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Innocent E Davidson, (M’92, SM’02), IEEE, USA; Fellow, IET, UK; Fellow, SAIEE; CEng, UK; P Eng. (ECSA). He received the BSc (Eng.) with Honours, MSc (Eng.) degrees in Electrical Engineering, University of Ilorin, Nigeria in 1984, 1987; PhD in Electrical Engineering, University of Cape Town, Rondebosch, South Africa, 1998; Post-graduate Diploma in Business Management, University of KwaZulu-Natal (UKZN), 2004. He was Assoc. Professor of Electrical Engineering and Research Coordinator, University of Namibia, 2012 to 2014. He was Director, Eskom Centre of Excellence in HVdc Engineering, UKZN, 2014 to 2016. He is a Full Professor and Chair, Department of Electrical Power Engineering; Director, Centre of Excellence in Smart Grids, Durban University of Technology, Durban, South Africa. His current research interests include grid integration of renewable energy using power electronics, DC delivery systems and Innovation for Smart Cities. He is the recipient of numerous awards and industry research grants. Prof Davidson is the recipient of the award of “Top Faculty Researcher of the Year (Platinum Category)”, Durban University of Technology's Annual Research & Innovation Awards (based on 2018 research outputs). Dr Davidson received the Associate Certificate in Sustainable Energy Management (SEMAC), from the British Columbia Institute of Technology, Burnaby, BC, Canada, 2011, and Course Certificate in Artificial Intelligence, University of California at Berkeley, USA in 2020.
Advances in voltage-source converters (VSCs), as well as their successful application in VSC-HVDC systems, have motivated growing interests and research in medium-voltage direct current (MVDC) traction power systems (TPSs) for high-speed rail (HSR) applications. As an emerging power-converter-based infrastructure, this study reviewed developments that shape two key evolving pieces of equipment—namely, high-power traction substation (TSS) converters, and power electronic transformers (PETs)—for MVDC TPS as well as prospects for smart grid (SG) applications in the future. It can be deduced that cost-effective and robust high-power TSS converters are available from hybrid modular multilevel converters (MMCs) for enhanced performance and fault-tolerance capability. In addition, silicon carbide (SiC) MMC-based PETs with input-series-output-parallel (ISOP) configuration are present for greater weight/size reduction and efficiency for MVDC rolling stock design. Finally, the implementation of a smart MVDC TPS incorporating a sophisticated railway energy management system (REM-S) based on the smart grid principles is feasible in the future, with numerous benefits. However, there are related challenges, like knowledge gaps on these technologies, the high costs involved, and lack of standardization to overcome to realize widespread future commercial deployment.
Patrobers Simiyu; I. Davidson. MVDC Railway Traction Power Systems; State-of-the Art, Opportunities, and Challenges. Energies 2021, 14, 4156 .
AMA StylePatrobers Simiyu, I. Davidson. MVDC Railway Traction Power Systems; State-of-the Art, Opportunities, and Challenges. Energies. 2021; 14 (14):4156.
Chicago/Turabian StylePatrobers Simiyu; I. Davidson. 2021. "MVDC Railway Traction Power Systems; State-of-the Art, Opportunities, and Challenges." Energies 14, no. 14: 4156.
Withstanding fault is a crucial technical challenge for inverter-based systems. Evolving grid codes require microgrids to possess fault ride-through (FRT) capabilities and support the grid voltage recovery. The traditional grid forming and grid feeding models lack such abilities. Consequently, this article enhanced these traditional models with droop control-virtual impedance and secondary power reference generation to form two models of a grid-supporting system. The first is a current source for grid feeding control, and the second is regulated as a voltage source for grid forming control. The result presents grid fault impact and FRT compliance in the proposed and traditional systems. Furthermore, the fault current curtailment and FRT improvement of the virtual impedances in the grid forming control were investigated within the MATLAB/Simulink environment. These proposed systems achieved FRT under a dynamic period and reverted to appropriate power delivery control under a static period.
Elutunji Buraimoh; Innocent E. Davidson. Fault Ride-Through Analysis of Current- and Voltage-Source Models of Grid Supporting Inverter-Based Microgrid. IEEE Canadian Journal of Electrical and Computer Engineering 2021, 44, 189 -198.
AMA StyleElutunji Buraimoh, Innocent E. Davidson. Fault Ride-Through Analysis of Current- and Voltage-Source Models of Grid Supporting Inverter-Based Microgrid. IEEE Canadian Journal of Electrical and Computer Engineering. 2021; 44 (2):189-198.
