Local capacitance-voltage profiling and high voltage stress effect study of SiO2/SiC structures by time-resolved scanning nonlinear dielectric microscopy

2021 ◽  
pp. 114284
Author(s):  
K. Yamasue ◽  
Y. Cho
Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1112
Author(s):  
Yu-En Wu ◽  
Jyun-Wei Wang

This study developed a novel, high-efficiency, high step-up DC–DC converter for photovoltaic (PV) systems. The converter can step-up the low output voltage of PV modules to the voltage level of the inverter and is used to feed into the grid. The converter can achieve a high step-up voltage through its architecture consisting of a three-winding coupled inductor common iron core on the low-voltage side and a half-wave voltage doubler circuit on the high-voltage side. The leakage inductance energy generated by the coupling inductor during the conversion process can be recovered by the capacitor on the low-voltage side to reduce the voltage surge on the power switch, which gives the power switch of the circuit a soft-switching effect. In addition, the half-wave voltage doubler circuit on the high-voltage side can recover the leakage inductance energy of the tertiary side and increase the output voltage. The advantages of the circuit are low loss, high efficiency, high conversion ratio, and low component voltage stress. Finally, a 500-W high step-up converter was experimentally tested to verify the feasibility and practicability of the proposed architecture. The results revealed that the highest efficiency of the circuit is 98%.


2008 ◽  
Vol 23 (6) ◽  
pp. 2630-2647 ◽  
Author(s):  
Ting-Ting Song ◽  
Huai Wang ◽  
H.S.-H. Chung ◽  
S. Tapuhi ◽  
A. Ioinovici

Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 3032 ◽  
Author(s):  
Hongchen Liu ◽  
Xi Su ◽  
Junxiong Wang

In this paper, two types of high step-up coupled inductor inverters based on qSBIs (quasi- switched boost inverters) are proposed. By applying the coupled inductor to the qSBIs, the voltage gain of the proposed inverter is regulated by turn ratio and duty ratio. Thus, a high voltage gain can be achieved without the circuits operating at the extreme duty cycle by choosing a suitable turn ratio of the coupled inductor. In addition, the proposed circuits have the characteristics of continuous input current and low voltage stress across the passive components. A boost unit can be added to the proposed inverters for further improvement of the voltage gain. In this paper, the working principle, steady state analysis, and the comparisons of the proposed inverter with other impedance-source inverters are described. A 200 W prototype was created and the experimental results confirm the correctness of the analysis in this paper.


Author(s):  
G.Vijaykumar and Dr.V.Geetha

A high voltage gain modified SEPIC converter is proposed in this paper. This proposed converter has many advantages i.e., high output voltage, lower voltage stress, high efficiency, voltage gain is high without any coupled inductor and transformer, continuous input current. Thus, there is no overshoot voltage at turn-off process for switches. By using single switches, the CCM mode operation can be easily controlled by this converter, so control system is simple and also wide output values is obtained only by modifying the duty cycle. This modified converter has lower components than conventional converter. The operating modes and design of modified converter are discussed. The output power of this converter is 6 watts. By this converter, this converter capable of developing the two and half times of input voltage. The PV system also used this converter to develop high voltage gain. This high voltage gain is achieved by using MATLAB/SIMULIMK platform.


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