This article introduces a new fully soft switched ultra-high step-up quadratic converter. The proposed converter benefits from several advanced features including high voltage gain at low duty cycle, low switch voltage stress, low sum of diodes voltage stress, switching at ZVS condition for switches, low ripple continuous input current, and common ground between the input and load. These advantages are achieved by integrating the quadratic structure with an auxiliary circuit consisting of coupled inductors, switched capacitors, and active clamp techniques. Furthermore, the presented converter mitigates the reverse recovery problem of all diodes especially the input side diodes which is a challenge in many quadratic base converters. These properties have contributed to providing an efficient converter with wide applicability. The converter is fully analyzed, its superiority to other structures is shown, and a 200 W laboratory prototype validates the theoretical analysis.@en

A novel single-stage LED driver for street lighting application is proposed in this article which combines a totem-pole boost PFC and a non-isolated LCCL resonant network. The converter offers several benefits, including: appropriate total harmonic distortion (THD) level and high power factor (PF) of the input current; reduced conduction losses and suppressed electromagnetic interference (EMI) thanks to its bridgeless structure; zero-voltage switching (ZVS) for the main switches and zero-current switching (ZCS) for rectifier diodes across the entire input voltage range and load conditions; a constant output current to an LED string load due to the LCCL network characteristic at the resonant frequency; and fixed-frequency operation via the main switches duty cycle for regulating the output current. The paper provides a detailed explanation of the proposed driver operating modes and theoretical analysis, as well as a comprehensive analysis of the impact of parameters on DC-link voltage level and main switches voltage stress. A design procedure is also presented. Experimental verification is demonstrated through a 100W prototype circuit operating at 200 kHz.

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In this paper, a novel interleaved high step-up (HSU) converter is presented. The proposed converter features a large voltage gain and common input-output grounding. In this interleaved HSU converter, by using only one zero voltage transition (ZVT) auxiliary circuit with one auxiliary switch and low number of elements, soft switching (SS) performance for all the semiconductors over a wide range of load variations is achieved. This leads to advantages of high efficiency and low complexity, expense, and size. The characteristics of the proposed converter are compared to similar state of the art converters, and to confirm its effectiveness, the simulation results of the proposed converter are presented.@en