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Open Journal of Applied Sciences 2022年第7期12卷 1262-1270页

作者： Abdoulaye Zongo frédéric ouattara Laboratoire de Recherche en énergétique et Météorologie de l’Espace (LAREME) Unités de Formations et de Recherches en Sciences et Technologies (UFR-ST) Université Norbert ZONGO Koudougou Burkina Faso

The electrical energy produced must be consumed at the same time, hence the need to achieve a balance between supply and demand. Therefore, the production, transport, and distribution systems together constitute an electricity network. The distribution networks are designed to deliver energy to consumers. Unacceptable voltage drops are observed in the distribution networks of developing countries such as Burkina Faso. A study was carried out on the distribution network of the city of Bobo-dioulasso in Burkina Faso. It allowed for experimentation with the “Megger MPQ1000” network analyzer to evaluate the quality of the voltage supplied to households. To this end, tests were carried out in a public distribution station and at a few subscribers in the Sarfalao district of the city of Bobo-dioulasso. These tests were used to assess the percentage of voltage drops. These values, which are higher than 8% of the nominal voltage, are not regulatory. The load curves of the consumers in the district were also drawn. Indeed, the period of the high load is between 19:00 and 23:00 Local Time (LT), while the period of the medium and low load is between 00:00 and 18:00 LT.

关键词： Experimental Voltage drop MV/LV Networks Network Analyzer

Modeling of Residential Photovoltaic (PV) System Connected to Low Voltage (LV) Network: Application to Public distribution Network of Burkina Faso

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Journal of Applied Mathematics and Physics 2022年第9期10卷 2698-2707页

作者： Abdoulaye Zongo daouda Konane frédéric ouattara Laboratoire de Recherche en énergétique et Météorologie de l’Espace (LAREME) Unités de Formations et de Recherches en Sciences et Technologies (UFR-ST) Université Norbert Zongo Koudougou Burkina Faso Laboratoire de Matériaux et Environnement (LAME) Université Joseph KI-ZERBO Ouagadougou Burkina Faso

Residential photovoltaic (PV) systems connected to the grid are used for self-consumption. Any surplus production is fed into the grid and contributes to improving the voltage. Several techniques are developed to model their connection. However, studies on methods of injecting energy production into the Low Voltage (LV) network are nowadays a problem. This paper proposes a mathematical model to determine the current to be injected and calculate each node’s voltage. The current equation is a recurrence relation with an initial condition. This initial condition is for the case of a single PV system connected to the LV grid. The equation can also be written in matrix form. Similarly, the voltage solution is a recurrence relation. It also has an initial condition for the first node. Both mathematical formulae with the proposed initial conditions are consistent and can be used for the determination of the current and voltage of the different nodes in the grid.

关键词： Residential PV System Low Voltage Grid Node Mathematical Model Electric Current

The Geomagnetic Effects of Solar Activity as Measured at Ouagadougou Station

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International Journal of Astronomy and Astrophysics 2018年第2期8卷 178-190页

作者： Aristide Marie frédéric Gyébré doua Allain Gnabahou frédéric ouattara Laboratoire de Recherche en Energétique et Météorologie de l’Espace (LAREME) Université Norbert Zongo (anciennement Université de Koudougou) Koudougou Burkina Faso

The coronal mass ejections (CMEs) produce by Sun poloidal magnetic fields contribute to geomagnetic storms. The geomagnetic storm effects produced by one-day-shock, two-days-shock and three-days-shock activities on Ouagadougou station F2 layer critical frequency time variation are analyzed. It is found that during the solar minimum and the increasing phases, the shock activity produces both positive and negative storms. The positive storm is observed during daytime. At the solar maximum and the decreasing phases only the positive storm is produced. At the solar minimum there is no three-days-shock activity. during the solar increasing phase the highest amplitude of the storm effect is due to the one-day-shock activity and the lowest is produced by the two-days-shock activity. At the solar maximum phase the ionosphere electric current system is not affected by the shock activity. Nevertheless, the highest amplitude of the storm effect is caused by the two-days-shock activity and the lowest by the one-day-shock activity. during the solar decreasing phase, the highest amplitude provoked by the storm is due to the three-days-shock activity and the lowest by the one-day-shock activity.

