模块化多电平动态电压恢复器的研究

Study of modular multilevel dynamic voltage restorer

提出了一种新型模块化多电平动态电压补偿器(Modular Multilevel Dynamic Voltage Restorer,MM-DVR),对其工作原理进行了介绍,对单相模块化多电平换流器的组成和工作特性进行了分析。对几种常用的补偿策略进行了对比介绍,对所采用的最小电压补偿策略的原理和实现方法进行了阐述,介绍了所采用的瞬时电压dq分解电压暂降检测法的工作原理和应用优势。对比目前常用的换流器调制策略,介绍了最近电平逼近调制方式,并分析了最近电平逼近调制方式在动态电压恢复器应用中的优势。通过在PSCAD/EMTDC环境下搭建的仿真模型对模块化多电平动态电压恢复器的工作特性和补偿效果进行了验证。

A new type modular multilevel dynamic voltage restore （MM-DVR） is proposed, its working principle is introduced and the topological structure and working principle of single phase modular multilevel converter are analyzed. The minimum voltage compensation strategy is adopted in modular multilevel dynamic voltage restore and its principle is elaborated. Several commonly used compensation strategies are compared. The principle and advantages of voltage sag detection method based on d-q conversion of voltages are introduced. The general modular multilevel converters （MMC） are compared, the nearest level modulation is chosen and its advantages adopted in dynamic voltage restore are analyzed. Through the simulation in PSCAD/EMTDC environment, the working characteristics and compensation effect of modular multilevel dynamic voltage restore are verified.