2021 Southern African Universities Power Engineering Conference/Robotics and Mechatronics/Pattern Recognition Association of South Africa (SAUPEC/RobMech/PRASA)最新文献

{"title":"Induction motor modelling in dynamic power system studies-a comparison of two methods","authors":"T. Carter, J. D. Kock","doi":"10.1109/SAUPEC/RobMech/PRASA52254.2021.9377019","DOIUrl":"https://doi.org/10.1109/SAUPEC/RobMech/PRASA52254.2021.9377019","url":null,"abstract":"The purpose of this study is to accurately characterize the electrical and mechanical parameters of an induction motor. It is important to accurately characterize induction motors for motor bus transfer studies to be performed on systems to determine if the system can safely undergo such a transfer should a fault occur at the main supply and the motor need to be transferred to a backup supply.","PeriodicalId":442944,"journal":{"name":"2021 Southern African Universities Power Engineering Conference/Robotics and Mechatronics/Pattern Recognition Association of South Africa (SAUPEC/RobMech/PRASA)","volume":"177 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116642209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Remote Mechanical Switch to Regulate Electricity Consumption in a Household","authors":"Gerald K. Kirui, Learn L. Chiloane, Yu-Chieh J. Yen","doi":"10.1109/SAUPEC/RobMech/PRASA52254.2021.9377208","DOIUrl":"https://doi.org/10.1109/SAUPEC/RobMech/PRASA52254.2021.9377208","url":null,"abstract":"This report presents the design and testing of a remote mechanical switch for external mounting and the control of an appliance such as a geyser. The switch has applications under household energy regulation and load shedding recovery. It uses a servo motor as an actuator, measures current using a non-invasive current sensor, and provides back-up power of up to 9 hours 40 minutes with a lithium-ion battery. It is a non-invasive IoT-based system for energy management. Two forms of control are available to the user, namely manual Wi-Fi and a timer. A web application is implemented as a user-interface to control the device via Wi-Fi. A SHA-256 encrypted password secures the web application. A user can control the device and view device information on the web application. The timer can control the device automatically in 15-minute intervals. The system request latency is 6 – 7 seconds. If the operation of the geyser is restricted to off-peak periods, savings can be made, and the payback period of the device is less than 2 years.","PeriodicalId":442944,"journal":{"name":"2021 Southern African Universities Power Engineering Conference/Robotics and Mechatronics/Pattern Recognition Association of South Africa (SAUPEC/RobMech/PRASA)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127053654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design of Low-Frequency Quasi-dc GIC Voltage Stability Laboratory Protocol","authors":"N. S. Sithebe, D. Oyedokun, H. Chisepo","doi":"10.1109/saupec/robmech/prasa52254.2021.9377232","DOIUrl":"https://doi.org/10.1109/saupec/robmech/prasa52254.2021.9377232","url":null,"abstract":"Low-frequency currents in electrical power systems driven by a geomagnetic disturbance (GMD) are known as geomagnetically induced currents (GIC). These have several effects on transformers and power systems. The main concern for power system operators is the voltage stability of the networks in presence of GIC. There are several reports on GIC and system voltage collapse during significant GMDs. However, very little information is available on the dynamic analysis of the resultant voltage instability. This paper presents a laboratory protocol that can be used to study voltage stability under GIC conditions. The testing protocol uses frequency-dependent transmission lines with both resistive and inductive elements. While almost all GIC studies use a straight direct current for steady-state analysis, this study proposes a special “quasi-dc” injection circuit which oscillates at a very low frequency - necessary to emulate better the dynamic behaviour of a real GIC. The design, fabrication, and characterization of each scaled down power system component is presented. To test the veracity of the protocol, simulations were carried out in PSCAD/EMTP. The simulation results showed that an increase in the quasi-dc injection drove the power system to voltage instability. The dynamic analysis which compared the conventional dc injection response to the low-frequency injection indicates the response to the latter is more representative of the real power system response reported in the literature. The implication of this study is an improved approach to modelling GIC for voltage stability studies.","PeriodicalId":442944,"journal":{"name":"2021 Southern African Universities Power Engineering Conference/Robotics and Mechatronics/Pattern Recognition Association of South Africa (SAUPEC/RobMech/PRASA)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115222890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Real-Time Simulation of