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SE-CEM Laboratory- Electrical System and Electromagnetic

Compatibility

Activity area, research objectives Keywords

Advanced materials for electrical engineering High efficiency electromechanical converters Advanced systems for monitoring, diagnosis and prognosis Electromagnetic compatibility Electromagnetic field theory

electrical engineering, electromagnetic perturbations, measuring techniques, modeling and simulation

Research group profile

SECEM Laboratory has developed inside of the Electrotechnics Department since 1970 with the purpose of optimization of the electrical and electronic equipments. Models and prototypes for synchronous and asynchronous machines, special electrical machines, systems for measuring the distortion power have been realized. Between 1970-2000, the research group, formed by A. Nicolaide, M. Ţaţa, D. Bidian, A. Gogioiu, has modeled and realized prototypes for pumps and magnetic-hydrodynamic generators. The scientific research included: electromagnetic field calculus, design, prototypes in alternative and direct current, and the operating parameters for direct current channels obtaining a first solution in finite terms. A. Nicolaide established a new method of representation with high accuracy, cited in papers from U.K., France, and U.S.A. The theoretic and experimental study of electromagnetic field propagation in ferromagnetic environments has been applied for optimal design of synchronous and asynchronous machines. By implementing the research contracts with the Electroprecizia Săcele Company, first series of induction machines with one or two speeds, optimized based on computer software, have been realized. During 1980-2011 new studies considering linear motors, electromagnetic chamfers for handling molten metal at high temperatures, have been initiated. Since 2004, with redefining research centers, areas of interest include new directions: electromagnetic noise, fault diagnosis and prognosis, electromagnetic compatibility.

R&D products, patents, use cases

1. Procedure and method of measure and automatic control of electromagnetic environment parameters for vehicles, , A. Maţoi, E. Helerea, Patent application no. A2011 published in BOPI no. 1/2012. The proposed solution enables the implementation of a flexible method for in-site measurement of electromagnetic environment parameters for vehicles and mobile systems, as alternative for tests in laboratory or in free space with low level of electromagnetic noise.

2. Transient regimes of electrical machines, magnetic materials, field calculus, studies regarding the theory of restricted and general relativity, prof. dr. eng. A. Nicolaide, Member of the Technical Sciences Academy from Romania

Achievements: High performance solvers utilization for induction motors behavior simulation, including a new

evaluation of the machine parameters. A new study of high accuracy for the calculus of the electromagnetic field produced by solenoids

with any cross-sectional form (sustained at the International Conference of Applied Mathematics

SE-CEM

EUT

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in London and published by the American Institute of Physics, 2008). Theoretic and experimental study of the magnetization characteristics. Studies regarding the restricted and general relativity (A. Nicolaide): simplification of tensor

calculation methods without reducing accuracy and some new results on the electromagnetic energy-momentum tensor (for which he was awarded the Certificate of Merit 2009, at World Congress on Engineering, London).

3. Method for partial discharge detection in electrical cables, Larisa Mariuţ, PhD thesis, 2012. The

method allows the characterization of operational safety monitoring, fault diagnosis and prognosis of

electrical cables.

4. Methods for modeling and simulation, and magnetic materials characteristics measuring

techniques. Modeling methods and techniques for investigation of magnetization processes / demagnetization of soft and hard magnetic materials, for evaluation and prediction the losses and optimal design of magnetic circuit structure of advanced electrical systems. The novelty consists in considering the magnetization curves modeling, including the switching curve characterizing the material in operating conditions.

The solutions are proposed within the doctoral program developed in the frame of SECEM laboratory: Numerical modeling in Lab View of the hysteresis cycle and losses calculus for soft magnetic materials, Septimiu Motoaşcă, PhD thesis , 2010; Soft and hard magnetic materials characteristics techniques determination, Şerafettin Öner, Marius Daniel Călin, PhD thesis, 2011.

Completed and ongoing research projects at national and international level

1. Noise modeling and analyze for variable speed induction motors - IDEI, Nr. 719/2009 (2009-2011,

project manager dr. eng. Gh. Scutaru). Software applications for variable speed induction motors noise modeling and analysis have been developed. The applications allow a numerical modeling of the noise of electromagnetic nature using Flux2D based on finite element, and the noise of mechanical nature using Ansys3D software based on finite element. With these applications the vibration spectra for single phase and three phase induction motors have been established, being important for improvement of the working conditions and environment.

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Prof. dr.ing.

Gheorghe Scutaru Drd.ing.

Ovidiu Pleşa Drd.ing.

Ciprian Nistor

2. Experimental model of the NdFeB Permanent magnet synchronous generator of 400 Hz. In the frame of the research contracts CNCSIS 429/2006-2008: Models and simulations regarding the behavior in dynamic regime of the magnetic materials with controlled properties, and CEEX No. 2-CEx06-8-85/2006-2008: Magnetic materials with superior performances used in electrical machines design (project managers – prof.dr.eng. A. Nicolaide, prof.dr.eng. E. Helerea), an experimental model of a rare earth salient pole synchronous machine had been designed and built with SC Electroprecizia SA Săcele, in collaboration with ICPE-CA Bucharest. The experimental model is located in L04 Laboratory in CDI Institute of the Transilvania University of Brasov. The Green function method by iterative procedure for non-linearity consideration and the medium spatial values methods for different sections of the magnetic circuit were used for the magnetic field calculus. By replacing the excitation winding with permanent magnet a higher reliability of this product is assured. It may be used as AC power generator where low speeds are required, for example, in cases of low level waterfalls.

