Isolated bias power supply for IGBT gate drives using the fly-buck converter

For high power IGBTs in the AC motor drive and inverter applications, the reliable gate drive bias supply is critical to the robust performance of the system. This paper introduces the Fly-Buck DC/DC converter to generate isolated bias rails for the IGBT gate driver. Comparing to the traditional isolated switched power supply topologies, the Fly-Buck converter offers several advantages such as good cross regulation, line transient response and low EMI, whilst its design is kept simple and flexible for multiple output configuration. It is suitable to provide positive/negative voltage rails for single or multiple IGBTs to ensure the stable turn on/off of the IGBT. In the paper, the operation analysis and design of the Fly-Buck is presented, and its application and benefits in supplying IGBT gate drive are discussed.