Ponències/Comunicacions de congressos
http://hdl.handle.net/2117/3834
2017-01-19T09:16:36ZDiscontinuous modulation of modular multilevel converters without the need for extra submodules
http://hdl.handle.net/2117/87610
Discontinuous modulation of modular multilevel converters without the need for extra submodules
Picas Prat, Ricard; Ceballos Recio, Salvador; Pou Félix, Josep; Zaragoza Bertomeu, Jordi; Konstantinou, Georgios; Agelidis, Vassilios; Balcells Sendra, Josep
2016-06-01T14:25:48ZPicas Prat, RicardCeballos Recio, SalvadorPou Félix, JosepZaragoza Bertomeu, JordiKonstantinou, GeorgiosAgelidis, VassiliosBalcells Sendra, JosepUtilising redundant voltage levels for circulating current control in modular multilevel converters
http://hdl.handle.net/2117/87608
Utilising redundant voltage levels for circulating current control in modular multilevel converters
Konstantinou, Georgios; Pou Félix, Josep; Ceballos Recio, Salvador; Picas Prat, Ricard; Zaragoza Bertomeu, Jordi; Agelidis, Vassilios
2016-06-01T14:19:35ZKonstantinou, GeorgiosPou Félix, JosepCeballos Recio, SalvadorPicas Prat, RicardZaragoza Bertomeu, JordiAgelidis, VassiliosMathematical efficiency modeling of static power converters
http://hdl.handle.net/2117/87487
Mathematical efficiency modeling of static power converters
Hoff Dupont, Fabrício; Zaragoza Bertomeu, Jordi; Rech, Cassiano; Pinheiro, José Renes
This paper presents a review and a comparative
analysis between mathematical models for the efficiency of power
converters. Two different types of models are considered, being
one for converters subject solely for output power variations,
and a second one also considering input voltage variations. Both
cases are particularly important for systems fed by renewable
sources as photovoltaic panels or wind turbines. Knowledge of
the appropriate models is of interest in the development of
high-performance systems, allowing one to optimize the global
efficiency of the converter system. Experimental results concludes
the comparison between the investigated models and a discussion
of pros and cons of each model are presented, providing to
authors a better choice for modeling the efficiency behavior of
power converters.
2016-05-30T12:25:01ZHoff Dupont, FabrícioZaragoza Bertomeu, JordiRech, CassianoPinheiro, José RenesThis paper presents a review and a comparative
analysis between mathematical models for the efficiency of power
converters. Two different types of models are considered, being
one for converters subject solely for output power variations,
and a second one also considering input voltage variations. Both
cases are particularly important for systems fed by renewable
sources as photovoltaic panels or wind turbines. Knowledge of
the appropriate models is of interest in the development of
high-performance systems, allowing one to optimize the global
efficiency of the converter system. Experimental results concludes
the comparison between the investigated models and a discussion
of pros and cons of each model are presented, providing to
authors a better choice for modeling the efficiency behavior of
power converters.Reducing circulating currents in interleaved converter legs under selective harmonic elimination pulse-width modulation
http://hdl.handle.net/2117/77278
Reducing circulating currents in interleaved converter legs under selective harmonic elimination pulse-width modulation
Konstantinou, Georgios; Pou Félix, Josep; Capellá Frau, Gabriel José; Ceballos Recio, Salvador; Agelidis, Vassilios
Interleaving of voltage source converter legs enables higher output currents per phase, effectively increasing the power rating without increasing semiconductor ratings. Different switching patterns between the converter legs increase the number of Thevenin output voltage levels and, hence, the quality of the waveform but also generate circulating currents within one phase. This paper proposes a controller for interleaved converter legs under selective harmonic elimination pulse-width modulation (SHE-PWM) aimed at reducing the circulating current within the legs of each phase. The controller is used in combination with optimally selected SHE-PWM patterns to minimise the peak value of the circulating current. The proposed controller is applied in two interleaved three-level active neutral-point-clamped converters and simulation results demonstrate their performance.
