ABSTRACT With the rapid growth of offshore wind power, large‐scale renewable energy integration via modular multilevel‐converter based high‐voltage direct current (MMC‐HVDC) transmission systems has become essential. However, the large volume and weight of energy storage units constrain their practical deployment. To address this challenge, this paper proposes a novel series‐connected low‐voltage energy storage MMC topology. In this configuration, the energy storage submodule valve group is installed in a grounded container near the electrode line, while the cell‐hybrid submodule valve group under high voltage remains tower‐mounted. This design not only reduces insulation requirements and installation complexity but also achieves up to 17.3% cost savings while lowering valve tower weight and volume. Additionally, coordinated control strategies, including dynamic power smoothing and AC/DC fault ride‐through, are proposed to enhance system stability and resilience. Simulation studies based on PSCAD/EMTDC confirm the feasibility of the proposed system across various operational and fault scenarios, providing a practical and cost‐effective solution for offshore wind integration.
Y et al. (Thu,) studied this question.