Use of Nonlinear Optics for Assessment of Cable Polymer Aging

Polymer jackets play an important protective role in distribution cabling by providing structure and resistance to moisture, heat, and exposure to harmful chemicals. Current methods of structural assessment, such as elongation at break (E-at-B), are inherently destructive. While other non-destructive methods such as indenter evaluation are available, they are not suitable for in-service use. We propose that second harmonic generation (SHG) could provide a non-destructive means of characterizing the aging of chlorosulfonated polyethylene (CSPE) cable jackets. SHG was used to study cables previously aged and characterized by the Electric Power Research Institute (EPRI). Comparative data between the SHG results and indenter modulus tests suggest that SHG can be used to qualitatively differentiate between minimally and significantly aged CSPE cable jackets. The results of this proof-of-concept study suggest additional work that could be done to better understand the mechanisms of the aging of CSPE cable jackets and how SHG could be used to monitor the aging process.

Uso do OpenDSS em Aplicações Reais para Concessionárias de Energia

Este trabalho apresenta algumas funcionalidades utilizadas em aplicações para concessionárias de energia que foram implementadas utilizando o software OpenDSS (Open Distribution System Simulator), desenvolvido pelo EPRI (Electric Power Research Institute). As funcionalidades desenvolvidas são o cálculo de perdas técnicas em redes de média e baixa tensão, cálculo de modelos reduzidos de alimentadores de média tensão, localização de faltas em redes de média tensão e simulação da operação de sistemas de distribuição com recursos energéticos distribuídos em tempo real. As estratégias para a implementação das funcionalidades e testes para a validação das mesmas são apresentados.

Análise de Perdas Técnicas em Sistemas de Distribuição com Controle de Potência Reativa da Geração Distribuída

Com o aumento da inserção de unidades de geração, principalmente fotovoltaica e eólica, nos sistemas de distribuição modernos, tem sido muito discutido como essas podem auxiliar no suporte a rede. O controle de tensão e compensação de reativos em redes têm sido os mais abordados, muitas vezes como forma de auxílio a reguladores de tensão e bancos de capacitores. O presente artigo tem como objetivo analisar as perdas técnicas em um alimentador de um sistema de distribuição real quando a geração é usada para suporte de reativo. Foram avaliados os controles de "fator de potência" e da tensão no ponto de conexão. Como caso de estudo foi usado um sistema de distribuição real disponibilizado pelo Electric Power Research Institute. Notou-se que o controle de reativo empregado pelasgerações distribuídas altera as perdas dos elementos do sistema.