Chicago/Turabian StyleElutunji Buraimoh; Innocent E. Davidson. 2021. "Fault Ride-Through Analysis of Current- and Voltage-Source Models of Grid Supporting Inverter-Based Microgrid." IEEE Canadian Journal of Electrical and Computer Engineering 44, no. 2: 189-198.
Earthing and protective devices such as line surge arrestors (LSAs) play an important role in areas with high lightning occurrence for overhead HVAC lines’ performance. A lightning stroke of high magnitude can lead to back flash-overs, and the resultant power surge on the phase conductor can cause instigate the line breaker operating to extinguish the power surge. This operation of the protective devices leads to consumer interruptions on the network, a loss of production, and negatively affects the economy. Studies have shown that reducing an earthing system’s values, which itself is costly, may not be sufficient to prevent back flashover and the associated customer production cost loss. A code was developed to determine the possibility of back flashover and the cost of various earthing schemes utilizing the MATLAB software analysis tool. This paper determines the possibility of a back flashover for various combinations of lightning strokes and earthing profiles. Tower Footing Resistances as low as 9.8 Ω can cause back flashover, provided the lightning stroke exceeds 12 kA. Furthermore, the paper presents and discusses an innovative hybrid power line protection scheme, which estimates and considers the high cost associated with establishing an earthing system; it examines the impracticality of re-engineering an earthing scheme for implementation and results obtained by the inclusion of lightning surge arrester’s (LSA). The cost-saving resulting from dips is also established over 25 years for an 88 kV line, and the breakeven point is established. The results showed that the best scenario would be to reduce the tower footing resistance to 29.1 Ω and install 11 LSA per phase.
Eddie Singh; Innocent E. Davidson; Sindisiwe C. Malanda. Lightning Performance and Economic Analysis of an Overhead 88 kV Power Delivery Network with Enhanced Protective Systems. Energies 2020, 13, 6519 .
AMA StyleEddie Singh, Innocent E. Davidson, Sindisiwe C. Malanda. Lightning Performance and Economic Analysis of an Overhead 88 kV Power Delivery Network with Enhanced Protective Systems. Energies. 2020; 13 (24):6519.
Chicago/Turabian StyleEddie Singh; Innocent E. Davidson; Sindisiwe C. Malanda. 2020. "Lightning Performance and Economic Analysis of an Overhead 88 kV Power Delivery Network with Enhanced Protective Systems." Energies 13, no. 24: 6519.
The paper focuses on assessing the level of digitalization in several developing maritime business environments in Albania, Bosnia and Herzegovina, Montenegro, and Serbia. The assessment has been done in reference to Holtham’s and Courtney’s Intelligent Information and Communication Technologies (ICT) Exploiter Model. The dimensions as maritime business system effectiveness, roles, and skills of information technology personnel, ladders of knowledge, ICT strategy, organizational culture, and manager’s mindset are analyzed. In addition, benchmarking with findings from developed maritime business environments in Croatia, Greece, Italy, and Slovenia, which belong to the European Union (EU), by using the same model, has been conducted. This is done with the aim to outline directions for improving the quality and speed of digitalization in non-EU countries, which have been functioning for decades in transitional conditions. The maritime ecosystem naturally has a tendency to be unique and to function smoothly as such. Alleviating the differences in the level and effectiveness of digitalization in developed and developing European countries is a path towards achieving this goal. By sharing their own expertise in the rational and intelligent use of ICT, developed EU countries can support developing non-EU countries towards ensuring sustainability in the entire European and worldwide maritime business ecosystem.
Nexhat Kapidani; Sanja Bauk; Innocent Davidson. Digitalization in Developing Maritime Business Environments towards Ensuring Sustainability. Sustainability 2020, 12, 9235 .
AMA StyleNexhat Kapidani, Sanja Bauk, Innocent Davidson. Digitalization in Developing Maritime Business Environments towards Ensuring Sustainability. Sustainability. 2020; 12 (21):9235.
Chicago/Turabian StyleNexhat Kapidani; Sanja Bauk; Innocent Davidson. 2020. "Digitalization in Developing Maritime Business Environments towards Ensuring Sustainability." Sustainability 12, no. 21: 9235.
The Ferranti effect could cause a rise in voltage along the cables on a wind farm if the circuit breakers at the receiving ends are switched off. Ferroresonance could also occur due to stuck pole(s) of the circuit breaker during de-energization. This paper reports on the temporary overvoltage (TOV) arising from the de-energization of the circuit breaker connecting the wind turbine to the feeder, the feeder breaker connecting an array of wind turbines to the point of common coupling (PCC), and the opening of the circuit breaker connecting the onshore to the offshore substation. Ferroresonance was characterized using a phase plane diagram and Poincaré map and was identified to be chaotic. The effect of the nonlinear characteristic of the wind transformer core on the ferroresonant overvoltage was examined and increased with the steepness of slope of the transformer curve. A damping resistor, shunt reactor and surge arrester were used to mitigate the overvoltage experienced during the ferroresonant event. The damping resistor was able to reduce the overvoltage to 1.24 P.U. and damped the ferroresonance from chaotic to fundamental mode.
