• Energy Research

Data availability: The authors do not have permission to share data. The adaptability of hydrogen across sectors such as transportation, heavy industry, and its support for intermittent renewable generation through flexible storage has sparked growing interest in electrolysis-based hydrogen production. While large-scale electrolyser integration enhances network stability by aiding constraint management and reducing renewable curtailment through storage, it also places considerable demand on electricity networks. This makes understanding the role of electrolyser deployment on distribution networks (DNs) increasingly crucial. While existing studies on hydrogen-integrated DNs often target specific operational costs or isolated constraints, they typically lack a comprehensive view that considers broader economic, operational, and environmental impacts. This study offers an extensive analysis across these dimensions, exploring diverse hydrogen supply configurations, including hydrogen pipeline and storage unit availability, within a real UK DN to provide a practical perspective. This study introduces a conflicting multi-objective function that improves load factor (LF) by 85.516% and reduces power loss by 22.947%, all while managing operational costs effectively. Findings underline that deploying electrolysers with efficient management algorithms can significantly enhance the operations of DNs. Additionally, this paper contributes to the field by detailing recent UK-based electrolysis projects, providing insights into the future of hydrogen–electricity coupled multi-energy networks. This research was supported by Engineering and Physical Sciences Research Council (EPSRC) Grant Reference EP/W524542/1. The authors thank UK Power Networks DSO for providing data during the corresponding author’s employment, which contributed significantly to the analysis presented in this study.

Abstract In this article, an investigation into different magnetization topologies for a long stator tubular permanent magnet linear generator is performed through a comparison based on the cogging force disturbance, the power output, and the cost of the raw materials of the machines. The results obtained from finite element analysis simulation are compared with an existing linear generator described in [1]. To ensure accurate results, the generator developed in [1] is built with 3D CAD and simulated using the finite-element method, and the obtained results are verified with the source.

Phasor Measurement Units (PMUs) are being rapidly deployed in power grids due to their high sampling rates and synchronised measurements. The devices high data reporting rates present major computational challenges, in the requirement to process potentially massive volumes of data, in addition to new issues surrounding data storage. Fast algorithms capable of processing massive volumes of data are now required in the field of power systems. This paper presents a novel parallel detrended fluctuation analysis (PDFA) approach for fast event detection on massive volumes of PMU data, taking advantage of a cluster computing platform. The PDFA algorithm is evaluated using data from installed PMUs on the transmission system of Great Britain, from the aspects of speedup, scalability and accuracy. The speedup of the PDFA in computation is initially analysed through Amdahl's Law, a revision to the law is then proposed, suggesting enhancements to its capability to analyse the performance gain in computation when parallelizing data intensive applications in a cluster computing environment

Abstract In this paper the performance of a longitudinal flux permanent magnet linear generator (PMLG) for wave energy converters (WEC) is investigated. The influence of the number of slots per pole, phase q and the number of stator's winding sections are analysed. The power output and the cogging forces in the PMLG are calculated and reviewed with respect to the above design parameters. In addition, an optimised PMLG model is designed and simulated. Three-dimensional Finite Element Method (FEM) is used for solving the combined field and circuit equations of the generator.

Abstract By continuing to use fossil fuels we are bound to pollute the atmosphere, and consequently, unwanted greenhouse and climate change effects will come to dominate every part of the earth. Wind power energy represents an interesting alternative to traditional forms of obtaining energy. However, the efficiency of wind power strongly depends on the control methods that play a significant role in eliminating the perturbing factors, decreasing the structural loads and increasing the amount and quality of the energy that is produced. A design of a model based control algorithm for a horizontal wind turbine is proposed. In a model-based control approach, increased model accuracy implies reduced uncertainty. The paper will include an analysis of the advantages that may arise from using such a control technique and also will focus on the robustness of the closed loop system.

