Adaptive order and step-size differential transformation method-based power system transient stability simulation

Abstract

ABSTRACT Power system transient stability simulation is of critical importance for utilities to assess dynamic security. Most of the commercially available tools use traditional Forth order Rang-kutta (Rk4) method to simulate transient stability, which is computationally intensive. This made difficult to identify any insecure contingency before it happens. It is already proved that differential transformation method (DTM) requires less computational effort and has improved simulation speed. But, it still requires further improvement regarding its accuracy and performance efficiency. This paper introduces a novel power system transient stability simulation method based on adaptive order and step-size DTM. Using the proposed method, the order and step-size are varied based on the estimated local solution error at each time step. The accuracy and speed of the proposed simulation approach are investigated in comparison with classical DTM and Rk4method using IEEE 9 and 39-bus test systems. The simulation results reveal that the proposed method increases the simulation speed by 14–34% and 70–80% compared with the classical DTM and Rk4 based simulation, respectively. compared with the DTM-based simulation, the proposed method also provides 77.84% to 78.32% and more than 90% accurate simulation results for IEEE 9 and IEEE 39 bus test systems, respectively. Therefore, the proposed simulation method is faster and relatively accurate and can be applied for online transient stability monitoring power system network.