Ajibola Akinrinde; Andrew Swanson; Innocent Davidson. Investigation and Mitigation of Temporary Overvoltage Caused by De-Energization on an Offshore Wind Farm. Energies 2020, 13, 4439 .
AMA StyleAjibola Akinrinde, Andrew Swanson, Innocent Davidson. Investigation and Mitigation of Temporary Overvoltage Caused by De-Energization on an Offshore Wind Farm. Energies. 2020; 13 (17):4439.
Chicago/Turabian StyleAjibola Akinrinde; Andrew Swanson; Innocent Davidson. 2020. "Investigation and Mitigation of Temporary Overvoltage Caused by De-Energization on an Offshore Wind Farm." Energies 13, no. 17: 4439.
Grid-connected micro-grids are subject to grid disturbances. This has undesirable effects on system operation. Riding through fault conditions is a crucial technical challenge. Evolving grid codes require micro-grids to possess fault ride-through capabilities and support the grid voltage recovery to imitate the behavior of the traditional electrical power systems. The paper proposes two models of a grid supporting inverter-based microgrid; the first controlled as a current source with a parallel impedance suitable for grid feeding applications; the second regulated as a voltage source with a virtual impedance suitable for grid forming applications. The main objective of these two systems is to achieve controlled power delivery to the grid using grid voltage and frequency regulation. This paper discusses power interaction under steady states and transient conditions. Grid voltage parameters, such as amplitude, phase angle, and frequency, are estimated using a synchronization system, as these are necessary for precise active and reactive power control. Results obtained provide an understanding of grid fault impact on grid supporting systems and fault ride-through compliance and evaluates the impacts of the virtual impedances on fault ride through and power interaction.
Elutunji Buraimoh; Innocent Davidson. Modeling and Assessment of the Fault Ride-Through Capabilities of Grid Supporting Inverter-Based Microgrids. 2020 Clemson University Power Systems Conference (PSC) 2020, 1 -7.
AMA StyleElutunji Buraimoh, Innocent Davidson. Modeling and Assessment of the Fault Ride-Through Capabilities of Grid Supporting Inverter-Based Microgrids. 2020 Clemson University Power Systems Conference (PSC). 2020; ():1-7.
Chicago/Turabian StyleElutunji Buraimoh; Innocent Davidson. 2020. "Modeling and Assessment of the Fault Ride-Through Capabilities of Grid Supporting Inverter-Based Microgrids." 2020 Clemson University Power Systems Conference (PSC) , no. : 1-7.
The increasing damaging effect of fossil fueled generators has necessitated the need for diversification into renewable energy sources. However, these abundant renewable sources are limited by their variability at various seasons which often results in stochastic output power. In this paper, short term variability analysis of wind resource in Afe Babalola University is presented from January 2018 to December 2018. Wind speed data were collected using the anemometer at various times and sites within this period and used to estimate the potential of wind resource in ABUAD. The results showed that the wind energy resource is higher between the months of April to September, but insufficient to meet the energy need of ABUAD, hence necessitating the need of a hybrid generating system. An optimized hybrid system comprising of one, 1650kW wind turbine, 2000kW PV panels, 1900kW Diesel generator, 2000kW Converter, and one Trojan T-105 battery was obtained from HOMER software, with levelized cost of energy (COE) of 0.414$/yr and Net Present Cost(NPC) of $41,353,948.
Oladimeji Joseph Ayamolowo; Benedict Omo-Irabor; Elutunji Buraimoh; Innocent E. Davidson. Short-term Wind Variability Analysis of Afe Babalola University. 2020 Clemson University Power Systems Conference (PSC) 2020, 1 -8.
AMA StyleOladimeji Joseph Ayamolowo, Benedict Omo-Irabor, Elutunji Buraimoh, Innocent E. Davidson. Short-term Wind Variability Analysis of Afe Babalola University. 2020 Clemson University Power Systems Conference (PSC). 2020; ():1-8.
Chicago/Turabian StyleOladimeji Joseph Ayamolowo; Benedict Omo-Irabor; Elutunji Buraimoh; Innocent E. Davidson. 2020. "Short-term Wind Variability Analysis of Afe Babalola University." 2020 Clemson University Power Systems Conference (PSC) , no. : 1-8.
