Comparison of perspective dual interleaved boost converters with demagnetizing circuit

This paper presents a comparison of the performance of a non-isolated dual interleaved boost converter with coupled inductors and reset winding, while various practical realization of the coupled inductor with demagnetizing coil is being considered. The evaluation of the performance of individual alternatives is done for the steady-state operation. There are two alternatives that are being considered as perspective solutions (alternative 2, alternative 3), while their origin is represented by alternative 1. The main differences regarding magnetic circuit design are initially described. It was discovered that the solution with tight magnetic coupling (alternative 2) enables to reach twice the output power of solution with weak magnetic coupling (alternative 3), whereby the same volume of the magnetic core is used. Final experimental results have demonstrated that the investigated alternatives have different behavior when duty cycle operation range is considered. Both alternatives have been tested for their nominal power, whereby it was found that the designed prototypes achieved the peak efficiency above > 95% and alternative 2 showed much better output voltage stability. The operational range of the voltage gain was also investigated, and it was found that for the given turn’s ratio, the voltage gain is similar for both alternatives. The main difference was when duty cycle was considered, alternative 2 can reach required voltage gain at duty cycle which is half of the duty cycle of alternative 3. The presented modifications of original converter (alternative 1) might be a much proper solution for applications where tight constant DC bus voltage is required because of the improved operational characteristics.