Photovoltaic System and its Performance Under Partial Shading Conditions","authors":"Ntuba Irene Nkhasi, A. Saha","doi":"10.1109/SAUPEC/RobMech/PRASA52254.2021.9377251","DOIUrl":"https://doi.org/10.1109/SAUPEC/RobMech/PRASA52254.2021.9377251","url":null,"abstract":"The green energy, energy conservation and sustainable development is globally receiving an increasing attention as the fossil fuels depletion is a global concern. Although they are not a new concept, renewable distributed generation have in the recent years garnered renewed interest within the energy sector. Solar photo voltaic systems as renewable energy nowadays takes on a fundamental role in the renewable energy sector. Photovoltaic systems output performance and efficiency relies largely on major factors such as irradiance, temperature and shading. Temporal inconsistency of the sun’s irradiance due to clouds or partial shading is the leading cause of fluctuating solar power generation. The purpose of the study is to illustrate in RSCAD the real-time modelling of photovoltaic generation system under partial shading conditions. Demonstrated along is the impacts of bypass diodes addition on a partially shaded photovoltaic system performance. The influence and impacts of partial shading due to moving clouds on the modelled generation system is addressed along with recommendations for future studies or work to be undertaken in solar energy systems. The paper incorporates the use of proposed real-time simulation, a method which many similar studies have not adopted.","PeriodicalId":442944,"journal":{"name":"2021 Southern African Universities Power Engineering Conference/Robotics and Mechatronics/Pattern Recognition Association of South Africa (SAUPEC/RobMech/PRASA)","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116563602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Comparative Evaluation of Conventional and Computational Intelligence Techniques for Forecasting Electricity Outage","authors":"A. K. Onaolapo, R. Pillay-Carpanen, D. Dorrell, E. Ojo","doi":"10.1109/SAUPEC/RobMech/PRASA52254.2021.9377243","DOIUrl":"https://doi.org/10.1109/SAUPEC/RobMech/PRASA52254.2021.9377243","url":null,"abstract":"Reliability of the electric grid structure for the transmission and distribution of power from the generating plants to the consumers, is an essential requirement for the reliability of electric supply. The components of the grid is exposed to weather events which cause faults to the grid’s structures. There is an expectation that as climate change alters the severity and number of weather events, electricity supplies and electricity grid reliability are expected to be affected. Computational intelligence models have been proven to be excellent predictive models for electricity reliability problems in previous studies. But there has not been sufficient literature reporting their applications in weather related electricity outage forecasting problems. In this study, weather related electricity outage was forecasted using artificial neural networks (ANNs) with back-propagation algorithm. Real-life data sets of the city of Pietermaritzburg, South Africa, was used to investigate the performance of the ANN model and was compared with a conventional model – exponential smoothing (ES). The ANN model gave satisfactory results as compared to the ES model. The result is a demonstration of the robustness of computation techniques.","PeriodicalId":442944,"journal":{"name":"2021 Southern African Universities Power Engineering Conference/Robotics and Mechatronics/Pattern Recognition Association of South Africa (SAUPEC/RobMech/PRASA)","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128643423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Review of Proactive Operational Measures for the Distribution Power System Resilience Enhancement Against Hurricane Events.","authors":"Okeolu Samuel Omogoye, K. Folly, K. Awodele","doi":"10.1109/SAUPEC/RobMech/PRASA52254.2021.9377252","DOIUrl":"https://doi.org/10.1109/SAUPEC/RobMech/PRASA52254.2021.9377252","url":null,"abstract":"Electricity supply is the backbone of any industrialized economy globally. Unfortunately, this important infrastructure is facing serious problems leading to large power outages recently. Human and natural disaster-induced threats have been identified as the major causes of these outages. The threat posed by a natural disaster, specifically hurricane events as it affects the power system distribution network is the main interest of this research. Natural disasters cannot be stopped from happening but luckily enough, weather stations around the globe have recorded a lot of successful accurate weather predictions over the years. While some natural disasters such as earthquakes can hardly be predicted, other can be predicted accurately, for instance, cyclones, hurricanes, etc. Therefore, leveraging accurate weather prediction of hurricane data, system operators can significantly improve the distribution power system network (DPSN) against hurricane