Papers del LCDA Aceptados en Conferencia IECON 2013
Varios trabajos de investigación de los integrantes del LCDA fueron aceptados para ser presentados en la conferencia IEEE IECON 2013 que se realizará en Viena, Austria. Los títulos y resúmenes presionando en 'Ver detalles'.
IECON 2013 es la 39ª Conferencia Anual de la Sociedad Electrónica Industrial de la IEEE, centrada en la teoría y aplicaciones de la electrónica, el control, las comunicaciones, la instrumentación y la inteligencia computacional industrial y manufacturera.
Los objetivos de la conferencia son proporcionar investigación de alta calidad y la interacción profesional para el avance de la ciencia, la tecnología y el compañerismo. Se alienta a presentar papers con nuevos resultados. IECON 2013 se llevará a cabo simultáneamente con la 7ª Conferencia Internacional IEEE sobre E-Learning en Electrónica Industrial (ICELIE 2013) y el primer Taller Internacional IEEE sobre Sistemas de Energía Inteligente (IWIES 2013, un evento conjunto con el IEEE Sistemas, Hombre y Sociedad Cibernética) y el Foro de la Industria IEEE IES.
A continuación los trabajos aceptados para el IECON 2013:
'A New Modulation Technique for 15-level Asymmetric Inverter Operating with Minimum THD' de los autores Eduardo Espinosa, José Espinoza, Roberto Ramirez, Jaime Rohten y Felipe Villarroel de la U. de Concepción, en conjunto con Pedro Melín y Johan Guzmán de la U. del Bío Bío y de la U. de Talca, respectivamente.
Resumen: Multilevel inverters are the alternative for medium voltage applications. Within the inverters types there are symmetric and asymmetric topologies. The asymmetric inverters have different DC voltage values. The most common topology is when the different cells are implemented in cascade arrangement, where the DC voltage are in multiples of 3, obtaining an AC voltage with 3n = 27 levels (n = 3 cascaded inverters). This topology provides a load voltage with low harmonic content, THD < 3%. However, this high quality voltage has a non-negligible drawback, which is the presence of regeneration in some of the inverters, independent of load type.
This phenomenon is due to the modulation technique (Nearest Level Modulation) used by this inverter. In this work, the asymmetric 15 level inverter is presented. This inverter is
designed to avoid the regeneration problem - power flow from the load to the inverter - in some of the power cells. This is achieved by obtaining the firing angles associated with the power
cells considering a minimum load voltage THD. Finally, a power flow analysis is accomplished and simulated results show the feasibility of this approach.
'Finite Control Set – Model Predictive Control Applied to Multicell Rectifiers ' de los autores Eduardo Espinosa, José Espinosa, Roberto Ramirez y Marcelo Reyes de la U. de Concepción, en conjunto con Pedro Melín de la U. del Bío Bío y Javier Muñoz y Carlos Baier de la U. de Talca.
Resumen: Multi-cell converters allow the use of AC motor drives for medium and high voltage level applications using low voltage semiconductors. This type of converter has a multi-pulse
transformer which performs the cancellation of the low frequency harmonics generated by the three-phase diode rectifiers. Despite this advantage, the multi-pulse transformer is
bulky, heavy, expensive, and must be designed according to the number of power cells, making the transformer topology dependent. This work proposes to reduce the complexity of the transformer in multi-cell converters using Active Front End rectifiers in combination with a Finite Control Set – Model Predictive Control strategy. This is achieved by the strategy as it emulates the multi-pulse transformer harmonic cancellation thanks to the predictive algorithm and the generation of input current references with a phase shift angle for each Active Front End rectifier.
'Improved Steady State and Transient Behavior of Static Power Converters by Means of an Operating Mode Identifier Algorithm' de los autores E. Maurelia, J. Espinoza, R. Ramirez, M. reyes y P. Melín de la U. de Concepción, en conjunto con César A. Silva de la U. Santa María y Javier Muñoz de la U. de Talca.
Resumen: Nowadays Finite-Control-Set Model Predictive Control (FCS-MPC) is being successfully used in static power converters. The algorithm requires defining a functional in order to optimize it and thus find the best switch combination. So far the functional optimizes either the steady state or the transient operation. In fact, for steady state operation, the minimization of
the switching frequency as well as high quality waveforms are the basic objectives. Contrary, during transient conditions the settling time minimization is usually used as a basic objective.