关键词： CMEs Activity Shock Activity F2 Layer Critical frequency Geomagnetic Activity Ionosphere Time Variation

Annual and diurnal Variabilities in the Critical frequency (foF2) during Geomagnetic Fluctuating Activity over Solar Cycles 21 and 22 at Ouagadougou

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Atmospheric and Climate Sciences 2018年第4期8卷 435-445页

作者： Abidina diabaté frédéric ouattara Jean Louis Zerbo Laboratoire de Recherche en Energétique et Météorologie de l’Espace (LAREME) Université Norbert Zongo Koudougou Burkina Faso Université Nazi Boni Bobo Dioulasso Burkina Faso Laboratoire d’Energies Thermiques Renouvelables (L.E.T.RE) Université Ouaga 1 Pr Joseph Ki-Zerbo Ouagadougou Burkina Faso

Geomagnetic activity is characterized by four solar wind conditions. Each condition has specific impact on ionosphere. This paper review on fluctuating activity effects on ionosphere F2 layer through its critical frequency foF2 variations. Under fluctuating wind conditions, we have investigated on annual, diurnal and seasonal variations of foF2 during solar cycles 21 and 22 phases covered by Ouagadougou ionosonde station data (Lat: 12.5°N;Long: 358.5°E;dip: 1.43°). Our investigations show that foF2 annual’ variability is in phase with solar cycle. The diurnal variation is “noon bite out” most of the time except for the solar maximum where we have a morning peak testifying to the fact that the vertical drift E × B is disturbed. The seasonal variations show that the fluctuating activity has no particular effect on certain characteristics of the equatorial ionosphere such as electrojet and vertical drift E × B. However, the increase of the electric field pre-reversal phenomenon in autumn is a characteristic effect observed during the fluctuating activity.

关键词： Critical frequency Solar Cycle Seasonal diurnal Fluctuating Activity

Peak of Electron density in F2-Layer Parameters Variability at Quiet days on Solar Minimum

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Journal of Modern Physics 2019年第3期10卷 302-309页

作者： Emmanuel Nanéma Moustapha Konaté frédéric ouattara Centre National de la Recherche Scientifique et Technologique (CNRST) Institut de Recherche en Sciences Appliquées et Technologies (IRSAT) Ouagadougou Burkina Faso Université Norbert ZONGO Laboratoire de Recherche en Météorologie de l’Espace (LAREME) Koudougou Burkina Faso

This study deals with Peak of electron density in F2-layer sensibility scale during quiet time on solar minimum. Peaks of electron density in F2-layer (NmF2) values at the quietest days are compared to those carried out from the two nearest days (previous and following of quietest day). The study uses International Reference Ionosphere (IRI) for ionosphere modeling. The located station is Ouagadougou, in West Africa. Solar minimum of phase 22 is considered in this study. Using three core principles of ionosphere modeling under IRI running conditions, the study enables to carry out Peak of electron density in F2-layer values during the quietest days of the characteristic months for the four different seasons. These parameters are compared to those of the previous and the following of the quietest days (the day before and following each quietest selected day) at the same hour. The knowledge of NmF2 values at the quietest days and at the two nearest days enables to calculate the relative error that can be made on this parameter. This calculation highlights insignificant relative errors. This means that NmF2 values at the two nearest days of each quietest day on solar minimum can be used for simulating the quietest days’ behavior. NmF2 values obtained by running IRI model have good correlation with those carried out by Thermosphere-Ionosphere-Electrodynamics-General Circulation Model (TIEGCM).

关键词： Ionosphere Peak of Electron density in F2-Layer Solar Cycle Quiet day International Reference Ionosphere Model

foF2 Long-Term Trend at a Station Located near the Crest of the Equatorial Ionization Anomaly

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International Journal of Geosciences 2020年第8期11卷 518-528页

作者： doua Allain Gnabahou Sibri Alphonse Sandwidi frédéric ouattara Laboratoire de Recherche en Energétique et Météorologie de l’Espace (LAREME) de l’Université Norbert ZONGO Koudougou Burkina Faso