2015-10-02T08:26:54ZKonstantinou, GeorgiosPou Félix, JosepCapellá Frau, Gabriel JoséCeballos Recio, SalvadorAgelidis, VassiliosInterleaving of voltage source converter legs enables higher output currents per phase, effectively increasing the power rating without increasing semiconductor ratings. Different switching patterns between the converter legs increase the number of Thevenin output voltage levels and, hence, the quality of the waveform but also generate circulating currents within one phase. This paper proposes a controller for interleaved converter legs under selective harmonic elimination pulse-width modulation (SHE-PWM) aimed at reducing the circulating current within the legs of each phase. The controller is used in combination with optimally selected SHE-PWM patterns to minimise the peak value of the circulating current. The proposed controller is applied in two interleaved three-level active neutral-point-clamped converters and simulation results demonstrate their performance.Modelling harmonics drawn by nonlinear loads
http://hdl.handle.net/2117/76228
Modelling harmonics drawn by nonlinear loads
Lamich Arocas, Manuel; Balcells Sendra, Josep; Mon González, Juan; Corbalán Fuertes, Montserrat; Griful Ponsati, Eulàlia
This paper is devoted to obtain a model of
nonlinear loads (NLL) connected to LV electric networks, in
order to predict the consequences of including parallel active or
passive filters. The model is based on Neural Networks (NNs) and
its purpose is the prediction of harmonic currents generated by a
certain load when supplied by a network with significant series
impedance, disturbed by other random and unknown neighbour
loads. The NNs have been trained by using data obtained from
several circuit simulations of a network supplying several
unknown neighbour loads beside the load of interest, consisting
of a set of rectifiers. The model is validated using the same
network structure, with different neighbour loads and different
load conditions.
2015-07-20T11:37:01ZLamich Arocas, ManuelBalcells Sendra, JosepMon González, JuanCorbalán Fuertes, MontserratGriful Ponsati, EulàliaThis paper is devoted to obtain a model of
nonlinear loads (NLL) connected to LV electric networks, in
order to predict the consequences of including parallel active or
passive filters. The model is based on Neural Networks (NNs) and
its purpose is the prediction of harmonic currents generated by a
certain load when supplied by a network with significant series
impedance, disturbed by other random and unknown neighbour
loads. The NNs have been trained by using data obtained from
several circuit simulations of a network supplying several
unknown neighbour loads beside the load of interest, consisting
of a set of rectifiers. The model is validated using the same
network structure, with different neighbour loads and different
load conditions.Del reto al proyecto una nueva experiencia docente en el marco del Espacio Europeo de Educacion Superior
http://hdl.handle.net/2117/26840
Del reto al proyecto una nueva experiencia docente en el marco del Espacio Europeo de Educacion Superior
Jaen Fernandez, Carles; Hervada Sala, Carme; Lamich Arocas, Manuel; Corbalán Fuertes, Montserrat; Pou Félix, Josep; Arias Pujol, Antoni
2015-03-19T12:35:07ZJaen Fernandez, CarlesHervada Sala, CarmeLamich Arocas, ManuelCorbalán Fuertes, MontserratPou Félix, JosepArias Pujol, AntoniLead current reduction in a three phase four wires Shunt Hybrid Filter
http://hdl.handle.net/2117/26801
Lead current reduction in a three phase four wires Shunt Hybrid Filter
Lamich Arocas, Manuel; Balcells Sendra, Josep; Castillo Martínez, Jose Luis; Pérez Robles, Daniel
2015-03-18T12:49:40ZLamich Arocas, ManuelBalcells Sendra, JosepCastillo Martínez, Jose LuisPérez Robles, DanielCoupled interleaved multicellular parallel converters operated under switching frequency modulation
http://hdl.handle.net/2117/26781
Coupled interleaved multicellular parallel converters operated under switching frequency modulation
Mon González, Juan; González Díez, David; Gautier, Cirylle; Labrousse, Denis; Costa, François
The Coupled Interleaved Multicellular Parallel (CIMP) topology is the subject of intense research
because of its advantages in terms of systems integration, power density increase, low level of EMI
emissions and dynamic performance. This paper evaluates the viability of application of switching
frequency modulation techniques to CIMP topology.
