Investigation of the limiting factors of the dead time minimization in a H-bridge IGBT inverter

Abstract

In order to avoid a bridge shoot-through, a simultaneous on-state of both IGBTs in a bridge leg is strictly forbidden. Therefore, the complementary switch is commonly turned on with a dead-time interval to ensure a complete turn-off the other IGBT. Due to the longer tail-current interval of IGBT switching process, for the purpose of absolute safe operation, the interlocking time to is empirically in microsecond range which normally is much longer than necessary. This raises the questions about whether the tail-current is real a matter of concern, and how can the dead-time be minimized? An IGBT H-bridge inverter with an adjustable interlock time was built in this project, and a series of experiments were carried out to investigate the limiting factors of the dead-time minimization.