Pub Date : 2020-06-14DOI: 10.17159/2413-3051/2020/v31i2a7514
M. F. Khan, A. Jarvis, E. Young, A. Swanson, J. Archer, R. Stephen
This paper proposes the development of a superconducting series reactor (SSR) as an alternative to traditionally employed technologies and superconducting fault current limiters when managing fault levels on the electrical power grid. By utilizing superconducting tape, which has negligible resistance, in the construction of a series reactor, it is proposed that fault level mitigation could be achieved in a more energy efficient manner. Once constructed the SSR will be installed and tested at a grid-connected power engineering research site, and the proposed impact of this installation is firstly simulated using Reticmaster® power system simulation software. Design parameters for the prototype SSR are then calculated enabling the total cost of the modifications and prototype SSR to be determined. A desktop SSR was also constructed and tested as a pre-cursor to the prototype construction to confirm functionality and design and was found to be up to four times more energy efficient as the equivalent copper reactor. Finally, the calorimetric method of power loss determination was investigated and experimentally shown to be a viable alternative to the traditional electrical method of power loss determination. In the past, the relatively cheap cost of electricity in South Africa had favoured the installation of poor power efficiency devices that required a lower initial capital investment. With increasing energy costs and a focus on carbon emission reductions, the development of the SSR augurs a new era in power system engineering in which designs are proposed considering both total lifecycle costs and energy efficiency. Design proposal for the first superconducting power device in Africa Alternative to less efficient fault current management technologies currently employed Construction and testing of a desktop superconducting series reactor Verification of the calorimetric method for power loss determination.
{"title":"The novel design of an energy efficient superconductor-based series reactor for installation at a grid connected research site","authors":"M. F. Khan, A. Jarvis, E. Young, A. Swanson, J. Archer, R. Stephen","doi":"10.17159/2413-3051/2020/v31i2a7514","DOIUrl":"https://doi.org/10.17159/2413-3051/2020/v31i2a7514","url":null,"abstract":"This paper proposes the development of a superconducting series reactor (SSR) as an alternative to traditionally employed technologies and superconducting fault current limiters when managing fault levels on the electrical power grid. By utilizing superconducting tape, which has negligible resistance, in the construction of a series reactor, it is proposed that fault level mitigation could be achieved in a more energy efficient manner. Once constructed the SSR will be installed and tested at a grid-connected power engineering research site, and the proposed impact of this installation is firstly simulated using Reticmaster® power system simulation software. Design parameters for the prototype SSR are then calculated enabling the total cost of the modifications and prototype SSR to be determined. A desktop SSR was also constructed and tested as a pre-cursor to the prototype construction to confirm functionality and design and was found to be up to four times more energy efficient as the equivalent copper reactor. Finally, the calorimetric method of power loss determination was investigated and experimentally shown to be a viable alternative to the traditional electrical method of power loss determination. In the past, the relatively cheap cost of electricity in South Africa had favoured the installation of poor power efficiency devices that required a lower initial capital investment. With increasing energy costs and a focus on carbon emission reductions, the development of the SSR augurs a new era in power system engineering in which designs are proposed considering both total lifecycle costs and energy efficiency. \u0000 \u0000Design proposal for the first superconducting power device in Africa \u0000Alternative to less efficient fault current management technologies currently employed \u0000Construction and testing of a desktop superconducting series reactor \u0000Verification of the calorimetric method for power loss determination.","PeriodicalId":15666,"journal":{"name":"Journal of Energy in Southern Africa","volume":"133 1","pages":"19-33"},"PeriodicalIF":0.0,"publicationDate":"2020-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77138283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-14DOI: 10.17159/2413-3051/2020/v31i2a6166
C. Adendorff, Harvey Keown, Ric Amansure
This study investigates the main contributors that can positively influence the socio-economic empowerment of women in the renewable energy sector in the Republic of South Africa, and recommends new and innovative approaches to mainstream gender in the sector. Empirical evidence showed that ethical leadership positively influences good governance and successful women’s empowerment. The results also indicated that social investment and broad-based black economic empowerment positively influence successful women’s empowerment. Finally, the results indicated that sustainable programmes are a positive contributing factor to good governance. However, the respondents did not consider stakeholder engagement statistically significant to good governance or successful women’s empowerment. This study also has the potential to contribute to the improvement of impoverished communities in South Africa and elsewhere.
