In this paper, an energy management strategy based on microgrid power forecasting is applied to a residential grid-connected electro-thermal microgrid with the aim of smoothing the power profile exchanged with the grid. The microgrid architecture under study considers electrical and thermal renewable generation, energy storage system (ESS), and loads. The proposed strategy manages the energy stored in the ESS to cover part of the energy required by the thermal generation system for supplying domestic hot water to the residence. The simulation results using real data and the comparison with previous strategy have demonstrated the effectiveness of the proposed strategy., This work is part of the project 2016-PIC-044 and 2018-REV-003 from the Research Group of Propagation, Electronic Control, and Networking (PROCONET) of Universidad de las Fuerzas Armadas ESPE. This work has been partially supported by the Spanish Ministry of Science, Innovation and Universities: grants DPI2013-41224-P, DPI2015-67292, DPI2016-80641-R, and DPI2017-85404-P.

This paper presents the design of a low complexity fuzzy logic controller of only 25-rules to be embedded in an energy management system for a residential grid-connected microgrid including renewable energy sources and storage capability. The system assumes that neither the renewable generation nor the load demand is controllable. The main goal of the design is to minimize the grid power profile fluctuations while keeping the battery state of charge within secure limits. Instead of using forecasting-based methods, the proposed approach use both the microgrid energy rate-of-change and the battery state of charge to increase, decrease, or maintain the power delivered/absorbed by the mains. The controller design parameters (membership functions and rule-base) are adjusted to optimize a pre-defined set of quality criteria of the microgrid behavior. A comparison with other proposals seeking the same goal is presented at simulation level, whereas the features of the proposed design are experimentally tested on a real residential microgrid implemented at the Public University of Navarre., This work was supported in part by the Secretaría Nacional de Educación Superior, Ciencia, Tecnología e Innovación SENESCYT and the Instituto de Fomento al Talento Humano del Ecuador under Grant 2013-AR2Q4081; in part by the Government of Navarra and the European Regional Development Fund under the Microgrids in Navarra: Design, Development, and Implementation Project; in part by the Spanish Ministry of Economy and Competitiveness under Grant DPI2013-42853-R; in part by the European Union under Project FP7-308468; in part by PVCROPS—Photovoltaic Cost Reduction, Reliability, Operational Performance, Prediction, and Simulation under Grant RUE CSD2009-00046; in part by the Consolider-Ingenio 2010 Programme; in part by the Spanish Ministry of Science and Innovation; and in part by the Spanish Ministry of Economy and Knowledge under Grant DPI2013-41224-P and Grant DPI2012-31580. Paper no. TSG-00712-2015.

This paper presents the design of an energy management strategy based on a low complexity Fuzzy Logic Control (FLC) for grid power profile smoothing of a residential grid-connected microgrid including Renewable Energy Sources (RES) and battery Energy Storage System (ESS). The proposed energy management strategy uses generation and demand forecasting to anticipate the future behavior of the microgrid. Accordingly to the microgrid power forecast error and the Battery State-of-Charge (SOC) the proposed strategy performs the suitable control of the grid power. A simulation comparison with previous energy management strategies highlights the advantages of the proposed work minimizing fluctuations and power peaks in the power profile exchanged with the grid while keeping the energy stored in the battery between secure limits. Finally, the experimental validation in a real residential microgrid implemented at Public University of Navarre (UPNA, Spain) demonstrates the proper operation of the proposed strategy achieving a smooth grid power profile and a battery SOC center close to the 75% of the rated battery capacity., This work is part of the project 2016-PIC-044 from the Universidad de las Fuerzas Armadas ESPE. This work was partially supported by the Spanish State Research Agency (AEI) and FEDER-UE under grants: DPI2015-67292, DPI2013-41224-P, DPI2013-42853-R and DPI2016-80641-R.

