Department of Computer Engineering
Permanent URI for this collectionhttp://197.255.125.131:4000/handle/123456789/23125
Browse
7 results
Search Results
Item Optimal sizing and techno-economic analysis of a hybrid solar PV/wind/diesel generator system(IOP Conference Series: Earth and Environmental Science, 2022) Tay, G.; Acakpovi, A.; Adjei, P.; Aggrey, G.K.; Sowah, R.; et al.Abstract. Hybrid power systems that combine wind and solar PV technology have been widely employed for power generation, particularly for electrification in remote and islanding locations, because they are more cost-effective and reliable than traditional power systems. This article intends to develop an environmentally friendly and cost-effective hybrid power system for selected critical loads in the Avuto community of Ghana. Following the acquisition of site data, a hybrid solar PV, wind, diesel generator, and converter analysis was conducted using HOMER software to establish the appropriate sizing of system components based on technical and economic parameters such as load served, annual electricity production, net present cost (NPC), emission, Operating cost, Fuel consumption and energy cost (COE). Based on the optimization computational results, it can be stated that the combination of system components, including solar photovoltaic, wind turbine, and diesel generator, is a good fit for the application region and might be used for rural and island electrification in the future. The suggested energy system has an LCOE of 0.39 US$/kWh for the 1.08 US$/litre diesel fuel cost and a 3.33-year payback period, with 58.8 kW for PV, 7 units for 3 kW wind turbines, 10 kW for diesel generator, and 6.99 kW for the converter. In terms of emission reduction, the proposed case presented a 55% emission reduction from the base case scenario.Item Innovative design of grid connected solar/diesel hybrid system using RETScreen software(IOP Conference Series: Earth and Environmental Science, 2022) Kof, D.; Acakpovi, A.; Adjei, P.; Sowah, R.; Aggrey, G.K.; et al.Abstract. Accessibility to dependable energy resource is vital to the emerging economy to function appropriately in this contemporary world for both residential and commercial purposes. Technological advancement has opened avenues for more sophisticated technologies to combine multiple energy sources to generate affordable electricity for residential and industrial purposes. The study, therefore aims at analyzing the fiscal benefits of hybrid Solar PV and Diesel Generator (DG) (PV-DG) grid-connected system using RETSceen software. The study focused on a specific location, J. A. Plant Pool Ghana Limited, warehouse Department. The study recommended and proposed an effective design of a hybrid PV-DG grid connected electricity supply for the warehouse Department. The economic viability of the project and the payback period obtained through computation were very attractive. Also, the total revenue of electricity exported to the grid annually and GHG emission reduction were within the standard benchmark. The study finally concurred that renewable energy sources such as solar when hybridized with any other energy systems, lead to a noticeable electrical cost reduction. Therefore, this system design provides multiple benefits, including; improved reliability, reduced emission and significant cost reduction.Item Impact Analysis of Induced FM Radio Interferences on Aeronautical Radio Navigation Systems: Case Study of Kotoka International Airport, Accra-Ghana(International Conference on Computing, Computational Modelling and Applications, 2019-03-29) Sowah, R.; Acakpovi, A.; Tefutor, I.; Quist-Aphetsi, K.; Nwulu, N.; Abubakar, R.This paper investigates the effect of interference on Aeronautical Navigation systems by Frequency Modulation (FM) broadcasting signals. Precisely, the paper evaluated the impact of 3rd order intermodulation distortion on the VHF omnidirectional range and the instrument landing system (Localizer) used at the Ghana Civil Aviation Authority (GCAA). The necessity of this study stems from the fact that, electromagnetic compatibility (EMC) between FM audio broadcast and aeronautical radio communication services operating in the range of 85.7-108MHz and 108-117.975 MHz respectively is essential for safe flight operation. An analytical method of estimating the 3rd order intermodulation distortion has first been presented followed by simulation approach with the intermodulation analysis software v.10 and subsequent simulation with the Matlab software to determine and display the power spectral density of the output signals. All FM station frequencies in the Greater Accra region have been considered and paired to form dual tone signals that were considered input signal before assessing the impact of the 3rd order intermodulation harmonic. It was found that multiple 3rd order intermodulation harmonics distort and perturbate the aeronautical communication system in the Greater Accra region and these lead to severe safety implications for the operation of the aeronautical navigation system. It was recommended that broadcasting stations should implement cavity filters to reduce the effect of 3rd order intermodulation harmonics; they should respect the specification prescribed to them by the NCA and operate within limits allocated to them in order not