基于斯蒂芬逊迭代的刚性电力系统时域计算交替求解法

Steffensen Iteration Based Alternating Solution Method for Time-domain Computation of Rigid Power System

相比于传统电力系统,新型电力系统动态过程时间常数差异增大、外部扰动不确定性增强,基于交替求解的时域仿真分析面临着微分方程组刚性变强导致相应非线性代数方程组迭代求解过程中收敛性变差、计算效率降低等问题。为此,文中基于不动点迭代理论,分析了时域仿真交替求解过程迭代收敛机理,提出了改善新型电力系统时域仿真收敛性和计算效率的思路。针对传统交替方法收敛性恶化因素,提出基于标量式斯蒂芬逊迭代的改进交替求解法,并分析了所提方法的迭代计算效率。最后,基于IEEE标准16机68节点系统和某2 970节点实际电网,验证了所提方法的有效性。

Compared with the traditional power system,the time constant difference of the dynamic process of the new power system increases and the uncertainty of the external disturbance is enhanced.The time-domain simulation analysis based on the alternating solution faces the problem that the rigidity of the differential equations becomes stronger,which leads to poor convergence and reduced computational efficiency in the iterative solution process of the corresponding nonlinear algebraic equations.To this end,based on the fixed-point iteration theory,the iterative convergence mechanism of the alternating solution process of time-domain simulation is analyzed and the ideas to improve the convergence and computing efficiency of the timedomain simulation of the new power system are proposed.In view of the convergence deterioration factors of traditional alternating methods,an improved alternating solution method based on scalar Steffensen iteration is proposed,and the iterative calculation efficiency of the proposed method is analyzed.Finally,based on the IEEE standard 16-generator 68-bus system and an actual power grid with 2 970 buses,the effectiveness of the proposed method is verified.