Decoupled Interpolation-based Method for Numerical Simulation of Digital Controllers

All modern electric power systems employ digital controllers to ensure their secure and optimized operation. The time-domain simulation of such systems requires the solution of a set of hybrid (both continuous and discrete variables) differenti-alalgebraic equations. This is not an easy task, since the discontinuities introduced by the digital controllers lead to constant time-step reductions and an increased computational burden. A method that is able to effectively perform such simulations with no time step reduction is the interpolation-based method (IBM). In this paper, we extend the IBM into the decoupled interpolation-based method to increase the computational performance while maintaining the same high simulation accuracy. The performance and accuracy of the proposed methods is employed on several small and medium system models.