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A comparative study based on proportional integral and backstepping controllers for doubly fed induction generator used in wind energy conversion system

Moumani Youssef, Laafou Abdeslam Jabal, Madi Abdessalam Ait

Archives of Electrical Engineering

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2023

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Vol. 72, nr 1

211--228

EN

This paper presents a comparative study between the conventional PI (Proportional Integral) and backstepping controllers applied to the DFIG (Doubly Fed Induction Generator) used in WECS (Wind Energy Conversion System). These two different control strategies proposed in this work are developed to control the active and reactive power of the DFIG on the one hand, and to maintain the DC-link voltage constant for the inverting function on the other hand. This is ensured by generating control signals for two power electronic converters, RSC (Rotor Side Converter) and GSC (Grid Side Converter). In order to optimise the power production in the WT (Wind Turbine), an MPPT (Maximum Power Point Tracking) algorithm is applied along with each control technique. To simulate the effectiveness of the proposed controllers, MATLAB/Simulink Software is used, and the obtained results are analysed and discussed to compare PI and backstepping controllers in terms of robustness against wind speed variations and tracking performance in dynamic and steady states.

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Consequences of Mercury Used by Artisanal and Small-Scale Gold Mining Processes a Case of River Nile State Sudan

Ahmed Ali M.A., Purwanto Purwanto, Sunoko Henna Rya

Journal of Ecological Engineering

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2019

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Vol. 20, nr 2

106--115

EN

On the discovery of gold reserves in 14 states in Sudan, traditional gold mining suddenly started to flourish and hundreds of thousands of laymen became engaged in gold extraction. The new source of revenue generation added much to the empty treasury and the loss in petroleum revenue due to cessation of the south in 2011 could thus be compensated. Since gold extraction by artisanal and small-scale gold mining does not require much finance or advanced technology, it suited unskilled workers and many young people found their way into the new business. Although gold extraction generates high revenues, the use of mercury in gold extraction poses much threat to the environment and general health of miners and the surrounding areas. The research tries to investigate the effects of traditional gold mining in Alebedia area, Berber Locality in the River Nile State. The investigation includes A/ the effects of extraction methods on the environment and general health. B/ the level of education and its distribution within the miners and how it affected the awareness of the miners about the dangers of mining activities. C/ the period of stay that miners spend in the mining area its contribution on the awareness about the dangers and diseases inflicted on the miners, D/ the effects of traditional gold mining activities on natural environmental impacts and E/ the effects of the meteorological and topographical factors, the distribution and concentration of mercury in the area and their effects on the environment and general health. The research adopted the techniques of using random sampling and quantitative qualitative in addition to the analytical techniques. The research finally concluded that traditional gold mining has positive effects on the economic side and negative effects on the environment and general health.

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Effect of pressure of photopolymer plate to the ground on the compression resistance of transport containers made from tri-layer corrugated board during inline flexographic printing

Nowak T., Modzelewska I.

Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology

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2014

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No. 88

182--186

EN

In the following article, an attempt was made to empirically determine an impact of technological errors on compression resistance of corrugated fiberboard transport containers during inline flexographic printing on industrial slotted – printing – gluing and folding machine. Investigation proves that the printing process has an influence on packaging resistance. It has been shown how important press photopolymer printing plates are to corrugated board adjustment by a machine operator and a correct production technology preparation. Adjusted high pressure due to male/female creasing occurred, caused resistance loss by 13%.