This paper proposes a single-switch converter with high step-up gain and low diode voltage stress, suitable for green power-source conversion. By employing a coupled inductor and switched capacitor, the proposed converters achieve high step-up conversion ratio without adopting extremely high duty ratio or high turns ratio. The voltage spike that occurs on the power switch is alleviated, which allows a low-voltage-rated power switch with low R DS(ON) to be adopted, thus reducing the conduction losses. Because the energy of the leakage inductor is recycled, the efficiency is improved. In addition, all diodes' voltage stresses are lowered and are the same, so the selection of power diodes is convenient. Finally, a 300 W prototype circuit with an input voltage of 24 V and an output voltage of 400 V is implemented to verify the performance and functionality of the presented converter. Moreover, the measured highest efficiency is 95.4%.
This paper presents a high step-up converter, which utilizes a three-winding coupled inductor and a rectified voltage-doubler circuit to obtain high step-up gain for fuel cells. The proposed converter functions as an active-clamp circuit, which relieves large voltage spikes across the power switches. Thus, power switches with low-voltage-rated can be utilized to reduce conduction losses and circuit cost. Energy stored in leakage inductances of the coupled inductor is recycled to the output terminal, resulting in efficiency improvements. In addition, the coupled inductor in the presented converter can also have extra windings in order to achieve higher voltage gain. Finally, a prototype circuit with an input voltage of 60 V and an output voltage of 380 V is developed for a 1000 W-rated fuel cell power-generation system to validate its performance, and experimental waveforms and measured efficiency under different input voltages and output power level are demonstrated.
Palladium-catalyzed heteroannulation of N-substituted benzamides with [60]fullerene, which proceeds through direct sp(2) C-H bond activation to form 7-membered ring pallada-intermediate with C(60), led to formation of [60]fulleroisoquinolinones in moderate to good yields (8-64% based on recovered C(60)). A plausible reaction pathway is proposed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.