Les systèmes photovoltaïques (PV) peuvent réduire les émissions de gaz à effet de serre tout en fournissant une alimentation réactive rapide au réseau électrique. Au niveau du réseau de distribution, les onduleurs photovoltaïques sont contrôlés pour réduire la perte de puissance active du système et pour résoudre les problèmes causés par les systèmes photovoltaïques eux-mêmes. Par exemple, le réseau de distribution peut faire face à des surtensions dues à une production photovoltaïque élevée pendant les heures creuses. Dans cet article, une approche de contrôle de la puissance réactive pour les onduleurs photovoltaïques est proposée pour contrôler l'injection/absorption de puissance réactive afin de réduire la perte de puissance active du système tout en résolvant le problème de surtension. Pour ce faire, le contrôleur proposé envoie périodiquement les points de consigne de puissance réactive et applique un algorithme volt/var en temps réel. La méthode proposée utilise des distributions probabilistes pour tenir compte des incertitudes de la production photovoltaïque et de la demande de charge. Le contrôleur est mis en œuvre au niveau latéral, ce qui simplifie la plate-forme de communication requise et réduit le coût de calcul. La commande volt/var en temps réel coordonne le fonctionnement des différents onduleurs dans des conditions de surtension afin que l'augmentation de tension soit limitée en utilisant le moins de puissance réactive possible par les onduleurs. En conséquence, la perte de puissance active due au flux de puissance réactive dans le système est réduite. Deux systèmes de distribution sont simulés à l'aide d'Open Distribution System Simulator (OpenDSS) et utilisés pour évaluer le contrôleur proposé et comparer avec deux autres méthodes. Une simulation quotidienne de séries chronologiques est effectuée pour tester différentes conditions de fonctionnement. Les résultats de simulation montrent que le contrôleur proposé est capable de réduire la perte de puissance active en général et de résoudre le problème de surtension avec une demande de puissance réactive plus faible que les autres méthodes volt/var. Los sistemas fotovoltaicos (PV) pueden reducir las emisiones de gases de efecto invernadero al tiempo que proporcionan un rápido apoyo de energía reactiva a la red eléctrica. A nivel de la red de distribución, los inversores fotovoltaicos se controlan para reducir la pérdida de potencia activa del sistema y para abordar los problemas causados por los propios sistemas fotovoltaicos. Por ejemplo, la red de distribución puede sufrir sobretensiones debido a la alta generación fotovoltaica durante las horas de menor actividad. En este documento, se propone un enfoque de control de potencia reactiva para inversores fotovoltaicos para controlar la inyección/absorción de potencia reactiva para reducir la pérdida de potencia activa del sistema mientras se resuelve el problema de sobretensión. Para lograr esto, el controlador propuesto envía periódicamente los puntos de ajuste de potencia reactiva y aplica un algoritmo de voltaje/VAR en tiempo real. El método propuesto utiliza distribuciones probabilísticas para tener en cuenta las incertidumbres en la generación fotovoltaica y la demanda de carga. El controlador se implementa a nivel lateral, lo que simplifica la plataforma de comunicación requerida y reduce el coste computacional. El control de tensión/VAR en tiempo real coordina el funcionamiento de los diferentes inversores durante las condiciones de sobretensión para que el aumento de tensión se limite utilizando la menor potencia reactiva posible por parte de los inversores. En consecuencia, se reduce la pérdida de potencia activa debido al flujo de potencia reactiva en el sistema. Dos sistemas de distribución se simulan utilizando Open Distribution System Simulator (OpenDSS) y se utilizan para evaluar el controlador propuesto y compararlo con otros dos métodos. Se realiza una simulación diaria de series de tiempo para probar diferentes condiciones de operación. Los resultados de la simulación muestran que el controlador propuesto es capaz de reducir la pérdida de potencia activa en general y resolver el problema de sobretensión con un requisito de potencia reactiva menor que los otros métodos de voltaje/VAR. Photovoltaic (PV) systems can reduce greenhouse gas emissions while providing rapid reactive power support to the electric grid. At the distribution grid level, the PV inverters are controlled to reduce the system's active power loss and to address problems caused by the PV systems themselves. For example, the distribution grid may face overvoltages due to high PV generation during off-peak hours. In this paper, a reactive power control approach for PV inverters is proposed to control the injection/absorption of reactive power to reduce the active power loss of the system while solving the overvoltage problem. To achieve this, the proposed controller periodically dispatches the reactive power setpoints and applies a real-time volt/var algorithm. The proposed method uses probabilistic distributions to account for the uncertainties in PV generation and load demand. The controller is implemented at the lateral level which simplifies the required communication platform and reduces the computational cost. The real-time volt/var control coordinates the operation of the different inverters during overvoltage conditions so that the voltage rise is limited using as little reactive power as possible by the inverters. Accordingly, the active power loss due to reactive power flow in the system is reduced. Two distribution systems are simulated using Open Distribution System Simulator (OpenDSS) and used to evaluate the proposed controller and compare with two other methods. A daily time series simulation is performed to test different operating conditions. The simulation results show that the proposed controller is able to reduce the active power loss in general and solve the overvoltage problem with a lower reactive power requirement than the other volt/var methods. يمكن للأنظمة الكهروضوئية أن تقلل من انبعاثات غازات الدفيئة مع توفير دعم سريع للطاقة التفاعلية للشبكة الكهربائية. على مستوى شبكة التوزيع، يتم التحكم في المحولات الكهروضوئية لتقليل فقدان الطاقة النشط للنظام ومعالجة المشاكل الناجمة عن الأنظمة الكهروضوئية نفسها. على سبيل المثال، قد تواجه شبكة التوزيع جهدًا زائدًا بسبب توليد الطاقة الكهروضوئية العالية خلال ساعات الذروة. في هذه الورقة، يتم اقتراح نهج للتحكم في الطاقة التفاعلية للمحولات الكهروضوئية للتحكم في حقن/امتصاص الطاقة التفاعلية لتقليل فقدان الطاقة النشط للنظام مع حل مشكلة الجهد الزائد. ولتحقيق ذلك، ترسل وحدة التحكم المقترحة بشكل دوري نقاط ضبط القدرة التفاعلية وتطبق خوارزمية فولت/فار في الوقت الفعلي. تستخدم الطريقة المقترحة التوزيعات الاحتمالية لمراعاة أوجه عدم اليقين في توليد الطاقة الكهروضوئية والطلب على الحمل. يتم تنفيذ وحدة التحكم على المستوى الجانبي مما يبسط منصة الاتصال المطلوبة ويقلل من التكلفة الحسابية. ينسق التحكم في الجهد/التغيير في الوقت الفعلي تشغيل المحولات المختلفة أثناء ظروف الجهد الزائد بحيث يكون ارتفاع الجهد محدودًا باستخدام أقل قدر ممكن من القدرة التفاعلية بواسطة المحولات. وفقًا لذلك، يتم تقليل فقدان الطاقة النشط بسبب تدفق الطاقة التفاعلي في النظام. تتم محاكاة نظامين للتوزيع باستخدام محاكي نظام التوزيع المفتوح (OpenDSS) ويستخدمان لتقييم وحدة التحكم المقترحة والمقارنة مع طريقتين أخريين. يتم إجراء محاكاة السلاسل الزمنية اليومية لاختبار ظروف التشغيل المختلفة. تظهر نتائج المحاكاة أن وحدة التحكم المقترحة قادرة على تقليل فقدان الطاقة النشط بشكل عام وحل مشكلة الجهد الزائد بمتطلبات طاقة تفاعلية أقل من طرق الفولت/الفار الأخرى.

