2021 IEEE PES/IAS PowerAfrica最新文献

Preliminary Study of Wind Farm-Grid Connection: A Nigerian Power System Test Case 风电场与电网并网的初步研究:尼日利亚电力系统试验案例

2021 IEEE PES/IAS PowerAfrica Pub Date : 2021-08-23 DOI: 10.1109/PowerAfrica52236.2021.9543269

I. O. Ozioko, N. S. Ugwuanyi, A. Ekwue

引用次数: 0

Integration of an off-grid solar-PV-battery system after grid connection using model predictive control: A case study in Kenya 使用模型预测控制的离网太阳能-光伏-电池系统并网后的集成:肯尼亚案例研究

2021 IEEE PES/IAS PowerAfrica Pub Date : 2021-08-23 DOI: 10.1109/PowerAfrica52236.2021.9543248

Fhazhil Wamalwa, Nathaniel J. Williams

{"title":"Integration of an off-grid solar-PV-battery system after grid connection using model predictive control: A case study in Kenya","authors":"Fhazhil Wamalwa, Nathaniel J. Williams","doi":"10.1109/PowerAfrica52236.2021.9543248","DOIUrl":"https://doi.org/10.1109/PowerAfrica52236.2021.9543248","url":null,"abstract":"Due to low rates of grid access in many countries in Sub Sahara Africa (SSA), many households with the ability to pay rely on off-grid stand-alone systems for their electricity supply. However, the arrival of the grid in households previously served by these off-grid systems comes with technical integration challenges considering that currently many African countries do not have grid-feed-in policies for small micro-generation. The problem is further complicated by a lack of unified industry standards of practice for deployment of microgrid control systems, leading to suboptimal use of distributed generation assets. In this paper, model predictive control (MPC) algorithm is employed to solve the dispatch problem of a grid connected solar PV-Battery microgrid without grid feed in option. The proposed model is applied to a case study in Kenya and its performance compared with the switched control strategy currently implemented at the case study site to test the economic gains of the MPC. We find that the investment required to implement the MPC algorithm has a payback period of about 7 years.","PeriodicalId":370999,"journal":{"name":"2021 IEEE PES/IAS PowerAfrica","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122414132","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}

引用次数: 0

Characteristic Pulse Pattern Features of Different Types of Partial Discharge Sources in Power Cables 不同类型电力电缆局部放电源的特征脉冲模式特征

2021 IEEE PES/IAS PowerAfrica Pub Date : 2021-08-23 DOI: 10.1109/PowerAfrica52236.2021.9543366

I. Kiitam, M. Shafiq, P. Taklaja, M. Parker, I. Palu, L. Kütt

引用次数: 3

Optimal Coordination of Directional Overcurrent Relays in Interconnected Networks utilizing User- Defined Characteristics and Fault Current Limiter 利用用户自定义特性和故障限流器的互联网络中定向过流继电器的优化协调

2021 IEEE PES/IAS PowerAfrica Pub Date : 2021-08-23 DOI: 10.1109/PowerAfrica52236.2021.9543303

Hassan Eid, H. Sharaf, M. Elshahed

{"title":"Optimal Coordination of Directional Overcurrent Relays in Interconnected Networks utilizing User- Defined Characteristics and Fault Current Limiter","authors":"Hassan Eid, H. Sharaf, M. Elshahed","doi":"10.1109/PowerAfrica52236.2021.9543303","DOIUrl":"https://doi.org/10.1109/PowerAfrica52236.2021.9543303","url":null,"abstract":"In this paper, the effect of using user defined characteristics relay on the sizing of fault current limiters (FCLs) are investigated. FCL is implemented in series with utility to tackle protection issues in looped networks due to incorporation of distributed generation (DG) in distribution systems. A protection coordination strategy is applied through employing user-defined characteristics which classifies directional overcurrent’ constants for relay characteristics (A) and for the inverse time type (B) as adjustable setting variables in addition to conventional setting variables; pick-up current (IP) and time multiplier setting (TDS). The four relay settings are picked up optimally along with optimum value of FCL. The problem is formulated as a constrained non-linear programming (NLP) problem with main objective of minimizing overall operating time of relays. The proposed approach is tested on meshed power distribution network of IEEE 30-bus. Results achieved by the proposed strategy show a reduction in overall relay operating time and the minimum value of FCL.","PeriodicalId":370999,"journal":{"name":"2021 IEEE PES/IAS PowerAfrica","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114401884","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}

