Pembuatan dan Pengujian Bulk Density, Fluks Magnetik, dan Mikrostruktur pada Hybrid Magnet Berbasis NdFeB / BaFe12O19

Telah dilakukan pembuatan hybrid magnet permanen berbasis NdFeB dengan penambahan BaFe12O19 ( 5, 10, 15, dan 20 % wt). Aplikasi hybrid magnet permanen NdFeB untuk komponen motor dan generator listrik skala kecil. Tujuan penelitian ini adalah untuk mengetahui pengaruhnya penambahan BaFe12O19 terhadap densitas, fluks magnetik dan mikrostruktur dari hybrid magnet NdFeB. Proses preparasi bahan baku mulai dari pencampuran serbuk NdFeB tipe MQP-B+ dengan BaFe12O19, digerus dan dicampur bahan perekat Epoxy Resin sebanyak 6 %wt dan dicetak dengan gaya 8 tonf sehingga membentuk pellet dengan diameter 18,5 dan tebal 4,3 mm. Sampel yang telah dicetak kemudian dikeringkan pada kondisi vacuum (±15 mbar) dengan temperatur 80°C ditahan selama 1 jam. Karakterisasi yang dilakukan meliputi pengukuran bulk density, microstructurer menggunakan Optical Microscope dan sifat magnet dengan menggunakan Gaussmeter. Dari hasil karakterisasi secara keseluruhan diperoleh kondisi optimum pada komposisi hybrid magnet NdFeB adalah 95% NdFeB, 5 %wt BaFe12O19 . Sifat-sifat hybrid magnet NdFeB tersebut adalah bulk density = 4,469 g/cm3, Fluks magnetik = 1029,85 Gauss, ukuran bulir (grain size) sekitar 4,1 – 5,2 µm

Penentuan Waktu Standar Dan Jumlah Tenaga Kerja Optimal Pada Produksi Batik Cap (Studi Kasus: IKM Batik Saud Effendy, Laweyan)

Effendy Saud Batik is one of IKM batik Batik Kampoeng Laweyan, Surakarta. Types produced batik is batik and batik with most types of batik is batik produced. IKM Batik Effendy Saud's production strategy make to order and there are no guidelines for production time. Besides the workload at each work station lacks balance, which of the existing value stream mapping, the tasting station in the settlement of 1 lot production yield as much as 120 meters the longest time compared to other work stations, which is 434 minutes with 3 workers. The purpose of this study was to determine the standard time and the optimal number of workers at each stage of the process. From the research results and the calculation of standard time for each of the production process, ie cutting mori (17.46 minutes), taste (582.15 minutes), coloring (84.06 min), drying and washing (207.98 minutes) , penglorodan of 99.87 minutes, drying 1123.2 minutes, and packing of 75.24 minutes. Proposed labor provided SMEs can save expenses by 12%

Method of Equivalencing for a Large Wind Power Plant with Multiple Turbine Representation: Preprint

This paper focuses on our effort to develop an equivalent representation of a Wind Power Plant collector system for power system planning studies

Modelling and upscaling of transport in carbonates during dissolution: validation and calibration with NMR experiments

We present an experimental and numerical study of transport in carbonates during dissolution and its upscaling from the pore (∼ μm) to core (∼ cm) scale. For the experimental part, we use nuclear magnetic resonance (NMR) to probe molecular displacements (propagators) of an aqueous hydrochloric acid (HCl) solution through a Ketton limestone core. A series of propagator profiles are obtained at a large number of spatial points along the core at multiple time-steps during dissolution. For the numerical part, first, the transport model—a particle-tracking method based on Continuous Time Random Walks (CTRW) by Rhodes et al. (2008)—is validated at the pore scale by matching to the NMR-measured propagators in a beadpack, Bentheimer sandstone, and Portland carbonate Scheven et al. (2005). It was found that the emerging distribution of particle transit times in these samples can be approximated satisfactorily using the power law function ψ(t) ∼ t −1 −β, where 0 < β < 2. Next, the evolution of the propagators during reaction is modelled: at the pore scale, the experimental data is used to calibrate the CTRW parameters; then the shape of the propagators is predicted at later observation times. Finally, a numerical upscaling technique is employed to obtain CTRW parameters for the core. From the NMR-measured propagators, an increasing frequency of displacements in stagnant regions was apparent as the reaction progressed. The present model predicts that non-Fickian behaviour exhibited at the pore scale persists on the centimetre scale

Active Power Controls from Wind Power: Bridging the Gaps

This paper details a comprehensive study undertaken by the National Renewable Energy Laboratory, Electric Power Research Institute, and the University of Colorado to understand how the contribution of wind power providing active power control (APC) can benefit the total power system economics, increase revenue streams, improve the reliability and security of the power system, and provide superior and efficient response while reducing any structural and loading impacts that may reduce the life of the wind turbine or its components. The study includes power system simulations, control simulations, and actual field tests using turbines at NREL's National Wind Technology Center (NWTC). The study focuses on synthetic inertial control, primary frequency control, and automatic generation control, and analyzes timeframes ranging from milliseconds to minutes to the lifetime of wind turbines, locational scope ranging from components of turbines to large wind plants to entire synchronous interconnections, and additional topics ranging from economics to power system engineering to control design

