On-State Desaturation Current Prediction Model Of IGBT For DC Circuit Breaker And Its Application

VSC-HVDC has the characteristics of active power and reactive power can be controlled independently and flexibly.It provides an effective solution for large-scale renewable energy access and is an important choice of national energy strategy.Hybrid DC circuit breaker is the key equipment to remove faults in VSC-HVDC system.Insulated Gate Bipolar Transistor(IGBT)is the core device widely used in DC circuit breakers.The reliability of IGBT is the basic guarantee of good breaking ability of DC circuit breakers.It is necessary for IGBT to avoid the high loss phenomenon of on-state desaturation.Therefore,it is of great significance to establish a predictive model to analyze the on-state desaturation characteristics of IGBT under the target operating conditions and rationally configure the device driving parameters accordingly.In this paper,IGBT in the working condition of hybrid DC circuit breaker is taken as the main research object.,the working characteristics of IGBT used in circuit breaker are analyzed,and an on-state desaturation current prediction model of IGBT considering electrothermal comprehensive stress is established,which can be used to predict on-state desaturation in target operating conditions,and the extraction method of model parameters is proposed.An IGBT test platform with device protection function is built.The protection principle,the selection principle of main equipment,the control system and output voltage adjustable driver are expounded.The test platform can effectively reduce the damage risk of IGBT in high current stress test and the function of the platform is checked by experiment.The platform is used to test IGBT and the prediction model is verified based on the measured data.The influence of relevant factors on the on-state desaturation current of IGBT is analyzed by the model.Based on the established on-state desaturation current prediction model of IGBT,and taking the 500 kV hybrid DC circuit breaker to be adopted in Zhangbei Flexible DC Demonstration Project as an object,the configuration scheme of IGBT driving voltage for DC circuit breaker is proposed,and using the model to guide the parameter design of practical engineering.