基于线性-定弧长混合校正的连续追踪暂态仿真算法

延拓参数算法在电力系统连续潮流分析中已获得成功应用,该算法进一步发展为连续参数化轨迹追踪(CPTT)仿真算法,应用于暂态仿真计算中。CPTT方法避免了传统仿真方法由代数奇点引起的数值积分发散问题。但是,CPTT仿真算法中常用的切向预测存在一定缺陷,在故障开始阶段或故障趋于平缓阶段,可能出现预测失败,导致线性校正发散而无法继续。本文提出一种线性-定弧长混合校正技术的CPTT方法,解决了上述预测失败问题;通过合理选择延拓参数,不仅克服定弧长校正可能引发的振荡问题,而且改善了仿真曲线出现"削峰平底"的现象,即轨迹失真问题。本文算法收敛精度等价于一般隐式仿真算法,计算速度优于传统CPTT仿真算法,算例证明了该方法的合理性和工程应用前景。

A Transient Stability Simulation of Continuous Trajectory Tracing Based on Linearity-Arc Length Hybrid Correction Technology

The continuous parameterization-based tracing method has been used for power system continuation power flow. It is further developed into transient stability simulation, called continuous parameterization-based trajectory tracing (CPTT) method. The numerical integration problem caused by algebraic singularity can be avoided by CPTT method. However, tangential prediction of CPTT method might fail to solve when fault occurs or disappears, which could lead to numerical instability of linearity correction. In this paper, a novel CPTT method was presented by using linearity-arc length hybrid correction technology. Prediction problem can be then solved. Furthermore, the numerical instability of linearity correction can be solved by selecting reasonable continuous parameters. Finally, the problem of simulation trajectory distortion can be solved. The test results show that the new method is equivalent to classical implicit integration method in accuracy, and better than classical parameter-switching tracing method in computing speed, and has good prospect of engineering application.