The Higher Education Partnerships project in Sub Saharan Africa funded by the British Royal Academy of Engineering, which ran from April 2017 to March 2019. It is a network of engineering faculties and schools from the Hub University (Lead University) - University of Namibia (UNAM), UK Partner University - University of Cambridge; and three Spoke Universities (Satellite universities): Durban University of Technology, University of Nairobi Kenya and the University of Addis Ababa, with the aim of enhancing quality engineering education and training. This paper presents the outcomes of the project, namely: graduate engineers and technicians who meet the expectations of modern industry and engineering professional bodies; and are relevant and therefore employable nationally and regionally; academic and technical staff with enhanced practical experience and better teaching skills, and enriched and relevant engineering curriculum at universities.
Innocent Davidson. Successes in University - Industry Partnerships - Perspectives from Durban University of Technology. 2020 International SAUPEC/RobMech/PRASA Conference 2020, 1 -5.
AMA StyleInnocent Davidson. Successes in University - Industry Partnerships - Perspectives from Durban University of Technology. 2020 International SAUPEC/RobMech/PRASA Conference. 2020; ():1-5.
Chicago/Turabian StyleInnocent Davidson. 2020. "Successes in University - Industry Partnerships - Perspectives from Durban University of Technology." 2020 International SAUPEC/RobMech/PRASA Conference , no. : 1-5.
Multi-terminal HVDC grid is one of the promising solutions of the electrical power network configuration that ensures the reliability of power supply and economy of the power generated from numerous renewable sources. The benefits of using HVDC grids are the possibilities of trading energy in different AC systems and transporting large scale of power over long distances. This paper will be showing the importance of DC voltage control strategies in a multi-terminal VSC-HDVC system following a system disturbance caused by an asymmetrical three-phase fault. Conventional and Droop methods are the two control strategies that will be compared in this paper. MATLAB/Simulink software simulator will be used to evaluate the response of a DC grid when a three-phase to ground AC fault occurs. The results show that droop-controlled DC grids are highly reliable during abnormal operating conditions compared to the conventional method.
Sindisiwe Malanda; Innocent Davidson; Grain A. Adam. Comparison of DC voltage Control Strategies for Multi-terminal HVDC Network during AC Faults. 2020 International SAUPEC/RobMech/PRASA Conference 2020, 1 -6.
AMA StyleSindisiwe Malanda, Innocent Davidson, Grain A. Adam. Comparison of DC voltage Control Strategies for Multi-terminal HVDC Network during AC Faults. 2020 International SAUPEC/RobMech/PRASA Conference. 2020; ():1-6.
Chicago/Turabian StyleSindisiwe Malanda; Innocent Davidson; Grain A. Adam. 2020. "Comparison of DC voltage Control Strategies for Multi-terminal HVDC Network during AC Faults." 2020 International SAUPEC/RobMech/PRASA Conference , no. : 1-6.
In this paper, an early attempt is made to design the optimal control technique based on discrete law for load frequency control (LFC) of an interconnected power delivery system having the electric power generation via hydro turbines in interconnected areas. In addition to above the effect of diverse sampling time on optimal LFC in discrete mode is also investigated. The performance evaluation of design LFC is carried out for standard load disturbance in one of the control area and the comparative analysis of diverse sampling time are shown via LFC responses, eigen values and closed loop feedback gains. At last, the unified power flow controller (UPFC) is added in series with the tie-line as well as the redox flow battery is integrated in area-2 of the interconnected system and the application results are assessed in order to show the merits of these devices in the enhancement of LFC performance.
Milan Joshi; Gulshan Sharma; Innocent Davidson. Investigation of Diverse Sampling Time for LFC of Hydro Power System using Discrete LQR with UPFC and RFB. 2020 International SAUPEC/RobMech/PRASA Conference 2020, 1 -6.
AMA StyleMilan Joshi, Gulshan Sharma, Innocent Davidson. Investigation of Diverse Sampling Time for LFC of Hydro Power System using Discrete LQR with UPFC and RFB. 2020 International SAUPEC/RobMech/PRASA Conference. 2020; ():1-6.
Chicago/Turabian StyleMilan Joshi; Gulshan Sharma; Innocent Davidson. 2020. "Investigation of Diverse Sampling Time for LFC of Hydro Power System using Discrete LQR with UPFC and RFB." 2020 International SAUPEC/RobMech/PRASA Conference , no. : 1-6.
