IJIRAE Published Papers by Bakari Mwinyiwiwa
IJIRAE:: AM Publications,India, 2019
This work deals with voltage regulation of solar photovoltaic based minigrid. In this regulator, ... more This work deals with voltage regulation of solar photovoltaic based minigrid. In this regulator, DC-DC boost converter embedded with maximum power point Tracking (MPPT) voltage regulation without controlling charging and discharging of batteries through bidirectional converter. The proposed voltage regulator managed to regulate dc voltage and maintaining the dc bus voltage at its reference value. The DC voltage regulation has been done by corrected duty cycle of estimated duty cycle through MPPT controller. The DC voltage regulator was tested at slow varying and moderately varying solar Insolation at Constant Temperature. Simulation results using MATLAB/SIMULINK software show that the DC voltage regulator is capable of regaining voltage regulation after step load changes
Papers by Bakari Mwinyiwiwa
Simulation studies, confirmed by laboratory experiments, show that the undesirable third harmonic... more Simulation studies, confirmed by laboratory experiments, show that the undesirable third harmonic inherently present on the DC link capacitor voltages of multilevel converters can be eliminated by a 6-phase configuration in a shunt multilevel STATCOM. The principle can be extended to eliminate the residual sixth harmonic by configuring a 12-phase STATCOM.
Zenodo (CERN European Organization for Nuclear Research), Nov 12, 2021
Tanzania has several places which lack the access to grid. These areas can be powered by utilizin... more Tanzania has several places which lack the access to grid. These areas can be powered by utilizing hybrid energy systems (HES) such as solar photovoltaic, wind, and biodiesel. However, such a system produces voltage control challenges at the DC bus due to stochastic nature of those sources, if battery is not coupled. Therefore, this paper first proposes a HES that is coupled to a battery. Secondly, it proposes a control that can regulate the three sources of energy such that the DC bus is maintained at 750 V. Simulation results have shown that a conventional proportional and integral controller can achieve DC bus voltage regulation for the system proposed in this paper regardless of irradiance variation, wind speed variation, or the load variation. This type of energy sources is feasible for use in rural arrears of Tanzania.
In response to address different development challenges, Tanzania is striving to achieve its four... more In response to address different development challenges, Tanzania is striving to achieve its fourth attribute of the National Development Vision, i.e. to have a well educated and learned society by the year 2025. One of the most cost effective methods that can reach a large part of the society in a short time is to integrate ICT in education through e-learning initiatives. However, elearning initiatives are challenged by limited or lack of connectivity to majority of secondary schools, especially those in rural and remote areas. This paper has explores the possibility for rural secondary school to access online e-Learning resources from a centralized e- Learning Management System (e-LMS). The scope of this paper is limited to schools that have computers irrespective of internet connectivity, resulting in two categories schools; those with internet access and those without. Different connectivity configurations have been proposed according to the ICT infrastructure status of the resp...
HVDC Light systems range from 3MW to about 1000MW transmission technology combining power convert... more HVDC Light systems range from 3MW to about 1000MW transmission technology combining power converters and DC cables. The power converters are based on Voltage Source Converters (VSC) and Pulse Width Modulation (PWM) control. The use of series connection of power semiconductors such as IGBTs is fundamental to the development of the HVDC Light technology. HVDC Light is excellent for underground and under water power transmission. By use of HVDC Light power converters and cables, it is possible to overcome the technical difficulties to connect small loads and small scale generating units to the AC grid and to make the connection economical and environmentally friendly. This paper presents viability analysis of using HVDC Light technology for electrification of Mafia Ireland (Tanzania) from the national grid. In the paper the load demand forecast has been performed to estimate the load for the next 25 years at Mafia Island. HVDC Light model has been developed and simulated using MATLAB/Simulink software. The simulation results show that HVDC Light system performance is capable of delivering reliable and quality power when the Mafia Island is supplied by national grid using HVDC Light system. The benefits include more reliable power supply reduced environmental effects.
International Journal of Computer Applications, 2018
The aim of this paper is to study the effect of traffic differentiation and priority scheduling i... more The aim of this paper is to study the effect of traffic differentiation and priority scheduling in providing Quality of Service (QoS) for e-learning applications in Universal Mobile Telecommunication System (UMTS) networks. A simulation model of the UMTS network has been developed and used to study performance of e-learning applications as perceived by users. Priority scheduling is used to prioritize traffic between e-learning and other conventional users according to their QoS requirements. Simulation results show that a UMTS network configured with traffic differentiation and priority scheduling can deliver e-learning services with page response time of less than 4 seconds. This performance is within the acceptable values of web-based applications quality of service.
Photovoltaic (PV) energy is one of the most important energy resources since it is clean, polluti... more Photovoltaic (PV) energy is one of the most important energy resources since it is clean, pollution free, and sustainable. Maximum Power Point Tracking (MPPT) is used in photovoltaic (PV) systems to maximize the photovoltaic output power, irrespective of the temperature and radiation conditions. In MPPT system, the PV output power is fed directly to dc/dc converter and the output of MPPT control is used to control the dc/dc converter in order to operate at the maximum possible power point (MPP). In this paper it is proposed to track the MPP in PV module using incremental conductance algorithm. CUK converter is used as dc/dc converter to achieve the power/voltage level conversion. The MPPT system has been simulated using MATLAB/Simulink software to track the maximum output power from PV array and charge a battery bank. Simulation results show that the proposed MPPT system is capable of maximum power tracking of the PV array as desired. Keywords— Cuk converter, PV cell, PV module, Max...
Uploads
IJIRAE Published Papers by Bakari Mwinyiwiwa
Papers by Bakari Mwinyiwiwa