events using proactive operational planning measures. A comprehensive review of the methodologies used for proactive operational resilience enhancement scheme is explored in this review. Statistical models have been generally utilized leveraging historical weather data and power system components’ failure data in various regression strategies to foresee and estimate damages and outages caused by the hurricane in the past. The topology-based approach for power framework weakness and resilience, and the use of system components’ fragility curveMonte Carlo simulation (MCS) model have also been explored. Although, all these models are suitable in estimating the damage caused by the predicted approaching hurricane events, high computational complexity/time limits their application for a real-time proactive prediction of the DPSN line outage caused by the hurricane events. To enhance the DPSN resilience against hurricanes events, a real-time proactive system line outage prediction model under hurricane events is needed for system pre-disaster operational optimization scheduling and resource allocation. In this view, this research explored the past, present and this paper presents researchable operational measures that can greatly enhance the DPSN against hurricane events.","PeriodicalId":442944,"journal":{"name":"2021 Southern African Universities Power Engineering Conference/Robotics and Mechatronics/Pattern Recognition Association of South Africa (SAUPEC/RobMech/PRASA)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125370062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis and Harmonic Mitigation in Distribution Transformers for Renewable Energy Applications","authors":"L. S. Sikhosana, U. B. Akuru, B. A. Thango","doi":"10.1109/SAUPEC/RobMech/PRASA52254.2021.9377218","DOIUrl":"https://doi.org/10.1109/SAUPEC/RobMech/PRASA52254.2021.9377218","url":null,"abstract":"As renewable energy generation in South Africa continues to take a lion share of the republic’s energy generation, the design of distribution transformers for renewable energy applications has introduced several design and performance challenges that have not previously been taken into consideration during the design stage. Transformers in RE application have failed as a result of challenges associated with harmonics and distortion, distorted load cycle, over-voltages and oil-gassing issues. This study is used to give an analysis of various transformers ranging from 100 kVA to 1500 kVA that have failed within RE plants. In the study, the harmonic spectrum is considered to adequately specify the harmonic loading of the transformers during service. Three results from analytical method, Finite Element Method (FEM) and practical measurements are considered to ascertain the transformer service losses under the supplied harmonic spectrum. The improvement in computational accessibility of designing the transformers in FEM has proven to produce reliable results yielding about 98 % in comparison to measured results. In the end, the study reveals that the use of FEM in the transformer design for RE application has high prediction accuracy, and that these transformers failed on account of the loading exceeding the transformer ratings due to underestimation of the harmonic-induced losses during the design stage.","PeriodicalId":442944,"journal":{"name":"2021 Southern African Universities Power Engineering Conference/Robotics and Mechatronics/Pattern Recognition Association of South Africa (SAUPEC/RobMech/PRASA)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133952253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adaptive Model Predictive Control for Frequency Control for Two Area Interconnected Power System","authors":"Igbineweka Ernest Uyioghosa, A. Saha","doi":"10.1109/SAUPEC/RobMech/PRASA52254.2021.9377021","DOIUrl":"https://doi.org/10.1109/SAUPEC/RobMech/PRASA52254.2021.9377021","url":null,"abstract":"Reliability in of importance in load frequency control (LFC) in modern power generation, In LFC scheme, local load disturbance, inter-area ties power fluctuation, frequency deviation, and generation rate constraints (GRC), are the major nonlinear factors on the control scheme that affect the dynamic response of the system. In this paper, two-area hydro-thermal interconnected power system (IPS) is used to develop an adaptive model predictive control (AMPC) as a controller scheme for LFC scheme and compared with both robust distributed model predictive control (RDMPC) and proportional integral derivative (PID) controller, using MATLAB/Simulink, result shows that AMPC shows robustness over RDMPC and PID when compared in frequency deviation, area control error (ACE) and tie-line active power deviations.","PeriodicalId":442944,"journal":{"name":"2021 Southern African Universities Power Engineering Conference/Robotics and Mechatronics/Pattern Recognition Association of South Africa (SAUPEC/RobMech/PRASA)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122727279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Empirical