A trans-inverse coupled-inductor semi-SEPIC DC/DC converter with full control range

© 1986-2012 IEEE. This letter proposes a single switch magnetically coupled dc-dc converter with a high voltage gain. The unique features of the converter are summarized as follows: 1) voltage gain of the converters is raised by lowering its magnetic turn ratio; 2) wide control range (0< D< 1); 3) continuous current from the source that makes it a suitable candidate for renewable energy applications; and 4) there is no dc current saturation in the core due to the presence of capacitor in the primary winding of the inductor. The feasibility of the proposed converter is studied in details supported by circuit analysis and simulation results. Furthermore, the proposed converter is analyzed and compared with other converters with similar features. Finally the superior performance of the circuit is validated experimentally

A Family of High Step-Up A-Source Inverters with Clamped DC-Link Voltage

A family of novel impedance source inverters based on an auto-transformer is presented in this manuscript. The proposed topologies utilize minimal coupled inductors turns ratio to obtain high voltage boost ability in comparison with previous magnetically coupled impedance source inverters. The impedance source inverters using coupled inductors attain high voltage gain in smaller shoot-through interval compared to transformer-less group, but they suffer dc-link voltage spikes due to leakage inductances of their coupled inductors. So, in presented inverters, absorbing circuits are utilized to reduce these spikes. Besides that, absorbing circuits lead to higher voltage boost ability, lower shoot-through duty cycle and better modulation index. In addition, all the novel structures have continuous input current which is suitable for renewable energy sources such as fuel cell and photovoltaic systems. Theoretical analysis in steady state and simulation results are presented to verify the inverters performance.Scopu