Hybrid Control of DC-DC Power Converters

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Editorial for the Special Issue on Emerging Power Electronics Technologies for Sustainable Energy Conversion

Power electronic (PE) technology became considered a mature technology over the last century [...

Sample-Data Modeling of a Zero Voltage Transition DC-DC Converter for On-Board Battery Charger in EV

Battery charger is a key device in electric and hybrid electric vehicles. On-board and off-board topologies are available in the market. Lightweight, small, high performance, and simple control are desired characteristics for on-board chargers. Moreover, isolated single-phase topologies are the most common system in Level 1 battery charger topologies. Following this trend, this paper proposes a sampled-data modelling strategy of a zero voltage transition (ZVT) DC-DC converter for an on-board battery charger. A piece-wise linear analysis of the converter is the basis of the technique presented such that a large-signal model and, therefore, a small-signal model of the converter are derived. Numerical and simulation results of a 250 W test rig validate the model

Robust Stabilization of Linear Switched Systems with Unstable Subsystems

This paper deals with the robust stability of a class of uncertain switched systems with possibly unstable linear subsystems. In particular, conditions for global uniform exponential stability are presented. In addition, a procedure to design a mode dependent average dwell time switching signal that stabilizes a switched linear system composed of diagonalizable subsystems is established, even if all of them are stable/unstable and time-varying (within design bounds). An illustrative example of the stabilizing switching law design and numerical results are presented

Switched Polytopic Controller Applied on a Positive Reconfigurable Power Electronic Converter

The reconfigurable power electronic converters (RPECs) are a new generation of systems, which modify their physical configuration in terms of a desired input or output operation characteristic. This kind of converters is very attractive in terms of versatility, compactness, and robustness. They have been proposed in areas such as illumination, transport electrification (TE), eenewable energy (RE), smart grids and the internet of things (IoT). However, the resulting converters operate in switched variable operation-regions, rather than over single operation points. As a result, there is a complexity increment on the modeling and control stage such that traditional techniques are no longer valid. In order to overcome these challenges, this paper proposes a kind of switched polytopic controller (SPC) suitable to stabilize an RPEC. Modeling, control, numerical and practical results are reported. To this end, a 400 W positive synchronous bi-directional buck/boost converter is used as a testbed. It is also shown, that the proposed converter and robust controller accomplish a compact, modular and reliable design during different working configuration, operation points and load changes

Design and Implementation of a Germicidal UVC-LED Lamp

In the last years, low pressure ozone UVC mercury germicidal lamps have been widely used to decontaminate air, surfaces, and water. This technology is mature, and it has been widely used during the pandemic as a measure against SARS-CoV-2, the coronavirus that causes COVID-19; because the exposure of this virus to the wavelength wave of 254 nm has been proven to be an effective way to eliminate it. However, the Minamata Convention in 2013 decided to limit mercury lamps by 2020; therefore, the development of new technology devices based on UVC-LEDs (short-wave ultraviolet, light-emitting diodes) are receiving a lot of attention. Today, this technology is commercially available from 265 to 300 nm peak wavelengths, and recently up to 254 nm. Notwithstanding, due to the characteristics of these LEDs, arrangements with a precisely dosed power supply are regularly required to provide effective decontamination. Thus, this article reports the design and implementation of a power electronic converter for an array of 254 nm UVC-LEDs, which can be used to decontaminate from SARS-CoV-2 in a safe way

DSP-HIL Comparison between IM Drive Control Strategies

Due to their high robustness and simple maintenance, induction motors (IM) are commonly applied in household appliances and industry. Recently, advanced control techniques are being applied to traditional controllers such as field-oriented control (FOC) and torque control (DTC). Dynamic performance improvement, hardware simplification and software resource reduction are some of the characteristics reported by these advanced techniques, where a comparison of the new proposal with a traditional structure is generally reported for its validation. However, an assessment between advanced techniques is usually missing. Therefore, we evaluated the traditional FOC and DTC with two additional advanced control modifications, fuzzy and predictive. The resulting six structures were numerically evaluated using MATLAB SIMULINK in a 5 HP four-pole three-phase IM and practically validated using hardware-in-the-loop (Typhoon HIL 402 and DSP TMS320F28035). Speed, torque, phase current and flux response are reported for the six controllers and practical insights are summarized

On the n-Dimensional Phase Portraits

The phase portrait for dynamic systems is a tool used to graphically determine the instantaneous behavior of its trajectories for a set of initial conditions. Classic phase portraits are limited to two dimensions and occasionally snapshots of 3D phase portraits are presented; unfortunately, a single point of view of a third or higher order system usually implies information losses. To solve that limitation, some authors used an additional degree of freedom to represent phase portraits in three dimensions, for example color graphics. Other authors perform states combinations, empirically, to represent higher dimensions, but the question remains whether it is possible to extend the two-dimensional phase portraits to higher order and their mathematical basis. In this paper, it is reported that the combinations of states to generate a set of phase portraits is enough to determine without loss of information the complete behavior of the immediate system dynamics for a set of initial conditions in an n-dimensional state space. Further, new graphical tools are provided capable to represent methodically the phase portrait for higher order systems