模块化多电平电压源换流器的数学模型

Modeling of Modular Multi-level Voltage Source Converter

为了得到能够直观反映装置运行规律的数学模型,为装置性能的研究、主电路参数设计及控制系统设计等提供研究基础,将开关函数和瞬时功率结合,建立模块化多电平换流器(modular multi-level converter,MMC)的时域解析数学模型。该模型给出换流器交直流电压、桥臂电流电压、桥臂子模块电容电压总和以及单个子模块电容的电压电流的时域解析表达式,可以正确反映上述各电气量与主回路参数的关系。计算和仿真结果表明,该建模方法是可行的,并具有较高的精确度。

A mathematical model that can distinctly reflect device operation principle is extremely needed for deep research on steady and transient performance analysis, main circuit design, control system design etc. In this paper, by using a combination of switch function and instantaneous power, a mathematical model describing time domain analytic function of Modular Multi-Level Converter was presented. Based on it, the transient value of converter AC and DC voltage, arm voltage and current, sub-module capacitor voltage sum in an arm, sub-module capacitor voltage and current related to main circuit parameter can be calculated. From the calculation and simulation results, it is concluded that the modeling method is available and its calculation results are comparatively precise.