Anfeng Zhu¹, Qiancheng Zhao^1,*, Lin Gui¹, Tianlong Yang¹, Xuebing Yang²

Energy Engineering, Vol.120, No.2, pp. 425-444, 2023, DOI:10.32604/ee.2023.023049

Abstract To ensure wind turbine (WT) safe operations and improve the utilization rate of wind energy, effective evaluation of the operation state of the pitch system is critical. Therefore, a new method was proposed to evaluate the operation state of the pitch system of WT based on fuzzy comprehensive evaluation. Firstly, based on SCADA data, the working state of the pitch system under rated power state and power state of WT were analyzed. Secondly, through the analysis of characteristic parameters and physical mechanism of the pitch system, the consistency principle of characteristic parameters, the stability principle of power under rated state,… More >

Sainan Zhang, Jing Xue^*, Xudong Sun

Energy Engineering, Vol.119, No.4, pp. 1547-1567, 2022, DOI:10.32604/ee.2022.019450

Abstract Since there are multiple influencing factors and lack of evaluation standards for the construction of hydrogen production and hydrogenation station in China, this paper establishes the suitability evaluation index system of hydrogen production and hydrogenation station from four aspects of technology, economy, environment and safety. Combined with actual conditions, this paper uses Analytic Hierarch Process (AHP) and Fuzzy Comprehensive evaluation to evaluate water electrolysis hydrogen and hydrogenation production station and natural gas reformation hydrogen production and hydrogenation station. The results show that hydrogen producing by water electrolysis is more efficient than natural gas reformation in hydrogen production and hydrogenation station,… More > Graphic Abstract

Zhongfu Tan^1,2, Jing Wang^1,*, Caixia Tan¹, Gejirifu De^3,4

Energy Engineering, Vol.119, No.1, pp. 331-357, 2022, DOI:10.32604/EE.2022.015700

Abstract At present, there are few studies on the comprehensive evaluation of green power grid development in China, and all aspects of green power grid need to be evaluated. Therefore, this paper studies the green development level of power distribution network. This paper proposes a multi-level fuzzy comprehensive evaluation method, which first needs to classify the influencing factors. Therefore, this paper constructs an indicator system for the evaluation of green development of power distribution network from three dimensions. In order to avoid the influence of subjective factors, this paper adopts the model combining analytic hierarchy process and entropy weight method to… More >

Hua Yan^1,2,3,*, Bo Song^1,3, Mansheng Wang⁴

Structural Durability & Health Monitoring, Vol.14, No.3, pp. 265-282, 2020, DOI:10.32604/sdhm.2020.06403

Abstract Analyze and compare the basic principles of ultrasonic detection of voids in concrete, choose ZBL-U520/510 non-metallic ultrasonic detector, and use the opposite detection method to test the void size in the joints of prefabricated concrete structures. The results show that: ultrasonic method by testing the waveform, sound, and speed of sound analysis can effectively determine the position of the defect, and through the conversion formula can estimate the void size. Ultrasonic parameters are used to distinguish the internal defects of Assembly concrete. Sometimes there are different results with different parameters. It is difficult for engineers to directly determine the internal… More >