A Novel Discharging Control Strategy for Modular Multilevel Converter Submodules without Using External Circuit

A novel discharging control strategy is proposed and implemented for submodules in modular multilevel converters (MMCs). By sequentially controlling the arm currents of a MMC to the arm resistors, all submodule capacitors are discharged safely and rapidly without adding additional devices and circuits, resulting in improved performance and reduced cost. Both open- and closed-loop control methods are evaluated for effectiveness of the new control strategy. Simulation and experimental results are provided to validate the new control strategy.

[1]  Maryam Saeedifard,et al.  Operation, Control, and Applications of the Modular Multilevel Converter: A Review , 2015, IEEE Transactions on Power Electronics.

[2]  Bin Wu,et al.  A Simple and Cost-effective Precharge Method for Modular Multilevel Converters by Using a Low-Voltage DC Source , 2016, IEEE Transactions on Power Electronics.

[3]  Zheng Xu,et al.  Self-Start Control With Grouping Sequentially Precharge for the C-MMC-Based HVDC System , 2014, IEEE Transactions on Power Delivery.

[4]  Fan Zhang,et al.  Hardware design of a 1.7 kV SiC MOSFET based MMC for medium voltage motor drives , 2018, 2018 IEEE Applied Power Electronics Conference and Exposition (APEC).

[5]  Michael W. Degner,et al.  DC bus capacitor discharge of permanent magnet synchronous machine drive systems for hybrid electric vehicles , 2017, 2016 IEEE Applied Power Electronics Conference and Exposition (APEC).

[6]  Fan Zhang,et al.  Development of a 1.5 MVA Universal Converter Module for Traction Drive and Utility Applications , 2005, 2005 IEEE 36th Power Electronics Specialists Conference.

[7]  Samir Kouro,et al.  Circuit Topologies, Modeling, Control Schemes, and Applications of Modular Multilevel Converters , 2015, IEEE Transactions on Power Electronics.

[8]  Alireza Nami,et al.  Modular Multilevel Converters for HVDC Applications: Review on Converter Cells and Functionalities , 2015, IEEE Transactions on Power Electronics.

[9]  Anandarup Das,et al.  A method for charging and discharging capacitors in Modular Multilevel Converter , 2011, IECON 2011 - 37th Annual Conference of the IEEE Industrial Electronics Society.

[10]  H. Akagi,et al.  Control and Experiment of Pulsewidth-Modulated Modular Multilevel Converters , 2009, IEEE Transactions on Power Electronics.

[11]  Longya Xu,et al.  Low frequency operation and comparison study of 4-level hybrid clamped converter with modular multilevel converter , 2017, 2017 IEEE Energy Conversion Congress and Exposition (ECCE).