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In this paper we describe the design of hybrid fuzzy predictive control based on a genetic algorithm (GA). We also present a simulation test of the proposed algorithm and a comparison with two hybrid predictive control methods: Explicit Enumeration and Branch and Bound (BB). The experiments involved controlling the temperature of a batch reactor by using two on/off input valves and a discrete-position mixing valve. The GA-hybrid predictive control strategy proved to be a suitable method for the control of hybrid systems, giving similar performance to that of typical hybrid predictive control strategies and a significant saving with respect to the computation time.

One of the well-known methods to share active and reactive power in microgrids, is droop control. A disadvantage of this method is that in steady state the frequency of the microgrid deviates from the nominal value, and has to be restored using a Secondary Control System (SCS). The signal obtained at the output of the SCS is transmitted using a communication channel to the generation sources in the microgrid, correcting the frequency. However, communication channels are prone to time delays which should be considered in the design of the SCS; otherwise, the operation of the microgrid could be compromised. In this paper, two new SCSs control schemes are discussed to deal with this issue: a Model Predictive Controller (MPC) and a Smith predictor based controller. The performance of both control methodologies are compared to that obtained using a conventional PI-based SCS using simulation work. Stability analysis based on small signal models and participation factors is also realised. It is concluded that in terms of robustness, the MPC has better performance.

Microgrids (MGs) are sustainable solutions for rural zone electrification that use local renewable resources. However, only careful planning at the start of an MG project can ensure its future optimal operation. In this paper, a novel methodology for MG planning by using the uncertainty characterization of renewable resources and demand is presented. Additionally, a model of electricity consumption is proposed and applied in an isolated rural community. In such communities, consumption patterns typically need to be derived as model inputs because consumption measurements are not available for the planning stage. To obtain these inputs, clustering algorithms based on self-organizing maps (SOMs) and fuzzy c-means are used to classify the families of the community given sociodemographic information obtained via surveys. Subsequently, Markov chains (MCs) are employed to generate consumption patterns based on consumption measurements in some dwellings and surveys applied to the community. The nonlinearities and uncertainties associated with renewable resources and consumption are modeled by using prediction interval (PI) models. These PI models provide the required consumption and generation scenarios for deriving the optimal sizing and topological information to address the MG planning problem. The results of the robust planning approach based on scenarios are useful at the feasibility and design phases of an MG project. The proposed methodology is successfully applied to MG planning for a rural Mapuche community, where a conservative criterion was considered to minimize the investment risk. This criterion corresponds to the worst-case scenario in which the demand increases by 19.9% compared to that of the baseline scenario and a lower energy cost is obtained. However, the net present cost and operational costs increase by 14% and 11.75% compared to those of the baseline scenario, respectively. Railway Engineering

This paper presents the design and evaluation of a dynamic simulator for an ISCC (integrated solar combined cycle) plant. The design of the simulator is based on the phenomenological equations for both a combined cycle plant and a solar plant. The simulator incorporates a regulatory control strategy based on PI (proportional-integral) controllers and was developed in the MATLAB/Simulink® environment. A MPC (model predictive control) strategy established at a supervisory level is presented. The intent of the strategy is to regulate the steam pressure of the superheater of the ISCC plant. The combined use of the simulator and the supervisory control strategy allows for the quantification of the reduction in fuel consumption that can be achieved when integrated solar collectors are used in a combined cycle plant. The ISCC plant simulator is suitable for designing, evaluating and testing control strategies and for planning the integration of solar and combined cycle

Summary This paper proposes a novel simulator of energy consumption patterns that allows designing demand side management (DSM) strategies without economic incentives. The simulator emulates consumers' patterns with and without installed DSM interfaces, based on both actual consumption measurements and surveys applied to the inhabitants of an existing isolated microgrid (Huatacondo, Chile) that has a particular DSM strategy without economic incentives. The simulator uses Markov chains to generate data characterizing consumption patterns without DSM and Bayesian networks for cases in which the users respond to the DSM strategy. Data obtained from the simulator are used to derive a response model of the consumers to the DSM interface, which can be included for the energy management system design. Results show that the implemented strategy can be effective and can generate savings up to 4.45% in diesel consumption for an ideal case where all the dwellings have the interface installed. Copyright © 2016 John Wiley & Sons, Ltd.