{"title":"The development of a socio-economic model to promote women’s empowerment initiatives in the renewable energy sector of South Africa","authors":"C. Adendorff, Harvey Keown, Ric Amansure","doi":"10.17159/2413-3051/2020/v31i2a6166","DOIUrl":"https://doi.org/10.17159/2413-3051/2020/v31i2a6166","url":null,"abstract":"This study investigates the main contributors that can positively influence the socio-economic empowerment of women in the renewable energy sector in the Republic of South Africa, and recommends new and innovative approaches to mainstream gender in the sector. Empirical evidence showed that ethical leadership positively influences good governance and successful women’s empowerment. The results also indicated that social investment and broad-based black economic empowerment positively influence successful women’s empowerment. Finally, the results indicated that sustainable programmes are a positive contributing factor to good governance. However, the respondents did not consider stakeholder engagement statistically significant to good governance or successful women’s empowerment. This study also has the potential to contribute to the improvement of impoverished communities in South Africa and elsewhere.","PeriodicalId":15666,"journal":{"name":"Journal of Energy in Southern Africa","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78152881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-03-10DOI: 10.17159/2413-3051/2020/V31I1A7430
O. Oni, A. Swanson, R. P. Carpanen
Inter-area oscillation caused by weak interconnected lines or low generator inertia is a critical problem facing power systems. This study investigated the performance analysis of a multi-terminal high voltage direct current (MTDC) on the damping of inter-area oscillations of a modified two-area four-machine network. Two case studies were considered, utilising scenario 1: a double alternating current (AC) circuit in linking Bus_10 and Bus_11; and scenario 2: a three-terminal line commutated converter high voltage direct current system in linking Bus_6 and Bus_11 into Bus_9. It was found that scenario 2 utilising MTDC link with a robust controller provided quick support in minimising the network oscillations following a fault on the system. The MTDC converter controllers’ setup offered sufficient support for the inertia of the AC system, thus providing efficient damping of the inter-area oscillation of the system.
{"title":"Small signal stability analysis of a four-machine system with placement of multi-terminal high voltage direct current link","authors":"O. Oni, A. Swanson, R. P. Carpanen","doi":"10.17159/2413-3051/2020/V31I1A7430","DOIUrl":"https://doi.org/10.17159/2413-3051/2020/V31I1A7430","url":null,"abstract":"Inter-area oscillation caused by weak interconnected lines or low generator inertia is a critical problem facing power systems. This study investigated the performance analysis of a multi-terminal high voltage direct current (MTDC) on the damping of inter-area oscillations of a modified two-area four-machine network. Two case studies were considered, utilising scenario 1: a double alternating current (AC) circuit in linking Bus_10 and Bus_11; and scenario 2: a three-terminal line commutated converter high voltage direct current system in linking Bus_6 and Bus_11 into Bus_9. It was found that scenario 2 utilising MTDC link with a robust controller provided quick support in minimising the network oscillations following a fault on the system. The MTDC converter controllers’ setup offered sufficient support for the inertia of the AC system, thus providing efficient damping of the inter-area oscillation of the system.","PeriodicalId":15666,"journal":{"name":"Journal of Energy in Southern Africa","volume":"44 1","pages":"73-87"},"PeriodicalIF":0.0,"publicationDate":"2020-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85443388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-02-28DOI: 10.17159/2413-3051/2020/V31I1A7571
M. Vumbugwa, J.L. Crozier McCleland, E. Van Dyk, F. Vorster, T. Serameng
Photovoltaic (PV) module operation is critical in PV systems for optimum generation of electrical power. Modules installed in the field suffer uneven soiling caused by bird droppings and dust build-up on their front surface. This study investigated the impact of partial shading caused by non-uniform soiling on the electrical characteristics of multi-crystalline silicon (mc-Si) modules and strings, and compared this with simulated I-V parameters. Light and heavy uneven soiling on mc-Si solar cells resulted in current mismatch which can be simulated. The effects of partial soiling on the I-V characteristics of mc-Si module strings were experimentally measured and agreed with the simulated results.
