Hybrid Modular Multilevel Rectifier: A New High-Efficient High-Performance Rectifier Topology for HVDC Power Delivery

This letter presents a novel three-phase rectifier topology, namely hybrid modular multilevel rectifier (HMMR) for medium or high voltage ac-dc power conversion applications. Compared with modular multilevel converter (MMC), up to 50% of the IGBTs and submodules (SMs) including capacitors can be replaced by simple high-efficient high-voltage line-frequency diode stacks. HMMR can keep the key benefits of MMC, such as modularity, reliability, and excellent harmonic performance, while significantly reducing the power losses, costs, and volume. Unlike the thyristor-based line-commutated converter (LCC) rectifier, HMMR can operate under different grid conditions and can even provide reactive power support, making it a strong candidate of rectifier unit for point-to-point MV and HV power delivery. The feasibility of proposed converter is verified by the simulation as well as experimental results.