Real-Time Simulation of VSC-based HVDC Systems using Rectification Capable Switching Function-Based 3-Level Inverter Models

This paper presents a simulation model of a 3-level Neutral-Point Clamped IGBT inverter bridge suitable for realtime simulation testing. The model is switching-function based but also works in rectifying mode. Because of the large number of individual switches that compose such an inverter, the switchingfunction approach produces exceptional computational speed gain when compared to piecewise time-segment linear algorithms such as SimPowerSystems, both in off-line and real-time modes. A benchmark comparison of the model used in an HVDC-VSC application with the RT-LAB simulator has shown a 10-fold increase in hard real-time computational speed.