桥臂交替导通换流器的模块最优冗余配置方法

桥臂交替导通换流器是混合多电平换流器的一种,在高电压大容量架空线直流输电领域具有广泛的应用前景。文中首先兼顾换流器正常运行和直流故障穿越能力,分析桥臂交替导通换流器整形电路和导通开关的模块初始数目。其次,根据器件承受应力和开关频率,结合器件实际结构,分析了桥臂交替导通换流器中整形电路和导通开关的重要器件的可靠性,以计算其整形电路和导通开关的模块可靠性。在此基础上,考虑换流器的可靠性和经济性,提出桥臂交替导通换流器中整形电路和导通开关中模块的冗余配置方法,筛选出最优冗余配置方案,并引入具体算例验证了所提出的冗余配置方法的有效性。

Optimal Redundancy Configuration of Modules in Alternate Arm Converter

The alternate arm converter(AAC)is one of the promising hybrid multi-level converters(HMCs)for high voltage direct current(HVDC)transmission over long-distance through high-capacity overhead lines(OHL). Firstly, the initial numbers of sub-modules in wave-shaping circuits and modules in the director switches are calculated to promise the steady-state operation and dc-fault blocking capability. Then the reliabilities of important devices are evaluated in terms of their electrical stresses, switch frequencies and actual structure. Furthermore, the redundant configuration method of wave-shaping circuits and director switches are proposed to sift the optimal redundant configuration, in which an objective function is established that reconciles reliability with investment in converters. Finally, the effectiveness of the proposed configuration strategy is verified by numerical calculation. This work is supported by State Grid Corporation of China(No. SGFJDK00DWJS1500031).