HYDRO-GEOMORPHIC FACTORS AND THE POTENTIAL OF HYDROKINETIC POWER PRODUCTION UPSTREAM OF IKERE GORGE DAM, NIGERIA

The operation of hydrokinetic turbine depends on river flow and pressure head (∆H) which are of high potential in many parts of Nigeria. This study attempts the analysis of the potential of the area upstream of Ikere Gorge dam for hydrokinetic potential. Soil and Water Assessment Tool (SWAT) was used to determine the hydrological parameters of the sub-basins. Pearson Moment Correlation and linear regression methods were used to find the relationships between morphometric properties and the discharge parameters. Hydrological modeling and statistical computations were done to estimate the theoretical potential of the catchment. The result shows that River Oshe has 9.542 MW, which is the highest potential while River Konsun with 1.161 MW has the lowest potential Pearson Moment Correlation shows that there is strong positive relation of 0.7 between slope and pressure head (∆H) at 0.05 significant levels. The result of the multiple regression show that hydro-geomorphic factors explained 59.1% of the variance in the explanation of hydrokinetic power potential upstream of Ikere gorge dam. References Alaska Center for Energy and Power (ACEP) (2011). Hydrokinetic energy (In-River, Tidal and Ocean Current), Retrieved from http://energy-alaska.wikidot.com/ on April 20th, 2014 Aschenbrenner, F. (2008). Innovation on traditional waterwheels for renewable energy // Power electronics and motion Control conference, Portoroz, Slovenia, pp.1625 Bahleda, M., and Hosko, M. A. (2007). Assessment of water power potential and development Needs: Electric power research institute, California Bhattacharya, A.K., and Bolaji, G.A. (2012). Fluid Flow Interactions in Ogun River, International Journal of Research and Reviews in Applied Sciences, 2 (2): 22-23. Electric Power Research Institute, EPRI (2012). Fish passage through turbine: Application of convectional hydropower data to hydrokinetic technology Palo Alto, USA Energy Information Administration (2014). Retrieved on Dec. 20th, 2014 from www.eia.gov/electricity Epler, J. (2010). Tidal Resources characteristics from acoustics Doppler current profiler, An Unpublished M.Sc.Thesis, Department of Mechanical Engineering, University of Washington, USA Evan, M. (2012). Hydrokinetic Power: An Analysis of Its Performance and Potential in the Roza and Kittas Canals. An Unpublished M. Sc. Thesis, the Evergreen State College, USA Ifabiyi, I.P. and Wahab, S. (2017). Theoretical potential of hydrokinetic energy in the Upper Ogun and Upper Kaduna River basins, Nigeria. Journal of Sustainable Development in Africa, 19 (1): 242-256. Clarion University of Pennsylvania, Clarion, USA. ISSN: 1520-5509. [email protected] Kosnik, L. (2008). The Potential of Water Power in the Fight against Global Warming in the USA, Energy policy, doi: 10.1016/ J. enpol. (05), 009. Kusakana, K., and Vermaak, H. J. (2013). Hydrokinetic Power Generation for Rural Electricity Supply: Case of South Africa. Renewable Energy, 1 (55): 467-73. Ladokun, L.L., Ajao, K.R., and Sule, B.F. (2013). Hydrokinetic Energy Conversion System: Pros -pects and Challenges in Nigerian Hydrological setting, Nigerian Journal of Technology, 3 (32): 538-549. Miller, V.B, Ramde, E.W., Grandoville, R.T., and Schaefer, L.A. (2010). Hydrokinetic Power for Energy Access in Rural Ghana, Renewable Energy International Journal, 1(36): 671-675. Mohibullah, M., Radzi, A. M., and Hakim, M.I.A. (2004). Basics Design Aspects of Micro Hydropower Plant and Its Potential Development in Malaysia // Power and Energy Conference, Kualar Lumpur, pp. 220-223. Neitsch, S.L, Arnold, J.G., Kiniry, J.R and Williams, J.R. (2009). Soil and Water Assessment Tool Theoretical Documentation Version 2009 Grassland, Soil and Water Research Laboratory-Agriculture Research Service, Blackland Research Center- Texas Agrilife Research., USA. Ofuani, A.I. (2013). Combating climate change through renewable energy legislation in Nigeria: Prospects and Challenges. Paper Presented at university of Ilorin/ UCC (Ghana) International Conference held at university of Ilorin. May 1st-4th 2011. Stephen, V.A, Paul, T.A., and Daniel, J.G. (2012). Survival and Behaviour of Fish interacting With Hydrokinetic Turbines, 9th ISE, Vienna, USA Vermaak, H.J., Kusakana, K., and Koko, S.P. (2013). Status of Micro-hydrokinetic River Technology in Rural Applications: A Review of literature: Renewable and sustainable energy reviews, 29(14): 625-633. Wahab, S., Ifabiyi, I.P. and Adeogun, A.G. (20017). SWAT analysis of Ikere Gorge Basin for Hydrokinetic power estimation in selected rural settlement of Oke Ogun, Nigeria. Ruhuna Journal of Science. 8(2):24-43 Ruhuna, Faculty of Science, University of Ruhuna, Sri Lanka. eISSN: 2536-8400. DOI: http//:doi.org/10.4038/rjs.v8il. Copyright (c) 2018 Geosfera Indonesia Journal and Department of Geography Education, University of Jember This work is licensed under a Creative Commons Attribution-Share A like 4.0 International License

