Wenlu Ji, Yong Wang^*, Xing Deng, Ming Zhang, Ting Ye

Energy Engineering, Vol.119, No.5, pp. 1967-1983, 2022, DOI:10.32604/ee.2022.020011

Abstract Virtual power plants can effectively integrate different types of distributed energy resources, which have become a new operation mode with substantial advantages such as high flexibility, adaptability, and economy. This paper proposes a distributionally robust optimal dispatch approach for virtual power plants to determine an optimal day-ahead dispatch under uncertainties of renewable energy sources. The proposed distributionally robust approach characterizes probability distributions of renewable power output by moments. In this regard, the faults of stochastic optimization and traditional robust optimization can be overcome. Firstly, a second-order cone-based ambiguity set that incorporates the first and second moments of renewable power output… More >

Nada Yamoul^1,*, Latifa Dlimi¹, Baraka Achraf Chakir²

Energy Engineering, Vol.119, No.5, pp. 2135-2148, 2022, DOI:10.32604/ee.2022.020005

Abstract The building sector is one of the main energy-consuming sectors in Morocco. In fact, it accounts for 33% of the final consumption of energy and records a high increase in the annual consumption of energy caused by further planned large-scale projects. Indeed, the energy consumption of the building sector is experiencing a significant acceleration justified by the rapid need for the development of housing stock, wich is estimated at an average increase of 1,5% per year; furthermore, tant is an estimated increase of about 6,4%. In this sense, building constitutes an important potential source for rationalizing both energy consumption and… More >

Wenjun Wei^1,2, Hao Liang^1,*

Energy Engineering, Vol.119, No.5, pp. 2065-2080, 2022, DOI:10.32604/ee.2022.020002

Abstract Droop control is one of the main control strategies of islanded microgrid (MG), but the droop control cannot achieve reasonable power distribution of microgrid, resulting in frequency and voltage deviation from the rating value, which needs the upper control link to eliminate the deviation. However, at present, most layered control requires a centralized control center, which excessively relies on microgrid central controller (MGCC) and real-time communication among distributed generation (DG), which has certain limitations. To solve the above problems, this paper proposes a hierarchical distributed power and power quality optimization strategy based on multi-agent finite time consistency algorithm (MA-FTCA). Firstly,… More >

Felipe Mercês Biglia¹, Raquel da Cunha Ribeiro da Silva², Fátima de Moraes Lino³, Kamal Abdel Radi Ismail³, Thiago Antonini Alves^4,*

Energy Engineering, Vol.119, No.5, pp. 1771-1788, 2022, DOI:10.32604/ee.2022.019625

Abstract The frost growth on cold surfaces in evaporators is an undesirable phenomenon which becomes a problem for the thermal efficiency of the refrigeration systems because the ice layer acts as a thermal insulation, drastically reducing the rate of heat transfer in the system. Its accumulation implies an increase in energy demand and a decrease in the performance of various components involved in the refrigeration process, reducing its efficiency and making it necessary to periodically remove the frost, resulting in expenses for the defrost process. In the present work, a numerical-experimental analysis was performed in order to understand the formation process… More >

Wenpeng Guo^1,2, Yongtu Liang^1,*

Energy Engineering, Vol.119, No.5, pp. 2049-2064, 2022, DOI:10.32604/ee.2022.019526

Abstract In this paper, the transportation economy of two heated crude oil pipelines laid in one ditch is analyzed by taking into account the influence of operating temperature, interval between two pipelines, and distance between two heating stations on the heating energy consumption. To analyze the transportation economy, the two heated crude oil pipelines laid in one ditch are simulated under four operating conditions based on an unstructured finite volume method. Compared with laying two crude oil pipelines separately in two ditches, the results attest notably higher soil temperature, meaning reduced heat dissipation of each pipeline by laying two pipelines in… More >

Yan Jin^1,*, Dingmei Wang², Ruiping Zhang¹, Haiying Dong¹

Energy Engineering, Vol.119, No.5, pp. 1923-1940, 2022, DOI:10.32604/ee.2022.018750

Abstract Aiming at the low spatial resolution of meteorological data output from a numerical model in photovoltaic power prediction, a geographically weighted statistical downscaling method considers the influence factors such as normalized vegetation index (NDVI), digital elevation model (DEM), slope direction, longitude and latitude is proposed. This method is based on the correlation between meteorological data and NDVI, DEM, slope direction, latitude and longitude, and introduces DEM and local Moran index to improve the regression model, and obtains 100 * 100 m high-resolution meteorological spatial distribution data. Finally, combining the measured data of the study area and the established EOF iterative downscaling… More >

Tiecheng Li¹, Qingquan Liu¹, Hui Fan², Xianzhi Wang¹, Daming Zhou^3,*, Junan Guo³, Lee Li³, Kun Zhou³, Yujie Hu³

Energy Engineering, Vol.119, No.5, pp. 2105-2134, 2022, DOI:10.32604/ee.2022.017718

Abstract Accurate conditions monitoring and early wrong action warnings of relay protection in the Smart Substation is the basic guarantee to realize the normal operation of primary and secondary system of the power grid. At present, the traditional operation and maintenance monitoring methods of relay protections have poor timeliness, while some automatic monitoring methods have insufficient early warning performance, and lack the online action deduction function independent of the actual device. In this paper, a design method of integrated action deduction system including protection logic reasoning and software and hardware operation condition is proposed. The system can receive real-time operation information… More >

Gang Lei^1,*, Chunxiang Xu²

Energy Engineering, Vol.119, No.5, pp. 2005-2029, 2022, DOI:10.32604/ee.2022.021154

Abstract In the present paper, the distribution feeder reconfiguration in the presence of distributed generation resources (DGR) and energy storage systems (ESS) is solved in the dynamic form. Since studies on the reconfiguration problem have ignored the grid security and reliability, the non-distributed energy index along with the energy loss and voltage stability indices has been assumed as the objective functions of the given problem. To achieve the mentioned benefits, there are several practical plans in the distribution network. One of these applications is the network rearrangement plan, which is the simplest and least expensive way to add equipment to the… More >

Can Li^*, Xiaode Zuo

Energy Engineering, Vol.119, No.5, pp. 1879-1903, 2022, DOI:10.32604/ee.2022.020472

Abstract This work suggested a novel model for obtaining optimum bidding/offering strategy to improve the benefits in case of big users. Aiming this regard, several electrical energy resources including: micro turbines, green power sources (wind turbine and photovoltaic system), power storage unit such as Hydrogen storage system with fuel cell, as well as mutual treaties are taken into account in offered model. Considering various models for uncertain parameters based on their natures such as power demand, electricity market tariffs, solar irradiation, temperature and wind speed is one of the contributions of the proposed model. Uncertainty of power demand is modeled by… More >

Yunlei Zhang¹, Ruifeng Cao¹, Danhuang Dong², Sha Peng^3,*, Ruoyun Du³, Xiaomin Xu³

Energy Engineering, Vol.119, No.5, pp. 1829-1841, 2022, DOI:10.32604/ee.2022.020118

Abstract In the electricity market, fluctuations in real-time prices are unstable, and changes in short-term load are determined by many factors. By studying the timing of charging and discharging, as well as the economic benefits of energy storage in the process of participating in the power market, this paper takes energy storage scheduling as merely one factor affecting short-term power load, which affects short-term load time series along with time-of-use price, holidays, and temperature. A deep learning network is used to predict the short-term load, a convolutional neural network (CNN) is used to extract the features, and a long short-term memory… More >