摘要
在模块化多电平换流器(modular multilevel converter,MMC)中,针对阀控层的直流电压控制,在载波移相调制方式的基础上,提出了改进型子模块电容电压均衡控制方法,以降低开关器件的开关频率。针对极控层的直流电压控制,推导了稳态时MMC电流离散数学模型,设计了电流内环离散控制器,实现了系统直流电压控制和功率解耦控制。为抑制由交流系统故障引起的直流电压波动,提出了含直流电压控制环节的外环有功功率控制器,以提高系统的持续运行能力。算例仿真结果验证了所提方法的有效性。
In allusion to DC voltage control in valve control layer of modular multilevel converter （MMC）, based on carrier phase shifted pulse-width modulation （PWM） an improved capacitor voltage balancing control method for submodules is proposed to decrease the switching frequency of switching devices. In allusion to DC voltage control of polar control layer, a discrete mathematical model of MMC current under steady state is derived and an inner-loop current discrete controller for MMC is designed to implement the DC voltage control and decoupled power control of MMC based HVDC （MMC-HVDC） power transmission system. To suppress the DC voltage fluctuation caused by the fault occurred in AC system, an outer-loop active power controller containing DC voltage controller is put forward to enhance the continuous operation ability of MMC-HVDC power transmission system. The validity of the proposed method is verified by results of example simulation.
出处
《电网技术》
EI
CSCD
北大核心
2013年第9期2403-2409,共7页
Power System Technology
基金
国家863高技术基金项目(2013AA050105)
国家自然科学基金项目(51177042)~~
关键词
模块化多电平换流器
高压直流输电
直流电压控制
离散数学模型
电容电压平衡
modular multilevel converter
HVDC power transmission
DC voltage control
discrete mathematical model
capacitor voltage balancing
