RC-IGBT型双向直流变换器驱动控制方法

Drive Method for Bi-directional DC Converter With RC-IGBT Devices

在此研宄了一种逆导型绝缘栅双极型晶体管(RC-IGBT)型双向直流变换器的低功耗驱动控制方法,主要包括两个阶段:在快速恢复二极管(FRD)开通阶段采用负电平驱动,取代传统的高电平驱动,降低FRD深度饱和,减少FRD的导通损耗;而在FRD关断阶段通过退饱和控制来降低FRD的饱和程度,减小FRD的关断损耗。同时,为了避免FRD模式下退饱和控制引起IGBT开通死区增大,造成占空比受限,通过对脉冲宽度调制(PWM)进行改进,消除了退饱和控制对死区的影响。实验表明:退饱和控制可以有效地改善RC-IGBT工作于FRD模式时的反向恢复特性,同时所提改进型PWM方法能够保证IGBT驱动信号占空比的有效范围。

A low-power drive control method for reverse-conducting insulated gate bipolar transistor(RC-IGBT) type bi-directional DC converter is discussed, which mainly includes two stages. During the fast recovery diode (FRD) turn-on stage, a negative level drive is used to replace the traditional high level drive for reducing the deep saturation and the conduction losses of FRD.During the FRD tum-off instant,the saturation of the FRD is reduced by the desaturation control, and then the turn-off loss of the FRD is reduced. Moreover, to avoid the increase of the dead zone caused by the FRD in the desaturation control and the limitation of the duty ratio, the enhanced pulse width modulation (PWM) is proposed.Experiments show that the desaturation control effectively improves the reverse recovery characteristics of the RC-IGBT in the FRD mode,and the improved PWM method can guarantee the efTective range of duty cycle of the IGBT drive signal.