To get the maximum power point (MPP), the algorithms developed in the literature fail for the most part when the atmospheric conditions vary rapidly. This paper presents the optimization by the swarm particles (PSO) of a sliding mode... more
To get the maximum power point (MPP), the algorithms developed in the literature fail for the most part when the atmospheric conditions vary rapidly. This paper presents the optimization by the swarm particles (PSO) of a sliding mode controller (SMC) to optimize photovoltaic systems (PV) evolving under the conditions of a rapid variation of the sunshine. The stochastic PSO algorithm is used in particular to determine the optimal gains of the sliding mode controller, and this algorithm guarantees the stability and global fast convergence of the system. Efficiency of the proposed hybrid algorithm is proved by using a Solarex MSX-60 module connected to a step-up DC-DC converter supplying a resistive load. The performances are compared to the conventional perturb and observe technique (P&O), PSO, CUCKOO, grey wolf optimization (GWO), and Whale Optimization Algorithm (WOA) in terms of convergence speed, i.e., 0.05 s, tracking speed after extreme change in irradiance 0.03 s, high Ability ...
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Sustainable future development relies on solar radiation, which is the main source of renewable energy. Thus, in this article, the monthly average global solar irradiation of four sites in the Sudanian zone region of Chad is estimated... more
Sustainable future development relies on solar radiation, which is the main source of renewable energy. Thus, in this article, the monthly average global solar irradiation of four sites in the Sudanian zone region of Chad is estimated using different empirical models. The data used in this study were collected at the General Directorate of Meteorology of Chad. The reliability and accuracy of six models estimating global solar radiation were validated and compared by statistical indicators identifying the most accurate model. The results obtained show that the Allen model has the best performance for the Moundou site (5.760 kWh/m²/d, R2=0.843), the Angstrom Prescott model for the Sarh sites (5.658 kWh/m²/d, R2=0.805) and Pala (5.793 kWh/m²/d, R²=0.889), the Sabbagh model for the Bongor site (5.657 kWh/m²/d, R²=0.888). These models are validated against NASA data. The results show that the Sudanian zone of Chad has good solar potential and is therefore suitable for possible exploitation.
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This paper proposes a multisource power plant management strategy for the proposed structure. This power plant consists of photovoltaic, wind, and grid. The principle of this management strategy is based on the reference currents and... more
This paper proposes a multisource power plant management strategy for the proposed structure. This power plant consists of photovoltaic, wind, and grid. The principle of this management strategy is based on the reference currents and defines two components of the current namely a harmonic component related to the harmonics contained in the load current and current called fundamental related to the fundamental of the load current. This proposed strategy allows the different renewable sources to supply the load partially or totally. The harmonic component performs the power quality function while the fundamental component feeds the load and injects the surplus production into the grid. The power management is done according to the established scenarios and responds to the demand of the load. The simulations were carried out with Matlab software, and these results show the performance of this strategy for this structure studied to fulfill the following functions: power supply to the lo...
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The study area includes an area between 6° to 8°N and 11° to 15°E. Geologically, it belongs to Precambrian basement (granites, gneisses), Proterozoic, and Archean (volcanic) series, showing the main heat sources of Cameroon. The purpose... more
The study area includes an area between 6° to 8°N and 11° to 15°E. Geologically, it belongs to Precambrian basement (granites, gneisses), Proterozoic, and Archean (volcanic) series, showing the main heat sources of Cameroon. The purpose of this study deals to analyze and interpret the EMAG2 magnetic data in the Adamawa area using various advanced processing techniques. Thus, the mapping and depth estimation of underground structures are realized. The analysis of aeromagnetic map of the reduction to equator (RTE) in Adamawa area reveals rapidly evolving subsurface geological presented its lithological and structural. In the same, the power spectrum-processing tool clearly emphasizes shallow and deep underground heat sources. Two magnetic source location methods (source parameter imaging and analytical signal) are used to characterize of the source. The estimated magnetic source depths from source parameter imaging (SPI) are between 0.3 km and 22 km. The analytical signal ranges from ...
