Articles de revista
http://hdl.handle.net/2117/3651
20170124T15:29:35Z

Parameter estimation procedures for compact fluorescent lamps with electronic ballasts
http://hdl.handle.net/2117/99933
Parameter estimation procedures for compact fluorescent lamps with electronic ballasts
Sainz Sapera, Luis; Cunill Solà, Jordi; Mesas García, Juan José
20170124T11:20:40Z
Sainz Sapera, Luis
Cunill Solà, Jordi
Mesas García, Juan José

Theoretical study of the steinmetz circuit design
http://hdl.handle.net/2117/99931
Theoretical study of the steinmetz circuit design
Monjo Mur, Lluís; Sainz Sapera, Luis; Riera Galceran, Sara; Bergas Jané, Joan Gabriel
20170124T10:48:02Z
Monjo Mur, Lluís
Sainz Sapera, Luis
Riera Galceran, Sara
Bergas Jané, Joan Gabriel

Harmonic interaction influence due to current source shunt filters in networks supplying nonlinear loads
http://hdl.handle.net/2117/99846
Harmonic interaction influence due to current source shunt filters in networks supplying nonlinear loads
Sainz Sapera, Luis; Balcells Sendra, Josep
20170123T12:01:42Z
Sainz Sapera, Luis
Balcells Sendra, Josep

Influence of Steinmetz circuit capacitor degradation on series resonance of networks
http://hdl.handle.net/2117/99842
Influence of Steinmetz circuit capacitor degradation on series resonance of networks
Sainz Sapera, Luis; Caro Huertas, Manuel; Caro, Eduardo
20170123T11:51:39Z
Sainz Sapera, Luis
Caro Huertas, Manuel
Caro, Eduardo

Study of resonances in 1 x 25 kV AC traction systems with external balancing equipment
http://hdl.handle.net/2117/99309
Study of resonances in 1 x 25 kV AC traction systems with external balancing equipment
Mesbahi, Nadhir; Monjo Mur, Lluís; Sainz Sapera, Luis
AC traction systems are 1 × 25 or 2 × 25 kV/50 Hz singlephase, nonlinear, timevarying loads that can cause powerquality problems, such as unbalanced or distorted voltages. To reduce unbalance, external balancing equipment is usually connected to these systems, forming the Steinmetz circuit. Parallel resonances can occur in these types of circuits, exciting the harmonic emissions (below 2 kHz) of railwayadjustable speed drives. This paper studies these resonances at pantograph terminals and provides analytical expressions to determine their harmonic frequencies. The expressions are validated from several traction systems in the literature and PSCAD simulations.
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20170116T12:37:05Z
Mesbahi, Nadhir
Monjo Mur, Lluís
Sainz Sapera, Luis
AC traction systems are 1 × 25 or 2 × 25 kV/50 Hz singlephase, nonlinear, timevarying loads that can cause powerquality problems, such as unbalanced or distorted voltages. To reduce unbalance, external balancing equipment is usually connected to these systems, forming the Steinmetz circuit. Parallel resonances can occur in these types of circuits, exciting the harmonic emissions (below 2 kHz) of railwayadjustable speed drives. This paper studies these resonances at pantograph terminals and provides analytical expressions to determine their harmonic frequencies. The expressions are validated from several traction systems in the literature and PSCAD simulations.

Aeronautical ground lighting system study: field measurements and simulations
http://hdl.handle.net/2117/99215
Aeronautical ground lighting system study: field measurements and simulations
Vidal, Daniel; Monjo Mur, Lluís; Sainz Sapera, Luis
Aeronautical ground lighting (AGL) systems are singlephase series circuits where constant current regulators supply transformers and luminaires. These systems provide visual reference to aircraft during airport operations. There is a lack of AGL system models and measurements in the literature to study AGL system behaviour and predict their response to electrical events and future technological changes. The study contributes to AGL system modelling with an equivalent circuit useful to study AGL system concerns by Matlab/Simulink simulations. It also presents field measurements taken at Reus airport (Catalonia, Spain) for the validation of the proposed model and understanding of AGL system behaviour in the event of luminaire failure.
20170113T11:28:58Z
Vidal, Daniel
Monjo Mur, Lluís
Sainz Sapera, Luis
Aeronautical ground lighting (AGL) systems are singlephase series circuits where constant current regulators supply transformers and luminaires. These systems provide visual reference to aircraft during airport operations. There is a lack of AGL system models and measurements in the literature to study AGL system behaviour and predict their response to electrical events and future technological changes. The study contributes to AGL system modelling with an equivalent circuit useful to study AGL system concerns by Matlab/Simulink simulations. It also presents field measurements taken at Reus airport (Catalonia, Spain) for the validation of the proposed model and understanding of AGL system behaviour in the event of luminaire failure.

