• Energy Research

The Internet of things (IoT) enables a diverse set of applications such as distribution automation, smart cities, wireless sensor networks, and advanced metering infrastructure (AMI). In smart grids (SGs), quality of service (QoS) and AMI traffic management need to be considered in the design of efficient AMI architectures. In this article, we propose a QoS-aware machine-learning-based framework for AMI applications in smart grids. Our proposed framework comprises a three-tier hierarchical architecture for AMI applications, a machine-learning-based hierarchical clustering approach, and a priority-based scheduling technique to ensure QoS in AMI applications in smart grids. We introduce a three-tier hierarchical architecture for AMI applications in smart grids to take advantage of IoT communication technologies and the cloud infrastructure. In this architecture, smart meters are deployed over a georeferenced area where the control center has remote access over the Internet to these network devices. More specifically, these devices can be digitally controlled and monitored using simple web interfaces such as REST APIs. We modify the existing K-means algorithm to construct a hierarchical clustering topology that employs Wi-SUN technology for bi-directional communication between smart meters and data concentrators. Further, we develop a queuing model in which different priorities are assigned to each item of the critical and normal AMI traffic based on its latency and packet size. The critical AMI traffic is scheduled first using priority-based scheduling while the normal traffic is scheduled with a first-in–first-out scheduling scheme to ensure the QoS requirements of both traffic classes in the smart grid network. The numerical results demonstrate that the target coverage and connectivity requirements of all smart meters are fulfilled with the least number of data concentrators in the design. Additionally, the numerical results show that the architectural cost is reduced, and the bottleneck problem of the data concentrator is eliminated. Furthermore, the performance of the proposed framework is evaluated and validated on the CloudSim simulator. The simulation results of our proposed framework show efficient performance in terms of CPU utilization compared to a traditional framework that uses single-hop communication from smart meters to data concentrators with a first-in–first-out scheduling scheme.

