Alarcon Gallo, Eduardo
Total activity: 5
Research group
SEPIC - Power and Control Electronics Systems
Department
Department of Electronic Engineering
E-mail
eduardo.alarcon-galloestudiant.upc.edu
Contact details
UPC directory Open in new window

Graphic summary
  • Show / hide key
  • Information


Scientific and technological production
  •  

1 to 5 of 5 results
  • A study on multi-level PWM and asynchronous Sigma Delta modulations for enhanced bandlimited signal tracking in switching power amplifiers

     Garcia Tormo, Albert; Poveda Lopez, Alberto; Alarcon Gallo, Eduardo; Guinjoan Gispert, Francisco
    IEEE transactions on circuits and systems I: regular papers
    Vol. 60, num. 6, p. 1621-1634
    DOI: 10.1109/TCSI.2012.2220463
    Date of publication: 2013-06
    Journal article

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    This work deals with multi-level switching amplifiers, in the context of high-efficiency power amplification for signal tracking applications. In particular, this paper evaluates the reduction in the error signal's power due to multi-level power amplification (compared to conventional two-level amplifiers) and compares the performance of two multi-level pulse modulations: PWM and Asynchronous Modulation. First the intrinsic bandwidth limits of multi-level switching amplifiers are inferred, to clearly state the advantages and limitations of multi-level power amplification. From the existing analyses of Pulse Width Modulation already reported in the literature, PWM is herein extended to multiple levels based on an equivalent representation, which allows to derive a closed expression for the power spectrum of multi-level PWM in bandlimited signal tracking. The Asynchronous Modulation is extended to multiple levels and the resulting multi-level encoding algorithm is analyzed in both time and frequency domains. The performance of both modulations is characterized and compared at different operating frequencies and using different number of levels. The main outcomes of this in-depth characterization show that, if the switching frequency is high enough, the tracking error is independent of the modulation and the switching frequency, i.e., it only depends upon the number of levels, which points out the suitability of asynchronous modulations for relatively low switching frequencies (compared to the number of levels).

    This work deals with multi-level switching amplifiers, in the context of high-efficiency power amplification for signal tracking applications. In particular, this paper evaluates the reduction in the error signal's power due to multi-level power amplification (compared to conventional two-level amplifiers) and compares the performance of two multi-level pulse modulations: PWM and Asynchronous ${{Sigma}} {{Delta}}$ Modulation. First the intrinsic bandwidth limits of multi-level switching amplifiers are inferred, to clearly state the advantages and limitations of multi-level power amplification. From the existing analyses of Pulse Width Modulation already reported in the literature, PWM is herein extended to multiple levels based on an equivalent representation, which allows to derive a closed expression for the power spectrum of multi-level PWM in bandlimited signal tracking. The Asynchronous ${{Sigma}} {{Delta}}$ Modulation is extended to multiple levels and the resulting multi-level encoding algorithm is analyzed in both time and frequency domains. The performance of both modulations is characterized and compared at different operating frequencies and using different number of levels. The main outcomes of this in-depth characterization show that, if the switching frequency is high enough, the tracking error is independent of the modulation and the switching frequency, i.e., it only depends upon the number of levels, which points out the suitability of asynchronous modulations for relatively low switching frequencies (compared to the number of levels).

  • Flexible voltage support control for three-phase distributed generation inverters under grid fault

     Camacho Santiago, Antonio; Castilla Fernandez, Miguel; Miret Tomas, Jaume; Vasquez Quintero, Juan Carlos; Alarcon Gallo, Eduardo
    IEEE transactions on industrial electronics
    Vol. 60, num. 4, p. 1429-1441
    DOI: 10.1109/TIE.2012.2185016
    Date of publication: 2013-04
    Journal article

