Research on the Model and Control Strategy of One Multi-Module-Converter Based BTB VSC-HVDC

This paper presents a model and control strategy for multi-module-converter based back-to-back VSC-HVDC system. The converter operates with a fairly low switching frequency, and thus it is applicable to select high-power electronic device such as IGCT or GTO in a high-power application. A mathematical model is developed for the overall multi-module cascade BTB VSC-HVDC system. A controller is designed systematically for the HVDC system based on the developed system model. Performance of the overall HVDC system and effectiveness of the designed controller are evaluated based on digital time-domain simulations in the MATLAB software environment.