Modular Multilevel Converter




Worldwide Leadership in Modular Multilevel Converter Testing

The Modular Multilevel Converter (MMC) system offers many advantages over conventional voltage source converters and in DC power transmission, micro grid or renewable energy applications. MMC’s distinctive topology provides a wide variety of new features, necessitating the use of a sophisticated controller for extra control requirements.

Over the course of two decades, OPAL-RT has grown into a major real-time solution provider for testing and validating new MMC’s sophisticated controls within an HIL platform. OPAL-RT provides Rapid Control Prototyping technologies to help engineers develop and test new MMC control algorithms, enhancing technological solutions through the provision of MMC lab scale test benches.

OPAL-RT’s HIL MMC Solution

MMC HIL Testing real-time simulation solution

The OPAL-RT MMC solution includes a real-time simulator for the Power Grid network section. Connected to the real-time simulator, multiple I/O extension boxes specifically designed to interface with MMC controllers can be added depending on the number of cells required.

View simulators OP7020 and the OP5607, both specifically designed for MMC Control.

OPAL-RT HIL MMC testing solution can be used for:

  • Pole Control and Protection (PCP) functionality
  • Valve Base Controller (VBC) functionality
  • Communication Interface among controllers
  • Coordination among controllers for different MMCs
  • Evaluation of interactions between the MMC system and large-scale power systems.

MMC options support three submodule (SM) topologies: half-bridge, full-bridge and double-clamped.

Unique MMC Real-Time Simulation Capabilities

The FPGA MMC Models design in Simulink can be edited by users with RT-XSG. Always evolving to meet the highest possible standard in functionality and speed, the FPGA MMC Models provide capabilities including:

Supported MMC size in a standard VC707 FPGA1000 cells X 6 valves X 4 stations
Typical time-step of Grid connected model (CPU) 25 μs
Typical time-step of MMC Model (FPGA) 250 ns
Lowest achievable time step (FPGA)100 ns
Submodule typesHalf-bridge, Full-bridge, Clamped-double, T-type Mixed types of submodules in a valve, Custom
Features and supported faults Deadtime, Capacitance Discrepancy, Debugging Mode and all faults including submodule to ground, valve inductor to ground and between submodules of different valves

Turnkey Modular Multilevel Converter (MMC) Test Bench for Rapid Control Prototyping and Laboratory Research

MMC HIL Testing Turnkey Test Bench

The OP1200 offers researchers the ideal platform for performing rapid control prototyping (RCP) of novel power electronics converters on actual hardware. Researching innovative HVDC converter topologies with a test bench has never been easier, giving researchers more time to focus on applications including HVDC transmission and distributed energy resource interconnection.

Recommended Modular Multilevel Converter Systems

OPAL-RT offers eMEGASIM and HYPERSIM®, two innovative systems for MMC applications. The two systems follow the same MMC evolution are linked with FPGA MMC models. eMEGASIM is designed for working with Simulink and SimPowerSystems, providing values for multipurpose MMC applications. HYPERSIM offers dedicated graphical tools for HVDC grid connected real-time applications.

The Perfect System for Testing MMC Controls

The Perfect System for Testing MMC Controls

Discover how RTE was able to test control system functions in the France-Spain Interconnection and ensure its proper operation using HYPERSIM.

"The commissioning of INELFE replicas in the RTE laboratory was a clear success. Thanks to the test bench developed in collaboration with OPAL-RT, the technical challenges were analyzed prior to commissioning." - Sébastien Dennetière, RTE

Customer Success Stories

NR Electric uses RT-LAB real-time simulators to test the control and protection system for the Zhoushan Multi-terminal MMC-HVDC project.

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Rapid Control Prototyping enables development of control for novel converter topologies and HVDC networks at Imperial College London.

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CSG uses OPAL-RT real-time simulators and FPGA MMC simulators to build and simulate the world’s 1st three-terminal MMC-based HVDC systems.

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