A double-input flyback DC/DC converter with single primary winding

The traditional isolated multiple-input converter (MIC) has a simple configuration and can be used in the system with two or more sources. However, it has some disadvantages such as complex transformer structure due to multiple primary windings, higher voltage stresses on the power switches, and only one source transferring energy to the load at any time. This paper proposes a novel family of isolated MICs, in which the number of the transformer primary windings is reduced and the voltage stresses on the power switches are lower than that in the traditional multiple-input converter. A double-input Flyback DC/DC converter is taken as an example to analyze its operation principle in detail, and the voltage conversion ratio between the input and output is also deduced. Then the power management strategy for the proposed converter to distribute the power reasonably to the sources is proposed and it achieved the priority of the new energy utilization. A 120 W prototype with two input sources was built and tested, and the experimental results are presented to verify the theoretical analysis and the effectiveness of the control strategy.