The Design Of High-power IPM Driver And Protection Circuit

IPM is identified as the further development product of the IGBT module and driver protection circuit,which is integrated with the main power device,driver protection circuit and radiator,so reducing the size of the system and shorten the development cycle,easier to use,it is the future direction of the power module.Currently,home appliances,automotive electronics,frequency control,switching power supply and other fields have been occupied by small and medium power IPM,at the same time,the market of high-power IPM is also expanding in electric cars,electric traction,photovoltaic power generation,wind power generation and other fields,the outlook is bright.However,the performance of driver and protection circuit of high-power IPM directly affects performance of its inner core power device IGBT and reliable and stable operation of converter system.The basic structure,working principle and the switching process of IGBT have been analyzed in detail,safe working area and failure causes of IGBT have been introduced.In addition,the requirements of IGBT driver circuit,various faults and the protection strategy have been studied in this paper.Based on the analysis of IGBT characteristics,a digitally programmable high-power IPM driver and protection circuit have been designed,including high isolation voltage DC/DC converter,signals isolation transmission part,the CPLD digital control section,the closed-loop multi-level dynamic gate driver section,a variety of faults detection and protection section,the state feedback section.The closed-loop multi-level dynamic gate driver structure was used in order to implement soft turn-on and soft turn-off.For short-circuit fault detection,using the strategy of two levels di/dt detecting two types of short-circuit fault can discover the short-circuit state in blocking time of the conventional V_CEdesaturation detection method,which greatly limits the short-circuit current.For the protection of fault occurred,the soft turn-off method based on multi-level dynamic gate resistance has been proposed,to avoid the traditional active clamp when the bus voltage oscillation resulting in the risk of half-bridge topology up and down IGBT straight.The control programs based on Altera's CPLD were designed and the driver circuits were developed.The experimental platform has been set up and double-pulse and short-circuit test were made for driver board designed.Compared to the conventional control strategies,the reliability and superiority of the driver-protection circuit designed in the paper is verified.