Loss Estimation of Modular Multi-Level Converters using Electro-Magnetic Transients Simulation

The power losses of the Modular Multi-level Converter (MMC), recently introduced for HVDC transmission are evaluated in this paper. The paper discusses the two capacitor voltage balancing algorithms that have been proposed for the MMC operation based on; (a) ranking of capacitor voltage values and (b) pulse-width modulation (PWM) and the impact of control methods for the MMC on the power losses is also studied. The paper also compares the operating losses of MMC converter with the two-level conventional voltage sourced converters (VSC). In this paper, all type of converters power losses are estimated using a recently developed electro-magnetic transients simulation (EMT) model for accurate representation of switching losses and thermal performance in power electronic systems.