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The novel forward-based converter for low-power solar applications is presented in this work. The proposed converter provides an efficient performance in a wide range of the input voltage with low component count. The proposed dc-dc topologies are advanced forward dc-dc converters with an additional clamped output capacitor. The idea of such a type of converter is to transfer magnetizing energy of transformer to the output side, instead of using an input clamp circuit. Two possible topologies are considered to cover this feature. The design guidelines of the passive component of the proposed solutions are discussed. The converter may work in continuous conduction mode and discontinuous conduction mode due to different levels of the input power. A comparison between proposed topologies is made and discussed. Experimental prototype of the proposed forward-based dc-dc converter along with experimental results of the dc grid connection system are presented. The parameters of commercial photovoltaic panels have been chosen to validate the maximum power point tracking based on Perturb and Observe algorithm. The efficiency of the proposed solution is studied and discussed.

This paper compares grid-connected flyback-based microinverters employing primary and secondary side fundamental power ripple decoupling approaches. The passive decoupling techniques involve the use of the unfolding circuit on the primary side and an H-bridge inverter on the secondary side to achieve the same number of passive components. The unfolding circuit operates at the grid frequency, unfolding/folding the rectified sinusoidal waveform and providing a current pathway to the grid. Comparative assessments encompass energy accumulation in inductances and capacitors, conduction and switching losses, and voltage stress across semiconductors. Proportional Resonant controllers govern grid current. The theoretical evaluation is complemented by cost analysis using existing component prices, and experimental setups utilizing four-layer printed circuit boards for primary and secondary side decoupling. The results provide a comprehensive comparison, and conclusions offer valuable recommendations based on both theoretical and experimental insights.

Abstract:In this investigation, conventional hydrodistillation (HD) and microwave assisted hydrodistillation (MAHD) were used for extraction of essential oil from roots of Rosa canina, also, the effect of a chemical modifier was investigated. At first, magnetic nanoparticles were modified with a thermosensitive polymer. Then its effect on microwave extraction efficiency was investigated. The results obtained from the conventional HD extraction showed that the quantity and number of extracted compounds is low (30 compounds). Extraction yields were 0.47, 0.78 and 1.12 by hydrodistillation, microwave and microwave assisted hydrodistillation, respectively. Thus, the percent of the extraction yield was significantly increased through the MAHD method, particularly in the presence of the modified magnetic nanoparticles. In addition, extracted compounds were increased from 46 to 80 compounds by adding modified magnetic nanoparticles, respectively. Modified magnetic nanoparticles with cell compatible polymer could increase the efficiency of the extraction significantly. As simultaneous use of microwave and modified magnetic nanoparticles significantly increase the quality and quantity of volatile essential oils of Rosa caninaL.