Implementation of a Fixed Timing Coupled Inductor Soft-Switching Inverter

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Virginia Tech


In research environments, many soft switching inverters have been conceived, simulated, designed, implemented and proven to have advantages over hard switched inverters. To date however, no soft-switching inverters have reached commercial production for various reasons. The fixed timing coupled inductor soft-switching inverter is of interest because in simulation and previous implementation it exhibits load and source adaptability using simple RC timer circuitry and can be implemented with low cost active auxiliary devices. During the course of this implementation, it is noted that attempting to use excessively small/inexpensive active auxiliary devices has reliability ramifications related to device packaging. The issue of auxiliary active device reliability is conjectured upon by referencing available datasheet information, application specific requirements, device pulse testing and secondary research findings related to semiconductor failure characteristics. It is also noted that aspects of the simple fixed timing circuitry operation, in conjunction with coupled inductor and saturable inductor design, can lead to coupled inductor saturation if not properly addressed. Simulation is performed and validates various causes for this non-ideal behavior.



fixed timing, soft switching, inverter, coupled inductor