{"title":"Effects of current mismatch due to uneven soiling on the performance of multi-crystalline silicon module strings","authors":"M. Vumbugwa, J.L. Crozier McCleland, E. Van Dyk, F. Vorster, T. Serameng","doi":"10.17159/2413-3051/2020/V31I1A7571","DOIUrl":"https://doi.org/10.17159/2413-3051/2020/V31I1A7571","url":null,"abstract":"Photovoltaic (PV) module operation is critical in PV systems for optimum generation of electrical power. Modules installed in the field suffer uneven soiling caused by bird droppings and dust build-up on their front surface. This study investigated the impact of partial shading caused by non-uniform soiling on the electrical characteristics of multi-crystalline silicon (mc-Si) modules and strings, and compared this with simulated I-V parameters. Light and heavy uneven soiling on mc-Si solar cells resulted in current mismatch which can be simulated. The effects of partial soiling on the I-V characteristics of mc-Si module strings were experimentally measured and agreed with the simulated results.","PeriodicalId":15666,"journal":{"name":"Journal of Energy in Southern Africa","volume":"27 1","pages":"62-72"},"PeriodicalIF":0.0,"publicationDate":"2020-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83073084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-02-28DOI: 10.17159/2413-3051/2020/V31I1A6430
Vitus O. Ejesieme, N. Vorster, J. Riaza, Gary M. Dugmore, Ben Zeelie
Combustion of South African discard ultra-fine coal (i.e. coal dust), charcoal, microalgae biomass, and composites of the three under air were studied. The study involves to find out the effect of Scenedesmus microalgae biomass on the comprehensive combustion characteristics of the ultra-fines. Coal dust is considered as waste material, but it could be modified and combusted for energy. The composites were designed with Design Expert, and unlike blending with the dry microalgae biomass, fresh slurry was blended with the ultra-fine coal and charcoal. Non-isothermal combustion was carried out at heating rate of 15 C/min from 40 – 900 oC and at flow rate of 20 ml/min, O2/CO2 air. Combustion properties of composites were deduced from TG-DTGA and analysed using multiple regression. On combustion, the interaction of coal-charcoal-microalgae was antagonistic (b = - 1069.49), while coal-microalgae (b = 39.17), and coal-charcoal (b = 80.37), was synergistic (p = 0.0061). The coal-microalgae (Coalgae®) indicated first order reaction mechanism unlike, coal, and the charcoal. Comprehensive combustion characteristics index of Coalgae®, (S-value = 4.52E8) was superior relative to ultra-fine (S-value = 3.16E8), which indicated high quality fuel. This approach to combusting ultra-fine coal with microalgae biomass is partly renewable, and it would advance the production of heat and electricity. Key words: coal-dust, combustion, s-value, Coalgae®, renewable.
{"title":"Reclamation of ultra-fine coal with scenedesmus microalgae and comprehensive combustion property of the Coalgae® composite","authors":"Vitus O. Ejesieme, N. Vorster, J. Riaza, Gary M. Dugmore, Ben Zeelie","doi":"10.17159/2413-3051/2020/V31I1A6430","DOIUrl":"https://doi.org/10.17159/2413-3051/2020/V31I1A6430","url":null,"abstract":"Combustion of South African discard ultra-fine coal (i.e. coal dust), charcoal, microalgae biomass, and composites of the three under air were studied. The study involves to find out the effect of Scenedesmus microalgae biomass on the comprehensive combustion characteristics of the ultra-fines. Coal dust is considered as waste material, but it could be modified and combusted for energy. The composites were designed with Design Expert, and unlike blending with the dry microalgae biomass, fresh slurry was blended with the ultra-fine coal and charcoal. Non-isothermal combustion was carried out at heating rate of 15 C/min from 40 – 900 oC and at flow rate of 20 ml/min, O2/CO2 air. Combustion properties of composites were deduced from TG-DTGA and analysed using multiple regression. On combustion, the interaction of coal-charcoal-microalgae was antagonistic (b = - 1069.49), while coal-microalgae (b = 39.17), and coal-charcoal (b = 80.37), was synergistic (p = 0.0061). The coal-microalgae (Coalgae®) indicated first order reaction mechanism unlike, coal, and the charcoal. Comprehensive combustion characteristics index of Coalgae®, (S-value = 4.52E8) was superior relative to ultra-fine (S-value = 3.16E8), which indicated high quality fuel. This approach to combusting ultra-fine coal with microalgae biomass is partly renewable, and it would advance the production of heat and electricity. \u0000Key words: coal-dust, combustion, s-value, Coalgae®, renewable.","PeriodicalId":15666,"journal":{"name":"Journal of Energy in Southern Africa","volume":"8 1","pages":"14-27"},"PeriodicalIF":0.0,"publicationDate":"2020-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84723814","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-02-28DOI: 10.17159/2413-3051/2020/V31I1A7008
