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

The transient-dynamic characteristics of the modern distribution network are complex, and multi-time-scaled. Generally, the contradiction between the computational speed and accuracyis 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. © 2020, Power System Technology Press. All right reserved.