宇航高可靠宽占空比磁隔离MOSFET驱动电路研究

A Highly Reliable Magnetic isolated MOSFET Driver with Wide Range of Duty Cycles for Aerospace Power Supply

基于驱动变压器的磁隔离MOSFET驱动电路已经在宇航二次电源中得到广泛应用,针对现有磁隔离驱动电路存在的问题,结合宇航应用特点提出新型磁隔离驱动电路的6条设计目标,基于此设计了一种新型磁隔离驱动电路。详细分析了该电路的工作原理,推导出参数计算公式,并完成了全面的仿真验证。该电路具有:Vgs驱动电压幅值不随占空比发生变化以确保MOSFET高效导通;工作占空比可达90%以上且无失真传输;Vgs零负压从而保证功率MOSFET单粒子性能不受影响;占空比瞬变时驱动波形无异常震荡等特点。新一代宇航高效高功率密度电源拓扑的核心驱动问题得到解决,对提高星载二次电源效率具有重要的意义。

MOSFET gate driver based on magnetic isolation has been widely used in aerospace power supply.In order to solve the disadvantages of the traditional magnetic coupling circuits,six design criteria which meet the space power supply needs has been proposed first,then a novel magnetic isolated MOSFET driver has been designed.The driver's operation principle is analyzed,and the design method for its key parameters is presented.The performance analysis is validated via simulation.The driving voltage amplitude is nearly constant which ensures MOSFET fully conducted.Duty cycle can reach above 90%without any distortion.Vgs turn off voltage remains above zero,which ensures MOSFET performance is not affected by SEE.And most importantly,the driving voltage has no ringing when duty cycle changes rapidly,which improves the reliability to a new level.This highly reliable driving circuit is perfectly suitable for next generation space high power density topology requiring high frequency and wide range of duty cycles.