摘要
针对MMC(modular multilevel converter)型VSC-HVDC(voltage source converter-high voltage direct current)在并网运行模式与孤岛运行模式相互切换过程中易于发生切换失败、冲击电流大的难题,将虚拟同步控制运用到MMC的运行模式切换中。在虚拟同步控制和MMC基本原理的基础上,提出基于虚拟同步控制的MMC-HVDC(modular multilevel converter-high voltage direct current)无缝切换控制方法。引入的虚拟同步控制无需采用专门的同步控制电路,并网前可自动与电网同步;并网后能准确跟随电网频率,实现友好并网。当电网出现故障或需要检修时,MMC仍可孤岛运行,从而实现了运行模式的无缝切换。PSCAD/EMTDC平台下的仿真结果验证了所述控制策略的可行性和有效性。
Modular multilevel converter （MMC） based voltage source converter high voltage direct current （VSC- HVDC） systems are susceptible to large inrush currents or system failure when switching between the grid-connected and islanded operation modes. This paper introduces a virtual synchronization control to realize a seamless mode switch control method for the MMC to solve this problem. The virtual synchronization control method allows automatic synchro- nization with the grid without requiring any dedicated physical synchronization control units, and it follows the grid frequency accurately after being connected to the grid, realizing a friendly connection. When the grid fails or needs offline maintenance, the MMC can continue to operate in an islanded mode to realize a seamless switch between operation modes. The validity and effectiveness of the proposed control strategy is verified by simulaticns on PSCAD/EMTDC plat- form.
出处
《电力系统及其自动化学报》
CSCD
北大核心
2016年第11期88-94,共7页
Proceedings of the CSU-EPSA
基金
国家自然科学基金资助项目(51377051)
整晶圆特大容量IGBT器件研究项目(51277060)
智能电网中宽频域谐波及其串并联谐振问题与对策研究项目(51207048)
关键词
虚拟同步控制
无缝切换
模块化多电平直流输电
并网控制
孤岛运行
virtual synchronization control（VSC）
seamless transfer
modular multilevel converter-high voltage direct current（MMC-HVDC）
grid-connected control
islanded operation
