RT22 | Experimental Assessment of Modular Multilevel Converters for HVDC Transmission Systems

Modular Multilevel Converters are widely used in high-power applications such as High-Voltage Direct Current (HVDC) transmission due to scalability, modular configuration and high-quality power. For industrial applications, hundreds of power cells have to be connected in a cascade to reach high-power ratios. However, most of the current academic research is validated using prototypes equipped with a low number of power cells. Consequently, this paper presents the testing and start-up procedure of a back-to-back Modular Multilevel Converter test-bench based on OPAL-RT real-time controllers and power stage. Partial experimental results obtained with 120 power cells MMC are presented for HVDC operation.