to breach the international regulation of ITU that deems it an offense to interfere with the aeronautical communication system and to further ensure safety to the aviation navigation system.Item Modelling an Efficient Gap Filler for DTT Network Using ADS Software(International Conference on Computing, Computational Modelling and Applications, 2019-03-29) Sowah, R.; Mensah, F.; Acakpovi, A.; Osumanu, F.; Fifatin, F.N.; Nounangnonhou, T.C.This paper proposes the modelling and simulation of a special gap filler intended to cover grey areas in the DTT network of Accra. This has become necessary due to the numerous areas of low signal coverage in the Accra DTT and the incapability of previous methods to efficiently address the problem. The ADS simulation consists of arrangements of components from the DBV-T library which consists of filters, amplifiers and a power source. This setup mimics a gap filler system with a better noise reduction implementation, several frequency values are being used for the simulation process. A significant increase in the output signal as in comparison to the input means the shaded areas will be properly covered. The results derived from the simulation of the ADS setup highly improved upon the output signal values, when compared to the ITU standard. Three (3) out of five (5) simulation results show values beyond the minimum signal level requirement. Also using MATLAB, the RF propagation toolbox which has the map tool feature was able to implement the gap fillers into the Accra area and gave a visual representation of the signal strength. Modelling a gap filler system which has better noise cancellation and which propagates better with a dipole antenna was achieved in this paper. The outcome of the paper shows that the gap filler modelling increase signals in grey areas.Item A relay-based technique to reduce uplink transmit power in multi-operator mobile communication systems(Proceedings of the 2012 IEEE 4th International Conference on Adaptive Science and Technology, ICAST 2012, 2012-10) Koumadi, K.M.; Acakpovi, A.; Kogue, D.W.; Hountondji, J.A.Coverage, capacity, and total power consumption are key issues in mobile communication systems. With the explosion of multimedia services, energy consumption of Mobile Stations (MS) becomes a special limiting factor in achieving high capacity in uplink transmission as well as in guaranteeing applications' required Quality of Service (QoS). Under a certain number of reasonable assumptions, this paper proposes a relay technique in which a Base Station (BS) of a foreign network provider (FBS) serves as a relay node between an MS and the base station of its registered home network (HBS). A proposed algorithm compares the power required for uplink transmission over the relay link (MS-FBS-HBS) and that required over the direct link (MS-HBS), under the various channel conditions, and then chooses the less-power-consuming link. Simulation results show that the proposed algorithm significantly reduces power comsumption. Furthermore, no core network equipment is actively involved, confirming the possiblibily of radio access network sharing among operators, as total capacity and coverage are boosted. © 2012 IEEE.Item Joint bandwidth and power allocation at mobile stations for QoS-constrained multimedia applications(Proceedings of the 2012 IEEE 4th International Conference on Adaptive Science and Technology, ICAST 2012, 2012-10) Koumadi, K.M.; Sowah, R.A.; Acakpovi, A.Various multimedia applications will be supported by beyond third generation (B3G) mobile communication systems. Mobile users may choose to simultaneously launch various applications with quality of service (QoS) constraints. Subject to the chosen applications' respective QoS constraints, the user may have to allocate her/his available resources for satisfaction maximization. In this paper, a utility-based algorithm is proposed to jointly allocate available power and uplink bandwidth, at mobile station (MS) level. Using Karush-Kuhn-Tucker (KKT) conditions and simulation, the algorithm is proved to be optimal. Under certain conditions, the algorithm (which may be applied in both downlink and uplink) is iterative and its convergence is shown by simulation. © 2012 IEEE.Item Transmission power minimization for a multi-application user in OFDMA systems(Proceedings of the 2012 IEEE 4th International Conference on Adaptive Science and Technology, ICAST 2012, 2012-10) Koumadi, K.M.; Acakpovi, A.; Sowah, R.A.When a user in Beyong third generation (B3G) mobile communication systems launches multiple applications simultaneously, the user's radio resources (subcarriers, symbols, power,⋯) need to be efficiently allocated to these applications while maintaining their quality of service (QoS) requirements and user utility. In this paper, a power minimization subcarrier, symbol, and power allocation problem is formulated, solved, and algorithms are derived. The problem formulation differs from those in existing works in that all the applications are from the same user. This relaxes some subcarrier allocation constraints that exist in multiuser single-application-per-user cases, leading to different solution techniques. Furthermore, the multiuser diversity which is the basis for many existing algorithms does not exist in the context of this paper. © 2012 IEEE.