In this paper, an adaptive fuzzy sliding mode controller is proposed to control a two-stage single-phase photovoltaic (PV) grid-connected inverter. Two key technologies are discussed in the presented PV system. An incremental conductance method with adaptive step is adopted to track the maximum power point (MPP) by controlling the duty cycle of the controllable power switch of the boost DC-DC converter. An adaptive fuzzy sliding mode controller with an integral sliding surface is developed for the grid-connected inverter where a fuzzy system is used to approach the upper bound of the system nonlinearities. The proposed strategy has strong robustness for the sliding mode control can be designed independently and disturbances can be adaptively compensated. Simulation results of a PV grid-connected system verify the effectiveness of the proposed method, demonstrating the satisfactory robustness and performance.
Original scientific paper https://doi.org/10.2298/TSCI191129119YThe core carrier working substances of heat accumulation of solar thermal generator units are analyzed through computer numerical simulation analysis and simulation experiments, including the selection criteria of working substances, the mechanism of heat accumulation system, the correlation between power generation efficiency and the evaporation temperature of working substance, the correlation between the condensing temperature and condensing pressure of working substance, and the influence of working substance velocity on heat accumulation capacity. The results show that under the same radiation intensity, the greater the flow velocity of the working substance is, the worse the heat accumulation and heat conduction of the working substance is. As the condensing temperature of the working substance increases, the condensing pressure also increases. As the evaporation temperature of the working substance increases, the power generation efficiency of the working substance also increases significantly. In summary, the heat accumulation system based on the high efficiency working substances is vital for the normal operation of solar thermal generator units. Once the solar radiation intensity cannot meet the needs of power generation, the heat accumulation system will output previously-stored thermal energy. Meanwhile, its collection and release of thermal energy depend on the photovoltaic intensity. The constructed hot-oil working substance-based heat accumulation system satisfies the normal operation needs for thermal generator units, which is significant for subsequent research.
In our country, gas-fired has been widely applied to the residents and the life. All reasons of gas leaks cause personal injury and property damage. And those cause huge energy waste. The current gas leaks detector in family is single alarm function, at the same time it is not widely used. To solve these problems, paper designed a gas leaks automatic detection and processing device by using the Fujitsu MB95204K.The device through the indoor corresponding gas concentration measurement and the concentration of the gas software installed state threshold ways to judge whether to make the each level operation. In order to overcome the shortcomings of current single alarm function device. Device has LIN-UART interface expanding for the future wireless upgrade. It is convenient to use ZIGBEE etc wireless technology to compose intelligent monitoring net, intelligent household and a net node in The Internet of things.
In view of the white LED problems being medium and high color temperature, the poor CRI of warm color temperature, and single control on the market, a plan is given based on ZigBee wireless communication technology of the LED color temperature and brightness independent control system. Through the wireless sensor network, controls the MCU to produce PWM signal, controls the duty cycle of each LED current, and makes each color of LED mixing to a desired color temperature and brightness. The device not only realizes the LED color temperature and brightness adjustable independently, but also has the advantages of high photosynthetic efficiency and high color rendering.
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.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.