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Your search keyword '"Villarruel-Parra, Alejandro"' showing total 14 results
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14 results on '"Villarruel-Parra, Alejandro"'

1. Digital average-current control for the dual interleaved boost converter

Author

Villarruel-Parra, Alejandro and Forsyth, Andrew

Subjects
621.31, interleaved, dc-dc, multiphase, boost, digital, control, average-current, average, current control, dual, converter, high power, modelling, sampler decomposition, small-signal, coupled inductors, transformer
Abstract

This Thesis addressed the challenge of ensuring balanced currents in the phases of a multi-kW, interleaved dc-dc converter by means of closed-loop digital control. The Thesis examines uniformly-sampled, valley-current, peak-current and average-current control for a dual interleaved boost converter with inter-phase transformer which might form part of the power train of an electric vehicle. Also, an enhancement of the average-current control is investigated in which the transistor duty-ratio is updated more rapidly, which allows an improvement of approximately ten times in the response speed of the system. Based on the theoretical analysis, the average-current control methodology was determined to be the most suitable technique for this type of converter as it ensures well-balanced phase currents over a wide range. To provide a basis for control system analysis and design for interleaved converters, a modelling methodology is developed based on a combination of multi-rate data-sampled theory and a small-signal averaged converter model. The model is shown to represent accurately the interaction between the interleaved phases, revealing a reduced stability range compared with a non-interleaved converter. The modelling and control methods are validated using switched and average value simulations obtained with the SABER software and by experimental results from a 25 kW, 30 kHz converter prototype. The control techniques were implemented on a Texas Instruments TMS320F28335 digital signal controller.

Published
2015

11. Enhanced Average-Value Modeling of Interleaved DC?DC Converters Using Sampler Decomposition.

Author

Villarruel-Parra, Alejandro and Forsyth, Andrew J.

Subjects
*CONVERTERS (Electronics), *PREDICTION models, *TRANSFER functions, *NUCLEAR counters, *SWITCHING circuits
Abstract

To provide a basis for controller design in interleaved dc–dc converters, an improved small-signal averaged model is presented. Sampler decomposition techniques are used to represent the interleaved operation of the individual control loops within the converter. The resultant model reveals interaction effects and instability phenomena that are not predicted by a simple noninterleaved model, and which impose significant restrictions on the selection of control parameters. The model is validated by detailed simulations and experimental results from a digitally controlled dual-interleaved boost converter. [ABSTRACT FROM AUTHOR]

Published
2017
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14. Characterising the baseband impedance of supply modulators using simple modulated signals

Author

Alt, Alexander, Villarruel-Parra, Alejandro, Chen, Peng, Alsahali, Sattam, Forsyth, Andrew, Tasker, Paul J., Lees, Jonathan, Alt, Alexander, Villarruel-Parra, Alejandro, Chen, Peng, Alsahali, Sattam, Forsyth, Andrew, Tasker, Paul J., and Lees, Jonathan

Abstract

Envelope tracking is one of the promising technologies for 5G power amplifiers, providing high power efficiency over a wide output power range by modulating the supply voltage. Although the baseband impedance, the output impedance of the supply modulator, plays a crucial role in the linearity of the PA, it is often not measured or considered during the modulator design. This paper presents a new, simplified approach to characterising this impedance using a PA with a simple multi-tone modulation as a load. It describes the measurement setup and verifies the results by characterising the baseband impedance of a state-of-the-art buck converter and comparing this to its static model. The results demonstrate that multi-tone signals and complex modulations yield comparable results and are both suitable for measuring and modelling the baseband impedance. This shows that using simple multi-tone measurements and basic equipment, the full static impedance characteristic can be obtained.

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