LMI-fuzzy control design for non-minimum-phase DC-DC converters: An application for output regulation

Indexación ScopusRobust control techniques for power converters are becoming more attractive because they can meet with most demanding control goals like uncertainties. In this sense, the Takagi-Sugeno (T-S) fuzzy controller based on linear matrix inequalities (LMI) is a linear control by intervals that has been relatively unexplored for the output-voltage regulation problem in switching converters. Through this technique it is possible to minimize the disturbance rejection level, satisfying constraints over the decay rate of state variables as well as the control effort. Therefore, it is possible to guarantee, a priori, the stability of the large-signal converters in a broad operation domain. This work presents the design of a fuzzy control synthesis based on a T-S fuzzy model for non-minimum phase dc-dc converters, such as boost and buck-boost. First, starting from the canonical bilinear converters expression, a Takagi-Sugeno (T-S) fuzzy model is obtained, allowing to define the fuzzy controller structure through the parallel distributed compensation technique (PDC). Finally, the fuzzy controller design based on LMIs is solved for the defined specification in close loop through MATLAB toolbox LMI. Simulations and experimental results of a 60 W prototype are presented to verify theoretical predictions. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.https://www.mdpi.com/2076-3417/11/5/228

Model-Free Predictive Current Control of a Voltage Source Inverter

Indexación: Scopus.Conventional model predictive control (MPC) of power converter has been widely applied to power inverters achieving high performance, fast dynamic response, and accurate transient control of power converter. However, the MPC strategy is highly reliant on the accuracy of the inverter model used for the controlled system. Consequently, a parameter or model mismatch between the plant and the controller leads to a sub-optimal performance of MPC. In this paper, a new strategy called model-free predictive control (MF-PC) is proposed to improve such problems. The presented approach is based on a recursive least squares algorithm to identify the parameters of an auto-regressive with exogenous input (ARX) model. The proposed method provides an accurate prediction of the controlled variables without requiring detailed knowledge of the physical system. This new approach and is realized by employing a novel state space identification algorithm into the predictive control structure. The performance of the proposed model-free predictive control method is compared with conventional MPC. The simulation and experimental results show that the proposed method is totally robust against parameters and model changes compared with the conventional model based solutions.https://ieeexplore.ieee.org/document/926284

An Overview of Microgrids Challenges in the Mining Industry

Indexación: Scopus.The transition from fossil fuels to renewable energies as power sources in the heavy industries is one of the main climate change mitigation strategies. The carbon footprint in mining is related to its inherent extraction process, its high demand of electric power and water, and the use of diesel. However, considering its particular power requirements, the integration of microgrids throughout the whole control hierarchy of mining industry is an emergent topic. This paper provides an overview of the opportunities and challenges derived from the synergy between microgrids and the mining industry. Bidirectional and optimal power flow, as well as the integration of power quality have been identified as microgrid features that could potentially enhance mining processes. Recommendations pertaining to the technological transition and the improvement of energy issues in mining environments are also highlighted in this work.https://ieeexplore.ieee.org/document/9229426

Evaluating Power Converters using a Wind-System Simulator

10.1109/SSD.2013.6564080Urban integration of wind generators demands direct injection of the energy produced to the grid. Battery-based electrical storage is usually expensive in terms of direct cost, space, and maintenance. Direct grid-injection implies AC-AC conversion where the input source, a synchronous alternator, has a variable output voltage and frequency. This conversion is usually realized with two converters. The first stage has to accomplish a power factor corrected rectification, whereas the second one implements the DC-to-AC conversion. Different converter topologies can be proposed for both stages. To optimize the overall system, a wind-system simulator is required to make repeatable experiments. MPPT algorithms can also be examined. This paper considers the development of such experimental tool, boarding the evaluation of some three-phase PFC rectifiers