On variational mode decomposition of wind speed for real-time thermal rating determination in power transmission system

2021 ◽  
pp. 0958305X2110339
Author(s):  
Salah K ElSayed ◽  
Mohammad Alsharef ◽  
Mohamed K Metwaly

Power transmission line capacity is restricted with the maximum temperature that can withstand without inadmissible of line sag. Regardless of the carried current, the temperature of the transmission line conductors was affected by various weather variables. However, the maximum capacity of the line current known as static thermal rating was determined based on the conservative weather conditions for safe operation, but the restriction of the line capacity may be modified which results in the additional capacity of the line. As a result, real-time thermal rating technique was applied on thermal model of the transmission line. Generally, the information about weather conditions is considered uncertainty, however, the weather variables should be dealt with and studied statistically for determining the accurate rise in the conductor temperature. The real-time thermal rating technique is evaluated using weather variables. The most important parameter is the wind speed, which greatly influence s conductor temperature and implicitly affects power transmission line capacity. Thus, in this study, the real-time thermal rating technique is developed by weather variable model based on the variational mode decomposition technique that applied only on the wind speed for adapting wind speed measurements to produce conservative evaluation of convective cooling on the conductors of power transmission system without violating the maximum operating temperature inside the core of conductors. The developed real-time thermal rating is implemented on sections of the power transmission system of western Saudi Arabia. The developed technique is compared with other techniques to investigate its applicability.

2018 ◽  
Vol 55 (7) ◽  
pp. 070606 ◽  
Author(s):  
谢凯 Xie Kai ◽  
张洪英 Zhang Hongying ◽  
赵衍双 Zhao Yanshuang ◽  
田野 Tian Ye ◽  
吕中宾 Lü Zhongbin ◽  
...  

2020 ◽  
Vol 4 (41) ◽  
pp. 29-34
Author(s):  
LEONID YUFEREV ◽  
◽  
ANTON SPOROV

Resonant power transmission systems are designed for power supply to remote consumers of small and medium power, as well as for lighting of premises and territories. The systems include frequency conversion devices, power lines, and reverse voltage conversion devices to the required voltage for the consumer. This system can be used for transmitting electricity via power lines to Wi-Fi access points. (Research purpose) The research purpose is in analyzing LPWAN networks, developing a set of equipment for resonant power transmission, calculating the project cost and describing the operation of the resonant system set. (Materials and methods) During the study, the next materials, equipment, and devices were used: a three-phase rectifier with a capacitor filter, an electronic transmission control circuit, power switches and a resonant oscillating circuit (transformer). (Results and discussion) To design and manufacture the installation, authors used the principle of operation of the resonant power transmission system based on the use of two transformers, operating at a frequency of 5-15 kilohertz, and single-wire line between them with a line voltage of 1-10 kilovolts when operating in a resonant mode at which the system operates at a frequency of 7-9 kilohertz, and the voltage in the transmission line of 1500 volts allows to transmit electricity through the single-wire transmission line with a capacity of up to 8,000 watts at a distance of 1.5 kilometers. Authors analyzed the features of the LPWAN network and developed a set of equipment for resonant power transmission, transmitting and receiving units. (Conclusions) The scientific and practical significance of the results is in: a set of resonant power transmission systems, calculated the cost of the project, and the principle of operation of the system.


Author(s):  
Hyunho Lee ◽  
Changhwan Kim ◽  
Sunggi Park ◽  
Seok Lee ◽  
Jaehun Kim ◽  
...  

2018 ◽  
Vol 11 (3) ◽  
pp. 222-226
Author(s):  
M. V. Timofeeva

Accidents in power transmission lines under icing conditions, in particular, those of cables, cause a great economic damage in Russia. Because of the lack of the possibility to forecast and evaluate reliably the consequences of weather conditions contributing to icing of transmisison line cables, power grid services often have to go to the place of a potential accident relying on guesswork. This leads to considerable losses of time and material resources, while the average recovery time of a damaged high voltage power transmission line is 5–10 days.For the effective prediction and timely prevention of negative consequences of icing of on power line cables, an analytical model that describes the growth of ice on the surface of the electrical cable has been developed. The model is based on a widely applicable analytical model of [1], supplemented with dependence of the growth of ice sleeve on the angle between the wind direction and the cable, and on the electric field strength of the cable.The results obtained using the new analytical model and the [1], model have been compared and show that as the angle between the wind direction and the cable decreases, the intensity of the ice growth decreases significantly. At the same time, the strength of the electric field of the cable affects negligibly the trajectory of water droplets.A conclusion is drawn about insignificance of electrical field strength of the electric cable as a factor of growth of ice deposits. It is stated that the ice thickness value obtained using the developed model can be increased under specific weather conditions and design parameters of transmission lines. The obtained model can be improved by using other physical effects that affect icing of electric cables. Further, the model can be introduced in operation of energy companies to monitor the condition of power transmission lines and to carry out anti-icing activities.


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