Research Interests: Geology, Geophysics, Tectonics, Seismology, Proterozoic, and 6 moreArchean, Precambrian, Gneiss, Magnetic Anomaly, Prospecting, and Basement
This paper presents the study, modelling, and simulation of the DCSVM (Duty Cycle Space Vector Modulation) control technique applied to a new inverter topology dedicated to isolated or grid-connected photovoltaic systems using the... more
This paper presents the study, modelling, and simulation of the DCSVM (Duty Cycle Space Vector Modulation) control technique applied to a new inverter topology dedicated to isolated or grid-connected photovoltaic systems using the MATLAB/Simulink software. This inverter is based on the structures of a stacked multicell converter (SMC) and an H-bridge. This new topology allows the voltage stresses of the converter to be distributed among several switching cells. It also allows the input voltage to be divided into several fractions so that the number of switching power semiconductors is reduced. The DCSVM is a control technique that generates control signals to the two-level voltage converter as well as the intermediate times. The main advantage of this control technique is the reduction in the number of calculations, especially for the trigonometric functions and the generation of the reference voltage. In this contribution, the general topology of this microinverter is described and...
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Active filters based on multicellular inverters are an efficient, robust, and reliable means of large-scale photovoltaic systems for the next generation of smart grids. This paper presents active filters based on a cascaded multicellular... more
Active filters based on multicellular inverters are an efficient, robust, and reliable means of large-scale photovoltaic systems for the next generation of smart grids. This paper presents active filters based on a cascaded multicellular inverter for three-phase PV systems connected to the North Cameroon interconnected grid. The proposed system consists of the boost chopper connected to the grids, via the 7-level inverters located before the multicellular active filters with five switching cells per arm. The contribution of this paper is due to the improved P&O MPPT algorithm for the extraction of the maximum power produced by the PV generators and the appropriate choice of the active filters to reduce the harmonic distortion rate to an acceptable value by the grid regulations for a decentralized generation. After synchronization of the system with the electrical grids, the voltage and current of the grid remain in phase. This means that the power factor is corrected. The results show that the system can reduce the harmonic distortion from 23.06% to 0.42% when the active power of the photovoltaic generators is injected into the electrical grids.
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This article presents a method for the reduction of harmonics generated by photovoltaic the smart grid connected. Photovoltaic generators always produce harmonics due to the nature of the direct current they generate. In order to... more
This article presents a method for the reduction of harmonics generated by photovoltaic the smart grid connected. Photovoltaic generators always produce harmonics due to the nature of the direct current they generate. In order to eliminate these harmonics, parallel active filters are used. They are based on seven-level inverters. For the extraction of maximum power produced by the photovoltaic generators, the modified perturb and observe algorithm is used. Furthermore, to reduce the distortions due to the injected continuous quantities, the filtering of the harmonic quantities is done by four levels active filters using three switching cells per arm connected downstream of the seven-level inverters. The proposed algorithm and the model of active filter are evaluated, by calculating of the total harmonic distortion of the current after filtering. The rate of 0.21% is obtained. Additionally, the simulation results show this rate is lower than that of the standard Institute of Electric...
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A techno-economic study of a hybrid PV/Battery/Grid-connected system for energy supply is carried out in this paper to respond to the problem of electrical load shedding. An optimal design of the system is realized thanks to a... more
A techno-economic study of a hybrid PV/Battery/Grid-connected system for energy supply is carried out in this paper to respond to the problem of electrical load shedding. An optimal design of the system is realized thanks to a double-objective optimization based on a proposed operational strategy of the system and on Firefly Algorithm (FA). The system is designed for household energy supply in three different towns of the northern part of Cameroon. For different LPSP (Loss of Power Supply Probability), the double objective simulation determines the optimal configurations of the system with their related cost. The optimal and reliable PV/Battery subsystem configuration corresponding to LPSP of 0% obtained for one household is composed for the towns of Maroua and Garoua by 8 PV modules and a battery capacity of 11.304 kWh with 1-day autonomy. For the town of Ngaoundéré, it is composed by 10 PV modules and battery capacity of 11.304 kWh with 1-day autonomy. The related investment costs...
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A wind energy conversion system applied to battery charge is proposed in this paper. A permanent magnet synchronous generator (PMSG) is used as a variable speed generator in the proposed system. In order to extract the maximum power, the... more
A wind energy conversion system applied to battery charge is proposed in this paper. A permanent magnet synchronous generator (PMSG) is used as a variable speed generator in the proposed system. In order to extract the maximum power, the generator torque control is carried out by the pulse width modulation (PWM) converter, which requires controllers (PI controllers are used). A new approach is developed to settle easily and effectively the PI controller for the first order system. This approach is based on the compensation pole method. The system is simulated in the Matlab/Simpower environment and the results show that the new approach is better than the conventional method.
