Modular Multilevel HVDC Converter using Switched Capacitor Submodule

日期 : Sep 2017 - May 2018

Renewable Electric Power Generation is becoming popular these days, as it is environmental friendly. These sources produce DC Voltages that are required to be transmitted over long distances across different countries to transmit bulk power to load centers, with the help of HVDC transmission lines. As, most of the load operates on AC so the DC must be converted to AC near the Load Centers. Modular Multilevel Converters (MMC) are amongst the most popular techniques for high voltage DC-AC conversion. A new Switched Capacitor Submodule (SCSM) has been proposed for the converter that will be capable of blocking any kind of DC side fault, increasing the system reliability and there is no need of High Voltage DC Circuit Breakers. Each submodule is capable of producing three level voltage by switching the MOSFETs in defined sequence with the help of Pulse Width Modulated (PWM) Signals. Moreover, the voltage balancing is done with half the number of voltage sensors, compared to other MMC topologies, thus making the implementation of the control system simpler.