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    Ancillary services for distributed generation (DG)systems become a challenging issue to smartly integrate renewable-energy sources into the grid. Voltage control is one of these ancillary services which can ride through and support the voltage under grid faults. Grid codes fromthe transmission system operators describe the behavior of the energy source, regulating voltage limits and reactive power injection to remain connected and support the grid under fault. On the basis that different kinds of voltage sags require different voltage support strategies, a flexible control scheme for three-phase grid-connected inverters is proposed. In three-phase balanced voltage sags, the inverter should inject reactive power in order to raise the voltage in all phases. In one- or two-phase faults, the main concern of the DG inverter is to equalize voltages by reducing the negative symmetric sequence and clear the phase jump. Due to system limitations, a balance between these two extreme policies is mandatory. Thus, over- and undervoltage can be avoided, and the proposed control scheme prevents disconnection while achieving the desired voltage support service. The main contribution of this work is the introduction of a control algorithm for reference current generation that provides flexible voltage support under grid faults. Two different voltage sags have been experimentally tested to illustrate the behavior of the proposed voltage support control scheme.

  • Fast grid synchronization technique based on a multiple cascaded general integrator scheme for distributed generation inverters

     Matas Alcala, Jose; Castilla Fernandez, Miguel; Garcia de Vicuña Muñoz de la Nava, Jose Luis; Miret Tomas, Jaume; Alarcon Gallo, Eduardo; Camacho Santiago, Antonio
    IEEE International Symposium on Industrial Electronics
    p. 1003-1010
    DOI: 10.1109/ISIE.2012.6237226
    Presentation's date: 2012
    Presentation of work at congresses

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    This paper proposes a new structure for grid synchronization based on generalized integrators (GI) that lead to fast detection of positive and negative components of the grid voltage. The GI are used as a band pass filter (GI-BPF) mainly to provide in-phase and quadrature components of grid voltage. The proposed structure consists in the cascaded connection of multiple GI-BPF to achieve a faster time response than a single GI-BPF but with the same bandwidth characteristics. This structure is used with a frequency locked loop and a positive sequence detector to operate under unbalanced voltage sags. Simulations and experimental results of a photovoltaic power system injecting power to the grid in the stationary reference frame are shown to validate this proposal. Comparisons between this proposal and one that uses a single GI-BPF in the sequence detector are provided. The results show that the proposed cascaded GI-BPF achieves a considerably time response reduction in the sequence grid detection under a fault with the same quality-filter characteristics.

  • Coordinated reactive power control for static synchronous compensators under unbalanced voltage sags

     Castilla Fernandez, Miguel; Miret Tomas, Jaume; Camacho Santiago, Antonio; Matas Alcala, Jose; Alarcon Gallo, Eduardo; Garcia de Vicuña Muñoz de la Nava, Jose Luis
    IEEE International Symposium on Industrial Electronics
    p. 987-992
    DOI: 10.1109/ISIE.2012.6237223
    Presentation's date: 2012
    Presentation of work at congresses

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    Unbalanced voltage sags strongly deteriorate the performance of power converters and electrical machines connected to the distribution network. In particular, a reduction of the power quality is noticed in these equipments, which is caused by a ripple in the output power and an increase of the current harmonic distortion. Several solutions based on reactive power compensation have been introduced to cope with this problem. Among them, static synchronous compensators have confirmed the superior performance due to the possibility of using all rated power exclusively to voltage support. This paper presents a simple reactive power control algorithm for static synchronous compensators operating under unbalanced voltage sags. The main feature of the proposed algorithm is that it allows a fine adjustment of the amount of reactive power injected by the positive- and negative-sequence components. Thus the control algorithm provides voltage support at the output of the static synchronous compensator. Specifically the proposed control conveniently corrects both the positive- and negative-sequence voltage. Selected simulation results are provided to validate the proposal.

  • Decoupled sliding mode control for three-phase LCL VSI operating at fixed switching frequency

     Alarcon Gallo, Eduardo; Garcia de Vicuña Muñoz de la Nava, Jose Luis; Castilla Fernandez, Miguel; Miret Tomas, Jaume; Matas Alcala, Jose; Camacho Santiago, Antonio
    IEEE International Symposium on Industrial Electronics
    p. 1572-1578
    DOI: 10.1109/ISIE.2012.6237326
    Presentation's date: 2012
    Presentation of work at congresses

    View View Open in new window  Share Reference managers Reference managers Open in new window