Papers by Nduwamungu Aphrodis
International Journal of Education, 2017
In Rwandan School, Head Teachers are confronted with a variety of issues as they provide leadersh... more In Rwandan School, Head Teachers are confronted with a variety of issues as they provide leadership and management to their schools. This study utilized a mixed methods approach to explore the role of M& E on assessing VVOB Rwanda Projects paradigm in improving the school Management and Leadership in order to deal with those issues. Quantitative methods were coupled with qualitative methods to obtain more complete picture of conventional monitoring and evaluation practices and as validity check to balance deficiencies that were found. Self-Administered Questionnaire was made by two categories of questionnaires such as the one concerning monitoring and evaluation in VVOB Rwanda Programme with challenges encountered. Administered questions to the VVOB staff taken as sample. While the other category was about the extent to which VVOB projects has helped in improving the school management and leadership. The questions of this category are based on eight (8) dimensions of successful lead...
Modelling and Optimization of Clean and Affordable Electricity Solution for Small-Scale Savings and Credit Cooperatives (SACCOs)
Energy Engineering
PV system grid as backup connected management using automatic changeover switch
2022 IEEE PES/IAS PowerAfrica
Faults in electrical networks are among the key factors and sources of network disturbances. Cont... more Faults in electrical networks are among the key factors and sources of network disturbances. Control and automation strategies are among the key fault clearing techniques responsible for the safe operation of the system. Several researchers have revealed various constraints of control and automation strategies such as a slow dynamic response, the inability to switch the network on and off remotely, a high fault clearing time and loss minimization. For a system with wind energy technologies, if the power flow of a wind turbine is perturbed by a fault, the intermediate circuit voltage between the machine side converter and line side converter will rise to unacceptably high values due to the accumulation of energy in the DC link capacitor. To overcome the aforementioned issues, this paper used MATLAB simulations and experiments to analyze and validate the results. The results revealed that fault ride through capability with Supervisory Control and Data Acquisition (SCADA) viewer softwa...
Energy Management and Control Strategy of DC Source and Microturbine Generation System by Using PQ Controller and Droop Control in Islanded Mode
International Journal of Energy and Power Engineering, 2018
The requirements of power quality, public environment policy and expansion power demand are provi... more The requirements of power quality, public environment policy and expansion power demand are providing better opportunity to the microturbine (MTG) to be best microsources for improving the system stability, reliability and power quality. This paper presents modelling and control strategy of MTG system by using PQ controller and Droop control in islanded mode. The model developed in this work includes the individual components of prime mover like, compressor, heat exchanger, burner and turbine. The model of MTG system consists of microturbine, permanent magnet synchronous machine and power electronics interfacing circuit for generation and conversation from AC/DC/AC respectively and design of PQ controller including droop control with current and voltage loop and power loop. The simulations are carried out in islanded mode of the system to observe its behavior when supplying customer under variable load. It also incorporates modeling and simulation of microturbine with speed control,...
Design, Control and Validation of a PV System Based on Supervisory Control and Data Acquisition (SCADA) Viewer in Smartgrids
The performance and output of PV cells depends upon different factors: irradiance, shaded modules... more The performance and output of PV cells depends upon different factors: irradiance, shaded modules, shadow, temperature, inverter capability, wind speed, wind direction and the number of PV installed are one of them. Maximum Power Point Tracking (MPPT) is required to control various effects caused by one of the aforementioned factors. Researchers have employed many MPPT techniques. However, these techniques showed some limitations such as slow response and inability to be remotely controlled. This has been observed during the higher number of PV grid connected inverters installed in some regions of Rwanda where the power generated via peak conditions sometimes exceeds the transmission capacity limits. In this case, the classical MPPT cannot respond efficiently. With the aim to alleviate these issues, the paper uses perturb and observe MPPT with SCADA viewer software so that inverter can operate with its design limits. This involves the de-rating and control of inverter capability cur...
