Abstract: Power electronic switches are usually modeled by L/C-based small time-step model to satisfy the speed requirement of real-time simulation.However,the parameter setting of this switch model is complicated,and may cause significant transient errors during the high-frequency switching processes.This paper presents a general small time-step model based on the parameterized history current sources,which is independent of the real physical circuits and integration methods.The proposed model is represented by two Dommel’s discrete circuits corresponding to the switches at ON and OFF state,respectively.The equivalent admittances of these discrete circuits are of the same value.The history current expressions of these circuits have four coefficients,two of which are determined by the steady-state characteristics of switches.The other two coefficients are optimized based on the transient error analysis of the small time-step model.In the case study,the general small time-step model with the optimized history current sources shows the absolute advantage of accuracy over the traditional one in simulating the ideal switch.