Showing papers by "Patricio Cortes published in 2013"
01 Nov 2013
TL;DR: A phase-modular isolated three-phase AC/DC converter topology and its modulation and control scheme is proposed and an analytical calculation of the component stresses is presented.
Abstract: A phase-modular isolated three-phase AC/DC converter topology and its modulation and control scheme is proposed. The topology, denominated as IMY-Rectifier, is based on a star connection of single-phase mains frequency to high frequency AC/AC matrix converters at the input, feeding high-frequency isolation transformers. The transformer secondary windings are connected in series to the input of a diode rectifier with LC output filter. The converter provides a controlled output voltage and sinusoidal input currents in phase with the mains voltages. A description of the converter, its operating principle and an analytical calculation of the component stresses is presented.
16 citations
28 Oct 2013
TL;DR: In this article, a four-leg inverter output stage uses three bridge legs to generate the phase output voltages with reference to the neutral point potential, which is defined by the fourth bridge leg.
Abstract: A control scheme for a high-performance three-phase AC power source is presented. The four-leg inverter output stage uses three bridge legs to generate the phase output voltages with reference to the neutral point potential, which is defined by the fourth bridge leg. The inverter is controlled using a phase-oriented control in order to achieve precise control of each output phase with unbalanced voltages and any kind of load. The neutral potential is controlled for maximum modulation range in case of floating load and controlled to zero for grounded load. The control scheme for the input PWM rectifier stage considers the control of the zero sequence voltage in order to prevent the appearance of circulating currents through the ground loop when the load star point is connected to ground. The control of the circulating currents also allows the safe parallel connection of two or more AC sources. Simulation results under balanced and unbalanced conditions demonstrate the performance of the AC source in terms of output voltage control and prevention of circulating ground currents.
10 citations
23 Jun 2013
TL;DR: In this paper, an inner loop power flow programming (PFP) control for buck-type SWISS rectifiers is proposed, which provides a well damped behavior of output filter and decoupled input filter and converter dynamics.
Abstract: A novel control scheme is proposed for a three-phase buck-type SWISS rectifier. This control is based on an inner loop power flow programming that provides a well damped behavior of the output filter and decoupled input filter and converter dynamics. A DC/DC equivalent circuit of the SWISS rectifier is used for the analysis and evaluation of different control concepts for the switching stage of the converter. By using different feedforward loops for the calculation of the duty cycles the behavior of the converter can be modified to suit a desired characteristic. In this way, the converter can be programmed for constant voltage transfer ratio, constant output voltage, constant power transfer or other input/output relations. A comparative evaluation of different inner loop control schemes is presented. The control schemes are compared analytically using small-signal linear models. The comparison considers the dynamic behavior as well as the decoupling of the input and output variables. Simulation results using the DC/DC equivalent circuit model and the actual three-phase SWISS rectifier are presented. According to the results, the PFP control achieves an improved behavior of the converter in terms of damping of the resonances and decoupling of the input and output variables, compared to the other control schemes.
6 citations