面向大容量海上风电机组的新型6相系统能量变换拓扑与控制关键技术

随着海上风电向深远海、大容量、中高压、直流汇集与传输方向发展，传统3相交流系统因固有电压和频率等稳定性问题，及不具备缺相容错运行功能，无法满足未来海上风电机组对安全性、可靠性和经济性的需求。本项目提出采用6相模块化多电平变流器（MP-MMC）驱动多相永磁同步电机（MP-PMSG）运行的新型海上风电机组系统，围绕其拓扑与控制深入展开。建立多工况下MP-PMSG的统一数学模型，研究基于矢量空间解耦控制的基础控制理论和缺相容错运行方法；提出6相子模块混合型MP-MMC拓扑结构，研究其混合调制方法和宽频域优化运行策略；探索装置运行参数波动、控制策略缺陷和各类故障等因素与装置运行稳定性之间的耦合机理，研究基于分数阶滑模控制理论的装置系统级优化运行策略，提升系统抗扰动性能和故障缺相运行能力，构建多工况下装置系统级多目标优化运行理论体系，为其安全、稳定、高效和经济运行提供理论依据和技术支撑。

With the development of offshore wind power to the direction of deep-sea, large-capacity, medium and high voltage, and DC collection and transmission, traditional three-phase AC systems cannot meet the demands for safety, reliability, and economy of future offshore wind turbines due to the stability problems of inherent voltage and frequency, as well as the lack of open-fault-tolerant operation function. In this proposal, a novel topology of offshore wind turbine system is proposed, which uses a six-phase modular multi-level converter (MP-MMC) to drive the multi-phase permanent magnet synchronous generator (MP-PMSG). The topology and control of the system are carried out in-depth. The unified mathematical model of MP-PMSG under multiple operating conditions is established to study the basic control theory and the open-fault-tolerant operation method based on vector decoupling control. The six-phase MP-MMC topology of the hybrid cascaded submodules, which consist of full bridge sub-modular (FBSM) and half bridge sub-modular (HBSM), is proposed to study the hybrid modulation method and the broadband optimization operation strategy. The mechanism of influence factors related to the operation stability are explored comprehensively, such as operation parameter fluctuations, control strategy defects, and various faults. The system-level optimal operation strategy based on fractional sliding mode control theory is further researched to improve the system anti-disturbance performance and open-fault-tolerant operation ability. The system-level multi-objective optimal operation theory of the novel offshore wind turbine under multiple operating conditions is constructed to provide theoretical basis and technical support for its safe, stable, efficient and economic operation.