scholarly journals A Couple of Generator and Motor as Electric Transmission System of a Driving Shaft to Long Distance Driven Shaft

2018 ◽  
Vol 67 ◽  
pp. 01013 ◽  
Author(s):  
Iswanjono ◽  
Y.B. Lukiyanto ◽  
Budi Setyahandana ◽  
Rines
Keyword(s):  
Electric Power ◽  
Electric Machines ◽  
Total Efficiency ◽  
Market Place ◽  
Electrical Transmission ◽  
Long Distance ◽  
Electric Generator ◽  
Electric Transmission ◽  
Shaft Power ◽  
Cable Lines

Wind energy converter commonly converts wind power to shaft and electric power. One of the problems of transmitting shaft power is the limited distance between the driving to the driven shaft. This paper describes an experimental study of electrical transmission from driving to the driven shaft that was carried out on three modes of cable lines transmission. The driving shaft was attached to an electric generator that converts shaft r to electric power. The driven shaft was coupled by electric motor which reconverts the electric to shaft power. The generator and motor were BLDC and BDC permanent magnet electric machines. The distance of the driving to the driven shaft was 300 meters. The electric power was transmitted using wires. The wires consisted of 2 and 3 cables commonly used by peoples and sold in market place. The results showed that electric transmission mode on the experiment has important role on performance of shaft power to electric power conversion on driving generator and energy losses on cables transmission. DC on small wires electric transmission gave total efficiency of 16.2 %. DC on large wires electric transmission gave total efficiency of 32.9 %. AC on large wires electric transmission gave total efficiency of 36.4 %.

Research on a simulating device for electric transmission characteristics of long-distance subsea umbilical cable

2020 ◽  
pp. 147509022092450
Author(s):  
Yufang Li ◽  
Honglin Zhao ◽  
Yongbiao Xu ◽  
Deguo Wang
Keyword(s):  
Voltage Drop ◽  
Low Cost ◽  
Signal Transmission ◽  
Transmission Characteristics ◽  
Electrical Transmission ◽  
Long Distance ◽  
The Real ◽  
Transmission Attenuation ◽  
Umbilical Cable ◽  
Attenuation Characteristics

Subsea umbilical cable is an important link to transmit power and signals in subsea production system, often lasts for tens of kilometers in deep-sea projects. It is expensive, bulky, and inconvenient to transport. In this article, a compact, low-cost umbilical cable electrical simulator is proposed, which can be equivalent to the real umbilical cable in power transmission characteristics and can adjust parameters in a certain range. By studying the electrical transmission characteristics of long umbilical cable, the calculation method of electrical transmission characteristics is determined. A simulation device for simulating the transmission characteristics of umbilical cable is designed, which can be used to simulate the umbilical cable diameter of 10 and 16 mm2. The voltage drop characteristics, signal transmission attenuation characteristics, and power carrier characteristics of the umbilical cable electrical simulation device are simulated and experimentally analyzed. The experimental results show that the voltage drop characteristics, signal transmission attenuation characteristics, and power carrier characteristics of the umbilical cable electrical simulator are in good agreement with the real umbilical cable. The simulation device of umbilical cable can well simulate the power and signal transmission characteristics of real umbilical cable.

Researches on Reactive Compensation for Long-Distance and Highcapacity Hybrid Submarine Cable Lines

2012 ◽  
Vol 433-440 ◽  
pp. 2406-2410
Author(s):  
Dong Mei Sun ◽  
Jun Wen
Keyword(s):  
High Voltage ◽  
Transmission Lines ◽  
Reactive Power ◽  
High Capacity ◽  
Reactive Power Compensation ◽  
Submarine Cable ◽  
Long Distance ◽  
Power Frequency ◽  
Electro Magnetic ◽  
Cable Lines

In order to balance reactive power, reduce line losses, prevent excessive power frequency and switching over-voltage and adjust and control the line voltage etc. The long-distance and high voltage transmission lines are needed reactive power compensation. High voltage overhead transmission lines and high voltage submarine cable (including mixed-submarine) transmission lines are different, for example, the capacitance in the submarine cable lines is larger than in the conventional overhead lines. Therefore, the reactive power compensation on the EHV transmission lines which contains submarine cable lines is focus on the compensation of submarine cable lines. The reactive power compensation in 500 kV AC submarine cable interconnection project for Hainan power grid and Guangdong power grid[1], which is the first 500 kV long-distance and high-capacity sea trails interconnection project in China and which is just completed soon, is researched by Electro-Magnetic Transient Program——PSCAD/EMTDC (Power System Computer Aided Design/ Electro Magnetic Transient in DC System in this paper). The simulation results verifies that the role of shunt reactor which could absorb charging power and suppress the power frequency overvoltage for the long-distance and high-capacity hybrid submarine cable lines. The conclusions can offer references to suppress power frequency overvoltage and the reactive power compensation in extra high voltage transmission lines which is the mixed mode of overhead transmission lines and submarine cables.