The use of renewable energy sources is increasing day by day due to their economic and environmental benefits. However, improper penetration of renewable energy into power grids can lead to problems such as over-voltages and higher active power losses. Therefore, the voltage regulation problem in distribution networks is critical due to the increasing integration of renewable energy sources. On the other hand, an increase in renewable energy penetration leads to lower operational costs due to decreased energy purchases from the overhead grid. Therefore, it can be challenging for distribution system operators (DSOs) to decide the trade-off between more Photovoltaic (PV) integration for cost minimization or less penetration to minimize voltage deviation from a rated value. In this study, we formulated this trade-off as a novel multi-objective optimization framework, aiming to minimize operating costs and voltage deviations from a rated value in an unbalanced distribution grid. The proposed formulation is applied to the modified IEEE 34-bus unbalanced distribution network, where the $\varepsilon $ -constraint method is utilized for solving the resulting multi-objective optimization problem along with the Exterior Penalty Functions (EPF) method. The simulation results show that the proposed approach provides the DSO with a better view of decision-making in the optimal operation of the distribution networks.

A prototype platform was designed, implemented and tested to act as the foundation of a novel intelligent home energy management system which can manage the overall consumption of a house while taking into account user preferences and dynamic tariffs. In order to reduce the implementation cost and to increase the platform stability, the system was designed to employ independent stand-alone devices based on microcontrollers.