Sumant Lalljith, A. Swanson, A. Goudarzi
Frequent escalations in fuel costs, environmental concerns, and the depletion of non-renewable fuel reserves have driven the power industry to significant utilisation of renewable energy resources. These resources cannot satisfy the entire system load demand because of the intermittent nature of variable generation resources (VGRs) such as wind and solar. Therefore, there is a need to optimally schedule the generating units (thermal and VGRs) to reduce the amount of fuel used and the level of emissions produced. In this study, an AC-power flow in conjunction with combined economic and environmental dispatch approach through the implementation of a modified constricted coefficient particle swarm optimisation was used to minimise the fuel cost and the level of emission gases produced. The approach was applied to the Institute of Electric and Electronic Engineers 30 bus test system through three different load conditions: base-load, increase-load and critical-load. The results showed the practicality of the proposed approach for the simultaneous reduction of the total generation cost and emission levels on a large electrical power grid while maintaining all the physical and operational constraints of the system.
{"title":"An intelligent alternating current-optimal power flow for reduction of pollutant gases with incorporation of variable generation resources","authors":"Sumant Lalljith, A. Swanson, A. Goudarzi","doi":"10.17159/2413-3051/2020/V31I1A7008","DOIUrl":"https://doi.org/10.17159/2413-3051/2020/V31I1A7008","url":null,"abstract":"Frequent escalations in fuel costs, environmental concerns, and the depletion of non-renewable fuel reserves have driven the power industry to significant utilisation of renewable energy resources. These resources cannot satisfy the entire system load demand because of the intermittent nature of variable generation resources (VGRs) such as wind and solar. Therefore, there is a need to optimally schedule the generating units (thermal and VGRs) to reduce the amount of fuel used and the level of emissions produced. In this study, an AC-power flow in conjunction with combined economic and environmental dispatch approach through the implementation of a modified constricted coefficient particle swarm optimisation was used to minimise the fuel cost and the level of emission gases produced. The approach was applied to the Institute of Electric and Electronic Engineers 30 bus test system through three different load conditions: base-load, increase-load and critical-load. The results showed the practicality of the proposed approach for the simultaneous reduction of the total generation cost and emission levels on a large electrical power grid while maintaining all the physical and operational constraints of the system.","PeriodicalId":15666,"journal":{"name":"Journal of Energy in Southern Africa","volume":"16 1","pages":"40-61"},"PeriodicalIF":0.0,"publicationDate":"2020-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77009845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-02-28DOI: 10.17159/2413-3051/2020/V31I1A7689
D. Kimemia, A. van Niekerk, H. Annegarn, M. Seedat
Energy-poor households in Africa’s burgeoning urban informal settlements are especially likely to suffer from heatwaves because of thermally inefficient dwellings and lack of affordable cooling options. This study utilised a controlled experiment to assess the effectiveness of passive cooling through specially formulated paints (cool coatings) in standard informal structures. The test structures were built to simulate typical shack dwellings in South Africa’s urban informal settlements. Results showed that the mean daily maximum temperatures of the coated structure were up to 4.3 °C lower than those in the uncoated structure. The same cooling trend was observed for the minimum daily temperatures, which were lower by an average of 2.2 °C. Besides, the annual frequency of maximum temperature exceedances beyond the critical heat stroke value of 40 °C dropped from 19% for the uncoated structure to 1% for the coated structure. These temperature differences were found to be statistically and subjectively significant, implying that cool coatings may be effective in promoting thermal comfort and climate resilience in poor urban communities. It is recommended that governmental authorities and relevant role players invest in the production and assisted application of cool coatings in urban informal settlements. The interventions promise hope of reduced energy burden on poor households and could be implemented in parallel with ongoing efforts focused on the design and implementation of low-cost, durable and thermally comfortable houses for indigent communities. Ultimately, the endeavours could be a potential policy change to assist in expanding poor households’ access to alternative and green energy resources.
