高压大容量柔性直流换流阀关键设计和发展趋势

Key Design and Development Trend of High-voltage Large-capacity VSC Valves for HVDC

柔性直流输电技术具有控制灵活性高、无换相失败问题和动态无功支撑能力强等突出优点,已广泛应用于点对点输电、背靠背联网和构建直流电网等场景。柔性直流换流阀通过功率器件的频繁开断来实现交、直流的电能转换,是柔性直流输电工程的核心设备。首先,结合工程实践经验,系统梳理并提出了不同应用场景下柔性直流换流阀的关键设计要求,对比分析了柔性直流输电工程中常用的功率器件及柔性直流换流阀拓扑,展望了柔性直流换流阀的发展趋势。此外,针对2种典型的未来应用场景,对比了不同的技术方案,可为柔性直流输电技术应用于高压大容量远距离输电场景提供有益借鉴。

Owing to its obvious advantages such as high control flexibility,no commutation failure and strong dynamic reactive power support capability,the voltage sourced converter based high-voltage direct-current(VSC-HVDC)transmission technology has been widely applied in scenarios including point-to-point transmission,back-to-back interconnections and DC grids.As a core piece of equipment in VSC-HVDC transmission engineering,the VSC valve achieves AC/DC energy conversion through frequent switching of power electronic devices.In this paper,the key design requirements for VSC valves in different application scenarios are systematically summarized by combining with practical experiences accumulated in engineering,the commonly used power devices and VSC valve topologies in VSC-HVDC transmission engineering are compared and analyzed,and their development trends are projected.In addition,different schemes for two typical application scenarios in the future are also compared,providing reference for the applications of VSC-HVDC transmission technology in high-voltage,large-capacity and long-distance transmission scenarios.