Accelerated Development of Hybrid Multilevel Converters

The development and integration of renewable energy sources have become paramount in meeting growing energy demands while curbing carbon emissions. Voltage-source-converter-based high voltage direct current (VSC-HVDC) transmission is crucial for integrating large-scale renewables into power grids, with modular multilevel converters (MMC) emerging as a leading technology due to their modularity, reduced harmonics, and enhanced efficiency.

Dr. Liwei Wang’s research team at the University of British Columbia, Okanagan, focuses on advancing hybrid multilevel converters, combining the benefits of conventional VSCs with those of MMCs. Utilizing OPAL-RT technologies, they employ advanced real-time simulation tools and hardware testbenches to develop and validate new converter topologies and control strategies swiftly.

An example includes the creation of a scaled-down prototype of a hybrid three-level converter with AC-side cascaded full-bridge submodules (SM), featuring complex circuitry, control loops and SM capacitor voltage balancing method. OPAL-RT’s simulation tools and FPGA-based platforms accelerate development by enabling switching modulation implementation and control algorithm execution.

The integration of Xilinx FPGA and RT-LAB/RT-XSG models allows for precise control and monitoring of SM operations, streamlining gating control through optical fiber interfaces between the OP45/0 and OP1200. Integrated measurement capabilities in OP1200 modules facilitate data logging for analysis.

In summary, OPAL-RT’s hardware testbenches and real-time control/simulation hardware expedite converter control prototyping, significantly advancing the development of new multilevel converters for efficient renewable energy integration.

Read the full edition of the magazine here.