| Abstract |
A direct DC/Low Frequency AC Dual-Active-Bridge (DAB) converter with Zero Voltage Switching, Resonant Transition (ZVS-RT) has been tested at 75 kHz at power levels up to 23 kW. lt has dual angle, constant frequency phase shift control, and is soft-switched with high efficiency in a large part of the output V-I-plane. There is an optimum set of control angles for each operating point. Efficiency up to 93,3% has been measured at DC output, and 89% at AC output. IGBT dynamic saturation at turn-on from zero current into a positive di/dt is shown to be an important loss factor, together with the diode forward recovery voltage spike. Experiments show the influence of package stray inductance on voltage wave forms and efficiency. The resonant transition is disturbed by semiconductor and stray component effects. |
