Modeling and Simulation of Flyback DC-DC Converter under Heavy Load

Appropriate simulation models of converters under heavy loads are crucial for designing a high reliability converter system. This paper presents the modeling and simulation of flyback DC-DC converters operating in heavy loads such as over-current and under-voltage modes, based on the concept of energy self-holding. An existing converter, which was once damaged in the experiment due to a short-circuited output, is analyzed by the presented simulation models and is found to be likely damaged under a heavy load. According to the simulated results, the circuit and parameters of the converter are modified. The redesigned converter can work safely in both steady state and heavy load modes.