Estimation of Sea Current Energy Potential by Using Calculation Models of Horizontal Axis Current Turbine in Toyapakeh Strait, Nusa Penida, Bali

Toyapakeh Strait has a fairly strong ocean current velocity with a velocity between 0.5 m/s – 3.2 m/s. The duration of the strong current (V> 0.5 m/s) ranges from 13-22 hours per day. The location of the strong current occurrence is located to the east of Nusa Lembongan Island, precisely at the stationary current measurement location. Vertical distribution of the direction and velocity currents at this location are not uniform from the top to the bottom, especially in the water column depths of 2 m, 4 m and 6 m, whereas at the water column depths of 8 m to 16 m are relatively uniform. Calculation results of potential electrical power by using the horizontal axis turbine model with a capacity of 35.9 kW (Rite Verdan), 100 kW (Tocardo DD702HT) and 250 kW (Tocardo DD1001HT) show that all of the values have the optimal electric powers, especially during the spring tide, whereas during the neap tide only the turbine with a capacity of 35.9 kW can retrieved an optimal electrical power. Calculation result of the electric power potential by using the method of calculation performed by the Electric Power Research Institute Inc. at the point of measurement, indicated that the total amount of energy 42.5 MWh per month for the turbine model Tocardo DD1001HT, 17.27 MWh per month for turbine model DD702HT Tocardo, and 9.08 MWh per month for the turbine model Rite Verdan.Keywords: Toyapakeh Strait, current velocity, time duration, electric power, depth of the water column Perairan Selat Toyapakeh mempunyai kecepatan arus laut yang cukup kuat dengan kecepatan berkisar antara 0,5 m/det – 3,2 m/det. Durasi terjadinya arus kuat (V>0,5 m/det) berkisar 13 – 22 jam per hari. Lokasi tempat terjadinya arus kuat terletak di sebelah timur Pulau Nusa Lembongan, tepatnya di lokasi tempat pengukuran arus stasioner. Secara vertikal distribusi arah dan kecepatan arus di lokasi ini tidak seragam dari atas ke bawah, terutama pada kedalaman kolom air 2 m, 4 m dan 6 m, sedangkan untuk kedalaman kolom air 8 m sampai 16 m relatif seragam. Hasil perhitungan potensi daya listrik dengan menggunakan model turbin sumbu horisontal dengan kapasitas 35,9 kW (Rite Verdan), 100 kW (Tocardo DD702HT) dan 250 kW (Tocardo DD1001HT) diperoleh daya listrik yang cukup optimal terutama saat spring tide, sedangkan saat neap tide hanya turbin dengan kapasitas 35,9 kW yang masih menghasilkan daya listrik secara optimal. Hasil perhitungan potensi daya listrik dengan menggunakan metode perhitungan yang digunakan oleh Electric Power Research Institute Inc. di titik pengukuran diperoleh total energi yang dihasilkan dari model turbin Tocardo DD1001HT adalah sebesar 42,5 MWh per bulan, model turbin Tocardo DD702HT adalah sebesar 17,27 MWh per bulan, dan model turbin Rite Verdan adalah sebesar 9,08 MWh per bulan.Kata Kunci : Selat Toyapakeh, kecepatan arus, durasi waktu, daya listrik, kedalaman kolom air

Numerical Validations of Flaw Shape Idealization Methods to Burst Pressure Estimations of Steam Generator Tube With Axial Surface Flaws