Analysis and Application of the Expectation-Maximization and Matrix Completion Algorithms for Varying Degrees of Missing Data","authors":"Evans Thulare, Ritesh Ajoodha, Ashwini Jadhav","doi":"10.1109/SAUPEC/RobMech/PRASA52254.2021.9377210","DOIUrl":"https://doi.org/10.1109/SAUPEC/RobMech/PRASA52254.2021.9377210","url":null,"abstract":"Incomplete data sets have been a problem in most studies, however, few studies have come to realise that imputation is a solution to this problem. Incomplete data can have a significant effect on the conclusion drawn and decision made. To solve the problem of incomplete data, one should use techniques to recover those missing values, depending on how much the data is missing, how big is the data, how the data has gone missing, etc. In this report, we aimed to compare the performance of the EM algorithm and matrix completion when imputing the missing values for varying degrees of missing data.Kullback-Leibler (KL) divergence was used as an evaluation metric to observe the performance of Expectation-Maximization (EM) algorithm and matrix completion when estimating missing values relative to the ground-truth distribution. The findings of this research shows that the EM algorithm outperformed matrix completion in both the theoretical (the simulated scenarios of learning from varying degrees of missing data) and the application (the application of theoretical model on real-world data on credit card fraud) models. Few similarities of the algorithms were observed when recovering missing values such as the increasing trend of error as missing values increases and the impact of increasing number of variables in a data set.Matrix completion only performed better when missing values were beyond approximately 75%. Therefore, from our findings, we conclude that when less than 50% of the data is missing, EM algorithm produces accurate predictions. The EM algorithm performed better compared to the matrix completion since it first learned the data itself and used maximum likelihood procedures to estimate the parameters of the model while the matrix completion analysed the existing pattern from rows and columns and imputes them using the pattern learned in the data.","PeriodicalId":442944,"journal":{"name":"2021 Southern African Universities Power Engineering Conference/Robotics and Mechatronics/Pattern Recognition Association of South Africa (SAUPEC/RobMech/PRASA)","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123373840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preliminary Design of a Bagasse Based Firm Power Plant for a Sugar Factory","authors":"M. J. B. Kabeyi, O. Olanrewaju","doi":"10.1109/SAUPEC/RobMech/PRASA52254.2021.9377242","DOIUrl":"https://doi.org/10.1109/SAUPEC/RobMech/PRASA52254.2021.9377242","url":null,"abstract":"This paper analysis the performance of the bagasse cogeneration power plant at Mumias Sugar Company in Kenya and recommends the development of a dual fuel cogeneration power plant. The main challenge facing bagasse cogeneration power plants is the intermittence of bagasse fuel supply and hence unreliability of the power plant as a grid connected power plant which leads to penalties and other related sanctions from the utility company. The study reviews the performance of an existing bagasse cogeneration power plant that uses bagasse alone as a fuel and seeks to improve its performance by conversion to a coal-bagasse cogeneration plant which is a firm power plant that utilizes bagasse and an alternative fuel in production of heat and electricity. The performance analysis showed a serious decline in availability and revenue from the power plant mainly due to unsteady supply of sugar cane leading heavy penalties from the electric utility for failure to meet contracted targets which led to the collapse of the entire sugar factory. In this study, a technical and economic viability was done to determine the performance of the current and proposed in technical and economic terms. Since it is cost effective as shown by the analysis, the study recommends that a dual fuel firm power plant will ensure the plant operates even when there is no sugarcane bagasse hence avoiding downtown due to sugar factory unavailability but will require significant investment in new and more efficient equipment for the boiler and fuel system. A simple analysis shows a payback of 4.05 years for the proposed plant. This will eliminate penalties and increase revenue, efficiency and profitability of the cogeneration plant and the entire sugar factory.Abbreviations: Cogen: Cogeneration, ESP: Electrostatic precipitator, mt: metric tons, h: specific enthalpy, ppa: power purchase agreement; ssf: specific steam consumption","PeriodicalId":442944,"journal":{"name":"2021 Southern African Universities Power Engineering Conference/Robotics and Mechatronics/Pattern Recognition Association of South Africa (SAUPEC/RobMech/PRASA)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116888247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}