Les réseaux de capteurs sans fil se composent de dispositifs à ressources limitées. La plus cruciale de ces ressources est la durée de vie de la batterie, car dans la plupart des applications telles que la surveillance des champs de bataille ou des zones volcaniques, il est souvent impossible de remplacer ou de recharger la source d'alimentation. Cet article présente un système de communication collaborative économe en énergie basé sur l'étalement du spectre pour atteindre l'efficacité énergétique ainsi que l'immunité contre le brouillage, les interférences naturelles, la suppression du bruit et la réutilisation de la fréquence universelle. Les performances du système proposé sont évaluées à l'aide de la puissance du signal reçu, du taux d'erreur binaire (ber) et de la consommation d'énergie. Les résultats montrent une proportionnalité directe entre le gain de puissance et le nombre de nœuds collaboratifs ainsi que le BER et le rapport signal sur bruit (Eb/N0). Les résultats d'analyse et de simulation du système proposé sont comparés au système SISO. La comparaison révèle que SISO fonctionne mieux que la communication collaborative en cas de petites distances alors que la communication collaborative fonctionne mieux que SISO en cas de longues distances. Sur la base de ces résultats, il est sûr de conclure que la communication collaborative dans les réseaux de capteurs sans fil utilisant des systèmes à large bande améliore la durée de vie des nœuds dans les réseaux, prolongeant ainsi la durée de vie du réseau. Las redes de sensores inalámbricos consisten en dispositivos con recursos limitados. El más crucial de estos recursos es la duración de la batería, ya que en la mayoría de las aplicaciones como el campo de batalla o el monitoreo de áreas volcánicas, a menudo es imposible reemplazar o recargar la fuente de energía. Este artículo presenta un sistema de comunicación colaborativa de eficiencia energética basado en espectro ensanchado para lograr la eficiencia energética, así como la inmunidad contra interferencias, interferencias naturales, supresión de ruido y reutilización universal de frecuencias. El rendimiento del sistema propuesto se evalúa utilizando la potencia de la señal recibida, la tasa de error de bits (Ber) y el consumo de energía. Los resultados muestran una proporcionalidad directa entre la ganancia de potencia y el número de nodos colaborativos, así como la BER y la relación señal-ruido (Eb/N0). Los resultados analíticos y de simulación del sistema propuesto se comparan con el sistema SISO. La comparación revela que el SISO funciona mejor que la comunicación colaborativa en el caso de distancias pequeñas, mientras que la comunicación colaborativa funciona mejor que el SISO en el caso de distancias largas. Sobre la base de estos resultados, es seguro concluir que la comunicación colaborativa en redes de sensores inalámbricos que utilizan sistemas de banda ancha mejora la vida útil de los nodos en las redes, prolongando así la vida útil de la red. Wireless sensor networks consist of resource limited devices. Most crucial of these resources is battery life, as in most applications like battle field or volcanic area monitoring, it is often impossible to replace or recharge the power source. This article presents an energy efficient collaborative communication system based on spread spectrum to achieve energy efficiency as well as immunity against jamming, natural interference, noise suppression and universal frequency reuse. Performance of the proposed system is evaluated using the received signal power, bit error rate (BER) and energy consumption. The results show a direct proportionality between the power gain and the number of collaborative nodes as well as BER and signal-to-noise ratio (Eb/N0). The analytical and simulation results of the proposed system are compared with SISO system. The comparison reveals that SISO perform better than collaborative communication in case of small distances whereas collaborative communication performs better than SISO in case of long distances. On the basis of these results it is safe to conclude that collaborative communication in wireless sensor networks using wideband systems improves the life time of nodes in the networks thereby prolonging the network's life time. تتكون شبكات الاستشعار اللاسلكية من أجهزة محدودة الموارد. وأهم هذه الموارد هو عمر البطارية، كما هو الحال في معظم التطبيقات مثل ميدان المعركة أو مراقبة المناطق البركانية، وغالبًا ما يكون من المستحيل استبدال مصدر الطاقة أو إعادة شحنه. تقدم هذه المقالة نظام اتصال تعاوني موفر للطاقة يعتمد على طيف الانتشار لتحقيق كفاءة الطاقة بالإضافة إلى المناعة ضد التشويش والتداخل الطبيعي وكبت الضوضاء وإعادة الاستخدام الشامل للتردد. يتم تقييم أداء النظام المقترح باستخدام طاقة الإشارة المستلمة ومعدل خطأ البت (BER) واستهلاك الطاقة. تظهر النتائج تناسبًا مباشرًا بين كسب الطاقة وعدد العقد التعاونية بالإضافة إلى نسبة BER ونسبة الإشارة إلى الضوضاء (Eb/N0). تتم مقارنة النتائج التحليلية والمحاكاة للنظام المقترح مع نظام SISO. تكشف المقارنة أن أداء SISO أفضل من التواصل التعاوني في حالة المسافات الصغيرة بينما يعمل التواصل التعاوني بشكل أفضل من SISO في حالة المسافات الطويلة. على أساس هذه النتائج، من الآمن أن نستنتج أن الاتصال التعاوني في شبكات الاستشعار اللاسلكية باستخدام أنظمة النطاق العريض يحسن من عمر العقد في الشبكات وبالتالي إطالة عمر الشبكة.

The magnetic levitation (MAGLEV) train uses magnetic field to suspend, guide, and propel vehicle onto the track. The MAGLEV train provides a sustainable and cleaner solution for train transportation by significantly reducing the energy usage and greenhouse gas emissions as compared to traditional train transportation systems. In this paper, we propose an advanced control mechanism using an Arduino microcontroller that selectively energizes the electromagnets in a MAGLEV train system to provide dynamic stability and energy efficiency. We also design the prototype of an energy-efficient MAGLEV train that leverages our proposed control mechanism. In our MAGLEV train prototype, the levitation is achieved by creating a repulsive magnetic field between the train and the track using magnets mounted on the top-side of the track and bottom-side of the vehicle. The propulsion is performed by creating a repulsive magnetic field between the permanent magnets attached on the sides of the vehicle and electromagnets mounted at the center of the track using electrodynamic suspension (EDS). The electromagnets are energized via a control mechanism that is applied through an Arduino microcontroller. The Arduino microcontroller is programmed in such a way to propel and guide the vehicle onto the track by appropriate switching of the electromagnets. We use an infrared-based remote-control device for controlling the power, speed, and direction of the vehicle in both the forward and the backward direction. The proposed MAGLEV train control mechanism is novel, and according to the best of our knowledge is the first study of its kind that uses an Arduino-based microcontroller system for control mechanism. Experimental results illustrate that the designed prototype consumes only 144 W-hour (Wh) of energy as compared to a conventionally designed MAGLEV train prototype that consumes 1200 Wh. Results reveal that our proposed control mechanism and prototype model can reduce the total power consumption by 8.3 × as compared to the traditional MAGLEV train prototype, and can be applied to practical MAGLEV trains with necessary modifications. Thus, our proposed prototype and control mechanism serves as a first step towards cleaner engineering of train transportation systems.