A fast automatic AC-DC switch is designed and fabricated mainly by a microcontroller and three double poles single throw reed relays.This new switch is introduced to establish a fully automated system for AC-DC measur...A fast automatic AC-DC switch is designed and fabricated mainly by a microcontroller and three double poles single throw reed relays.This new switch is introduced to establish a fully automated system for AC-DC measurements through ACDC transfer standards for the first time at the National Institute for standards(N IS)in Egypt.The implemented circuit of theautomatic AC-DC switch and its protection are presented in details.An AC voltage source is calibrated against DC voltagesource by using the demonstrated automatic switch as an application The calibrated voltage ranges are2V,6V,20V and60V as examples.The uncertainty budget is also evaluated for the calibrated values.展开更多
Today, energy saving is one of the main objectives for engineers. In the case of mobile applications, energy can be saved by two different ways： decreasing the total masse of the system and increasing the efficiency ...Today, energy saving is one of the main objectives for engineers. In the case of mobile applications, energy can be saved by two different ways： decreasing the total masse of the system and increasing the efficiency of the overall system. This paper presents two optimization strategies to design a predefined multichannel structure of a boost converter which is dedicated to a solar airplane and used to interface PV panels and the battery system. The first strategy is a multi-criterion method that is able to trace the dependency between the converter＇s efficiency and its power density through the intermediary of the Pareto front. The second method, a mono-criterion approach, maximizes efficiency while respecting the constraint imposed on power density. The mono-criterion method that is applied to maximizing the European efficiency criterion showed that an increase in the number of channels enhanced the quantity of energy collected over a day by increasing the power density of the converter. At the end of the paper, the optimal design calculated was built to give an example of the result obtained by this design methodology. The results of the efficiency measurements made on a realized prototype are presented in this paper.展开更多
文摘A fast automatic AC-DC switch is designed and fabricated mainly by a microcontroller and three double poles single throw reed relays.This new switch is introduced to establish a fully automated system for AC-DC measurements through ACDC transfer standards for the first time at the National Institute for standards(N IS)in Egypt.The implemented circuit of theautomatic AC-DC switch and its protection are presented in details.An AC voltage source is calibrated against DC voltagesource by using the demonstrated automatic switch as an application The calibrated voltage ranges are2V,6V,20V and60V as examples.The uncertainty budget is also evaluated for the calibrated values.
文摘Today, energy saving is one of the main objectives for engineers. In the case of mobile applications, energy can be saved by two different ways： decreasing the total masse of the system and increasing the efficiency of the overall system. This paper presents two optimization strategies to design a predefined multichannel structure of a boost converter which is dedicated to a solar airplane and used to interface PV panels and the battery system. The first strategy is a multi-criterion method that is able to trace the dependency between the converter＇s efficiency and its power density through the intermediary of the Pareto front. The second method, a mono-criterion approach, maximizes efficiency while respecting the constraint imposed on power density. The mono-criterion method that is applied to maximizing the European efficiency criterion showed that an increase in the number of channels enhanced the quantity of energy collected over a day by increasing the power density of the converter. At the end of the paper, the optimal design calculated was built to give an example of the result obtained by this design methodology. The results of the efficiency measurements made on a realized prototype are presented in this paper.
