南方电网多直流调制控制的交互影响与协调

受限于现有的小扰动分析软件无法对高压直流输电系统(HVDC)控制回路建模,直流控制器的分析和设计严重依赖于时域仿真,无法获得对于控制器性能的机理性认识.文中利用NETOMAC仿真软件中NEVA的自定义控制器功能,定义了新的HVDC控制回路模型.利用根轨迹技术,分析了2008年度南方电网3回直流调制采用广域信号反馈控制时各自的不同性能,发现了由于HVDC调制引发的模态谐振现象,这种现象的存在使得直流调制控制的阻尼效果被削弱.最后,提出一种利用多直流协调控制消除模态谐振的方案,并通过NETOMAC的时域仿真加以验证.

Interaction and Coordination of Modulation Controllers of Multi-infeed HVDC in CSG

Due to the limitation of modeling of HVDC control loops in small signal stability analysis,current works on HVDC modulation controller design strongly depend on time-domain simulation,which cannot give more insight into mechanism of controllers.The paper induces a novel HVDC modulation loop model through customized control function of NEVA.By using the root locus method,different impacts of three-HVDC modulation control of China Southern Power Grid(CSG) with wide-area feedback signals on CSG's oscillation modes are analyzed.A strong nonlinear modal interaction phenomenon called 'modal resonance' is observed,and modal resonance may result in deterioration of damping.Finally,a scheme of coordination of multiple HVDC modulation to mitigate modal resonance is proposed,which is validated by NETOMAC time-domain simulation.