Multiobjective optimization of a tubular pump to improve the applicable operating head and hydraulic performance

2020 ◽  
pp. 095440622094711
Author(s):  
Wenlong Zhao ◽  
Jian Zhang ◽  
Xiaodong Yu ◽  
Daqing Zhou ◽  
Melih Calamak
Keyword(s):  
High Efficiency ◽  
Guide Vane ◽  
Optimization Method ◽  
Critical Parameters ◽  
Long Distance ◽  
Blade Thickness ◽  
Weighted Matrix ◽  
Wide Range ◽  
Shaft Power ◽  
Water Conveyance

Tubular pumps are widely used in irrigation and water conveyance projects. However, the operating head of most of these pumps is low, and only a few studies have focused on the design of an efficient tubular pump with a head more than 5 m, which is common in long-distance water supply projects. This work aims to improve the operating head and efficiency of tubular pumps while maintaining a low shaft power. The multi-objective orthogonal optimization method was used to determine the critical parameters of the tubular pump, i.e., blade number, airfoil, blade thickness and guide vane distance, and nine design schemes were selected. Next, by using computational fluid dynamics (CFD), a 3D model of the tubular pumps under different schemes was established, and the results were compared. Subsequently, the range method and weighted matrix method were utilized to find the optimized scheme. In addition, an experimental investigation was performed to verify the simulation and the performance of the designed tubular pump. The results indicated that the optimized scheme improved the operating head to 6.9 m with higher efficiency of 84.2% and a lower shaft power of 27.7 kW. The modeling results were in agreement with the experimental measurements, and the designed tubular pump had a wide range of high-efficiency zones.

scholarly journals Supplying Baseload Power and Reducing Transmission Requirements by Interconnecting Wind Farms

2007 ◽  
Vol 46 (11) ◽  
pp. 1701-1717 ◽  
Author(s):  
Cristina L. Archer ◽  
Mark Z. Jacobson
Keyword(s):  
Wind Speed ◽  
Electric Power ◽  
Wind Power ◽  
Electric Energy ◽  
Wind Farms ◽  
Long Distance ◽  
Annual Average ◽  
Transmission Grid ◽  
Wind Speeds ◽  
Average Wind

Abstract Wind is the world’s fastest growing electric energy source. Because it is intermittent, though, wind is not used to supply baseload electric power today. Interconnecting wind farms through the transmission grid is a simple and effective way of reducing deliverable wind power swings caused by wind intermittency. As more farms are interconnected in an array, wind speed correlation among sites decreases and so does the probability that all sites experience the same wind regime at the same time. The array consequently behaves more and more similarly to a single farm with steady wind speed and thus steady deliverable wind power. In this study, benefits of interconnecting wind farms were evaluated for 19 sites, located in the midwestern United States, with annual average wind speeds at 80 m above ground, the hub height of modern wind turbines, greater than 6.9 m s−1 (class 3 or greater). It was found that an average of 33% and a maximum of 47% of yearly averaged wind power from interconnected farms can be used as reliable, baseload electric power. Equally significant, interconnecting multiple wind farms to a common point and then connecting that point to a far-away city can allow the long-distance portion of transmission capacity to be reduced, for example, by 20% with only a 1.6% loss of energy. Although most parameters, such as intermittency, improved less than linearly as the number of interconnected sites increased, no saturation of the benefits was found. Thus, the benefits of interconnection continue to increase with more and more interconnected sites.

scholarly journals Transmission of the AC electric power to a long distance

2018 ◽  
pp. 10-15
Author(s):  
Gennadii Ivanovich Davydov ◽  
◽  
Aleksandr Mikhailovich Khoiutanov ◽  
Pavel Filippovich Vasilev ◽  
Vitalii Petrovich Kobylin ◽  
...  
Keyword(s):  
Electric Power ◽  
Long Distance

Development of a Highly Efficient Diesel Engine Boiler System With a Secondary Combustor

2008 ◽  
Author(s):  
D. H. Lee ◽  
Y. S. Cha ◽  
J. S. Lee ◽  
D. K. Lee ◽  
H. J. Park ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Electric Power ◽  
Heat Exchangers ◽  
Waste Heat ◽  
Finned Tube ◽  
Total Efficiency ◽  
Generation Efficiency ◽  
Exhaust Gases ◽  
Highly Efficient ◽  
Unburned Fuel

We have developed a highly efficient boiler system using the 930 cc diesel engine. In this system, the co-generation concept is utilized in that the electric power is produced by the generator connected to the diesel engine, and waste heat is recovered from both the exhaust gases and the engine itself by the finned tube and shell & tube heat exchangers. A specially designed secondary combustor is installed at the engine outlet in order to completely reignite the unburned fuel from the diesel engine, thereby improving a system’s efficiency as well as reducing air pollution due to exhaust gases. It is found that the total efficiency (thermal efficiency plus electric power generation efficiency) of this system reaches maximum 94.4% which is about 20% higher than the typical diesel engine boiler system currently being used worldwide.

Influence of constructive features of symmetric data transmission chains on the process of optimizing the physical level of infocommunication systems

2018 ◽  
pp. 99-107
Author(s):  
А. B. Semenov ◽  
A. L. Zubilevich ◽  
T. S. Abbasova
Keyword(s):  
Attenuation Coefficient ◽  
Data Transmission ◽  
High Frequency ◽  
Wave Impedance ◽  
Electrical Transmission ◽  
Frequency Model ◽  
Twisted Pair ◽  
Electric Transmission ◽  
Physical Level ◽  
Twist Pitch

The influence of the twisting steps of twisted pairs of horizontal LAN cables of category 6 on the primary and key secondary parameters of the electrical transmission medium of infocommunication systems is investigated. The primary parameters are investigated, which make it possible to determine the secondary parameters of a symmetrical conductive path: wave impedance and attenuation coefficient. It is shown that, with respect to a twisted pair with the smallest twist pitch, it is expedient to apply the high-frequency model to calculate the electric transmission path.

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