摘要
提出一种基于模块化多电平结构的电气化铁路不断电过分相装置拓扑,该拓扑无需变压器,可直接接入27.5 k V等级的牵引供电系统。拓扑采用两相式结构,两个交流输出端子分别接于中性段与一条牵引供电臂,直流支撑电容支路的中点接在钢轨上。建立了所提出拓扑的数学模型,并与应用于直流输电领域的三相式模块化多电平换流器(modular multilevel converter,MMC)拓扑进行了比较,两相式MMC拓扑的公共直流电容电压中不仅包含直流分量,还包含工频基波分量。基波分量的大小与两相输出电流之和成正比,与电容容值成反比。设计了装置级控制策略,提出对上下桥臂电流都采用直接电流反馈的闭环控制方式,保证装置交流输出电流具有较好的波形。利用PSCAD仿真和样机实验验证了所提拓扑及控制策略的正确性和有效性。
A novel topology of uninterruptible phase-passing device based on modular multilevel converter （MMC） structure is proposed in this paper. It can be connected to the 27.5 kV traction power supply system without transformer. The topology is two-phaSe. Two AC output terminals are connected to neutral section and traction feeder, respectively and the middle point of common capacitors is connected to ground. The mathematical model of the topology is built and comparison between topology proposed in this paper and three-phase MMC topology used in HVDC is analyzed. The voltage of common capacitors contains both DC and AC components. The amplitude of AC component is directly proportional to the sum of two output current and inversely proportional to the capacitance. The device-level control strategy is designed and the direct current feedback loop control method of the upper and lower leg current is proposed to ensure fine output current waveform. Correctness and effectiveness are verified through PSCAD simulation and prototype experiment.
出处
《电网技术》
EI
CSCD
北大核心
2015年第10期2901-2906,共6页
Power System Technology
基金
国家自然科学基金项目(51107065)~~
关键词
不断电过分相
模块化多电平
两相式变流器
控制策略
uninterruptible phase-separation passing
modular multilevel converter
two-phase converter
control strategy