Une stratégie de contrôle distribué est proposée pour partager les courants déséquilibrés dans les micro-réseaux CA triphasés isolés à trois fils (MG). Il est basé sur une nouvelle approche où, plutôt que d'analyser le MG comme un système triphasé, il est analysé comme trois sous-systèmes monophasés. La proposition utilise un schéma de baisse $Q-E$ monophasé modifié dans lequel deux actions de contrôle secondaires supplémentaires sont introduites par phase. La première action de contrôle effectue la régulation de tension, tandis que la seconde réalise le partage des composantes de courant de séquence négative entre les convertisseurs de puissance à 3 branches situés dans le MG. Ces actions de contrôle secondaire sont calculées en ligne à l'aide d'un schéma de contrôle distribué consensuel pour partager les composantes de courant de séquence négative, la régulation de tension et la régulation du déséquilibre à la tension de sortie des convertisseurs pour répondre aux normes de qualité de l'alimentation IEEE. La méthodologie proposée présente les avantages suivants par rapport à d'autres solutions de commande distribuées, telles que celles basées sur les composants symétriques ou celles basées sur la théorie de puissance conservatrice : (i) elle réalise le partage des courants déséquilibrés, induisant des déséquilibres plus faibles dans les tensions de sortie des convertisseurs que ceux des autres méthodes, et (ii) le partage des courants déséquilibrés est réalisé simultanément à la fois dans le domaine de séquence et dans le domaine a-b-c. Ce dernier est difficile à réaliser en utilisant d'autres solutions, comme cela sera démontré dans ce travail. Une validation expérimentale approfondie de l'approche distribuée proposée est fournie à l'aide d'une MG à 3 fils à l'échelle du laboratoire. Se propone una estrategia de control distribuido para compartir corrientes desequilibradas en microrredes (MG) de CA aisladas trifásicas de tres hilos. Se basa en un enfoque novedoso en el que, en lugar de analizar el MG como un sistema trifásico, se analiza como tres subsistemas monofásicos. La propuesta utiliza un esquema monofásico modificado $Q-E$ DROOP donde se introducen dos acciones de control secundarias adicionales por fase. La primera acción de control realiza la regulación de voltaje, mientras que la segunda logra el intercambio de componentes de corriente de secuencia negativa entre los convertidores de potencia de 3 patas ubicados en la MG. Estas acciones de control secundario se calculan en línea utilizando un esquema de control distribuido basado en consenso para compartir componentes de corriente de secuencia negativa, regulación de voltaje y regulación del desequilibrio en el voltaje de salida de los convertidores para cumplir con los estándares de calidad de energía del IEEE. La metodología propuesta tiene las siguientes ventajas sobre otras soluciones de control distribuido, como las basadas en los componentes simétricos o las basadas en la Teoría del Poder Conservador: (i) logra compartir corrientes desequilibradas, induciendo desequilibrios más pequeños en las tensiones de salida de los convertidores que los de otros métodos, y (ii) el reparto de las corrientes desequilibradas se realiza simultáneamente tanto en el dominio de la secuencia como en el dominio a-b-c. Esto último es difícil de lograr con otras soluciones, como se demostrará en este trabajo. Se proporciona una amplia validación experimental del enfoque distribuido propuesto utilizando un MG de 3 hilos a escala de laboratorio. A distributed control strategy is proposed to share unbalanced currents in three-phase three-wire isolated AC Microgrids (MGs). It is based on a novel approach where, rather than analysing the MG as a three-phase system, it is analysed as three single-phase subsystems. The proposal uses a modified single-phase $Q-E$ droop scheme where two additional secondary control actions are introduced per phase. The first control action performs voltage regulation, while the second one achieves the sharing of negative sequence current components between the 3-legs power converters located in the MG. These secondary control actions are calculated online using a consensus-based distributed control scheme to share negative sequence current components, voltage regulation, and regulating the imbalance at the converters' output voltage to meet the IEEE power quality standards. The proposed methodology has the following advantages over other distributed control solutions, such as those based on the symmetrical components or those based on the Conservative Power Theory: (i) it achieves sharing of unbalanced currents, inducing smaller imbalances in the converters' output voltages than those of other methods, and (ii) the sharing of the unbalanced currents is simultaneously realised in both the sequence domain and the a-b-c domain. The latter is difficult to achieve using other solutions, as will be demonstrated in this work. Extensive experimental validation of the proposed distributed approach is provided using a laboratory-scale 3-wire MG. تُقترح استراتيجية تحكم موزعة لمشاركة التيارات غير المتوازنة في شبكات التيار المتردد المجهرية المعزولة بثلاث أسلاك ثلاثية الطور (MGS). وهو يعتمد على نهج جديد حيث، بدلاً من تحليل MG كنظام ثلاثي الطور، يتم تحليله على أنه ثلاثة أنظمة فرعية أحادية الطور. يستخدم الاقتراح مخططًا معدلاً للتدلي على مرحلة واحدة حيث يتم تقديم إجراءين إضافيين للتحكم الثانوي لكل مرحلة. يقوم إجراء التحكم الأول بتنظيم الجهد، بينما يحقق الإجراء الثاني مشاركة مكونات تيار التسلسل السلبي بين محولات الطاقة ثلاثية الأرجل الموجودة في MG. يتم حساب إجراءات التحكم الثانوية هذه عبر الإنترنت باستخدام مخطط تحكم موزع قائم على الإجماع لمشاركة مكونات تيار التسلسل السلبي، وتنظيم الجهد، وتنظيم عدم التوازن في جهد خرج المحولات لتلبية معايير جودة طاقة IEEE. تتمتع المنهجية المقترحة بالمزايا التالية على حلول التحكم الموزعة الأخرى، مثل تلك القائمة على المكونات المتماثلة أو تلك القائمة على نظرية القوة المحافظة: (1) تحقق مشاركة التيارات غير المتوازنة، مما يؤدي إلى اختلالات أصغر في فولتية خرج المحولات من تلك الخاصة بالطرق الأخرى، و (2) يتم تحقيق مشاركة التيارات غير المتوازنة في وقت واحد في كل من مجال التسلسل ومجال a - b - c. من الصعب تحقيق هذا الأخير باستخدام حلول أخرى، كما سيتضح في هذا العمل. يتم توفير التحقق التجريبي المكثف للنهج الموزع المقترح باستخدام MG على نطاق مختبري بثلاثة أسلاك.