NTAMBARA Sylvestre Owen - Academia.edu (original) (raw)

Papers by NTAMBARA Sylvestre Owen

Academia, 2024

This study examines the energy consumption profiles of five different electric vehicles (EV) mode... more This study examines the energy consumption profiles of five different electric vehicles (EV) models considering Gikondo-Rebero route of about 3km in Kigali, Rwanda. The study compares the performance of EVs with varying masses and frontal areas by analyzing energy usage data, including forces like rolling resistance, drag, and hill force.
The analysis incorporates data from a KML route file with road coordinates (latitude, longitude and altitude) with a focus on cumulative energy consumption and net energy per segment for each vehicle.
The results provide insights into the factors influencing energy efficiency, offering a framework for optimizing electric vehicle usage in urban and rural environments. Recommendations are made to improve energy efficiency and reduce overall consumption for EVs operating in similar terrains.

The penetration of electric vehicles in Rwanda is increasing following Rwanda's mission to elimin... more The penetration of electric vehicles in Rwanda is increasing following Rwanda's mission to eliminate the CO2 emissions to the atmosphere, it is in that regards, this paper presents a study on PV-Diesel hybrid system for charging station and compare the control scheme for the diesel generator to reduce levelized cost of energy for charging electric vehicles in Rwanda. Moreover, Load Following (LF) and Cycle Charging (CC) strategies were found to be simple and effective tools for the control of hybrid charging station, but they have some drawbacks. CC dispatch strategy provides more energy to the batteries. But this approach shuts down the generator during the low-load period, which results in a reduction of the total operating time of the generator. However, the sequence of the battery charging/discharging process may damage or ruin the battery, which leads to increased replacement costs. On the other hand, when the generator satisfies the load demand without charging the batteries, the LF dispatch strategy ensures that the batteries remain charged by the RES output power only, and this maximizes the use of available renewable energy.

Commercial losses (non-technical losses) are well understood and their reduction is finite and es... more Commercial losses (non-technical losses) are well understood and their reduction is finite and essential issue for utilities to adopt new innovative technologies like smart meters, wireless technologies and data analysis-based technologies to reduce commercial losses which destabilize power supply, voltage in the network and cause financial losses to the utility. The aim of this internship was to identify any kind of commercial losses using data analytics in Rwanda Energy Group. Utilizing some data from the utility helped to identify where there is a high chance of electricity theft or any other commercial loss between postpaid and prepaid customers or in power network infrastructures. The interpretation of the results is from past and current data depending on the type of non-technical loss that was being investigated but this method fails to localize where the suspect (thief) is or any other kind of commercial losses due to lack of real-time data.

Induction machines are widely used in various applications including industrial applications and ... more Induction machines are widely used in various applications including industrial applications and locomotive applications. The electric systems used in industrial applications are required to have higher performance and reliability requirement so three phase induction motors are preferable because they are simple to design, easy to maintain and are less costly.
However, induction motors do not have capability of variable speed operation, it is in that reason, the speed control of induction motor has become essential. This report deals with the investigation, experimental tests and compares the main concept of speed control of induction motor using V/F control method and vector control method with the help of AC2 - Space Vector PWM VSI Induction 3HP Motor Drive Simulink model.
Variable voltage and frequency (V/F control) method is the most suitable common method of speed control for the applications without position control requirements for high accuracy of speed control but V/F control is inferior to vector control for complex dynamic behavior of the induction motor so the vector control technique works with vector quantities, controlling the desired values by using space phasors which is a better solution so that the control on flux and torque become independent from each other and the induction motor is transformed from a non-linear to linear control plant.
In this report many experiments were investigated though the build in Simulink model did not allow any changes of some parameters, so the two methods of speed control of induction machine were not clearly investigated but it compares the main concepts of the two methods of controlling speed of induction motor.

Academia, 2024

This study examines the energy consumption profiles of five different electric vehicles (EV) mode... more This study examines the energy consumption profiles of five different electric vehicles (EV) models considering Gikondo-Rebero route of about 3km in Kigali, Rwanda. The study compares the performance of EVs with varying masses and frontal areas by analyzing energy usage data, including forces like rolling resistance, drag, and hill force.
The analysis incorporates data from a KML route file with road coordinates (latitude, longitude and altitude) with a focus on cumulative energy consumption and net energy per segment for each vehicle.
The results provide insights into the factors influencing energy efficiency, offering a framework for optimizing electric vehicle usage in urban and rural environments. Recommendations are made to improve energy efficiency and reduce overall consumption for EVs operating in similar terrains.

The penetration of electric vehicles in Rwanda is increasing following Rwanda's mission to elimin... more The penetration of electric vehicles in Rwanda is increasing following Rwanda's mission to eliminate the CO2 emissions to the atmosphere, it is in that regards, this paper presents a study on PV-Diesel hybrid system for charging station and compare the control scheme for the diesel generator to reduce levelized cost of energy for charging electric vehicles in Rwanda. Moreover, Load Following (LF) and Cycle Charging (CC) strategies were found to be simple and effective tools for the control of hybrid charging station, but they have some drawbacks. CC dispatch strategy provides more energy to the batteries. But this approach shuts down the generator during the low-load period, which results in a reduction of the total operating time of the generator. However, the sequence of the battery charging/discharging process may damage or ruin the battery, which leads to increased replacement costs. On the other hand, when the generator satisfies the load demand without charging the batteries, the LF dispatch strategy ensures that the batteries remain charged by the RES output power only, and this maximizes the use of available renewable energy.

Commercial losses (non-technical losses) are well understood and their reduction is finite and es... more Commercial losses (non-technical losses) are well understood and their reduction is finite and essential issue for utilities to adopt new innovative technologies like smart meters, wireless technologies and data analysis-based technologies to reduce commercial losses which destabilize power supply, voltage in the network and cause financial losses to the utility. The aim of this internship was to identify any kind of commercial losses using data analytics in Rwanda Energy Group. Utilizing some data from the utility helped to identify where there is a high chance of electricity theft or any other commercial loss between postpaid and prepaid customers or in power network infrastructures. The interpretation of the results is from past and current data depending on the type of non-technical loss that was being investigated but this method fails to localize where the suspect (thief) is or any other kind of commercial losses due to lack of real-time data.

Induction machines are widely used in various applications including industrial applications and ... more Induction machines are widely used in various applications including industrial applications and locomotive applications. The electric systems used in industrial applications are required to have higher performance and reliability requirement so three phase induction motors are preferable because they are simple to design, easy to maintain and are less costly.
However, induction motors do not have capability of variable speed operation, it is in that reason, the speed control of induction motor has become essential. This report deals with the investigation, experimental tests and compares the main concept of speed control of induction motor using V/F control method and vector control method with the help of AC2 - Space Vector PWM VSI Induction 3HP Motor Drive Simulink model.
Variable voltage and frequency (V/F control) method is the most suitable common method of speed control for the applications without position control requirements for high accuracy of speed control but V/F control is inferior to vector control for complex dynamic behavior of the induction motor so the vector control technique works with vector quantities, controlling the desired values by using space phasors which is a better solution so that the control on flux and torque become independent from each other and the induction motor is transformed from a non-linear to linear control plant.
In this report many experiments were investigated though the build in Simulink model did not allow any changes of some parameters, so the two methods of speed control of induction machine were not clearly investigated but it compares the main concepts of the two methods of controlling speed of induction motor.