Optimal fitting of highfrequency cable model parameters by applying evolutionary algorithms
http://hdl.handle.net/2117/98430
Optimal fitting of highfrequency cable model parameters by applying evolutionary algorithms
Bogarra Rodríguez, Santiago; Riba Ruiz, JordiRoger; Sala Caselles, Vicenç; García Espinosa, Antonio
Due to the widespread use of electronic power converters, lowvoltage highfrequency cable models are being increasingly applied in industry, automobile or aeronautics applications among others. It is known that depending on switching frequency, cable configuration and length, transient overvoltage effects comprising a wide frequency range from dc up to several tens of MHz can appear. However, to accurately reproduce the wideband frequency response, such models often require the use of ladder networks, thus being necessary to adjust the values of a relatively large number of R, L and C components, which is a complex task. This paper is focused to solve this problem, which is done by applying an iterative genetic algorithm (IGA) optimization approach. From a set of experimental short circuit and open circuit tests the highfrequency cable model of a given cable configuration is obtained, whose parameters are fitted by means of the proposed IGAbased method. Finally, the accuracy of the model obtained is validated experimentally by comparing the frequencydomain and timedomain responses through overvoltage predictions of different samples of the analyzed cable.
20161216T09:38:19Z
Bogarra Rodríguez, Santiago
Riba Ruiz, JordiRoger
Sala Caselles, Vicenç
García Espinosa, Antonio
Due to the widespread use of electronic power converters, lowvoltage highfrequency cable models are being increasingly applied in industry, automobile or aeronautics applications among others. It is known that depending on switching frequency, cable configuration and length, transient overvoltage effects comprising a wide frequency range from dc up to several tens of MHz can appear. However, to accurately reproduce the wideband frequency response, such models often require the use of ladder networks, thus being necessary to adjust the values of a relatively large number of R, L and C components, which is a complex task. This paper is focused to solve this problem, which is done by applying an iterative genetic algorithm (IGA) optimization approach. From a set of experimental short circuit and open circuit tests the highfrequency cable model of a given cable configuration is obtained, whose parameters are fitted by means of the proposed IGAbased method. Finally, the accuracy of the model obtained is validated experimentally by comparing the frequencydomain and timedomain responses through overvoltage predictions of different samples of the analyzed cable.

Statistical study of personal computer cluster harmonic currents from experimental measurements
http://hdl.handle.net/2117/83447
Statistical study of personal computer cluster harmonic currents from experimental measurements
Mesas García, Juan José; Sainz Sapera, Luis; Sala Pérez, Pau
The net harmonic currents generated by a cluster of desktop personal computers are studied statistically. Personal computers (PCs) are singlephase nonlinear loads with low individual consumption but significant collective distortion effects, as many of them can be connected to the same bus (personal computer cluster). This article reports experimental measurements of harmonic currents injected by singlephase rectifiers and seven personal computer types during four operating modes. The probability density functions (pdfs) of the harmonic currents (magnitude and phase angle) are investigated from the measurements. An analytical procedure to obtain these probability density functions for any typical personal computer working session is described and experimentally validated. The obtained probability density functions are found to be applicable to largescale harmonic penetration statistical studies. Furthermore, attenuation and diversity effects are analyzed from the previous probability density functions, and the harmonic current cancellation effect on personal computer clusters is investigated with Monte Carlo simulations.
20160225T14:32:56Z
Mesas García, Juan José
Sainz Sapera, Luis
Sala Pérez, Pau
The net harmonic currents generated by a cluster of desktop personal computers are studied statistically. Personal computers (PCs) are singlephase nonlinear loads with low individual consumption but significant collective distortion effects, as many of them can be connected to the same bus (personal computer cluster). This article reports experimental measurements of harmonic currents injected by singlephase rectifiers and seven personal computer types during four operating modes. The probability density functions (pdfs) of the harmonic currents (magnitude and phase angle) are investigated from the measurements. An analytical procedure to obtain these probability density functions for any typical personal computer working session is described and experimentally validated. The obtained probability density functions are found to be applicable to largescale harmonic penetration statistical studies. Furthermore, attenuation and diversity effects are analyzed from the previous probability density functions, and the harmonic current cancellation effect on personal computer clusters is investigated with Monte Carlo simulations.

