基于特征值分析的配电网多速率暂态仿真性能评估方法研究

Research on Computational Performance of Multi-rate Transient Simulation in Distribution Network Based on Eigen-value Analysis

现代配电网暂动态特性呈现出复杂多变、多时间尺度等特征,对单一速率电磁暂态仿真在计算速度和精度方面提出了挑战,一般通过多速率仿真解决计算速度与精度这一矛盾问题。然而,现有的多速率仿真涉及的电网分区、时间步长计算、接口位置评估等缺乏理论量化依据支撑。针对这一问题,提出了全系统多速率状态空间矩阵的特征值计算方法,通过特征值瞬时评估多速率仿真的数值准确性与稳定性。进一步地,提出了基于改进节点法的全系统状态空间矩阵生成方法,可将其应用于大规模配电网离散矩阵的特征值计算。采用CIGRE 14节点中压配电网标准算例,通过特征值计算与仿真结果的比对,验证了所提特征值评估方法的可行性与有效性。

The transient-dynamic characteristics of the modern distribution network are complex,and multi-time-scaled.Generally,the contradiction between the computational speed and accuracy is resolved through multi-rate simulation.However,the existing multi-rate simulation involves the factors such as grid partition,time step calculation,interface location evaluation and so on,which lack the theoretical support.In order to solve this problem,this paper proposes an eigenvalue calculation method for the multi-rate state space matrix of the whole system,and then the numerical accuracy and the stability of the multi-rate simulation are evaluated instantaneously by the eigenvalue.Furthermore,a method for generating the state space matrix of the whole system based on the modified node analysis method is proposed.Then it is applied to the eigenvalue calculation of discrete matrix of a large-scale distribution network.Using the benchmark example of CIGRE 14-bus medium-voltage distribution network,the effectiveness of the proposed evaluation method is verified through comparing the eigenvalue calculation with the simulation results.