{"title":"Passive cooling for thermal comfort in informal housing","authors":"D. Kimemia, A. van Niekerk, H. Annegarn, M. Seedat","doi":"10.17159/2413-3051/2020/V31I1A7689","DOIUrl":"https://doi.org/10.17159/2413-3051/2020/V31I1A7689","url":null,"abstract":"Energy-poor households in Africa’s burgeoning urban informal settlements are especially likely to suffer from heatwaves because of thermally inefficient dwellings and lack of affordable cooling options. This study utilised a controlled experiment to assess the effectiveness of passive cooling through specially formulated paints (cool coatings) in standard informal structures. The test structures were built to simulate typical shack dwellings in South Africa’s urban informal settlements. Results showed that the mean daily maximum temperatures of the coated structure were up to 4.3 °C lower than those in the uncoated structure. The same cooling trend was observed for the minimum daily temperatures, which were lower by an average of 2.2 °C. Besides, the annual frequency of maximum temperature exceedances beyond the critical heat stroke value of 40 °C dropped from 19% for the uncoated structure to 1% for the coated structure. These temperature differences were found to be statistically and subjectively significant, implying that cool coatings may be effective in promoting thermal comfort and climate resilience in poor urban communities. It is recommended that governmental authorities and relevant role players invest in the production and assisted application of cool coatings in urban informal settlements. The interventions promise hope of reduced energy burden on poor households and could be implemented in parallel with ongoing efforts focused on the design and implementation of low-cost, durable and thermally comfortable houses for indigent communities. Ultimately, the endeavours could be a potential policy change to assist in expanding poor households’ access to alternative and green energy resources.","PeriodicalId":15666,"journal":{"name":"Journal of Energy in Southern Africa","volume":"99 1","pages":"28-39"},"PeriodicalIF":0.0,"publicationDate":"2020-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88091802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-02-26DOI: 10.17159/2413-3051/2020/V31I1A7670
F. J. R. Real, Beatriz Tovar
This study analyses the determinants of the technical efficiency performance for Southern African Power Pool (SAPP) power utilities in the period 1998-2009, excluding South Africa’s Eskom. The study formulated an explicit model for technical inefficiency by considering the vertical structure of the utilities and the definition of the product, considering the specific characteristics of this sample. It was found that the most significant improvement in the average efficiency of the sample occurred from 2000 to 2002, coinciding with the first SAPP Energy Plan of 2001. Density in consumption, control of corruption and load factor also contributed to the different levels of efficiency. The results provided a new empirical evidence that can be useful for the design of energy policy and incentive regulation.
{"title":"Revisiting electric utilities’ efficiency in the Southern African Power Pool, 1998–2009","authors":"F. J. R. Real, Beatriz Tovar","doi":"10.17159/2413-3051/2020/V31I1A7670","DOIUrl":"https://doi.org/10.17159/2413-3051/2020/V31I1A7670","url":null,"abstract":"This study analyses the determinants of the technical efficiency performance for Southern African Power Pool (SAPP) power utilities in the period 1998-2009, excluding South Africa’s Eskom. The study formulated an explicit model for technical inefficiency by considering the vertical structure of the utilities and the definition of the product, considering the specific characteristics of this sample. It was found that the most significant improvement in the average efficiency of the sample occurred from 2000 to 2002, coinciding with the first SAPP Energy Plan of 2001. Density in consumption, control of corruption and load factor also contributed to the different levels of efficiency. The results provided a new empirical evidence that can be useful for the design of energy policy and incentive regulation.","PeriodicalId":15666,"journal":{"name":"Journal of Energy in Southern Africa","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90228776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-05DOI: 10.17159/2413-3051/2019/v30i4a2486
R. Thomas, S. V. van Zyl, R. Naidoo, R. C. Bansal, N. Mbungu, M. Bipath
The optimised placement of reclosers on a distribution network is known to improve the reliability of a power system. Furthermore, the protection settings on distribution systems rely heavily on the number and placement of such reclosers. This study examined the effect of using protection settings methodology with the placement of reclosers to ameliorate the damage sustained during faults on a distribution network. The aim of the study was to determine whether this ‘damage control factor’ should be a future consideration for recloser placement. It has been found that the determination of the number and placement of reclosers, which are the function of the energy exposure of feeder, helped to optimise the operation and reliability of a distribution network. This could benefit both energy users and energy suppliers, who often face different challenges during the fault levels on the network.