This work investigates the applicability of the flaw shape idealization methods to carry out the structural integrity assessment of steam generator (SG) tubes under internal pressure with complicated axial inner and outer surface flaws that were typically found during the in-service-inspection (ISI). In terms of flaw shape, three different shapes of flaws which can be detected during an actual ISI are considered, i.e., long symmetric flaw, asymmetric inclined flaw and narrow, symmetric deep flaw. As for flaw shape idealization methods for the predictions of burst pressures of these flaws, four different flaw shape idealization models, i.e., semi-elliptical, rectangular, maximum length with effective flaw depth and weakest subcrack model proposed by the Electric Power Research Institute (EPRI) are employed in this work. In order to validate the applicability of these idealization methods, the burst pressures of SG tubes with these flaws are investigated by using the finite element (FE) analyses. By comparing the predictions of the burst pressures based on the four different flaw shape idealization methods with those based on actual flaw shapes, it is found that the weakest subcrack model proposed by the EPRI and maximum length with effective flaw depth model provide the better agreement with actual complex flaw.

Failure of a Rotating Blade of a 200 MW Steam Turbine LP Rotor and Options for Eliminating other Similar Breakdowns

This contribution deals with the analysis of the failure of a rotating blade of the third wheel (L-1 stage) of the LP rotor of a 200 MW turbine at the power station in Počerady. Material analysis of the blade showed that the cause of the blade fracture was the initiation and growth of a fatigue crack from a corrosion pit. Failures of low-pressure blades have occurred repeatedly on machines of the same design in the power stations of the ČEZ group in recent years and by a similar mechanism. Therefore, based on the knowledge obtained by EPRI (Electric Power Research Institute), ČEZ, a.s. has developed a methodology which can, in real conditions during checks of turbines, reliably detect the parameters of corrosion pits and predict the possibility of development of fatigue damage from these pits. The work summarizes the methodology and the conditions of its use with an emphasis on the fields of its application.

Effects of Medium Containing Free Gas on Hydraulic Performance of Certain Single Stage Centrifugal Pump in 3rd Generation Reactor

Pumping medium containing gas has a negative impact on the centrifugal pump on mechanical properties (such as vibration, noise) and hydraulic performance, but also affect the accuracy of hydraulic test. in the GL2008-01 open letter, the United States Nuclear Regulatory (NRC) requires that some safety systems shall take into account the adverse effects of gas and the American Institute for Nuclear Research (NEI) and the Electric Power Research Institute (EPRI) pointed out the American Institute for Nuclear Research (NEI) and the Electric Power Research Institute (EPRI) pointed out that the gas in suction side shall not exceed the limit of 2% (volume ratio). In HPR1000, the 3rd generation reactor, it is the first time proposed that some systems are with long-term gas entrainment condition, and there is up to 3% (volume ratio) free gas in the horizontal centrifugal Spray Pump suction side water. In order to study the 3% gas entrainment condition effects on the hydraulic performance of Spray pump, a way is found to calculate the head drop by some equations and carried out a containing free gas hydraulic test. The results show that under the 3% gas condition, Spray pump head is 0.60% dropped by equation calculation and 0.66% dropped by test, comparing with no gas condition. The 3% gas effects on the Spray pump performance are very small. The reasons is that the structure of the Spray pump is well for vent during operation and the gas is not accumulate in the pump, so the performance of the pump has no effect.

The EPRI PWR Supplemental Surveillance Program (PSSP) Final Design and Implementation

There is a lack of pressurized water reactor (PWR) surveillance program transition temperature shift and upper shelf toughness decrease data due to neutron irradiation exposure especially at high fluences indicative of 60 to 80 years of plant operation. The Electric Power Research Institute (EPRI) has funded the development of a supplemental reactor pressure vessel (RPV) surveillance program to allow testing of additionally irradiated specimens in two new capsules being installed in two different commercial reactor surveillance capsule positions. The previously irradiated materials were strategically selected and will be further irradiated to give final fluence levels equal to or above those for PWRs operating up to 80 years. This paper describes the final design of the capsules and selection of the key previously irradiated RPV materials reconstituted into new Charpy-size specimens being irradiated in the two PWR Supplemental Surveillance Program (PSSP) capsules.