Growth and development within South Africa has led to an increase in the demand for electricity. This has resulted in the expansion of electric power networks and this evolution to the current power system networks. Thus far, there have been challenges, both technical and non-technical, however going forward there is likely to be challenges that are more complex. We are aware that these networks will change and the question is then how, when and how quick would they change. The paper deals with planning future high voltage power system networks. These supply cities, municipalities, large power users but also smaller communities and rural networks. The increase in electricity tariffs, load-shedding, introduction of renewable energy and the drive towards clean energy sources are among the key aspects that would have in impact on the energy sector. Policy and regulatory changes are will effect have signify key to facilitate change and can either hinder or promote these changes and the evolution of the network.
Vasu Chetty; Innocent Davidson. Challenges of Planning Future High Voltage Power Systems Networks. 2020 International SAUPEC/RobMech/PRASA Conference 2020, 1 -6.
AMA StyleVasu Chetty, Innocent Davidson. Challenges of Planning Future High Voltage Power Systems Networks. 2020 International SAUPEC/RobMech/PRASA Conference. 2020; ():1-6.
Chicago/Turabian StyleVasu Chetty; Innocent Davidson. 2020. "Challenges of Planning Future High Voltage Power Systems Networks." 2020 International SAUPEC/RobMech/PRASA Conference , no. : 1-6.
The interconnected energy system with merging of renewable energy sources such as solar power resulting into an extremely non-linear system and due to which the frequency and power interchange fluctuations becomes serious concerns for power system operators due to variable loading conditions of an energy delivery system. Hence, this paper seeks to study the integration of PV based power generation with thermal power plant resulting into an interconnected energy system for frequency regulation of modern energy system for variable loading conditions. Furthermore, several structures of secondary control actions are also design and checked for frequency regulation studies of interconnected solar thermal system. The gains of secondary control actions are evaluated using diverse tuning techniques and the comparative analysis of all control designs are presented to bring back the frequency and tie-line power fluctuations back to original value and to analyze the effective control action for frequency regulation of interconnected PV thermal power system.
Milton S Estrice; Gulshan Sharma; Kayode T Akindeji; Innocent Davidson. Frequency Regulation Studies of Interconnected PV Thermal Power System. 2020 International SAUPEC/RobMech/PRASA Conference 2020, 1 -5.
AMA StyleMilton S Estrice, Gulshan Sharma, Kayode T Akindeji, Innocent Davidson. Frequency Regulation Studies of Interconnected PV Thermal Power System. 2020 International SAUPEC/RobMech/PRASA Conference. 2020; ():1-5.
Chicago/Turabian StyleMilton S Estrice; Gulshan Sharma; Kayode T Akindeji; Innocent Davidson. 2020. "Frequency Regulation Studies of Interconnected PV Thermal Power System." 2020 International SAUPEC/RobMech/PRASA Conference , no. : 1-5.
The present paper discusses the integration as well as contribution of doubly fed induction generator (DFIG) based wind turbines in load frequency control (LFC) of the modern electric power system in order to supply the quality as well as pollution free electric power to the modern customers. In addition the control areas are connected via HVDC tie-line in parallel with EHVAC line with diverse sources i.e. hydro, thermal and gas based power generations in each area. Efforts have been made to propose an optimal LFC design based on the feedback of few state variables which are available for the measurement and contains good information of the complete power system. The LFC design based on few states are implemented and the obtained results are presented to show the LFC enhancement considering DFIG and parallel HVDC/EHVAC lines. Atlast, the beauty and effectiveness of LFC based on few states are compared with LFC design depends on all system states under similar working conditions and the application results are presented.
Gulshan Sharma; K. Narayanan; Innocent Davidson; K.T. Akindeji. Integration and Enhancement of Load Frequency Control Design for Diverse Sources Power System via DFIG Based Wind Power Generation and Interonnected via Parallel HVDC/EHVAC Tie-Lines. International Journal of Engineering Research in Africa 2020, 46, 106 -124.
AMA StyleGulshan Sharma, K. Narayanan, Innocent Davidson, K.T. Akindeji. Integration and Enhancement of Load Frequency Control Design for Diverse Sources Power System via DFIG Based Wind Power Generation and Interonnected via Parallel HVDC/EHVAC Tie-Lines. International Journal of Engineering Research in Africa. 2020; 46 ():106-124.
Chicago/Turabian StyleGulshan Sharma; K. Narayanan; Innocent Davidson; K.T. Akindeji. 2020. "Integration and Enhancement of Load Frequency Control Design for Diverse Sources Power System via DFIG Based Wind Power Generation and Interonnected via Parallel HVDC/EHVAC Tie-Lines." International Journal of Engineering Research in Africa 46, no. : 106-124.