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... These include establishing models [7] and [8] and indices [9], carrying out experiments in climate chambers [7] and ... on health issues like the Sick-Building-Syndrome [6]. These studies known as international thermal comfort... more
... These include establishing models [7] and [8] and indices [9], carrying out experiments in climate chambers [7] and ... on health issues like the Sick-Building-Syndrome [6]. These studies known as international thermal comfort standards such as the ASHRAE standards and the ...
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This paper presents the implementation of perturb and observe maximum power point tracking algorithm with Duty Cycle Modulation instead of pulse width modulator for photovoltaic power generators. Like all the different methods used for... more
This paper presents the implementation of perturb and observe maximum power point tracking algorithm with Duty Cycle Modulation instead of pulse width modulator for photovoltaic power generators. Like all the different methods used for tracking the maximum power point of photovoltaic system, perturb and observe method use a Pulse Width Modulation to control the DC-DC converter. Here, the Duty Cycle Modulation is used in the place of Pulse Width Modulation. A detailed analysis of the approach is proposed and simulations are performed using MATLAB/Simulink software. The results show the performance and speed at which this control reaches the maximum power point. The response times is very low and is between 0.0125s and 0.05s depending on the climatic variations. So, Duty Cycle Modulation can be used as an alternative to Pulse Width Modulation for the search of the maximum power point.
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Cameroon aspires to emergence by 2035. Since 2009, it has drawn up reference documents such as the “Vision 2035” and the “Strategy Document for Growth and Employment”, which include growth goals such as poverty reduction, economic... more
Cameroon aspires to emergence by 2035. Since 2009, it has drawn up reference documents such as the “Vision 2035” and the “Strategy Document for Growth and Employment”, which include growth goals such as poverty reduction, economic development, industrialization, democracy and unity. In addition, in the document of the Intended Determined Contribution to the National Plan submitted to the United Nations, the country undertakes to reduce its greenhouse gas emissions up to 32% by 2035, with particular emphasis on renewable energy which will contribute 25% of total electricity production. The Sudano-Sahelian region of Cameroon is the region most threatened by climate change. For more than a decade, actions have been carried out both under government leadership and private initiatives to reduce the effects of global warming on the socio-economic development of the region. In our work, we will present some of the local action plans experienced both in the laboratory and in the field based...
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Multi-lateral institutions and international agreements have acknowledged the link between poverty and energy, the importance of sustainable energy development for achieving Millennium Poverty Reduction Goals, and the need for... more
Multi-lateral institutions and international agreements have acknowledged the link between poverty and energy, the importance of sustainable energy development for achieving Millennium Poverty Reduction Goals, and the need for environmental suitability. Most of the African countries remain mainly dependent on fossil energies. But, the oil production is being continuously decreasing. According to some experts, the end, called "peakoil" is expected to occur within 40 to 50 years. In addition, these sources of energy emit important amounts of polluting gases responsible of the global warming. Renewable energies appear to be ideal alternatives to fossil energies. The development and ownership of renewable energy are a major concern of our world. It was therefore appropriate and even important to propose a reference book that presents all renewable energies in a crosscutting and synthetic manner. This book is indeed intended to address the whole list of issues raised by scholars and researchers in this field. Onshore or offshore wind energy, thermal or photovoltaic solar, hydroelectric, biomass energies are treated in a didactic and very precise manner. The book also intends to show that renewable energies are sometimes governed by legal provisions similar to those applicable to other energies, hence the plea for a more favourable legal regime.
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ABSTRACT A human being spends approximately one-third of his/her life in sleep. For an efficient and peaceful rest, he/she therefore needs some level of comfort. This includes acceptable environmental parameters as well as suitable... more
ABSTRACT A human being spends approximately one-third of his/her life in sleep. For an efficient and peaceful rest, he/she therefore needs some level of comfort. This includes acceptable environmental parameters as well as suitable bedding systems. While the theories of thermal comfort in workplaces at daytime are currently well established, research on thermal comfort for sleeping environment at night is limited. Further studies in relation with sleep are needed. This paper presents an investigation on thermal comfort in sleeping environments in the sub-Saharan Africa region. The comfort equation used is based on the energy balance of the human body derived from Fanger’s comfort model. Comfort charts for the dry-tropical sub-Saharan Africa region were established using indoor climatic conditions collected over five years in Ouagadougou (12°22′N, 1°32′W). Results obtained show that the suitable monthly total insulation values for bedding systems in the dry-tropical regions range between 0.81 clo and 0.94 clo. The thermoneutral operative temperature range between 29 °C and 32 °C, while the thermoneutral air temperature range between 27 °C and 30 °C.
