Determination of Transistor Losses in a Resonant Voltage Inverter

The article addresses experimental studies of losses in a resonant inverter during its operation with different detuning degrees. The study is prompted by the increasingly growing need to achieve more efficient operation of powerful energy converters and improve the characteristics of power electronics products in terms of increasing conversion operating frequencies, reducing power losses in power components, and reducing dynamic overloads. Resonant voltage inverters are one of the most energy-efficient types of converters. In many cases however, numerical simulation does not demonstrate a radical difference in energy efficiency when the converter operates with different degrees of its detuning, which can cause the converter failure. The results of experimental studies are compared with the relevant data predicted using standard transistor models. A test laboratory bench has been assembled to determine the dependence of power loss in the resonant inverter transistors on frequency. A computer Spice model of a resonant inverter has been developed to explain the differences in losses depending on the detuning degree. The simulation results demonstrate that the dependence of transistor cell power loss on the frequency is not very strong with deviation from the resonance frequency, and do not show that it has such a significant effect. The conducted study makes it possible to see a somewhat approximate distribution of losses depending on the detuning type and draw a conclusion that the models of semiconductor shall undergo verification.