The South African government policy to electrify all customers has placed immense demands on the electricity infrastructure. Several new connected customers in line with these government targets and plans are in networks that are already constrained, with the consequence of violating statutory performance requirements and electrical parameters, such as thermal loading, voltage limits and technical losses. Utilities' solutions to remedy these problems sometimes requires huge investments to upgrade infrastructure and this may take years for implementation. In many instances, short-term solutions are available and feasible. This study investigates Solar Roof-Top PV (RTPV) as a renewable energy resource for reticulation (11/22KV) networks. Currently RTPV is not well documented and guided when considering available Grid codes, Guidelines and Standards. This paper demonstrates that RTPV penetration is more worthwhile to consider than capital strengthening/refurbishment projects. The study demonstrates the supportive role of RTPV to meet electrification demands. With increased penetration of RTPV's on distribution networks, there is a benefit to the feeder tail-end voltages with reduced thermal loading and technical losses in distribution networks. This provides Utilities with the opportunity to electrify more customers and defer capital expenditure, while reducing the carbon footprint. The balance of the paper presents an accurate view of RTPV analysis, attributed to the accuracy of data, by using a practical network topology coupled with its related statistical loading. It further takes into account the associated customer connected at the LV transformers. With the imminent influx of RTPV, the results of this study will assist in equipping the South African Electricity Supply Industry (ESI) for the readiness of RTPV and the influence of RTPV on reticulation networks by quantifying the impacts and expectations for the Electric Power Utility and the customer.
Innocent Davidson; Rodney Reddy. Performance Evaluation of Solar Roof-Top PV on Eskom's LV Electric Power Distribution Networks. 2019 7th International Conference on Smart Grid (icSmartGrid) 2019, 97 -102.
AMA StyleInnocent Davidson, Rodney Reddy. Performance Evaluation of Solar Roof-Top PV on Eskom's LV Electric Power Distribution Networks. 2019 7th International Conference on Smart Grid (icSmartGrid). 2019; ():97-102.
Chicago/Turabian StyleInnocent Davidson; Rodney Reddy. 2019. "Performance Evaluation of Solar Roof-Top PV on Eskom's LV Electric Power Distribution Networks." 2019 7th International Conference on Smart Grid (icSmartGrid) , no. : 97-102.
The growing level of grid-connected renewable energy sources in the form of microgrids has made it highly imperative for grid-connected microgrids to contribute to the overall system stability. Consequently, secondary services which include the fault ride-through (FRT) capability are expected to be possessed characteristics by inverter-based microgrids. This enhances the stable operation of the main grid and sustained microgrid grid interconnection during grid faults in conformity with the emerging national grid codes. This paper proposes an effective FRT secondary control strategy to coordinate power injection during balanced and unbalanced fault conditions. This complements the primary control to form a two-layer hierarchical control structure in the microgrids. The primary level is comprised of voltage/power and current inner loops fed by a droop control. The droop control coordinates grid power-sharing amongst the voltage source inverters. When a fault occurs, the participating inverters operate to support the grid voltage, by injecting supplementary reactive power based on their droop gains. Similarly, under unbalanced voltage condition due to asymmetrical faults in the grid, the proposed secondary control ensures the positive sequence component compensation and negative and zero sequence components clearance using a delayed signal cancellation (DSC) algorithm and power electronic switched series impedance placed in-between the point of common coupling (PCC) and the main grid. While ensuring that FRT ancillary service is rendered to the main utility, the strategy proposed ensures relatively interrupted quality power is supplied to the microgrid load. Consequently, this strategy ensures the microgrid ride-through the voltage sag and supports the grid utility voltage during the period of the main utility grid fault. Results of the study are presented and discussed.
Elutunji Buraimoh; Innocent E. Davidson; Fernando Martinez-Rodrigo. Fault Ride-Through Enhancement of Grid Supporting Inverter-Based Microgrid Using Delayed Signal Cancellation Algorithm Secondary Control. Energies 2019, 12, 3994 .
AMA StyleElutunji Buraimoh, Innocent E. Davidson, Fernando Martinez-Rodrigo. Fault Ride-Through Enhancement of Grid Supporting Inverter-Based Microgrid Using Delayed Signal Cancellation Algorithm Secondary Control. Energies. 2019; 12 (20):3994.
Chicago/Turabian StyleElutunji Buraimoh; Innocent E. Davidson; Fernando Martinez-Rodrigo. 2019. "Fault Ride-Through Enhancement of Grid Supporting Inverter-Based Microgrid Using Delayed Signal Cancellation Algorithm Secondary Control." Energies 12, no. 20: 3994.