Prof. dr.ing. Andrei Nicolaide

Prof. dr.ing. Elena

Helerea

Ş.l. dr.ing. Septimiu

Motoaşcă

Ş.l. dr.ing. Marius Daniel

Călin

Drd.ing. Anca

Ciobanu

3. Advanced materials for electromagnetic shielding. Efficient investigation methods of electrical and magnetic properties of the conventional materials and nanomaterials have been established and promoted with the purpose of electromagnetic shielding capacity highlighting. The research has been conducted with the CNCSIS contracts: 21st Theme, Code 521 Improving the material properties and the components involved in electromagnetic compatibility (2002-2004, Project manager prof. dr.eng. E. Helerea) and CNCSIS 429/2006 contract: The shielding properties study of the materials obtained by nano-technologies and nano-processes for electrical and electronic systems integration with the purpose of improving the environment quality., (2006-2008, Project manager conf. dr.eng. L. Aciu).

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Ş.l. dr.ing. Laura Leluțiu

Ş.l. dr.ing. Carmen Lungoci

Drd.ing. CorneliuUrsachi

Drd.ing. Beatrice Moaşa

4. The post-doctoral research program Titu Maiorescu, No. 1246/02/02/2009, financed by the Education, Research and Innovation Ministry: „Energy management of feeding/recovering hybrid systems with super-capacitors with the purpose of achieving the standards imposed by the European Union, project manager dr.eng. C. Lungoci. A solution of optimal power management using super-capacitors in feeding/recovering power in terrestrial transportation has been developed. The method allows for optimal design methodologies development by elaboration of efficient management power legislature in terrestrial transportation applications considering the risk reduction and the pollution impact in urban transport.

5. Monitoring and improving the performance indicators of low voltage distribution systems in collaboration with SC FDEE Electrica Transilvania Sud (2009-2011, project manager conf. dr. eng. L. Aciu). Two intelligent monitoring systems have been designed and developed. One of these had been patented: Electronic breaker and method for protection in case of earth current leakage, registered at OSIM, with no. A00880/09.09.2011. The system allows the electromagnetic conducted perturbations characterization in low voltage electrical grids, and as well the implementation of an application for monitoring of the electrical energy quality.

Conf. dr. ing.

Lia Elena Aciu

6. Integrated system for tests at conducted electromagnetic distortions of electrical and electronic equipments. The system, purchased with the Research-Development-Innovation High-Tech Products for sustainable development Institute - PRO-DD, co-funded by the European Fund for Regional Development, Contract No. 11/2009, conducted during 2010-2013, complete the research laboratory infrastructure in electromagnetic compatibility domain, having multiple functions:

The conducted distortions determination produced by electrical and electronic equipments; Determining the level of immunity of electrical and electronically equipments; Testing the behavior of equipments subjected to electrostatic discharge.

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The domains in which tests at conducted distortions will be performed are: industry, renewable energy sources, telecommunications and vehicles. The system consists in: - Reflecting room which creates the specific environment for performing the tests, - Feeding sources, in accordance with every tested equipment, - Measuring/testing equipments, accessories necessary for simulating the testing conditions in

accordance with the actual standards.

Selections of 7 recent publications, representative for the research group

1. Măriuţ, L., Helerea, E., Cavallini, A., Correlation between PDIV and life distribution under different testing waveforms, Proceedings of IEEE International Conference on Optimization of Electrical and Electronic Equipment, pp. 130-135, Braşov, România, 2012.

2. Ciobanu A., Helerea E., Peter I, An Experimental Comparative Analysis for Broken Rotor Bars Diagnosis. 11th International Conference on Applied and Theoretical Electricity, Annals of the University of Craiova, October 25-27, 2012, Craiova, România, pp.75-78, ISSN 184-4805.

3. Motoaşca S., Nicolaide, A., Helerea E., Scutaru G., New analytical method for hysteresis modelling of soft magnetic materials using LabVIEW program. Industrial Electronics, 2009. IECON '09. 35th Annual Conference of IEEE, 3-5 Nov. 2009, pp.3285 – 3288.

4. Negoiţă A, Scutaru G., Peter I., Ionescu R. M., Wireless Sensor Network System for Measuring the Magnetic Noise of Inverter-Fed Three-Phase Induction Motors with Squirrel-Cage Rotor, IFIP Advances in Information and Communication Technology, DOCEIS’2011, Vol. 349, pp. 518-525, 2011.

5. Aciu L. E, Consumers protection and monitoring with microcontroller based device for low-voltage distribution systems, Przeglad Elektrotechnicz ( ISI Electrical Review), nr.6/2012, ISSN 0033-2097, pp.55-57.

6. Lungoci, C., Bouquain, D., Miraoui, A., Helerea, E., Modular test bench for a hybrid electric vehicle with multiples energy sources, The IEEE 11th International Conference on Optimization of Electrical and Electronic Equipment, OPTIM 2008, vol. II-A, pp.299-306.

7. Nicolaide, A.: Conformal Transformation Using Symbolic Language Facilities and Applications in Electrical Engineering. Proceedings of the World Congress on Engineering 2012, International Conference of Applied and Engineering Mathematics, 4-6 July, 2012, London, U.K., SSN: 2078-0958 (Print);-ISSN 2078-0966 (Online).

Contact

Name: Prof. dr. ing. Elena Helerea Position: SE-CEM Laboratory Coordinator, Head of Research Centre: Advanced Electrical Systems email: helerea@unitbv.ro

Tel. +40 744624682 Location: ICDT Institutului Street, no. 10, Braşov, Romania Laboratory 04