Lessons learned in the use of WIRIS quizzes to upgrade Moodle to solve electrical circuits
http://hdl.handle.net/2117/81933
Lessons learned in the use of WIRIS quizzes to upgrade Moodle to solve electrical circuits
Bogarra Rodríguez, Santiago; Corbalán Fuertes, Montserrat; Font Piera, Antonio; Plaza, Inma; Arcega Solsona, Francisco Javier
WIRIS quizzes is an online mathematics tool for educational purposes that
upgrades Moodle quizzes, and allows the development of personalized quizzes using
random data and conditional instructions. WIRIS quizzes can be used in any mathematics
or science degree; its complex operators allow it to be used to solve electrical circuits.
This tool promotes autonomous student learning and enables teachers to monitor that
learning and make adjustments if necessary. Therefore, this tool improves teaching
quality. It can also be used as an assessment tool by both the teacher and the student.
This paper shows how WIRIS quizzes has been integrated into the virtual campus of the
Polytechnic University of Catalonia (UPC), Spain to teach electrical circuits. Lessons
learned in performing and using WIRIS quizzes with second year students at the UPC are
shown.
20160125T09:05:18Z
Bogarra Rodríguez, Santiago
Corbalán Fuertes, Montserrat
Font Piera, Antonio
Plaza, Inma
Arcega Solsona, Francisco Javier
WIRIS quizzes is an online mathematics tool for educational purposes that
upgrades Moodle quizzes, and allows the development of personalized quizzes using
random data and conditional instructions. WIRIS quizzes can be used in any mathematics
or science degree; its complex operators allow it to be used to solve electrical circuits.
This tool promotes autonomous student learning and enables teachers to monitor that
learning and make adjustments if necessary. Therefore, this tool improves teaching
quality. It can also be used as an assessment tool by both the teacher and the student.
This paper shows how WIRIS quizzes has been integrated into the virtual campus of the
Polytechnic University of Catalonia (UPC), Spain to teach electrical circuits. Lessons
learned in performing and using WIRIS quizzes with second year students at the UPC are
shown.

Using the instantaneous power of a free acceleration test for squirrelcage motor parameters estimation
http://hdl.handle.net/2117/79352
Using the instantaneous power of a free acceleration test for squirrelcage motor parameters estimation
Kojooyan, Hengameh; Monjo Mur, Lluís; Córcoles López, Felipe; Pedra Durán, Joaquim
A new parameters determination method for squirrelcage induction motors is presented. As a main contribution, the method uses the instantaneous electrical power and the mechanical speed measured in a free acceleration test to estimate the doublecage model parameters. The parameters are estimated from the machine impedance calculated at several points. At speed points where the doublecage effect is significant, i.e., between the zero speed point and the maximum torque point, the machine impedance is evaluated by the instantaneous power method, and at speed points where the doublecage effect is not significant, i.e., between the maximum torque point and synchronism, the machine impedance is evaluated by a dynamicmodelbased linear leastsquare method. The proposed method has been applied to obtain the parameters of three motors tested in the laboratory. To check the method accuracy, the steadystate torque and currentslip curves predicted by the estimated parameters are successfully compared with those measured in the laboratory.
20151117T11:16:19Z
Kojooyan, Hengameh
Monjo Mur, Lluís
Córcoles López, Felipe
Pedra Durán, Joaquim
A new parameters determination method for squirrelcage induction motors is presented. As a main contribution, the method uses the instantaneous electrical power and the mechanical speed measured in a free acceleration test to estimate the doublecage model parameters. The parameters are estimated from the machine impedance calculated at several points. At speed points where the doublecage effect is significant, i.e., between the zero speed point and the maximum torque point, the machine impedance is evaluated by the instantaneous power method, and at speed points where the doublecage effect is not significant, i.e., between the maximum torque point and synchronism, the machine impedance is evaluated by a dynamicmodelbased linear leastsquare method. The proposed method has been applied to obtain the parameters of three motors tested in the laboratory. To check the method accuracy, the steadystate torque and currentslip curves predicted by the estimated parameters are successfully compared with those measured in the laboratory.