Algorithms for the Accounting of Multiple Switching Events in Digital Simulation of Power-Electronic Systems

Digital simulation of power systems containing power electronics apparatus is challenging due to the need to account multiple switching events within one simulation time-step. This paper describes a family of algorithms, with varying levels of computational complexity, for accounting such switching events in digital simulations. The proposed algorithms are applicable for both off-line and real-time simulations. A comparative study on their performance such as harmonic content, errors in fundamental component and simulation time requirement is presented. A Pulse Width Modulated (PWM) Voltage Source Converter (VSC) based D-STATCOM system is used as a case study for simulations. Simulation results indicate excellent performance (accuracy and efficiency) in comparison with a fixed time-step algorithm using a small step-size.