Critical frequency foF2 long-term trends at dakar station (14.4°N, 342.74°E) located near the crest of the equatorial ionization anomaly EIA, are analysed taking into account geomagnetic activity, increasing greenhouse gases concentration and Earth’s magnetic field secular variation. After filtering solar activity effect using F10.7 as a solar activity proxy, we determined the relative residual trends slopes α values for three different levels of geomagnetic activity. For example, at 1200 LT, the value of α goes from ǂ.27%/year for very magnetically quiet days to -0.19%/year for magnetically quiet days and to -0.13%/year for all days. It appears from the slopes α obtained, that they increase with the level of geomagnetic activity and their negative values are qualitatively consistent with the expected decreasing trend due to the increase in greenhouse gases concentration but are greater than 0.003%/year which would result from a 20% increase in CO2 emissions which actually took place during the analysis period. Regarding Earth’s magnetic field magnitude, B secular variation and the dip equator secular movement,dana;"> dakar station is located near the crest of the equatorial ionization anomaly, Earth’s magnetic field magnitude, B decreases there and the trough approaches the position of dakar during the period of analysis. These two phenomena induce a decreas

关键词： Geomagnetic Activity Long-Term Trend foF2 dip Equator

Statistical Study of the Occurrence of Coronal Mass Ejections (CMEs) from 1996 to 2018 (Solar Cycles 23-24)

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Journal of Modern Physics 2024年第12期15卷 2238-2255页

作者： Salfo Kaboré Abdoul Kader Segda Aristide Marie frédéric Gyébré frédéric ouattara Laboratory of Analytical Chemistry Space and Energy Physics (L@CAPSE) Koudougou Burkina Faso Norbert ZONGO University (UNZ) Koudougou Burkina Faso

The objective of this article was to carry out a statistical study of the occurrences of CMEs from solar cycles 23 and 24 and to deduce interpretations as a contribution to a greater understanding of heliosphere dynamics. Thus, from the statistical examination of the occurrences according to the phases it appeared that solar cycle 23 (SC23) counted 13207 occurrences of CMEs while 16510 were counted for solar cycle 24 (SC24). These occurrences of CMEs are correlated to the sunspot cycle because in each of these cycles we would note the predominance of the phase maximum (1478 for SC23 and 2338 for SC24) over the ascending phases (550 for SC23 and 1559 for the SC24) and descending (1197 for the SC23 and 1178 for the SC24) and these predominate on the minimum phase (206 for the SC23 and 834 for the SC24). However, the percentages per phase in each cycle show that SC23 was only predominant over SC24 at the maximum phase (43.08% for SC23 and 39.57% for SC24). from this correlation, some authors therefore suggest that the toroidal magnetic field would be the cause of the ejections of these CMEs. The annual statistical examination confirms the correlation with the sunspot cycle but nevertheless reveals in the descending phase of SC23 two unusual peaks in 2005 and 2007 and a drop-in sunspot activity of 42% from SC23 to SC24 while that we would note an increase in the activity of CME occurrences of 36% at SC24, thus suggesting that CMEs can occur without the toroidal magnetic field being the cause, particularly from the coronal holes. The seasonal statistical examination shows for its part that out of the total of 29717 occurrences of CMEs of the two cycles that spring (28%) was the most active than summer (25%) and summer over autumn (24%) and finally autumn over winter (23%) thus revealing that: The ascending phase of the cycle was only the most active during the winter seasons in spring and the descending phase only during the rest of the seasons. Finally, the monthly stat

关键词： CMEs Occurrence Solar Cycle Phase of the Solar Cycle Seasons Months

foF2 Seasonal Asymmetry Time Variation at Korhogo Station from 1992 to 2002

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International Journal of Geosciences 2018年第4期9卷 207-213页

作者： Karim Guibula frédéric ouattara doua Allain Gnabahou Laboratoire de Recherche en Energétique et Météorologie de l’Espace (LAREME) Université Norbert Zongo Koudougou Burkina Faso

foF2 seasonal asymmetry is investigated at Korhogo station from 1992 to 2002. We show that equinoctial asymmetry is less pronounced and somwhere is absent trough out solar cycle phase. In general, the absence of equinoctial asymmetry may be due to the fact that in equinox and for each solar cycle phase, the asymmetry is due to Russell-McPherron mechanism. The solstice anomaly or annual anomaly is always observed throughout solar cycle phase. The minimum value of ΔfoF2 is inferior than −60% seen during all solar cycle phase at 0700 LT. This annual asymmetry may be due to interplanetary corpuscular radiation.

