Hasil untuk "Applications of electric power"

P. Lund, Juuso Lindgren, Jani Mikkola et al.

Sina Parhizi, H. Lotfi, A. Khodaei et al.

The significant benefits associated with microgrids have led to vast efforts to expand their penetration in electric power systems. Although their deployment is rapidly growing, there are still many challenges to efficiently design, control, and operate microgrids when connected to the grid, and also when in islanded mode, where extensive research activities are underway to tackle these issues. It is necessary to have an across-the-board view of the microgrid integration in power systems. This paper presents a review of issues concerning microgrids and provides an account of research in areas related to microgrids, including distributed generation, microgrid value propositions, applications of power electronics, economic issues, microgrid operation and control, microgrid clusters, and protection and communications issues.

Florian Dörfler, F. Bullo

F. Fan, Z. Tian, Zhong Lin Wang

O. Gutfleisch, M. Willard, E. Brück et al.

V. C. Gungor, B. Lu, G. Hancke

Zhu-wei Du, Hao-ran Li, T. Gu

J. Vetter, P. Novák, M. Wagner et al.

G. Hart

A. Emadi, A. Khaligh, C. Rivetta et al.

Jun Gao, Wei Guo, Dan Feng et al.

Tingfeng Yi, Shuangyi Yang, Ying Xie

Xiaolong XIAO, Mingming SHI, Fan WU et al.

To fully leverage the characteristics of various distributed resources and the controllability of distribution grids for delivering higher-performance and dynamic ancillary services, a dynamic frequency aggregation control method for meshed distribution virtual power plants (MVPP) is proposed. Firstly, the overall architecture of MVPP is defined, and a frequency control model capable of aggregating the dynamic characteristics of its internal distributed resources for primary frequency regulation scenarios is established. Subsequently, an adaptive dynamic frequency matching control approach is employed to address the control design challenge of the dynamic frequency aggregation model. The desired characteristics are decomposed through online adaptive approach, and a local feedback controller is designed for each device using an H∞ optimal robust control method to precisely and dynamically match the decomposed desired characteristics for primary frequency regulation. The simulation results verify the effectiveness of the proposed control method, demonstrating that it can significantly improve the primary frequency regulation characteristics of the system through the complementation of various resources under scenarios such as load disturbance and new energy output fluctuations. The proposed strategy offers a new solution for spatially distributed aggregation units to participate in dynamic frequency regulation auxiliary services.

Mohammed AMRANI, Djamel BENAZZOUZ, Smail ADJERID

This paper introduces a novel approach for real-time diagnosis of a purified water station designed for pharmaceutical applications. The water is produced using the reverse osmosis principle. Taking into account both the physicochemical properties required by international health regulations and the stringent standards of drug manufacturing, a diagnostic model based on artificial neural networks (ANN) is proposed. The developed intelligent monitoring system employs a multilayer ANN with gradient backpropagation (5-15-5). Its primary objective is to detect and localize potential faults within the water production process. The monitoring focuses on the physicochemical parameters of the purified water. Simulation results demonstrate effective fault detection, characterized by high accuracy, fast response time, and reliable performance.

Adrian Chmielewski, Piotr Piórkowski, Krzysztof Bogdziński et al.

The development of energy storage systems is significant for solving problems related to climate change. A hybrid energy storage system (HESS), combining batteries with ultracapacitors, may be a feasible way to improve the efficiency of electric vehicles and renewable energy applications. However, most existing research requires comprehensive modelling of HESS components under different operating conditions, hindering optimisation and real-world application. This study proposes a novel approach to analysing the set of differential equations of a substitute model of HESS and validates a model-based approach to investigate the performance of an HESS composed of a Valve-Regulated Lead Acid (VRLA) Absorbent Glass Mat (AGM) battery and a Maxwell ultracapacitor in a parallel configuration. Consequently, the set of differential equations describing the HESS dynamics is provided. The dynamics of this system are modelled with a double resistive–capacitive (2-RC) scheme using data from Hybrid Pulse Power Characterisation (HPPC) and pseudo-random cycles. Parameters are identified using the Levenberg–Marquardt algorithm. The model’s accuracy is analysed, estimated and verified using Mean Square Errors (MSEs) and Normalised Root Mean Square Errors (NRMSEs) in the range of a State of Charge (SoC) from 0.1 to 0.9. Limitations of the proposed models are also discussed. Finally, the main advantages of HESSs are highlighted in terms of energy and open-circuit voltage (OCV) characteristics.