2015-03-18T09:02:47ZMon González, JuanGonzález Díez, DavidGautier, CirylleLabrousse, DenisCosta, FrançoisThe Coupled Interleaved Multicellular Parallel (CIMP) topology is the subject of intense research
because of its advantages in terms of systems integration, power density increase, low level of EMI
emissions and dynamic performance. This paper evaluates the viability of application of switching
frequency modulation techniques to CIMP topology.Improvement of driver to gate coupling circuits for SiC MOSFETS
http://hdl.handle.net/2117/26763
Improvement of driver to gate coupling circuits for SiC MOSFETS
Balcells Sendra, Josep; Mon González, Juan; Lamich Arocas, Manuel; Laguna, Alberto
This work presents a study of the influence of different gate driver circuits on the switching behavior of SiC MOSFET devices used in a buck converter. The paper is based on several tests performed to determine the switching times and switching losses, using different reverse bias VGS voltage levels and different passive RCD (Resistance Capacitor Diode) circuits to interface the driver to the SiC MOSFET gate.
2015-03-17T14:18:07ZBalcells Sendra, JosepMon González, JuanLamich Arocas, ManuelLaguna, AlbertoThis work presents a study of the influence of different gate driver circuits on the switching behavior of SiC MOSFET devices used in a buck converter. The paper is based on several tests performed to determine the switching times and switching losses, using different reverse bias VGS voltage levels and different passive RCD (Resistance Capacitor Diode) circuits to interface the driver to the SiC MOSFET gate.A comparative study between Elliptic Fourier and B-spline descriptors for object contour representation
http://hdl.handle.net/2117/26572
A comparative study between Elliptic Fourier and B-spline descriptors for object contour representation
Ferrer Arnau, Luis Jorge; Parisi Baradad, Vicenç; Soria Pérez, José Antonio; Nasreddine, Kamal; Benzinou, Abdesslam
In this work, a comparative study between Elliptic
Fourier and B-spline descriptors is carried out for comparing
their efficiency in characterizing the contour shape of image
objects. In both cases, the goal is to obtain the least
representation error using the fewest possible number of
coefficients. With Fourier descriptors, different number of
harmonics are used while the remaining ones are set to zero. In
the B-spline case, coefficients are obtained iteratively using a
least-square filter, followed by a decimation procedure. Linear
and cubic B-splines are considered. In general, data will be more
compressed when the lower number of coefficients is used, but
the representation error also increases considerably. We use a
signal/error ratio, expressed in dBs, to measure the similarity of
each approximation. The signal value is obtained from the
‘modulo’ addition of all coordinate points, whereas the error
value is computed accumulating the ‘modulo’ distance between
original and reconstructed shape. It can be shown that for a
lower compression rate, the results do not vary significantly in all
three methods. For higher compression rates, Elliptic Fourier
Descriptors are more efficient than linear and cubic B-splines,
especially in soft contours, but B-splines have lower
computational cost.
2015-03-04T08:44:19ZFerrer Arnau, Luis JorgeParisi Baradad, VicençSoria Pérez, José AntonioNasreddine, KamalBenzinou, AbdesslamIn this work, a comparative study between Elliptic
Fourier and B-spline descriptors is carried out for comparing
their efficiency in characterizing the contour shape of image
objects. In both cases, the goal is to obtain the least
representation error using the fewest possible number of
coefficients. With Fourier descriptors, different number of
harmonics are used while the remaining ones are set to zero. In
the B-spline case, coefficients are obtained iteratively using a
least-square filter, followed by a decimation procedure. Linear
and cubic B-splines are considered. In general, data will be more
compressed when the lower number of coefficients is used, but
the representation error also increases considerably. We use a
signal/error ratio, expressed in dBs, to measure the similarity of
each approximation. The signal value is obtained from the
‘modulo’ addition of all coordinate points, whereas the error
value is computed accumulating the ‘modulo’ distance between
original and reconstructed shape. It can be shown that for a
lower compression rate, the results do not vary significantly in all
three methods. For higher compression rates, Elliptic Fourier
Descriptors are more efficient than linear and cubic B-splines,
especially in soft contours, but B-splines have lower
computational cost.