This paper deals with a developed insulated gate bipolar transistor (IGBT) and diode based fault current limiter (FCL) for simple microgrid application. The developed FCL utilizes a three-phase circuit arrangement that has fault current limiting ability with an uncomplicated control strategy that simply samples the voltage at the point of common coupling (PCC) for the FCL control using Clarke’s Transformation, low pass filtering and pulse generating circuit. The IGBT-Diode based FCL regulates the magnitude of the fault current and enhances the PCC voltage under transient faults to ensure continuous supply of active and reactive power to the local load of the microgrid irrespective of the transient condition of the main grid. The power electronic switching arrangement employed interfaces the grid using an isolating transformer whose primary is connected in series with the feeder line and the secondary is shorted by an optimally sized AC reactor. The IGBT-Diode switching operations for the pre-fault, fault and post-fault conditions are triggered by the control proposed which detects fault occurrence in less than a period. The analytical investigation of the IGBT-Diode switched FCL is presented in details and the results of simulation lay credence to effectiveness of the developed FCL in improving Fault Ride-Through (FRT).
Elutunji Buraimoh; Innocent E. Davidson. Development of an IGBT-Diode based Fault Current Limiter for Fault Ride-Through Enhancement in Microgrid Application. 2019 IEEE PES/IAS PowerAfrica 2019, 146 -151.
AMA StyleElutunji Buraimoh, Innocent E. Davidson. Development of an IGBT-Diode based Fault Current Limiter for Fault Ride-Through Enhancement in Microgrid Application. 2019 IEEE PES/IAS PowerAfrica. 2019; ():146-151.
Chicago/Turabian StyleElutunji Buraimoh; Innocent E. Davidson. 2019. "Development of an IGBT-Diode based Fault Current Limiter for Fault Ride-Through Enhancement in Microgrid Application." 2019 IEEE PES/IAS PowerAfrica , no. : 146-151.
To address the gross deficit in electricity demand and supply in Nigeria requires a pragmatic and sequential approach to expanding generation capacity. Numerous studies have expatiated on the underlying problems with solution strategies that are comprehensive. However, many of those suggested solutions are either too steep cost-wise or the system is limited in the adaptive capacity to incorporate them. This paper proffers a stepped approach at expanding the capacity of supply as a function of the energy locational distance of the states and regions in the country. In this research, we interpret energy locational distance as a measure that is derived from the answer to two questions. First, how much is generation below the output capacity of the existing generating plants that are stationed across the country serving the national grid? Second, what is the minimum threshold of capacity expansion to achieve a set energy density or energy per person index across the regions of the country differentiated by energy poverty? With this exploration, energy planners in Nigeria, rather than seeking to address the dearth of electricity supply in the country in one step, could consider a piecemeal approach that indeed offers tremendous and relatively significant expansions in capacity. This outcome offers guidance to policy makers and investors on how to craft their investment efforts in a manner that is akin to viewing the problem at the proverbial context of effecting changes at the tree level rather than seeking to change the forest.
Olawale Ogunrinde; Ekundayo Shittu; Mobolaji Bello; Innocent Davidson. Exploring the Demand-Supply Gap of Electricity in Nigeria: Locational Evaluation for Capacity Expansions. 2019 IEEE PES/IAS PowerAfrica 2019, 587 -592.
AMA StyleOlawale Ogunrinde, Ekundayo Shittu, Mobolaji Bello, Innocent Davidson. Exploring the Demand-Supply Gap of Electricity in Nigeria: Locational Evaluation for Capacity Expansions. 2019 IEEE PES/IAS PowerAfrica. 2019; ():587-592.
Chicago/Turabian StyleOlawale Ogunrinde; Ekundayo Shittu; Mobolaji Bello; Innocent Davidson. 2019. "Exploring the Demand-Supply Gap of Electricity in Nigeria: Locational Evaluation for Capacity Expansions." 2019 IEEE PES/IAS PowerAfrica , no. : 587-592.
To enable secondary distribution network to perform optimally, it is critical to assess the performance of the system. Optimum performance means acceptable voltage profile, increase reliability of supply, no overloading of cables and distribution transformers, absence of imbalances in both voltage and current phases and acceptable loss. This work evaluates the performance of secondary distribution network as a result of voltage losses, voltage deviation, voltage variation and voltage imbalance using MATLAB software. This paper presents a performance analysis of a typical Eskom secondary 11/0.4 kV, unbalanced secondary distribution system. The network was modeled with standard network parameters for secondary Eskom distribution network using MATLAB/Simulink Sim Power System tool box. The summary of the paper gives recommendations on effectual techniques for improving the voltage profile and reducing the voltage imbalance and voltage drop to an allowable standard.