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Abstract-- Thermal comfort is an important parameter in buildings. It can significantly influence human health as well as his productivity. This paper presents the results of a field study conducted in the equatorial region of Cameroon.... more
Abstract-- Thermal comfort is an important parameter in buildings. It can significantly influence human health as well as his productivity. This paper presents the results of a field study conducted in the equatorial region of Cameroon. The adaptive approach coupled to the analytical approach was used to provide a holistic view of thermal comfort in buildings. A questionnaire, formulated according to the standards of ISO 7730 and ISO 10551 was used. Various values of environmental parameters were taken at the same time the occupants were filling the questionnaires. The study was conducted in 2011 during four seasons (long dry season, small rainy season, short dry season and long rainy season), more precisely in Yaounde city. The average comfort temperature obtained was 25.0°C while the thermo neutral temperature was 23.7 °C in modern habitat against 23.3°C in traditional ones. The preference temperature varied according to season and type of residence. In general, 77.5 % of voters f...
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In this paper, background on modelling PV module/array is established first; next, the combination of the optimization method least square estimator (LSE) algorithm and Newton Raphson resolution for identifying the five unknown parameters... more
In this paper, background on modelling PV module/array is established first; next, the combination of the optimization method least square estimator (LSE) algorithm and Newton Raphson resolution for identifying the five unknown parameters of single diode photovoltaic Module/Array is proposed. This predicted method is compared with other popular predictive and optimization methods such as Lambert solution, Villalva’s, modified Newton Raphson (NR), and nonlinear least square found in the literature. Here, two types of comparison are made: first, the dynamic variations of all five parameters values are carried out by graphs and compared in tables with the values found with the other methods (mentioned above); this evaluated the proposed method; secondly, the (I-V) and (P-V) curves are carried out at STC (Standard Test Conditions) and at 2 1000 / W m , 75 C , justifying the accuracy of the proposed method. The results proved the effectiveness of the least square estimator method, by a...
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Thermo PhotoVoltaic (TPV) system convert into electrical energy the radiation emitted from an artificial heat source (i.e., solar or combustion) by the use of photovoltaic cells. In the last decade, TPV system has gained an increasing... more
Thermo PhotoVoltaic (TPV) system convert into electrical energy the radiation emitted from an artificial heat source (i.e., solar or combustion) by the use of photovoltaic cells. In the last decade, TPV system has gained an increasing attention as cogeneration system for the distributed generation sector. Nevertheless, these systems are not fully developed and studied: several aspects need to be further investigated and completely understood. In this study, we modeled and investigated by performing numerical simulation on the feasibility of the TPV system exploiting waste heat energy during biomass combustion. To achieve this goal, we considered a TPV system in which we evaluated and analyzed the waste heat flux resulting from the combustion of the palm nuts shells as well as the corresponding temperature received at the surface of the TPV Thermal-emitter. Furthermore, we evaluated the heat intensity. Results obtained shows that the average temperature at the TPV absorber-emitter is...
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This work is an analysis of the data collected from 20 photovoltaic installations all over Cameroon. The objectives are to study the causes of the breakdown of the different installations and propose maintenance strategies to solve them... more
This work is an analysis of the data collected from 20 photovoltaic installations all over Cameroon. The objectives are to study the causes of the breakdown of the different installations and propose maintenance strategies to solve them and to evaluate the field lifetime of the different elements of the PV systems. The data analyzed were obtained from maintenance records and measurements over a period of nine years (from 2007 to 2015). It appears from this analysis that 29% of the batteries went bad (leading to curative intervention), contributing to about 64.9% of the total breakdown registered. About 58.5% of the installed batteries were replaced during preventive visits; according to that, the estimated average life expectancy of the batteries installed in the 20 sites was six years. At the same time, considering the various failures caused by other items of the system, 50% of the systems received curative interventions within the first four years of the study, the other 50% received their first curative intervention only from the fifth year. This study also permitted us to evaluate the quantity of preventive and corrective maintenance impacts on solar PV systems.
