A low component count high step up DC-DC converter using a coupled inductor

This paper introduces a non-isolated DC-DC boost converter specifically designed for renewable-energy applications, emphasizing low input-current ripple and a reduced number of components. The topology incorporates a coupled inductor with two windings, allowing the converter to achieve very high voltage step-up ratios at relatively modest duty cycles. Operating at lower duty ratios helps decrease conduction losses in the main switch and contributes to improved overall efficiency. The voltage conversion gain of the proposed high-step-up converter can be readily adjusted through two independent design parameters: the duty cycle of the primary switching device and the turns ratio of the coupled-inductor windings. This dual degree of freedom provides considerable design flexibility for meeting diverse application requirements. The proposed converter offers several notable benefits, including extremely high voltage amplification, reduced voltage stress on power semiconductor devices, a continuous input current profile, and a shared ground reference between the input source and the load. Furthermore, the use of a minimal number of components particularly semiconductor devices enhances efficiency and simplifies implementation. The topology also employs synchronized switching, which streamlines the control strategy and further improves performance. A detailed analysis of the converter's operating principle is presented, covering its various switching modes. To demonstrate its advantages, the proposed design is systematically compared with conventional high-gain converter topologies. Experimental verification is carried out using a 400 W laboratory prototype operating at a switching frequency of 50 kHz, which successfully steps up a 29 V input to a regulated 400 V output, thereby validating both the analytical results and the practical feasibility of the converter.