CAJ | 학술논문

向无源网络供电的模块化多电平换流器型高压直流输电(modular multilevel converter based HVDC, MMC-HVDC)系统是柔性直流输电技术的一个重要应用领域，因此有必要对其控制与保护策略进行研究。基于MMC电磁暂态数学模型，建立了 d-q 同步旋转坐标系下 MMC 欧拉-拉格朗日(Euler-Lagrange，EL)数学模型，推导了适于 MMC 控制的无源控制规律，设计了内环电流无源控制器及向无源网络供电的 MMC-HVDC 系统定交流电压控制器。针对电网电压不平衡或交流系统不对称故障引起的负序电流，提出了基于 EL 模型的正负序电流无源控制器。为保证故障时系统能满足安全运行的条件，提出了故障时的控制保护策略。最后在PSCAD/EMTDC中对MMC-HVDC系统各种运行工况进行了仿真验证，并对正负序无源控制器和矢量控制器的控制性能做了仿真对比，仿真结果表明，所提出的控制器和控制保护策略具有良好的动稳态控制性能，便于工程实际应用。
향무원망락공전적모괴화다전평환류기형고압직류수전(modular multilevel converter based HVDC, MMC-HVDC)계통시유성직류수전기술적일개중요응용영역，인차유필요대기공제여보호책략진행연구。기우MMC전자잠태수학모형，건립료 d-q 동보선전좌표계하 MMC 구랍-랍격랑일(Euler-Lagrange，EL)수학모형，추도료괄우 MMC 공제적무원공제규률，설계료내배전류무원공제기급향무원망락공전적 MMC-HVDC 계통정교류전압공제기。침대전망전압불평형혹교류계통불대칭고장인기적부서전류，제출료기우 EL 모형적정부서전류무원공제기。위보증고장시계통능만족안전운행적조건，제출료고장시적공제보호책략。최후재PSCAD/EMTDC중대MMC-HVDC계통각충운행공황진행료방진험증，병대정부서무원공제기화시량공제기적공제성능주료방진대비，방진결과표명，소제출적공제기화공제보호책략구유량호적동은태공제성능，편우공정실제응용。
This paper investigates the control and protection strategies for modular multilevel converter based HVDC (MMC-HVDC) supplying passive network. Based on the electromagnetic mathematical model of MMC, the Euler-Lagrange (EL) mathematical model ind-q synchronous reference frame is developed. The passive control law of MMC is deduced, then the corresponding inner-loop current passive controller and constant AC voltage controller for MMC-HVDC is designed. To suppress negative sequence current caused by unbalanced grid faults, the decoupled positive-negative sequence passive controller based on EL mathematical model is proposed. Moreover the control and protection strategies under fault conditions are proposed to ensure the MMV-HVDC meet the requirement of its safety operation. Finally the MMC-HVDC systems under different operating conditions are simulated in PSCAD/EMTDC, the control performances of the positive-negative sequence passive controller are compared to that of the vector controller. The results show that the proposed controller and protection strategies have good dynamic performance and can be valuable to the practical system.