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Solar energy is receiving attention in applying technologies and energy systems in recent years. Solar technologies for buildings relying on both passive and active systems are developed. Passive solar refers to those that absorb, store... more
Solar energy is receiving attention in applying technologies and energy systems in recent years. Solar technologies for buildings relying on both passive and active systems are developed. Passive solar refers to those that absorb, store and distribute the sun's energy without relying on mechanical devices, while active systems are those where heat is transferred mechanically by the use of a working fluid such as air or a fluid that is typically water, or water based. Some recent innovations in solar technologies for buildings are also presented. It is seen that, today solar architecture is undergoing a true revolution through the integration of renewable technologies into the fabric of buildings. Such systems are designed for heating, ventilation, thermal isolation, shading, electricity generation and lighting of buildings.
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ABSTRACT This research work presents an exploration of low enthalpy geothermal potential and ground water reservoirs in the Sudano-Sahelian region of Cameroon. In that region, and particularly in the Mayo Kani area, access to water as... more
ABSTRACT This research work presents an exploration of low enthalpy geothermal potential and ground water reservoirs in the Sudano-Sahelian region of Cameroon. In that region, and particularly in the Mayo Kani area, access to water as well as electricity is not easy. In fact, more than 70% of the population does not have access to potable water. The method used to solve the problem is based on the resistivity model. One hundred of Vertical Electrical Soundings (VES) with forty profiles were carried out in the Mayo Kani area using the Schlumberger array. The results obtained from VES curves revealed the presence of two potential geothermal reservoirs at Djangal (ρ < 0.5 Ω m) and Moundjou (ρ < 0.8 Ω m). Groundwater zones were also delineated at the center, southwestern and southeastern parts of the geothermal contour map of the study area.
Research Interests: Geology and Geophysics
The achievement of sustainable development depends on reliable energy sources. In Africa, rural electrification poses particular challenges. Autonomous energy resources such as solar, wind or hydropower are possible solutions. Africa has... more
The achievement of sustainable development depends on reliable energy sources. In Africa, rural electrification poses particular challenges. Autonomous energy resources such as solar, wind or hydropower are possible solutions. Africa has the greatest worldwide potential in solar energy. An overview of the current status of the research in solar energy in the central Africa region is presented. It appears that the research in the field of solar energy is promising. There are some research laboratories and private organizations working in the field, but the results are still under the expectations of the local populations. To boost these researches, it would be necessary to encourage and finance projects of regional integration. The Central African countries are aware of their potentiality in solar energy based ongoing projects
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Humans rely heavily on energy in their daily activities and the demand is increasing. The conventional energy resources are limited and unequally distributed. Hence, a global requirement for sustainable energy provision becomes... more
Humans rely heavily on energy in their daily activities and the demand is increasing. The conventional energy resources are limited and unequally distributed. Hence, a global requirement for sustainable energy provision becomes increasingly important. A feasibility study of electricity supply with solar photovoltaic energy at the University of Ngaoundere in Cameroon is presented. Evaluations showed that, for an estimated need of approximately 969 kWh/day, 3 162 solar panels (125 W, 24 V) are necessary to overcome the energy needs of the institution. The overall investment cost is estimated to 153 301 485 US dollars (approximately 77 billions CFA). A simulation showed that the payback time of the investment is approximately nine years while a gain of 3 671 893 US Dollar (approximately 2 billion CFA) is performed.
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Solar energy is receiving attention in applying technologies and energy systems in recent years. Solar technologies for buildings relying on both passive and active systems are developed. Passive solar refers to those that absorb, store... more
Solar energy is receiving attention in applying technologies and energy systems in recent years. Solar technologies for buildings relying on both passive and active systems are developed. Passive solar refers to those that absorb, store and distribute the sun’s energy without relying on mechanical devices, while active systems are those where heat is transferred mechanically by the use of a working fluid such as air or a fluid that is typically water, or water based. Some recent innovations in solar technologies for buildings are also presented. It is seen that, today solar architecture is undergoing a true revolution through the integration of renewable technologies into the fabric of buildings. Such systems are designed for heating, ventilation, thermal isolation, shading, electricity generation and lighting of building