关键词： Seasonal Asymmetry Annual Asymmetry Equinoctial Asymmetry F2 Layer Critical frequency Time Variation

Comparative Study of the Geomagnetic Activity Effect on foF2 Variation as defined by the Two Classification Methods at dakar Station over Solar Cycle Phases

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International Journal of Geosciences 2020年第8期11卷 501-517页

作者： Sibri Alphonse Sandwidi doua Allain Gnabahou frédéric ouattara Laboratoire de Recherche en Energétique et Météorologie de l’Espace (LAREME) de l’Université Norbert ZONGO Koudougou Burkina Faso

This paper aims to establish a comparison between both geomagnetic activity classification methods on foF2 diurnal variation over solar cycle phases. It concerns first a comparison of geomagnetic activity occurrences according to both classification methods;and second the geomagnetic effect on foF2 diurnal variation profiles as defined for the equatorial latitudes. The occurrences of the different disturbed geomagnetic activities (recurrent activity (RA), shock activity (SA) and fluctuant activity (FA)) according to both classifications (ancient classification (AC) and new classification (NC)) have been studied at dakar ionosonde station (Lat: 14.8°N;Long: 342.6°E). Regarding both classifications, the RA occurs more during the decreasing phase. And it’s observed that the RA occurs the most during the increasing phase for the AC and during the minimum phase for the NC. The maximum gap of occurrence (dit_***" alt="" />) between both classifications is ᆟ.1% (for the negative value which is observed during the increasing phase) and +16.74% (for the positive one which is observed during the decreasing phase). The occurrence of the SA in relation with both classifications is the lowest during the minimum phase and the maximum occurrence is observed during the maximum and decreasing phases, for the AC, with a value close to 37% and for the NC at the maximum phase with a percentage of 54.47%

关键词： Geomagnetic Activity Classification Method Solar Cycle Phases foF2 diurnal Profile

Energetic dynamics of the Inner Magnetosphere in Contact with Fast Solar Wind Currents: Case of the Period 1964-2009

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International Journal of Geosciences 2022年第5期13卷 329-348页

作者： Inza Gnanou Aristide Marie frédéric Gyébré Karim Guibula Christian Zoundi frédéric ouattara É cole Normale Supérieure Koudougou Burkina Faso Laboratoire de Recherche en Energétique et Météorologie de l’Espace (LAREME) Université Norbert ZONGO Koudougou Burkina Faso Laboratoire de Chimie @nalytique de Physique Spatiale et Energétique (LAC@PSE) Université Norbert ZONGO Kou-dougou Burkina Faso Université Norbert ZONGO Koudougou Burkina Faso Université Virtuelle du Burkina Faso Karpala Ouagadougou Burkina Faso

The Earth’s magnetosphere is a magnetic shield that protects Earth from high-energy particles and is subject to a series of internal processes caused by jets of the solar wind (SW) that destabilize it. These disturbances affect health as well as technology and become more extreme when SW is more accelerated. Thus, to better understand the impact of high-speed solar wind (HSSW) invasion on the dynamics of the magnetospheric system, a statistical study of HSSW populations was conducted for even (20 and 22) and odd (21 and 23) solar cycles. The regression analysis using the solar-derived fields from all solar cycles, indicates three states of the inner magnetosphere: 1) the 00:00UT-15:00UT period marked by a magnetic reconnection on the day side of the Earth closest to the Sun with the interplanetary magnetic field (IMF) facing South;2) the 15:00UT-21:00UT period where IMF changes from South to North and remains there until 21:00UT;and 3) the 21:00UT-24:00UT period where there is a reconnection on the night side with stretched field lines. Observations made at different phases of solar activity lead us to suggest that the magnetospheric electric field (EM) and the Bz component of IMF (IMF-Bz) are strongly correlated not only at a particular time scale, but at different time scales. We believe that the daily fluctuations of the electrical and magnetic effects of magnetospheric origin currents play a very important role in the dayside magnetic reconnection rate. Moreover, examination of the cycles with different parities shows important amplitudes of the solar causes for the even cycles compared to the odd solar cycles. Therefore, even solar cycles have a strong influence on our socio-economic system compared to odd cycles.

关键词： Magnetosphere Magnetospheric Electric Field Magnetic Field Solar Wind Solar Cycles