Quality and System Reliability
Technical Lecture Session
Reliability of Power Conversion Systems
Thermal Balancing Control, Modular Multilevel Converter, Lifetime Estimation, Reliability, Submodule Voltage Balancing
Modular multilevel converter is a typical topology suitable for high power level applications, such as HVDC transmission systems. Thermal loading imbalance of power semiconductor devices in different submodules due to the submodule capacitance mismatch is a problem of MMC operation, which leads to a negative effect on system reliability. In this paper, an improved active thermal balancing control method is proposed, with a better performance on capacitor voltage balancing and a lighter computational burden comparing with methods proposed previously.