Electronic Science and Technology ›› 2021, Vol. 34 ›› Issue (8): 71-78.doi: 10.16180/j.cnki.issn1007-7820.2021.08.012

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The Loss Calculation and Analysis of Hybrid Modular Multilevel Converter Considering Sub-Module Balancing Constraint


  1. School of Electronic and Electrical Engineering,Shanghai University of Engineering Science, Shanghai 201600,China
  • Online:2021-08-15 Published:2021-08-17
  • Supported by:
    National Natural Science Foundation of China(61603242);Mechanical and Electronic Engineering Subject Construction Project(2018xk-A-03)


The voltage level and transmission capacity of flexible DC transmission projects are constantly increasing, and the loss of modular multilevel converter has attracted much attention. At present, the commonly used loss analysis methods are for the analysis and calculation of full-bridge and half-bridge modular multilevel converters. Based on the operating characteristics of the hybrid modular multilevel converter, a hybrid MMC loss analysis method that considers the constraints of submodule voltage sharing is proposed in this study. According to the reference direction of the voltage and current of the hybrid MMC bridge arm in a control cycle, the sub-module switching situation is analyzed.The mathematical model of the hybrid MMC is established according to the switching situation of different types of sub-modules for loss analysis calculation. By extracting the loss data of the insulated gate bipolar transistor to fit and establish a mathematical model, the detailed analysis of the mutual influence between the junction temperature and the loss of the converter is carried out. Finally, experimental simulation analysis is performed to verify the accuracy of the proposed method.

Key words: modular multilevel converter, voltage balancing constraint, hybrid MMC, converter loss, junction temperature estimation, loss analysis, switching loss, conduction loss

CLC Number: 

  • TN710