Identification of Linearized RMS-Voltage Dip Patterns Based on Clustering in Renewable Plants

[EN] Generation units connected to the grid are currently required to meet low-voltage ride-through (LVRT) requirements. In most developed countries, these requirements also apply to renewable sources, mainly wind power plants and photovoltaic installations connected to the grid. This study proposes an alternative characterisation solution to classify and visualise a large number of collected events in light of current limits and requirements. The authors' approach is based on linearised root-mean-square-(RMS)-voltage trajectories, taking into account LRVT requirements, and a clustering process to identify the most likely pattern trajectories. The proposed solution gives extensive information on an event's severity by providing a simple but complete visualisation of the linearised RMS-voltage patterns. In addition, these patterns are compared to current LVRT requirements to determine similarities or discrepancies. A large number of collected events can then be automatically classified and visualised for comparative purposes. Real disturbances collected from renewable sources in Spain are used to assess the proposed solution. Extensive results and discussions are also included in this study.The authors thank the financial support from the 'Ministerio de Economia y Competitividad' (Spain) and the European Union - ENE2016-78214-C2-2-R, Fulbright/Spanish Ministry of Education Visiting Scholar - PRX14/00694. This work was also supported by the US Department of Energy under contract no. DE-AC36-08-GO28308 with the National Renewable Energy LaboratoryGarcía-Sánchez, TM.; Gómez-Lázaro, E.; Muljadi, E.; Kessler, M.; Muñoz-Benavente, I.; Molina-García, A. (2018). Identification of Linearized RMS-Voltage Dip Patterns Based on Clustering in Renewable Plants. IET Generation Transmission & Distribution. 12(6):1256-1262. https://doi.org/10.1049/iet-gtd.2017.0474S12561262126Craciun B. Kerekes T. Sera D.et al.: ‘Overview of recent grid codes for PV power integration’.13th Int. Conf. on Optimization of Electrical and Electronic Equipment (OPTIM) 2012 May2012 pp.959–965‘World Energy Outlook 2012’. Technical Report International Egency Agency (IEA) 2012. Available atwww.iea.orgBehrens C.E.: ‘Energy policy: 113th congress issues’.Congressional Research Service 2013Lopes, J. A. P., Hatziargyriou, N., Mutale, J., Djapic, P., & Jenkins, N. (2007). Integrating distributed generation into electric power systems: A review of drivers, challenges and opportunities. Electric Power Systems Research, 77(9), 1189-1203. doi:10.1016/j.epsr.2006.08.016Glassmire, J., Komor, P., & Lilienthal, P. (2012). Electricity demand savings from distributed solar photovoltaics. Energy Policy, 51, 323-331. doi:10.1016/j.enpol.2012.08.022Carvalho, D., Wemans, J., Lima, J., & Malico, I. (2011). Photovoltaic energy mini-generation: Future perspectives for Portugal. Energy Policy, 39(9), 5465-5473. doi:10.1016/j.enpol.2011.05.016Battaglini, A., Komendantova, N., Brtnik, P., & Patt, A. (2012). Perception of barriers for expansion of electricity grids in the European Union. Energy Policy, 47, 254-259. doi:10.1016/j.enpol.2012.04.065‘European Commission 2010a. Energy 2020. A strategy for competitive sustainable and secure energy’. Technical Report Brussels November2011Beurskens P.V.L.W.M. Hekkenberg M.: ‘Renewable energy projections as published in the national renewable energy action plans of the european member states’. Technical Report European Environment Agency (EEA) November2011Coll-Mayor, D., Paget, M., & Lightner, E. (2007). Future intelligent power grids: Analysis of the vision in the European Union and the United States. Energy Policy, 35(4), 2453-2465. doi:10.1016/j.enpol.2006.09.001Passey, R., Spooner, T., MacGill, I., Watt, M., & Syngellakis, K. (2011). The potential impacts of grid-connected distributed generation and how to address them: A review of technical and non-technical factors. Energy Policy, 39(10), 6280-6290. doi:10.1016/j.enpol.2011.07.027Sangroniz N. Mora J.A. Teixeira M.D.: ‘Review of international grid codes for wind generation’ 2009‘Global Market Outlook for Photovoltaics Until 2016’. Technical Report European Photovoltaic Industry Association 2012. Available atwww.epia.orgKim S. Bollen M.: ‘Towards the development of a set of grid code requirements for wind farms: transient reactive power requirements’. Technical Report Available as Elforsk Report 13 : 04. Part 3 Report of Vindforsk Project V‐369 Vindforsk III