A Fast and Stable Algorithm for Switching Treatment During EMTP-type Simulations

Simulation algorithm for switching treatment is essential for the electromagnetic transient simulation of the power electronic networks. A fast and stable switching treatment algorithm, which considers multiple switching events in the same time-step, is put forward in this paper. The proposed algorithm uses linear interpolation to estimate the accurate switching time instant for eliminating the switching delay. Combining the iterative switching status searching algorithm aims to obtain the accurate switch combination firstly. Then, the flexible multi-step backward Euler method with half time-step is employed to remove the numerical oscillations completely, and avoid costly recalculation and re-triangulation of the system admittance matrix. Finally, the variables are linearly interpolated back to the initial time-mesh, according to the second backward Euler integration step. Compared with the results of two typical cases from PSCAD/EMTDC, the proposed algorithm is proved to be more accurate and stable.