Ogunboyo Patrick Taiwo; Innocent Davidson. Assessment and Analysis of Typical Eskom Secondary Distribution Network under Normal Steady State. 2019 IEEE PES/IAS PowerAfrica 2019, 633 -638.
AMA StyleOgunboyo Patrick Taiwo, Innocent Davidson. Assessment and Analysis of Typical Eskom Secondary Distribution Network under Normal Steady State. 2019 IEEE PES/IAS PowerAfrica. 2019; ():633-638.
Chicago/Turabian StyleOgunboyo Patrick Taiwo; Innocent Davidson. 2019. "Assessment and Analysis of Typical Eskom Secondary Distribution Network under Normal Steady State." 2019 IEEE PES/IAS PowerAfrica , no. : 633-638.
Historically, distribution networks were made to connect consumer loads with no generating units at the point of consumption. For the last two decades, in response to increase electricity demand and environmental policies, decentralized generation, mainly constituted of Renewable Generation Sources (RES), also called Distributed Generators (DG), have massively and rapidly developed. The integration of DG units however, increase uncertainty in power system operation as they modify both the structure and the operation of the distribution networks, changing the magnitude and direction of network power flows. There is a need to investigate both the “effects and impact” of increasing penetration and siting of these intermittent RES on voltage and frequency stability power system and, the utilization of such sources to improve voltage stability margins. This paper presents different scenario of voltage stability studies in a static analysis mode in order to support voltage profile and reduce power line losses using photovoltaic systems. DigSILENT™ PowerFactory™ was used to conduct the investigation.
Kabulo Loji; Innocent Davidson; Remy Tiako. Voltage Profile and Power Losses Analysis on a Modified IEEE 9-Bus System with PV Penetration at the Distribution Ends. 2019 Southern African Universities Power Engineering Conference/Robotics and Mechatronics/Pattern Recognition Association of South Africa (SAUPEC/RobMech/PRASA) 2019, 703 -708.
AMA StyleKabulo Loji, Innocent Davidson, Remy Tiako. Voltage Profile and Power Losses Analysis on a Modified IEEE 9-Bus System with PV Penetration at the Distribution Ends. 2019 Southern African Universities Power Engineering Conference/Robotics and Mechatronics/Pattern Recognition Association of South Africa (SAUPEC/RobMech/PRASA). 2019; ():703-708.
Chicago/Turabian StyleKabulo Loji; Innocent Davidson; Remy Tiako. 2019. "Voltage Profile and Power Losses Analysis on a Modified IEEE 9-Bus System with PV Penetration at the Distribution Ends." 2019 Southern African Universities Power Engineering Conference/Robotics and Mechatronics/Pattern Recognition Association of South Africa (SAUPEC/RobMech/PRASA) , no. : 703-708.
The Higher Education Partnerships in Sub Saharan Africa project is funded by the British Royal Academy of Engineering, and runs for 2 years from April 2017 to March 2019. It is a network of engineering faculties and schools in some Eastern and Southern African universities linked to a UK university with the aim of enhancing quality of engineering education and training. The project objective is to enhance the quality of engineering education and training through: academic staff secondment to industry; invitation of industry experts to university as guest lecturers; collaborative research with industry, industry supported curriculum review and knowledge sharing workshops. This paper presents the activities at Durban University of Technology and our efforts to enhance engineering training of technical staff through short-term industry internships and postgraduate studies. The goal is to produce graduate engineers and technicians: who possesses relevant skills, meet the expectations of modern industry and engineering professional bodies; graduates who are employable nationally and regionally. It is also expected to produce academic staff with enhanced practical experience and better teaching skills, which will enrich the relevant engineering curriculum at universities.
Innocent Davidson. The HEPSSA Project – A Catalyst for Capacity Building at Durban University of Technology. 2019 Southern African Universities Power Engineering Conference/Robotics and Mechatronics/Pattern Recognition Association of South Africa (SAUPEC/RobMech/PRASA) 2019, 640 -642.
AMA StyleInnocent Davidson. The HEPSSA Project – A Catalyst for Capacity Building at Durban University of Technology. 2019 Southern African Universities Power Engineering Conference/Robotics and Mechatronics/Pattern Recognition Association of South Africa (SAUPEC/RobMech/PRASA). 2019; ():640-642.
Chicago/Turabian StyleInnocent Davidson. 2019. "The HEPSSA Project – A Catalyst for Capacity Building at Durban University of Technology." 2019 Southern African Universities Power Engineering Conference/Robotics and Mechatronics/Pattern Recognition Association of South Africa (SAUPEC/RobMech/PRASA) , no. : 640-642.