Faults in electrical power systems are among the key factors and sources to network disturbances,... more Faults in electrical power systems are among the key factors and sources to network disturbances, however control strategies are among key faults clearing techniques for the sake of safe operational mode of the system.Some researchers have shown various limitations of control strategies such as slow dynamic response,inability to switch Off and On network remotely and fault clearing time. For a system with wind energy technologies, if the power flow of a wind turbine is interrupted by a fault, the intermediate-circuit voltage between the machine-side converter and line-side converter will fall in unacceptably high values.To overcome the aforementioned issues, this paper used a Matlab simulations and experiments in order to analyze and validate the results.The results showed that fault ride through (FRT) with SCADA Viewer software are more adaptable to the variations of voltage and wind speed in order to avoid loss of synchronism. Therefore at the speed of 12.5m/s a wind produced a ra...
International Journal of Photoenergy
In recent years, several factors such as environmental pollution, declining fossil fuel supplies,... more In recent years, several factors such as environmental pollution, declining fossil fuel supplies, and product price volatility have led to most countries investing in renewable energy sources. In particular, the development of photovoltaic (PV) microgrids, which can be standalone, off-grid connected or grid-connected, is seen as one of the most viable solutions that could help developing countries such as Rwanda to minimize problems related to energy shortage. The country’s current electrification rate is estimated to be 59.7%, and hydropower remains Rwanda’s primary source of energy (with over 43.8% of its total energy supplies) despite advances in solar technology. In order to provide affordable electricity to low-income households, the government of Rwanda has pledged to achieve 48% of its overal electrification goals from off-grid solar systems by 2024. In this paper, we develop a cost-effective power generation model for a solar PV system to power households in rural areas in R...
International Journal of Photoenergy
The energy sector of today’s Rwanda has made a remarkable growth to some extent in recent years. ... more The energy sector of today’s Rwanda has made a remarkable growth to some extent in recent years. Although Rwanda has natural energy resources (e.g., hydro, solar, and methane gas, etc.), the country currently has an installed electricity generation capacity of only 226.7 MW from its 45 power plants for a population of about 13 million in 2021. The current national rate of electrification in Rwanda is estimated to 54.5% (i.e.; 39.7% grid-connected and 14.8% off-grid connected systems). This clearly demonstrates that having access to electricity is still a challenge to numerous people not to mention some blackout-related problems. With the ambition of having electricity for all, concentrated solar power (CSP) and photovoltaic (PV) systems are regarded as solutions to the lack of electricity. The production of CSP has still not been seriously considered in Rwanda, even though the technology has attracted significant global attention. Heavy usage of conventional power has led to the dep...
OALib
The integration of distributed Energy Resources (DER) is challenging electrical network quality w... more The integration of distributed Energy Resources (DER) is challenging electrical network quality which is the main vital and ubiquitous all over the world. Coordination and energy management of microgrids in grid connected and in islanded mode is one of solutions of distribution power quality with best reliability, and stability to ensure power system resilience. In this review, the coordination and energy management of microgrids broad based on PQ controller and droop control some useful information is given in details and analyzed. Additionally, possible structures, options and control methods of DER units are presented which is followed by the descriptions of system controls and energy management strategies. Eventually, future trends of microgrids are discuss, point out how this concept can be a key to select a best method of coordination and managing microgrids for future researchers in order to tackle some challenges based on power quality.
OALib
The integration of distributed Energy Resources (DER) is challenging electrical network quality w... more The integration of distributed Energy Resources (DER) is challenging electrical network quality which is the main vital and ubiquitous all over the world. Coordination and energy management of microgrids in grid connected and in islanded mode is one of solutions of distribution power quality with best reliability, and stability to ensure power system resilience. In this review, the coordination and energy management of microgrids broad based on PQ controller and droop control some useful information is given in details and analyzed. Additionally, possible structures, options and control methods of DER units are presented which is followed by the descriptions of system controls and energy management strategies. Eventually, future trends of microgrids are discuss, point out how this concept can be a key to select a best method of coordination and managing microgrids for future researchers in order to tackle some challenges based on power quality.
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Papers by Nduwamungu Aphrodis