[Resumen] Un Control Adaptativo por Modelo de Referencia (MRAC) con Síntesis de Controlador Mínima (MCS), es desarrollado con el objetivo de controlar un Inversor monofásico basado en un Filtro LCL conectado a la Red Eléctrica y adaptar el inductor de la red, que es un parámetro desconocido y que genera incertidumbre, manteniendo las prestaciones y la robustez del sistema. Para ello primero se revisara el algoritmo de MCS y en función de este, se muestran todos los pasos a seguir y el desarrollo de los componentes necesarios para el funcionamiento de MCS en tiempo continuo. Se desarrolla un modelo de simulación promediado y se presentan los resultados obtenidos., Este trabajo ha sido realizado gracias al apoyo de la Secretaría Nacional de Educación Superior, Ciencia y Tecnología e Innovación del Ecuador (SENESCYT), a la Universidad de Cuenca, y a los proyectos DPI2013-41224-P y DPI2015-69286-C3-2-R (MINECO/FEDER) y 2014 SGR 267 de la agencia AGAUR de la Generalitat de Catalunya, Generalitat de Catalunya; 2014 SGR 267, https://doi.org/10.17979/spudc.9788497498081

© 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works, This paper presents a novel active damping technique of current-controlled grid-connected power converters through LCL filters. Based on H8 synthesis algorithms, a grid current controller is obtained so that the grid-connected power converted-based application admittance resembles a given frequency reference. By defining a low resistive admittance as the reference, considered application resonance is effectively damped, reducing grid current oscillations under grid voltage variations and avoiding their associated stability problems. Presented grid current controller senses only the PCC grid voltage and current, and is experimentally tested in both time and frequency domains. Additionally, the effectiveness of presented damping method is proved under different grid impedance scenarios.

Este artículo presenta un nuevo método para es tablecer las condiciones que extienden el rango de estabilidad local de circuitos eléctricos de corriente continua con cargas de potencia constante a todo el rango de existencia de equilibrios. La técnica se basa en el análisis de estabilidad en el dominio de la frecuencia y en la propiedad de los sistemas negativo imaginarios trabajando sobre el sistema linealizado alrededor de un equilibrio. La condición suficiente obtenida por este método se expresa mediante desigualdades matriciales lineales que pueden ser verificadas mediante programación convexa. Se analizan dos ejemplos, cuando la carga de potencia constante i) es ideal, y ii) considerando que tiene una dinámica de primer orden. Este método puede ser extendido a redes con varias cargas de potencia constante (caso multipuerto).

© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting /republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works, This paper explores the problem of stability of linear time-invariant (LTI), multi-port AC circuits with instantaneous constant-power loads (CPLs), which model the behavior of some point-of-load converters. It is well-known that CPLs have a destabilizing effect that gives rise to significant oscillations or to network collapse, see [3]–[5], [7], and the references therein for a further discussion on the subject and [8] for a recent literature review. Clearly, a sine qua non condition for the correct behaviour of the network is the existence of a steady-state operating condition., Peer Reviewed

This work presents the control design guidelines of a passivity-based control of the active and the reactive power in single-phase PV inverters. The control ensures global asymptotic convergence of the tracking error to zero and the PV inverter shows robust current tracking with fast dynamics. The control is particularized in the cases of strong and weak grid operation. In the last case, the knowledge of the grid impedance and the injected active power allows to calculate the value of the required reactive power in order to set the amplitude of the voltage at the connection point to the ideal grid amplitude. The control is validated by means of numerical simulations when the power references are changed and when the PV irradiance varies., Peer Reviewed

© 20xx IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting /republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works, This paper presents a grid current control of a grid connected Voltage Source Converter (VSC) with an LCL filter. The control method enables to shape the input admittance of the converter in addition to track a given current reference. By specifying a low resistive admittance profile, a suitable controller is obtained by using an H8 synthesis, which will actively damp the filter resonance and the harmonics/inter-harmonics from the grid in a wide frequency range. Additionally, the proposed system presents good robustness with respect to grid uncertainty.

© 2016. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/, This paper proposes a new approach to control the grid-side current of LCL-grid connected voltage source converters using hysteretic relay feedback controllers. The closed loop system is stabilized by designing a local feedback around the relay element. The compensator allows the use of relay feedback controllers by making the controlled plant almost strictly positive real. The article proposes the use of the locus of the perturbed relay system as analysis and design tool and studies orbital stability for several plant and controller conditions. The approach is validated by means of simulation testing.

