有源型模块化多电平换流器桥臂全状态平均值仿真模型

Full-state Arm Average Value Model for Simulation of Active Modular Multilevel Converter

为了提高有源型模块化多电平换流器(MMC)的仿真效率并保证足够的计算精度,提出一种适用于有源型MMC的桥臂全状态平均值仿真模型。基于动态平均化理论,首先推导了有源型MMC的桥臂平均值数学模型及等效电路模型。然后,结合装置离散化伴随模型,建立了不同运行状态下的桥臂平均值仿真模型。最后,通过电路整合和化简,得出桥臂全状态平均值模型。该模型聚焦于桥臂内部子模块的低频动态共性,能够准确反映桥臂整体暂态特性,其计算速度不受子模块个数的影响。此外,该模型还能够用于有源型MMC闭锁状态下的仿真研究。基于PSCAD/EMTDC建立的仿真实例验证了所提模型的有效性。

To improve the simulation efficiency of the active modular multilevel converter(MMC)with enough computational accuracy,this paper proposes a full-state arm average value model appropriate for the simulation of the active MMC.Based on the dynamic averaging theory,this paper firstly deduces the average value mathematical model and the equivalent circuit model for the arms of the active MMC.Combined with the device discretized companion model,the average value models are established for the simulation of the arm in different operation states.Finally,the full-state arm average value model is obtained by the integration and simplification of circuits.This model focuses on the low-frequency dynamic commonalities of the submodules inside the arm,and can accurately reflect the overall transient characteristics of the arm.The simulation speed of this model is not affected by the number of submodules.Besides,the proposed model can also be used in the simulation of the active MMC in the blocking state.The simulation examples based on PSCAD/EMTDC verifies the validity of the proposed model.