引用次数: 1

Study of the Impact of Degree of Polymerization on the Remnant Life of Transformer Insulation 聚合度对变压器绝缘剩余寿命影响的研究

2021 IEEE PES/IAS PowerAfrica Pub Date : 2021-08-23 DOI: 10.1109/PowerAfrica52236.2021.9543450

B. A. Thango, A. Akumu, L. S. Sikhosana, A. Nnachi, J. Jordaan

{"title":"Study of the Impact of Degree of Polymerization on the Remnant Life of Transformer Insulation","authors":"B. A. Thango, A. Akumu, L. S. Sikhosana, A. Nnachi, J. Jordaan","doi":"10.1109/PowerAfrica52236.2021.9543450","DOIUrl":"https://doi.org/10.1109/PowerAfrica52236.2021.9543450","url":null,"abstract":"In South Africa, transformers are the most critical links in the power system's generation, transmission, and distribution. Their insulation system is comprised of dielectric oil and cellulose paper. The aging of the insulating system is influenced by several factors including high loading profile, temperature rise, and short circuits. Many diagnostic tests can be performed, and correctional measures may be taken to guarantee that consumers receive uninterrupted power supply. The remaining life of the transformer's cellulose paper insulation determines when the transformer's useful life ends. The mechanical or tensile strength of the solid insulation determines the aging of the paper insulation, which is calculated in terms of its Degree of Polymerization (DP). The direct method, which involves actual paper samples and is thus expensive and invasive, is the conventional method for calculating DP. Recently, a nonintrusive indirect approaches has been used to estimate the DP value from the furan compounds dissolved in the dielectric oil. In this work, the impact of the DP on the remnant life of four different transformer cellulose insulating materials is studied. An analysis of various cellulose insulation DP models are employed in estimating the DP and consequently the remnant life. The study further propose new formulae correlating 2-furaldehyde (2FAL) and DP in relation to the ageing process using regression analysis on a fleet of collected transformer oil samples. The results are compared with measured DP values and yield an estimation error of less than 3% and 4% respectively.","PeriodicalId":370999,"journal":{"name":"2021 IEEE PES/IAS PowerAfrica","volume":"107 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117258911","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}

引用次数: 1

Field Evaluation and Testing of Wind Turbine Earthing Resistance: A Case Study of Soetwater Wind Farm 风力发电机接地电阻的现场评估与测试——以咸水风电场为例

2021 IEEE PES/IAS PowerAfrica Pub Date : 2021-08-23 DOI: 10.1109/PowerAfrica52236.2021.9543198

Lerato F. Mashala, U. B. Akuru, O. Okoro, C. C. Awah

{"title":"Field Evaluation and Testing of Wind Turbine Earthing Resistance: A Case Study of Soetwater Wind Farm","authors":"Lerato F. Mashala, U. B. Akuru, O. Okoro, C. C. Awah","doi":"10.1109/PowerAfrica52236.2021.9543198","DOIUrl":"https://doi.org/10.1109/PowerAfrica52236.2021.9543198","url":null,"abstract":"This study focuses on the improvement of wind turbine foundation earthing. Earthing plays a huge role in the wind turbine construction. Thus, failing to adhere to protocols as per IEEE Std 80-2000: IEEE Guide for Safety in AC Substation Grounding may pose serious threat to wind turbines and affect production of electricity. Lightning protection systems (LPS) for wind power generation is becoming an important public issue. Damages and set-backs from breaking down of blades, accidents relating to low-voltage and control circuit breakdowns have been previously recorded from various wind farms around the world due to failure in the earthing system. Effective lightning protection for wind turbines is very important because areas where wind turbines are installed have a high isochronous level. In addition, increasing use of this renewable energy requires high reliability and adequate protection. In this paper, a case study of Soetwater Wind Farm in the Northern Cape Province of South Africa is undertaken to satisfy ground potential rise (GPR) performance criterion for HV and MV earth faults, as well as improvement of earthing to meet the requirements.","PeriodicalId":370999,"journal":{"name":"2021 IEEE PES/IAS PowerAfrica","volume":"97 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129274548","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}

引用次数: 1

Safety and Security Impacts on Integrated Use of Li-On Batteries in an Energy Island 锂离子电池在能源岛综合使用的安全与保障影响

