Inductor

About: Inductor is a research topic. Over the lifetime, 52565 publications have been published within this topic receiving 484068 citations. The topic is also known as: passive two terminal.

Analysis of integrated boost-flyback step-up converter

Abstract: The operating principles, theoretical analysis, and design methodology of a high-efficiency step-up converter are presented. The integrated boost-flyback converter (IBFC) uses coupled-inductor techniques to achieve high step-up voltage with low duty ratio, and thus the slope compensation circuit is disregarded. The voltage gain and efficiency at steady state are derived using the principles of inductor volt-second balance, capacitor charge balance and the small-ripple approximation for continuous-conduction mode. Finally, a 35 W, 12 V DC input, 48 V DC output, f/sub sw/= 40 kHz IBFC has been implemented in the laboratory to validate the theoretical analysis. A design procedure is expounded, and design guidelines for selecting critical components are also presented. It is shown that high voltage gain with high efficiency can be achieved by the IBFC system.

3C strategy for inverters in parallel operation achieving an equal current distribution

Abstract: A circular chain control (3C) strategy for inverters in parallel operation is presented in the paper. In the proposed inverter system, all the modules have the same circuit configuration, and each module includes an inner current loop and an outer voltage loop control. A proportional-integral controller is adopted as the inner current loop controller to expedite the dynamic response, while an H/sup /spl infin// robust controller is adopted to reach the robustness of the multimodule inverter system and to reduce possible interactive effects among inverters. With the 3C strategy, the modules are in circular chain connection and each module has an inner current loop control to track the inductor current of its previous module, achieving an equal current distribution. Simulation results of two-module and a three-module inverter systems with different kinds of loads and with modular discrepancy have demonstrated the feasibility of the proposed control scheme. Hardware measurements are also presented to verify the theoretical discussion.

An optimized self-powered switching circuit for non-linear energy harvesting with low voltage output

Abstract: Harvesting energy from environmental sources has been of particular interest these last few years. Microgenerators that can power electronic systems are a solution for the conception of autonomous, wireless devices. They allow the removal of bulky and costly wiring, as well as complex maintenance and environmental issues for battery-powered systems. In particular, using piezoelectric generators for converting vibrational energy to electrical energy is an intensively investigated field. In this domain, it has been shown that the harvested energy can be greatly improved by the use of an original non-linear treatment of the piezoelectric voltage called SSHI (Synchronized Switch Harvesting on Inductor), which consists in intermittently switching the piezoelectric element on a resonant electrical network for a very short time. However, the integration of miniaturized microgenerators with low voltage output (e.g. MEMS microgenerators) has not been widely studied. In the case of low voltage output, the losses introduced by voltage gaps of discrete components such as diodes or transistors can no longer be neglected. Therefore the purpose of this paper is to propose a model that takes into account such losses as well as a new architecture for the SSHI energy harvesting circuit that limits such losses in the harvesting process. While most of the study uses an externally powered microcontroller for the non-linear treatment, this circuit is fully self-powered, thus providing an enhanced autonomous microgenerator. In particular this circuit aims at limiting the effect of non-linear components with a voltage gap such as diodes. It is shown both theoretically and experimentally that the harvested power can be significantly increased using such a circuit. In particular, experimental measurements performed on a cantilever beam show that the circuit allows a 160% increase of the harvested power compared to a standard energy harvesting circuit, while the classical implementation of the SSHI shows an increase of only 100% of the output power in the classical case.

Transformerless Inverter With Virtual DC Bus Concept for Cost-Effective Grid-Connected PV Power Systems

Abstract: In order to eliminate the common-mode (CM) leakage current in the transformerless photovoltaic (PV) systems, the concept of the virtual dc bus is proposed in this paper By connecting the grid neutral line directly to the negative pole of the dc bus, the stray capacitance between the PV panels and the ground is bypassed As a result, the CM ground leakage current can be suppressed completely Meanwhile, the virtual dc bus is created to provide the negative voltage level for the negative ac grid current generation Consequently, the required dc bus voltage is still the same as that of the full-bridge inverter Based on this concept, a novel transformerless inverter topology is derived, in which the virtual dc bus is realized with the switched capacitor technology It consists of only five power switches, two capacitors, and a single filter inductor Therefore, the power electronics cost can be curtailed This advanced topology can be modulated with the unipolar sinusoidal pulse width modulation (SPWM) and the double frequency SPWM to reduce the output current ripple As a result, a smaller filter inductor can be used to reduce the size and magnetic losses The advantageous circuit performances of the proposed transformerless topology are analyzed in detail, with the results verified by a 500-W prototype

High-efficiency DC-DC converter with high voltage gain and reduced switch stress

Abstract: In this study, a high-efficiency DC-DC converter with high voltage gain and reduced switch stress is proposed. In the proposed topology, a three-winding coupled inductor is used for providing a high voltage gain without extreme switch duty-cycle and enhancing the utility rate of magnetic core. Moreover, the energy in the leakage inductor is released directly to the output terminal for avoiding the phenomenon of circulating current and the production of switch surge voltage. In addition, the delay time formed with the cross of primary and secondary currents of the coupled inductor is manipulated to alleviate the reverse-recovery current of the output diode. It can achieve the aim of high-efficiency power conversion. Furthermore, the closed-loop control methodology is utilized in the proposed scheme to overcome the voltage drift problem of the power source under the variation of loads. Some experimental results via an example of a proton exchange membrane fuel cell (PEMFC) power source with 250 watts nominal rating are given to demonstrate the effectiveness of the proposed power conversion strategy.