基于柔性直流阻尼控制器与附加励磁阻尼控制器协同抑制次同步振荡研究

Coordinated control of SSO via MMC_SSDC and SEDC

针对包含模块化多电平换流器型直流输电(MMC_HVDC)的交直流混合输电系统中出现的次同步振荡(SSO)问题,对基于MMC_HVDC的次同步阻尼控制器(MMC_SSDC)与附加励磁阻尼控制器(SEDC)的协同抑制问题进行了研究。首先针对待研究的交直流混合输电系统,设计了MMC_SSDC和SEDC的结构并针对实际算例整定其相位补偿及增益参数;然后分别从理论分析和系统电气阻尼特性的矢量叠加关系方面对MMC_SSDC和SEDC协同抑制策略的可行性进行了研究;最后在PSCAD/EMTDC上搭建模块化多电平换流器为335电平的交直流混合系统时域仿真模型,仿真结果验证了结论的正确性和协同抑制方案的有效性。研究结果表明:MMC_SSDC和SEDC在增加系统电气阻尼的效果上不仅不会相互影响且基本满足矢量叠加关系,利用两者协同抑制SSO的方案是可行的。

Aiming at the sub-synchronous oscillation（ SSO） of hybrid AC-DC transmission system which contained modular multilevel converter based High Voltage Direct Current（ MMC_HVDC）,the coordinated control of sub-synchronous oscillation damping controller（ MMC_SSDC） and supplementary excitation damping controller（ SEDC） was researched. Firstly,aiming at the hybrid system,the structure and parameters of MMC_SSDC and SEDC were designed. Then,the practicability of the coordinated control of SSO via MMC_SSDC and SEDC was studied in both theory and electrical damping characteristics. Finally,the simulation model with 335 levels was built on PSCAD/EMTDC,and the results validated the correctness of the conclusion and the efficiency of the coordinated control strategy. The results indicate that MMC_SSDC and SEDC can superpose each other on increasing the electrical damping characteristic of whole system,and the coordinated control strategy proposed in this paper is practicable.