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Abstract Ultrahigh-voltage electricity systems are a vital part of energy networks, often across wide regions passing through mountainous terrains. The instability of slopes forming tower foundations along transmission lines poses a large risk to the entire energy network. Moreover, the tower foundations along extra-high-voltage electricity transmission lines are a very special type of element that are also highly vulnerable to landslides. In this study, an integrative risk assessment framework, including a hazard assessment, vulnerability analysis for the specified element at risk, and consequence estimation, is proposed to quantify the direct and indirect risks of landslides to power transmission lines. The Yanzi landslide, where a tower of the major ultrahigh-voltage transmission line from Sichuan (western China) to Shanghai (eastern China) has just been constructed, is taken as a case study. The correlation between landslide displacement and tower structure tilting is studied. In terms of the precipitation return period, factors of safety, failure probability, and deformation are simulated. A physical vulnerability curve is fitted by assuming a Weibull relationship between the horizontal deformation (hazard intensity) of the landslide and the tower inclination ratio. The total risk is calculated as the sum of the direct and indirect losses, among which the potential indirect risk due to tower damage is much greater than the direct risk. This work demonstrates the importance of landslide treatment strategies along electricity transmission lines by considering the potential indirect risks. The risk assessment model of landslides affecting ultrahigh-voltage electricity transmission lines proposed in this study could be useful for other types of indirect landslide risk evaluations.

The current methods for evaluating the operating condition of electricity transmission lines (ETLs) and providing early warning have several problems, such as the low correlation of data, ignoring the influence of seasonal factors, and strong subjectivity. This paper analyses the sensitive factors that influence dynamic key evaluation indices such as grounding resistance, sag, and wire corrosion, establishes the evaluation criteria of the ETL operation state, and proposes five ETL status levels and seven principles for selecting evaluation indices. Nine grade I evaluation indices and twenty-nine grade II evaluation indices, including passageway and meteorological environments, are determined. The cloud model theory is embedded and used to propose a warning technology for the operation state of ETLs based on inspection defect parameters and the cloud model. Combined with the inspection defect parameters of a line in the Baicheng district of Jilin Province and the critical evaluation index data such as grounding resistance, sag, and wire corrosion, which are used to calculate the timeliness of the data, the solid line is evaluated. The research shows that the dynamic evaluation model is correct and that the ETL status evaluation and early warning method have reasonable practicability. [ABSTRACT FROM AUTHOR]

The current methods for evaluating the operating condition of electricity transmission lines (ETLs) and providing early warning have several problems, such as the low correlation of data, ignoring the influence of seasonal factors, and strong subjectivity. This paper analyses the sensitive factors that influence dynamic key evaluation indices such as grounding resistance, sag, and wire corrosion, establishes the evaluation criteria of the ETL operation state, and proposes five ETL status levels and seven principles for selecting evaluation indices. Nine grade I evaluation indices and twenty-nine grade II evaluation indices, including passageway and meteorological environments, are determined. The cloud model theory is embedded and used to propose a warning technology for the operation state of ETLs based on inspection defect parameters and the cloud model. Combined with the inspection defect parameters of a line in the Baicheng district of Jilin Province and the critical evaluation index data such as grounding resistance, sag, and wire corrosion, which are used to calculate the timeliness of the data, the solid line is evaluated. The research shows that the dynamic evaluation model is correct and that the ETL status evaluation and early warning method have reasonable practicability.

To understand anti-democratic barriers to accomplishing energy democracy, I examine how and why a centralised energy system can maintain itself based on an ethnographic analysis of the local protest of the Miryang community against the Korea Electric Power Corporation's construction of a 765,000-volt transmission line. In doing so, I incorporate the element of authoritarian communication into the framework of peripheralization – a socio-political reproduction of social, spatial, and environmental inequality caused by siting environmentally hazardous facilities in peripheral communities and reinforcing their powerlessness – to emphasize the aggressive role of government and industry actors. Composed of unidirectional projection, partial absorption, and forceful suppression, authoritarian communication makes the sacrifices of peripheral communities enduring, and consequently enables an undemocratic energy arrangement to be resilient and perpetual. To overcome this mechanism, I highlight the active roles of citizens to contest authoritarian communication and socio-environmental inequalities as a precondition to building a sustainable energy democracy. [ABSTRACT FROM AUTHOR]

Aiming at the problem of off‐line deicing in overhead transmission lines, such as poor continuity of power supply and possible damage of lines caused by over‐thick deicing, a new online anti‐icing and deicing method based on external excitation resonance is proposed. The theoretical basis of the external excitation resonance to anti‐icing and deicing is established. Then the modal characteristics of the external excitation resonance are determined through the modal analysis of the ice‐coated transmission lines, and the reasonable frequency range of the external excitation resonance is obtained. According to the theoretical analysis and calculation results, the anti‐icing and deicing robot system is designed by the external excitation resonance. Intelligent video technology is used to detect the icing condition of transmission lines in real time, and the vibration frequency range of transmission lines is analyzed and calculated. The vibration frequency is adjusted through the real‐time tracking of the resonance feedback mechanism to ensure the continuity of the resonance working state, so as to effectively realize the efficient anti‐icing and deicing of the transmission lines with the thickness of 1–3 mm at the initial icing stage. Finally, the parameters of the key components of the system are calculated and determined, and the related influencing factors are analyzed. A new deicing theory based on anti‐icing theory is proposed, and specific engineering measures are given. © 2020 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [ABSTRACT FROM AUTHOR]

Abstract Recently, parts of the solar energy (especially photovoltaic power station) could not be connected to power system, leading to a serious solar energy curtailment problem. Generally speaking, in 2017, 91.4% of the rejected solar energy occurs in the northwestern China with the total electricity reaching 6670 GW h. Because China is of a large amount of the installed solar capacity, the existing large-scale solar energy curtailment problem have greatly affected the development of the solar power industry (e.g. the investors' profits) and the long-term development of the China's clean energy policy. In this review, based on the statistical data released by the authorities, the current status of the solar energy curtailment are reviewed with a detailed analysis of the reasons from the aspects of power generation and electric grid. This review focuses on the cases of the two typical provinces (Gansu province and Xinjiang Uygur Autonomous Region) with large-scale solar energy curtailment together with related analysis. Several practical solutions are also proposed to further relieve the problem in the near future. Detailed comparisons between different schemes are also given in order to help policy makers in China and also other countries for the further development of the solar power generation. Highlights • Current status of solar energy curtailment are reviewed with analysis from the aspects of power generation and power grid. • Two typical provinces with large-scale solar energy curtailment are reviewed together with related analysis. • This review also proposed several practical solutions to further relieve the problem in the near future. • Detailed comparisons between different schemes are given for the policy makers. [ABSTRACT FROM AUTHOR]

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