Djamila TALAH, Mohammed TSEBIA, Hamid BENTARZI et al.

The advanced technologies in the combined cycle power plants offer more effectiveness and lower environmental effects compared to the conventional systems. Fuzzy logic control, one of the frequently advanced controllers, may well improve the performance of the control system in the power plant. This study focuses on improving a governing control system by using a fuzzy logic controller. Thus, a combined cycle gas turbine plant has been modeled and simulated on MATLAB/Simulink, and a fuzzy logic controller was implemented. The simulation results are compared with those of a conventional PID controller tuned by the Ziegler-Nichols method.  

Weifu Lu, Xijun Zhou, Hongjin Guo et al.

ABSTRACT Relative to the traditional pumped storage machines, the variable speed pumped storage machine (VSPSM) has strong frequency and voltage regulation capabilities by the AC excitation. However, the enhancement of the regulation capability also leads to the increment of the temperature rise. For the purpose of investigating the temperature variation in the end zone of the VSPSM, a 336‐MVA VSPSM is chosen as the research reference in this article. The electromagnetic‐fluid‐thermal coupled heat transfer calculation model in the end zone of the VSPSM is constructed. The flux density and loss distribution in the end zone of the VSPSM are calculated under different power factors and slips. The losses of the stator end parts are less influenced by the slip compared to the rotor end parts, which are more affected. The variations of temperature rise in the tooth plate, end core, clamping plate and the rotor retaining ring are revealed along with the power factor and slip. It is found that the stator tooth plate is the end part with the peak temperature. This research is able to lay a theoretical basis for optimising and designing the end structure of the VSPSM.

Selma Grebovic, Abdulah Aksamovic, Bozidar Filipovic-Grcic et al.

The increasing integration of solar power plants into transmission grids has raised concerns about their vulnerability to disturbances, particularly lightning strokes. Solar energy, while offering significant environmental and economic benefits, faces challenges when connected to transmission lines that are prone to lightning discharges. This paper investigates the impact of lightning events on solar power plants, focusing on overvoltage effects. Lightning stroke simulations were conducted at various distances from the solar power plant along the transmission line, considering scenarios with and without surge arrester. Key lightning parameters such as peak current, front time, and tail time were varied to simulate different lightning strokes. The study also includes a Fourier transform analysis of the resulting overvoltages with and without a surge arrester, along with the Hilbert marginal spectrum of these overvoltages. The results provide insights into the effectiveness of surge arresters in mitigating lightning overvoltages and highlight the importance of proper protective measures for enhancing the reliability and safety of solar power plants connected to transmission networks.

Jarne Van Mulders, Gilles Callebaut

This paper presents a preliminary study exploring the feasibility of designing batteryless electronic shelf labels (ESLs) powered by radio frequency wireless power transfer using commercial off-the-shelf components. The proposed ESL design is validated through a dedicated testbed and involves a detailed analysis of design choices, including energy consumption, energy conversion, and storage solutions. A leaded aluminium electrolytic capacitor is selected as the primary energy storage element, balancing cost and performance while maintaining compactness. Experimental evaluations demonstrate that an ESL can update its display within 4 to 120 minutes, depending on input power and RF frequency, with harvester efficiencies reaching up to 30 %. Challenges such as low harvester efficiency, extended update times, and hardware constraints are identified, highlighting opportunities for future optimizations. This work provides valuable insights into system design considerations for RF-powered ESLs and establishes a foundation for further research in energy-neutral Internet of Things applications.

Zachary J. Lythgoe, Thomas F. Long, Michael J. Buchholz et al.

Phasor measurement units (PMUs) provide a high-resolution view of the power system at the locations where they are placed. As such, it is desirable to place them in bulk in low voltage distribution circuits. However, the power consumption of a PMU/micro-PMU is in the order of Watts (W) that results in them requiring an external power supply, which in turn increases the overall cost. This work details the hardware design of a PMU capable of measuring and reporting voltage and current phasors for a single-phase system at an average power consumption of only 30.8 mW -- one to two orders of magnitude lower than existing academic and commercial PMUs. This enables the proposed PMU to run for two weeks using an 11-Wh battery or indefinitely if paired with an inexpensive solar panel. A test-bench developed in accordance with the 2018 IEC/IEEE 60255-118-1 PMU Standard confirms the accuracy of this PMU. Given its low power consumption, the proposed design is expected to accelerate adoption of PMUs in modern distribution grids.