摘要
为了均衡MMC各个子模块的电容电压,在采用载波移相调制方式的基础上,对传统的电容电压平衡方法进行了改进。通过在排序前依据桥臂电流方向引入不同的保持系数,使欲投入的子模块保持原来的状态,降低了开关器件的开关频率。对于MMC的控制,基于MMC两相旋转d-q坐标系的欧拉-拉格朗日EL数学模型和无源性,通过阻尼注入方法,提出了一种由状态期望稳定平衡点、状态及状态误差设计无源控制规律的新方法,并用该方法设计了无源控制器。该控制器可实现MMC-HVDC系统有功功率和无功功率的解耦控制,使MMC具有较好的动静态性能。最后在PSCAD/EMTDC中搭建了21电平MMC-HVDC系统的仿真模型,仿真结果表明,改进的电容电压平衡控制方法和无源控制器是有效的。
This paper investigates an Euler-Lagrange model based passive control for modular multilevel converters based HVDC（MMC-HVDC） system. The topology and operation principle of MMC are introduced first, and for the purpose of balancing the sub-module（SM） capacitor voltages, an improved capacitor voltage values based raking method is proposed which depends on two different maintaining factors that can significantly reduce the averaging switching frequency. Then based on the Euler-Lagrange（EL） mathematical model in synchronous d-q coordinates and its passivity, the passive control with expected state balance points, states and state errors is proposed by damp injection. The proposed control algorithm can realize the decoupled control of real and reactive power, and maintain very good static and dynamic performances. Finally 21-level MMC-HVDC model in electromagnetic transient（EMT） simulation program PSCAD/EMTDC shows the effectiveness and correctness of all the proposed control methods.
出处
《电工技术学报》
EI
CSCD
北大核心
2013年第10期224-232,共9页
Transactions of China Electrotechnical Society
基金
"十二五"国家科技支撑计划资助项目(2010BAA01B01)
关键词
模块化多电平换流器
子模块
电容电压均衡
欧拉-拉格朗日数学模型
无源控制
Modular multilevel converter（MMC）, sub modules, capacitance voltage balancing, Euler-Lagrange（EL） mathematical model, passive control