© 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works, This paper studies the problem of existence and stability of equilibria of dc linear time–invariant circuits with constant power loads. First, we correct an unfortunate mistake in our previous work [10] pertaining to the sufficiency of the condition for existence of equilibria in multiport systems given there. Second, we give two necessary conditions for existence
of equilibria. The first one is a simple linear matrix inequality hence it can be easily verified with existing software. Third, we prove that the latter condition is also sufficient if a set defined by the problem data is convex, which is the case for single and two–port systems. Finally, sufficient conditions for stability and instability for a given equilibrium point are given. The results are illustrated with two benchmark examples

© 2016. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/, This paper proposes a new approach to control the grid-side current of LCL-grid connected voltage source converters using hysteretic relay feedback controllers. The closed loop system is stabilized by designing a local feedback around the relay element. The compensator allows the use of relay feedback controllers by making the controlled plant almost strictly positive real. The article proposes the use of the locus of the perturbed relay system as analysis and design tool and studies orbital stability for several plant and controller conditions. The approach is validated by means of simulation testing., Postprint (author's final draft)

© 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works, This paper presents a novel active damping technique of current-controlled grid-connected power converters through LCL filters. Based on H8 synthesis algorithms, a grid current controller is obtained so that the grid-connected power converted-based application admittance resembles a given frequency reference. By defining a low resistive admittance as the reference, considered application resonance is effectively damped, reducing grid current oscillations under grid voltage variations and avoiding their associated stability problems. Presented grid current controller senses only the PCC grid voltage and current, and is experimentally tested in both time and frequency domains. Additionally, the effectiveness of presented damping method is proved under different grid impedance scenarios., Accepted version

© 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works, This paper studies the problem of existence and stability of equilibria of dc linear time–invariant circuits with constant power loads. First, we correct an unfortunate mistake in our previous work [10] pertaining to the sufficiency of the condition for existence of equilibria in multiport systems given there. Second, we give two necessary conditions for existence
of equilibria. The first one is a simple linear matrix inequality hence it can be easily verified with existing software. Third, we prove that the latter condition is also sufficient if a set defined by the problem data is convex, which is the case for single and two–port systems. Finally, sufficient conditions for stability and instability for a given equilibrium point are given. The results are illustrated with two benchmark examples, Accepted version

This work presents the control design guidelines of a passivity-based control of the active and the reactive power in single-phase PV inverters. The control ensures global asymptotic convergence of the tracking error to zero and the PV inverter shows robust current tracking with fast dynamics. The control is particularized in the cases of strong and weak grid operation. In the last case, the knowledge of the grid impedance and the injected active power allows to calculate the value of the required reactive power in order to set the amplitude of the voltage at the connection point to the ideal grid amplitude. The control is validated by means of numerical simulations when the power references are changed and when the PV irradiance varies., Peer Reviewed, Postprint (published version)

Este artículo presenta un nuevo método para es tablecer las condiciones que extienden el rango de estabilidad local de circuitos eléctricos de corriente continua con cargas de potencia constante a todo el rango de existencia de equilibrios. La técnica se basa en el análisis de estabilidad en el dominio de la frecuencia y en la propiedad de los sistemas negativo imaginarios trabajando sobre el sistema linealizado alrededor de un equilibrio. La condición suficiente obtenida por este método se expresa mediante desigualdades matriciales lineales que pueden ser verificadas mediante programación convexa. Se analizan dos ejemplos, cuando la carga de potencia constante i) es ideal, y ii) considerando que tiene una dinámica de primer orden. Este método puede ser extendido a redes con varias cargas de potencia constante (caso multipuerto)., Postprint (published version)

© 20xx IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting /republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works, This paper presents a grid current control of a grid connected Voltage Source Converter (VSC) with an LCL filter. The control method enables to shape the input admittance of the converter in addition to track a given current reference. By specifying a low resistive admittance profile, a suitable controller is obtained by using an H8 synthesis, which will actively damp the filter resonance and the harmonics/inter-harmonics from the grid in a wide frequency range. Additionally, the proposed system presents good robustness with respect to grid uncertainty., Postprint (author's final draft)

© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting /republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works, This paper explores the problem of stability of linear time-invariant (LTI), multi-port AC circuits with instantaneous constant-power loads (CPLs), which model the behavior of some point-of-load converters. It is well-known that CPLs have a destabilizing effect that gives rise to significant oscillations or to network collapse, see [3]–[5], [7], and the references therein for a further discussion on the subject and [8] for a recent literature review. Clearly, a sine qua non condition for the correct behaviour of the network is the existence of a steady-state operating condition., Peer Reviewed, Postprint (author's final draft)