Redundancy Configuration And Its Control For High Voltage High Power Converter

Power electronic technology makes the use of electrical more flexible,and it has been widely used in all the processes of power generation,transmission,distribution and consumption,which is an important technology for the upgrade of power systems.With more and more power electronic equipment displacing traditional devices,power systems become more efficient and controllable,but it also set up many potential problems,equipment reliability is one of them.Semiconductor based converters are important and fragile in the grids,especially in high voltage high power applications,so it is of vital importance to guarantee the safe and reliable operation.Redundancy is a common method for reliability improvement,which is simple and easy,and the modular design of high voltage high power converter is beneficial to redundancy configuration,so it is a valuable research work to combine them together.Firstly,the concept of reliability is applied to power electronic equipment,and the mathematical model is built with probability theory,parameters such as reliability function,failure rate and mean time to failure are used to evaluate the reliability,two reliability models for power electronic switches and three reliability models for power electronic system are discussed and compared.Then H-bridge topology and MMC topology with CPS-SPWM are analyzed,the redundancy configuration and redundancy control for them are unified.Parallel structure,series structure and universal module structure are discussed,warm standby and cold standby operations are compared,and some suggestions are presented for the redundancy design.Finally,the redundancy topology for different EPT is designed,an optimal design method for the balance of reliability and economy is proposed,which is suit for all the modular structure,a simulation model of EPT is built on Matlab/Simulink,and the feasibility and validity of the proposed method is verified.