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The simple boost control (SBC) method is usually used to control the shoot-through state in a single-phase single-stage quasi-switched boost inverter (qSBI). This paper proposes a new pulse-width modulation (PWM) control scheme to improve the modulation index for the qSBI. The advantages of the proposed method for the qSBI over the conventional SBC method are as follows: 1) the modulation index is larger; 2) the voltage stress on the capacitor, diodes, and switches is reduced significantly; 3) the high-frequency peak-to-peak inductor current and capacitor voltage ripples are smaller; 4) the shoot-through current is lower; and 5) the efficiency is higher. The operating principles and circuit analysis for the proposed PWM control scheme are shown. To verify the performance of the proposed PWM control method, a 400W prototype was built with a 110 V/50 Hz output voltage. The experimental results matched those of the theoretical analysis. [ABSTRACT FROM PUBLISHER]

Abstract: It is well known that, theoretically, thin-film cadmium telluride (CdTe) solar cell technology can improve on the conversion efficiency and production costs of conventional silicon solar cell technology. Due to the optimal band gap energy (about 1.4eV) for solar energy absorption, high light absorption capability and lower cost requirements for solar cell production, CdTe has been widely researched as being suitable for commercial cell production. In this study, the sputtering method, which can improve on the cost-efficiency and mass-production of solar cells, was employed to deposit the CdTe thin film with various processing conditions such as sputtering power, and gas pressure. The effects of the processing conditions on the thickness-uniformity and surface morphology of the CdTe thin films were investigated using atomic force microscope (AFM) and ellipsometry for large-area solar cells. The photovoltaic properties of CdTe thin films were analyzed in relation to the different thickness-uniformity and surface morphology caused by the various process conditions. The thickness-uniformity, which was controlled by the process conditions in the sputtering process, was found to affect the photovoltaic properties of the sputtering-deposited CdTe thin films. Higher carrier concentration and better optical absorbance were obtained in CdTe thin films with a good thickness-uniformity. [Copyright &y& Elsevier]

A non-isolated high boost DC-DC converter topology based on a switched-capacitor (SC) structure is introduced in this paper. By controlling the duty cycle in each period, the voltage gain of the converter is adjusted. The main features of the proposed SC converter are the continuous input current, achieving high voltage gain with low voltage and current stress on the power components, no use of a high-frequency transformer, and easy to increase the voltage by adding the SC cell. To correct the operating analysis, a 200-W output power prototype was built with the input voltage in the range of [25 V, 50 V] and the output voltage of 200 V. The proposed inverter reaches a maximum efficiency of 93% at the input voltage of 25 V and the output power of 150 W. The simulation and experimental verifications match the analysis. [ABSTRACT FROM AUTHOR]

A novel single-phase nine-level boost inverter is proposed in this paper. The proposed inverter has an output voltage which is higher than the input voltage by switching capacitors in series and in parallel. The maximum output voltage of the proposed inverter is determined by using the boost converter circuit, which has been integrated into the circuit. The proposed topology is able to invert the multilevel voltage with the high step-up output voltage, simple structure and fewer power switches. In this paper, the circuit configuration, the operating principle, and the output voltage expression have been derived. The proposed converter has been verified by simulation and experiment with the help of PSIM software and a laboratory prototype. The experimental results match the theoretical calculation and the simulation results. [ABSTRACT FROM AUTHOR]