January2013Tsili, M., & Papathanassiou, S. (2009). A review of grid code technical requirements for wind farms. IET Renewable Power Generation, 3(3), 308. doi:10.1049/iet-rpg.2008.0070Hossain, J., & Mahmud, A. (Eds.). (2014). Renewable Energy Integration. Green Energy and Technology. doi:10.1007/978-981-4585-27-9Sourkounis C. Tourou P.: ‘Grid code requirements for wind power integration in Europe’.Conf. Papers in Energy 2013 pp.1–9Voltage Ride-Through Capability Verification of Wind Turbines With Fully-Rated Converters Using Reachability Analysis. (2014). IEEE Transactions on Energy Conversion, 29(2), 392-405. doi:10.1109/tec.2013.2295168Mohseni, M., & Islam, S. M. (2012). Review of international grid codes for wind power integration: Diversity, technology and a case for global standard. Renewable and Sustainable Energy Reviews, 16(6), 3876-3890. doi:10.1016/j.rser.2012.03.039‘Royal Decree 1565/2010 by which regulates and modifies certain aspects of the activity of production of electric energy in special regime. (In spanish)’. Technical Report November2010Sourkounis C. Tourou P.: ‘Grid code requirements for wind power integration in Europe’.Conf. Papers in Science 2013Jiménez, F., Gómez-Lázaro, E., Fuentes, J. A., Molina-García, A., & Vigueras-Rodríguez, A. (2011). Validation of a double fed induction generator wind turbine model and wind farm verification following the Spanish grid code. Wind Energy, 15(4), 645-659. doi:10.1002/we.498Montoro D.: ‘Recommendations for unified technical regulations for grid‐connected PV systems’. Technical Report SUNRISE project – European Photovoltaic Industry Association the European Construction Industry Federation the European Association of Electrical Contractors International Union of Architects 2009. Available athttp://www.pvsunrise.eu/Merino, J., Mendoza-Araya, P., & Veganzones, C. (2014). State of the Art and Future Trends in Grid Codes Applicable to Isolated Electrical Systems. Energies, 7(12), 7936-7954. doi:10.3390/en7127936deAlmeida P. Barbosa P. Duque C.et al.: ‘Grid connection considerations for the integration of PV and wind sources’.IEEE 16th Int. Conf. on Harmonics and Quality of Power (ICHQP) May2014 pp.6–9‘Network code requirements for grid connection applicable to all generators’. Technical Report European Network of Transmission System Operators for Electricity ENTSO‐E October2013. Available athttps://www.entsoe.eu/Kagan N. Ferrari E. Matsuo N.et al.: ‘Influence of rms variation measurement protocols on electrical system performance indices for voltage sags and swells’.Proc. Ninth Int. Conf. on Harmonics and Quality of Power 2000 2000 vol.3 pp.790–795Bollen, M. H. J. (2003). Algorithms for characterizing measured three-phase unbalanced voltage dips. IEEE Transactions on Power Delivery, 18(3), 937-944. doi:10.1109/tpwrd.2003.813879Bollen M.H.: ‘Comparing voltage dip survey results’.Power Engineering Society Winter Meeting 2002 2002 vol.2 pp.1130–1134Moreno‐Muñoz A. de laRosa J.: ‘Voltage sag in highly automated factories’.Industry Applications Society Annual Meeting IAS'08 2008 pp.1–6Gomez-Lazaro, E., Fuentes, J. A., Molina-Garcia, A., & Canas-Carreton, M. (2009). Characterization and Visualization of Voltage Dips in Wind Power Installations. IEEE Transactions on Power Delivery, 24(4), 2071-2078. doi:10.1109/tpwrd.2009.2027513Gunther, E. W., & Mebta, H. (1995). A survey of distribution system power quality-preliminary results. IEEE Transactions on Power Delivery, 10(1), 322-329. doi:10.1109/61.368382Belloni F. Chiappa C. Chiumeo R.et al.: ‘Voltage dip measurements along MV lines vs primary substations measurements’.Int. Conf. on Renewable Energies and Power Quality (ICREPQ'12) March2012 pp.28–30Garcia-Sanchez, T., Gomez-Lazaro, E., Muljadi, E., Kessler, M., & Molina-Garcia, A. (2016). Statistical and Clustering Analysis for Disturbances: A Case Study of Voltage Dips in Wind Farms. IEEE Transactions on Power Delivery, 31(6), 2530-2537. doi:10.1109/tpwrd.2016.2522946Barrera Nunez V. Melendez Frigola J. Herraiz Jaramillo S.: ‘A survey on voltage sag events in power systems’.IEEE/PES Transmission and Distribution Conf. and Exposition: Latin America 2008 August2008 pp.1–3‘IEEE Standard 519‐1992: Recommended practices and requirements for harmonic control in electrical power systems’. Technical Report 1993. Available athttp://ieeexplore.ieee.org/servlet/opac?punumber=2227‘1159‐2009‐IEEE Recommended practice for monitoring electric power quality’. Technical Report June2009. Available athttp://ieeexplore.ieee.org/servlet/opac?punumber=515405