A Study on Numerical Integration Method for Long-Term Power System Dynamic Simulation

Abstract

Large power system frequency/voltage excursion due to severe faults in trunk transmision line or major generating unit may cause trip-off of other facilities and result in large-scale power system blackout. To prevent such blackout, development of an accurate and fast long-term power system dynamic simulation tool is required. In the development stage, selection of a numerical integration method available for the step size adjustment and development of a scheme for the adjustment are principal subjects.
The trapezoidal and the 2nd Gear methods were selected as possible candidates for the step size adjustment from the viewpoint of numerical stability, then the trapezoidal method are finally selected from the viewpoint of accuracy and applicability to power system dynamic simulations.
A new scheme for the automatic step size adjustment is proposed for the trapezoidal method to achieve fast simulation of the long-term power system dynamics. The validity of the proposed scheme is verified through simulation studies on a single-machine-to-infinite bus system.