BUSCADOR RECOLECTA

This work deals with the design of a Fuzzy Logic Control (FLC) based Energy Management
System (EMS) for smoothing the grid power prole of a grid-connected electro-thermal microgrid. The
case study aims to design an Energy Management System (EMS) to reduce the impact on the grid power
when renewable energy sources are incorporated to pre-existing grid-connected household appliances. The
scenario considers a residential microgrid comprising photovoltaic and wind generators, at-plate collectors,
electric and thermal loads and electrical and thermal energy storage systems and assumes that neither
renewable generation nor the electrical and thermal load demands are controllable. The EMS is built through
two low-complexity FLC blocks of only 25 rules each. The first one is in charge of smoothing the power
prfile exchanged with the grid, whereas the second FLC block drives the power of the Electrical Water
Heater (EWH). The EMS uses the forecast of the electrical and thermal power balance between generation
and consumption to predict the microgrid behavior, for each 15-minute interval, over the next 12 hours.
Simulations results, using real one-year measured data show that the proposed EMS design achieves 11.4%
reduction of the maximum power absorbed from the grid and an outstanding reduction of the grid power
profile ramp-rates when compared with other state-of-the-art studies., This work was supported in part by the projects 2019-PIC-003-CTE and 2020-EXT-007 from the Research Group of Propagation,
Electronic Control, and Networking (PROCONET) of Universidad de las Fuerzas Armadas ESPE, in part by the Belgian Development
Cooperation (DGD) and the VLIR-UOS under the project EC2020SIN322A101, in part by the Spanish Ministry of Industry and
Competitiveness under Grant DPI2017-85404 and Grant PID2019-111443RB-100, and in part by the Spanish State Research Agency
(AEI/10.13039/501100011033) under Grant PID2019-110816RB-C21 and Grant PID2019-111262RB-I00.

In this paper, the quadratic buck converter (QBC) is proposed as competitive alternative to implement a battery charger. Since QBC is a high order system, the required control is designed to follow the conventional constant-current constant-voltage protocol by means of three loops. Namely, 1) an inner-loop operating in sliding mode to control the current of the closest inductor to the input port providing the proper stability of the system, 2) a first outer loop designed to regulate the battery voltage providing the reference of the inner loop, and finally 3) a second outer loop to regulate the battery current modifying the reference of the voltage loop. Proportional Integral (PI) controllers are used in both outer loops, one of them synthesized by means of the robust loop shaping M-constrained integral gain optimization (RLS-MIGO) method, and the other designed using classical considerations for cascaded controllers. Both simulation and experimental results are presented validating the theoretical study and confirming the feasibility of the proposed control by means of analogue electronics., This work was supported in part by Universidad Santo Tomás, Colombia, under Contract 2024-AI026; in part by Spanish Ministerio de Ciencia, Innovación y Universidades (MICIU) through grant PID2019-111443RB-I00, in part through the grant MSCA IF EF-ST 2020/PCI2021-122066-2B financed by MICIU/AEI/10.13039/501100011033 and by the European Union NextGeneration EU/PRTR; in part through the project PID2023-150839OB-I00 financed by MICIU/AEI/10.13039/501100011033 and FEDER, UE; in part by the Agencia Nacional de Investigación y Desarrollo (ANID) through projects FONDECYT Iniciación 11220863; and in part by the Solar Energy Research Center (SERC) Chile (CONICYT/FONDAP/1523A0006).

This paper analyzes for the first time a two-loop sliding-mode control (SMC) of a high-order converter supplying a constant power load (CPL). The converter is a single- switch quadratic buck structure (QBC) interfacing a domestic 380 V DC bus to a CPL requiring a regulated voltage of 48 V DC. The converter is unstable in the absence of control and even after the insertion of an inner loop based on SMC of the input inductor current. The addition of an appropriate linear outer loop establishing the reference to the inner loop stabilizes the system and provides output voltage regulation. The regulated QBC shows a fast recovery of the output voltage with negligible overshoot in response to step-type changes of the output power or the input voltage. It is also shown that the implemented regulator for CPL supply can be used directly in the case of a constant current load (CCL) or a constant resistance load (CRL) resulting in similar performance to the CPL case. PSIM simulations and experimental results in a 400 W prototype are in good agreement with theoretical predictions., This work was supported in part by the Universidad Santo Tomás, Colombia, Proyecto Semillero, under Contract 2054506; in part by the Spanish Ministerio de Ciencia e Innovación under Grant PID2019-111443RB-I00; and in part by the Agencia Nacional de Investigación y Desarrollo (ANID) through projects FONDECYT Iniciación and SERC Chile, under Grant 11220863 and Grant CONICYT/FONDAP/15110019, respectively.