Power converters in system-level real-time simulations are usually emulated by using an L/C associated discrete circuit (L/C-ADC)in a fixed time-step simulation. However, there are several potential inaccuracies in L/C-ADC based simulation results: unrealistically high virtual loss especially at high PWM frequencies, fictitious current oscillations between the Land C represented devices, and limitations in the impedance ratio between OFF and ON switch representations. Therefore, there are potential benefits from using switched-resistance representations of electronic switch devices. Fortunately, such simulation has recently become feasible due to the higher performance of newer computer processor cores. However, the switched-resistance representation of switches requires reliable prediction of the ON/OFF statuses of the switch devices before each simulation time-step. This paper describes a method for highly reliable prediction of ON/OFF switch statuses for voltage source converters with switched-resistance switch representations in fixed time-step simulation. Real-time simulation results are presented for systems containing 2-level and 3-level voltage source converters. The technique could be practised in non-real-time simulation for much more complicated converters.
T. Maguire, S. Elimban, E. Tara and Y. Zhang, "Predicting Switch ON/OFF Statuses in Real Time Electromagnetic Transients Simulations with Voltage Source Converters," 2018 2nd IEEE Conference on Energy Internet and Energy System Integration (EI2), Beijing, 2018, pp. 1-7, doi: 10.1109/EI2.2018.8582110.
KEYWORDS: real-time simulation, voltage source converter, switched resistance simulation