混合级联多电平换流器最优冗余配置方法

Optimal Redundancy Configuration of Hybrid Cascaded Multi-level Converters

混合多电平换流器具备直流故障处理的能力,且使用的器件数目少,在直流架空线输电领域具有广泛的应用前景。首先在保证换流器正常运行和直流故障穿越能力的条件下,分析了HCMC中整形电路和导通开关的模块初始数目。根据器件承受应力的不同,分析了HCMC中整形电路和导通开关的重要器件的可靠性,以用于计算整形电路子模块和导通开关模块的可靠性。在保证换流器可靠性并兼顾经济性的原则下,提出HCMC中整形电路子模块和导通开关模块的冗余配置方法。最后在基于高电压大容量架空线输电系统的具体算例下,验证所提出的冗余配置方法的有效性。

The hybrid cascaded multi-level converter （HCMC） is characterized by the capability of handling DC-fault and fewer modules which enjoys promising application prospects in high voltage direct current （HVDC） transmission. Firstly, under the circumstance of steady-state operation and unchanged DC-fault ride-through capability, the initial quantity of modules in wave-shaping circuits and director switches of HCMC are calculated. And on the basis of their electrical stresses, reliability of important devices is evaluated and then reliability of sub-modules of wave-shaping circuits and modules of director switches can be deducted. Furthermore, the optimal redundancy configuration of waveshaping circuits and director switches are proposed which will guarantee reliable and economic performance of the converter. And case studies in HVDC transmission system verify the effectiveness of the proposed configuration strategy.