High step-up DC-DC converter based on three-winding coupled inductor

In this paper a novel topology for high step-up DC-DC converter is introduced. The converter makes use of coupled inductor and voltage multiplier cell to reach the desired high step-up voltage gain. The main advantages of the proposed converter are simple topology, high step-up voltage gain, continuous input current, recycling the energy of the leakage inductance of the coupled inductor, and utilizing only one active switch with reduced voltage stress. Reduced switch voltage stress results in selection of switch with low on-resistance which improves the efficiency. Operational principles of the converter in steady state are studied and an analytical approach is used to attain voltage gain and switch voltage stress. Some of the determinant factors are compared with similar coupled inductor converters. Modular extension of the proposed converter to reach even more step-up voltage gain is also discussed. Finally appropriate performance of the proposed topology is verified by simulating a 30V/400V, 750W converter.