2021 IEEE PES/IAS PowerAfrica Pub Date : 2021-08-23 DOI: 10.1109/PowerAfrica52236.2021.9543384

B. A. Gran, Coralie Esnoul, Julia Wind, P. Vie, Torleif Lian

引用次数: 0

Real-Time Dynamic Disturbance Estimation of Stand-Alone Microgrids Based on Unknown Input Observer for Frequency Regulation 基于未知输入观测器的独立微电网频率调节实时动态干扰估计

2021 IEEE PES/IAS PowerAfrica Pub Date : 2021-08-23 DOI: 10.1109/PowerAfrica52236.2021.9543142

A. Aluko, R. P. Carpanen, D. Dorrell, E. Ojo

引用次数: 0

A Weighting Factor-Fuzzy logic based Transformer Residual Life Estimation Model 基于加权因子-模糊逻辑的变压器剩余寿命估计模型

2021 IEEE PES/IAS PowerAfrica Pub Date : 2021-08-23 DOI: 10.1109/PowerAfrica52236.2021.9543460

Edwell T. Mharakurwa, S. Juma

{"title":"A Weighting Factor-Fuzzy logic based Transformer Residual Life Estimation Model","authors":"Edwell T. Mharakurwa, S. Juma","doi":"10.1109/PowerAfrica52236.2021.9543460","DOIUrl":"https://doi.org/10.1109/PowerAfrica52236.2021.9543460","url":null,"abstract":"Further utilization of ageing fleet of power system assets can be enhanced by acquiring better knowledge of life-threatening factors. In this paper, further exploration of power transformer residual life estimation is articulated. Previously, focus has been on diagnostic capabilities and degradation agencies in forecasting the remnant life of a power transformer. In this study, a weighting factor approach cascaded with fuzzy inference system was adopted in realizing the residual life of a power transformer. Instead of using individual attributes, the proposed model utilizes the grouping factor of technical life threatening agencies. A multi-criteria analysis was employed in developing the model, whereby the outcome of the model is accomplished by including the collective effect of distinct sub outcomes using fuzzification of all the active grouping attributes. Assessment of the developed residual life model was confirmed by utilization of data set attained from several in-service mineral oil immersed transformers. The simulation results were comparable with utility expert's outcome, thus confirming the applicability of the proposed model.","PeriodicalId":370999,"journal":{"name":"2021 IEEE PES/IAS PowerAfrica","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125454696","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}

引用次数: 1

Finite Element Modeling of Fields Distributions in a Three-core XLPE Cable with Multiple Cavities 多腔三芯交联聚乙烯电缆场分布的有限元模拟

2021 IEEE PES/IAS PowerAfrica Pub Date : 2021-08-23 DOI: 10.1109/PowerAfrica52236.2021.9543183

U. Musa, A. Mati, A. Mas’ud, G. Shehu

{"title":"Finite Element Modeling of Fields Distributions in a Three-core XLPE Cable with Multiple Cavities","authors":"U. Musa, A. Mati, A. Mas’ud, G. Shehu","doi":"10.1109/PowerAfrica52236.2021.9543183","DOIUrl":"https://doi.org/10.1109/PowerAfrica52236.2021.9543183","url":null,"abstract":"Three-core cross-linked polyethylene (XLPE) power cables are widely deployed for underground power distribution and transmission. The presence of cavities within the cable insulation serves as field enhancement regions which may lead to partial discharge capable of causing failure. In this paper, the distribution of electric and potential fields in a three-core XLPE power cable without and with cavities using finite element approach in COMSOL are presented. The results indicate a clear variation in the fields (electric and equipotential line) across the insulations of the cable cores without and with cavities. The highest field intensity across the healthy and defected model are contained in the upper core as compared to the right- and lefthand cores respectively. For the unhealthy cable configuration, the maximum electric field magnitude obtained in the upper core with three arbitrary cavities 1, 2, 3, was approximate 12. 1371 kV/mm. As such, increasing the overall average cable field strength by 88.06% as compared to the default field magnitude (1.3371kV/mm). The introduction of cavities, is observed to cause a significant increase in electric field magnitude within the cable.","PeriodicalId":370999,"journal":{"name":"2021 IEEE PES/IAS PowerAfrica","volume":"363 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115968910","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}

引用次数: 3