This work presents an algorithm that is able to detect if the system is either under steady state or transient operating mode and applies the appropriate control algorithm. Hence, both operating modes are controlled under optimum conditions. Simulated results show the performance of the proposed control scheme.
'Predictive Control for Static Power Converters Working in Wide Frequency Ranges' de los autores Jaime Rohten, José Espinoza, Felipe Villarroel, Javier Muñoz, Carlos Baier, Pedro Melín y Daniel Sbarbaro de la U. de Concepción.
Resumen: Distributed and nonconventional power generation sources could lead to a wide varying grid frequency, particularly in weak systems or islanding mode operation of micro-grids.
This work studies a predictive control scheme for power converters that are directly connected to the AC network featuring large frequency variations. The proposed scheme considers a fixed number of samples per period independent of the network frequency, leading to a variable sampling time
under varying frequency conditions. This feature is advantageous when frequency has an important operating range because it ensures a constant resolution of the measured system variables. As discrete predictive control requires the sampling time to make accurate predictions, a synchronization system is proposed that ensures a fixed number of samples per cycle through continuous adjustment of the sampling time. Simulations show good performance of the proposed algorithms.
'Analysis and Design of a Cascaded H-Bridge Topology based on Current-Source Inverters ' de los autores Pedro Melín, José Espinoza, Johan Guzmán, Marco Rivera, Eduardo Espinosa y Jaime Rohten de la U. de Concepción.
Resumen: This work deals with the use of single-phase converters based on current-source inverters connected in a cascaded array (CSI-CHB) in order to get the dual topology of the classic Cascaded H-Bridged based on voltage-source inverters (CHB). The proposed configuration has similar advantages as the classic voltage source CHB as the use of semiconductors with
lower voltage rating with respect to the load voltage. Moreover the CSI-CHB load voltage has a smaller distortion than the classic CHB due to the first order capacitive filter used at the
inverters AC side. Also, the use of modulation techniques as phased-shifted carrier sinusoidal pulse modulation (PSC-SPWM) allows both, reduce the capacitive filter size and reduce the
commutation frequency of the inverter switches. A theoretical analysis of the proposed topology and design guidelines for the capacitive filter are presented, considering a desired Total
Harmonic Distortion (THD) on the load voltage and the SPWM modulation technique. Simulation results confirm the topology features.
'On the DC Inductors Size Reduction in a Multi-Cell Topology based on Current Source Converters by Means of Magnetic Couplings' de los autores Pedro E. Melín, Carlos R. Baier, José R. Espinoza, Javier A. Muñoz, Roberto O. Ramirez y Eduardo A. Maurelia de la U. de Concepción.
Resumen: This work deals with a multi-cell topology based on current-source converters based power cells. The main disadvantage of this configuration is the bulky DC inductor required in each cell which must be designed in order to compensate the oscillating power drained by the single-phase inverter. In order to avoid the use of a large DC inductor, the use of magnetic couplings among DC links of different power cells is considered. Additionally, active front end rectifiers are used in order to control the DC current and ensure a unitary displacement power factor in each power cell. A control scheme based on non-linear controllers is proposed in order to control each cell in a decoupled way. The topology feasibility is tested experimentally, while the control scheme performance is tested by simulation, showing that it is possible to obtain an excellent overall input current quality and a load voltage with lesser dv/dt than the classic multi-cell topology, reducing the requiered DC inductor from 400 mH to 30 mH for the studied case.
'A Novel Hybrid Finite Control Set Model Predictive Control Scheme with Reduced Switching' de los autores Roberto O. Ramírez, José R. Espinoza, Felipe A. Villarroel, Eduardo A. Maurelia, Marcelo E. Reyes y Eduardo E. Espinosa de la U. de Concepción.
Resumen: This work presents a new control scheme based on a finite states model predictive control aimed to fix the switching frequency and to reduce the spectrum dispersion on the output
variables of static converters while regulating the sate variables as required by the references. These topics are particularly important in the operation of power converters including filters
with resonant modes and in the overall efficiency due to the switching losses. The proposed scheme allows obtaining continuous outputs from the optimization process of MPC, thus exploiting the advantages of modulated schemes like known spectrum and fixed switching frequency. Simulated results show the proper performance of the proposed scheme, without significant reduction on the dynamic response in comparison to previous schemes using direct, non-modulated outputs.