柔性直流输电系统分层协同故障诊断和容错控制研究

Due to the advantages such as large transmission capacity and long transmission distance, High-Voltage Direct-Current (HVDC) transmission technology has become the most effective technology for grid-connected and long-distance transmission of large-scale renewable energy generation. The main power devices are important basic elements of the HVDC transmission system. The failure of the main power devices will pose a huge challenge to the reliable operation of the system. This project will study the reliable operation of the HVDC transmission system under the fault of the main power devices by adopting fault diagnosis and fault-tolerant control. The project will study the hierarchical coordination fault diagnosis based on depth learning, and diagnose the faults of single or multiple main power devices synergistically through the system layer, arm layer and module layer of the HVDC transmission system; study hierarchical fault-tolerant control based on the reconfiguration of the internal circuit of the module, and optimize the system fault structure and fault-tolerant control by refactoring the module circuit; study three stress hierarchical coordinative control based on multi-objective optimization model, and optimize main power device temperature, voltage and current stress distribution in the system by coordinating and controlling the fault-tolerant control of system layer, bridge arm layer and module layer, so as to realize the fault diagnosis and fault-tolerant control of the HVDC transmission system under the fault of the main power device and improve the reliability of the HVDC transmission system. The project will lay a theoretical and experimental foundation for promoting the application and development of HVDC transmission system in renewable energy generation.

柔性直流输电凭借其输电容量大、输电距离远等优点已成为实现大规模可再生能源发电并网和远距离传输的最有效技术。主功率器件是柔性直流输电系统的重要基本元素，其发生故障将对系统的可靠运行带来巨大的挑战。本项目将通过故障诊断和容错控制实现主功率器件故障下柔性直流输电系统可靠运行。本项目将研究基于深度学习的多层协同故障诊断策略，通过系统层、桥臂层和模块层协同诊断单个或多个主功率器件故障；研究基于模块电路重构的系统分层容错控制，通过重构模块电路优化系统故障结构以及容错控制；研究基于多目标优化模型的三大应力分层协调控制策略，通过协调控制系统层、桥臂层和模块层的容错控制，优化系统主功率器件温度、电压和电流应力的分配，从而实现主功率器件故障下柔性直流输电系统故障诊断和容错控制，提高柔性直流输电系统的可靠性。本项目将对推动柔性直流输电系统在可再生能源中的应用与发展奠定理论和实验基础。

柔性直流输电凭借其输电容量大、输电距离远等优点已成为实现大规模可再生能源发电并网和远距离传输的最有效技术。主功率器件是柔性直流输电系统的重要基本元素，其发生故障将对系统的可靠运行带来巨大的挑战。本项目主要对柔性直流输电系统的故障诊断和容错控制展开了相应研究，主要研究成果如下：研究了模块化多电平变流器信息网络模型，并在此基础上研究了基于深度学习的模块化多电平变流器故障诊断策略；研究并提出了基于电路重构以及电网电压畸变时的模块化多电平变流器的容错控制策略；研究了模块化多电平变流器主功率器件应力分布机理，并在此基础上研究并提出了模块化多电平变流器的性能优化策略。搭建了一台模块化多电平换流器实验平台，针对所提出的模块化多电平变流器系统故障诊断以及容错控制的方法进行了技术验证。本项目将对推动柔性直流输电系统在可再生能源中的应用与发展奠定理论和实验基础。