, introducing the penalty function to gradually force these relaxed variables into integer values during the optimization process. Then, the multiple shooting method is used to transform this dynamic optimization problem into a nonlinear programming model, which can be solved by the reduced space sequential quadratic programming algorithm. Finally, in terms of decoupling of contingencies and time intervals, a two-level parallel framework is designed to improve computational efficiency. Furthermore, simulation results on IEEE 10-machine 39-bus test system and a real 165-machine 1003-bus provincial system demonstrate the effectiveness of the proposed method.