{"title":"Recloser based energy exposure assessment of a distribution network","authors":"R. Thomas, S. V. van Zyl, R. Naidoo, R. C. Bansal, N. Mbungu, M. Bipath","doi":"10.17159/2413-3051/2019/v30i4a2486","DOIUrl":"https://doi.org/10.17159/2413-3051/2019/v30i4a2486","url":null,"abstract":"The optimised placement of reclosers on a distribution network is known to improve the reliability of a power system. Furthermore, the protection settings on distribution systems rely heavily on the number and placement of such reclosers. This study examined the effect of using protection settings methodology with the placement of reclosers to ameliorate the damage sustained during faults on a distribution network. The aim of the study was to determine whether this ‘damage control factor’ should be a future consideration for recloser placement. It has been found that the determination of the number and placement of reclosers, which are the function of the energy exposure of feeder, helped to optimise the operation and reliability of a distribution network. This could benefit both energy users and energy suppliers, who often face different challenges during the fault levels on the network.","PeriodicalId":15666,"journal":{"name":"Journal of Energy in Southern Africa","volume":"36 1","pages":"41-50"},"PeriodicalIF":0.0,"publicationDate":"2019-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89958992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-05DOI: 10.17159/2413-3051/2019/v30i4a5694
F. Lubbe, T. Harms, J. Maritz
Gathering quality wind speed data can be time-consuming and expensive. The present study established whether interval-deficient wind speed data could be rendered useful for wind power assessments. The effect of interval deficiency on the quality of the wind speed data was investigated by studying the behaviour of the Weibull scale and shape factors as the interval size between wind speed measurements increased. Five wind speed data sets obtained from the Southern African Universities Radiometric Network (Sauran) were analysed, based on a proposed procedure to find the true Weibull parameters from an interval-deficient wind speed data set. It was found that the relative errors in the Weibull parameters were, on average, less than 1%, compared with the Weibull parameters computed from a wind speed data set that complies with the IEC 61400-12-1:2005(E) standard. This finding may contribute to time and cost reduction in wind power assessments. It may also promote the application of statistical methods in the renewable energy sector.
{"title":"A statistical exploration of interval-deficient wind speed data for application to wind power assessments","authors":"F. Lubbe, T. Harms, J. Maritz","doi":"10.17159/2413-3051/2019/v30i4a5694","DOIUrl":"https://doi.org/10.17159/2413-3051/2019/v30i4a5694","url":null,"abstract":"Gathering quality wind speed data can be time-consuming and expensive. The present study established whether interval-deficient wind speed data could be rendered useful for wind power assessments. The effect of interval deficiency on the quality of the wind speed data was investigated by studying the behaviour of the Weibull scale and shape factors as the interval size between wind speed measurements increased. Five wind speed data sets obtained from the Southern African Universities Radiometric Network (Sauran) were analysed, based on a proposed procedure to find the true Weibull parameters from an interval-deficient wind speed data set. It was found that the relative errors in the Weibull parameters were, on average, less than 1%, compared with the Weibull parameters computed from a wind speed data set that complies with the IEC 61400-12-1:2005(E) standard. This finding may contribute to time and cost reduction in wind power assessments. It may also promote the application of statistical methods in the renewable energy sector.","PeriodicalId":15666,"journal":{"name":"Journal of Energy in Southern Africa","volume":"12 1","pages":"13-25"},"PeriodicalIF":0.0,"publicationDate":"2019-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89833746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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