• Journal of Wind Energy
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• v.3 no.2
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• pp.11-17
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• 2012

An offshore(submarine) cable has been used for more than a century, however it has been used mainly for communication or power supply to near-shore island. Therefore, offshore cable has not been got more attention than other types of cable and the related standards have also not been established well. However wind farms have been shifting from land to offshore because of better wind condition. Consequently, it has been pushing up demand for offshore cable. Hence, this paper introduces the trend of offshore cable industry and related standards or recommendations only focusing on offshore wind farm. In details, the installed offshore cables in offshore wind farms, the main offshore cable makers and up to date technologies are covered. In addition, the related standards or recommendations are also analyzed and compared each other.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.4
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• pp.451-456
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• 2013

Development of the technologies for offshore wind power is proceeding actively and the installation capacity is continuously increasing because of its many advantages in comparison with the land wind power. Accordingly, project for Southwestern 2.5GW offshore wind power plant is in progress in Korea. Design of electric power systems for offshore wind power plant is very important due to its high investment and operational costs. Hence, it needs to be designed in order to minimize costs. This way can be employed in determining the installation location of offshore substation for HVAC wind power plant. According to the offshore substation site, MV inter-array cable and HV export cable lengths vary and they change a total cost regarding submarine cable. This paper represents cost models with variables which are MV inter-array cable and HV export cable lengths to locate the offshore substation for HVAC wind power plant. It is classified into submarine cable installation cost, reactive power compensator installation cost, ohmic losses, and unsupplied energy cost. By minimizing a total cost, an appropriate installation site of the offshore substation is determined.

• Progress in Superconductivity and Cryogenics
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• v.20 no.4
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• pp.60-64
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• 2018

As the offshore wind farms increase, interest in the efficient power system configuration of submarine cables is increasing. Currently, transmission system of the offshore wind farm uses almost AC system. High temperature superconducting (HTS) power cable of the high capacity has long been considered as an enabling technology for power transmission. The HTS cable is a feasible way to increase the transmission capacity of electric power and to provide a substantial reduction in transmission losses and a resultant effect of low CO2 emission. The HTS cable reduces its size and laying sectional area in comparison with a conventional XLPE or OF cable. This is an advantage to reduce its construction cost. In this paper, we discuss the economic feasibility of the 22.9 kV HTS power cable and the conventional AC power cables for an offshore wind farm connections. The 22.9 kV HTS power cable cost for the offshore wind farm connections was calculated based on the capital expenditure and operating expense. The economic feasibility of the HTS power cable and the AC power cables were compared for the offshore wind farm connections. In the case of the offshore wind farm with a capacity of 100 MW and a distance of 3 km to the coast, cost of the 22.9 kV HTS power cable for the offshore wind farm connections was higher than 22.9 kV AC power cable and lower than 70 kV AC power transmission cable.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.2
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• pp.97-103
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• 2015

This paper introduces two on-going projects for DC high temperature superconducting (HTS) cable systems in South Korea. This study proposes the application of DC HTS cable systems to enhance power transfer limits of a grid-connected offshore wind farm. In order to develop the superconducting DC transmission system model based on HTS power cables, the maximum transfer limits from offshore wind farm are estimated and the system marginal price (SMP) calculated through a Two-Step Power Transfer (TSPT) model based on PV analysis and DC-optimal power flow. The proposed TSPT model will be applied to 2022 KEPCO systems with offshore wind farms.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.6
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• pp.570-575
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• 2023

Demand and necessity for eco-friendly offshore wind farms have been increasing. Research on submarine cables is constantly being considered for a reliable and stable power transmission. This study aimed to evaluate the thermal aging characteristic of submarine cables inside the J-tube of offshore wind farms. In this study, a submarine cable was set in three sections: The first is the part exposed to the air above the sea level at high temperature. The second is the section exposed to repeated temperature fluctuation as the sea level rises and falls. The third is the part submerged at low temperature below the sea level. Aged samples were tested by using the method of electrical evaluation to obtain insulation characteristics. The experimental results show that the dielectric breakdown of the sample with temperature fluctuation was 7% lower than the sample with a constant temperature; thereby, demonstrating that the section where the temperature fluctuation occurred in the submarine cables was weaker than the other. The sections of submarine cable with temperature fluctuations are believed as a weak point during operation; therefore, this part should be monitored preferentially.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.9
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• pp.1192-1198
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• 2014

With an increase in the penetration of offshore wind farm, the need of an accurate economic evaluation of offshore wind farm has become crucial. This paper presents an economic evaluation method of offshore wind farm in Korea reflecting the cost of offshore wind farm infrastructure (offshore substation, submarine cable and foundation) in its cost model. Each cost of offshore substation, submarine cable, and foundation is represented as a function of installed capacity, distance to shore, and water level, respectively. We have applied the method to the case study of offshore in Jeju Island and analyzed the economics under various conditions. The results show that the distance to shore is of importance in economics of offshore wind farm.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.632-637
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• 2019

The cable tray design of an offshore plant production design is to optimally arrange the 3D modeling so that the cable can be installed without interfering with the structural members and various outfit equipment, and it is performed using a PDMS (Plant design management system), which is a 3D CAD system for an offshore plant layout. This study reviewed the development of PML (Programmable macro language) for a PDMS supporting offshore plant cable tray design and examined the efficiency compared to the existing method. Cable tray design PML developed in this paper enables fully parametric design using electrical outfit template library, allowing a rapid response to frequent modifications due to design changes and minimizing repetitive work fatigue by reflecting the accumulated design experience. In addition, the developed system was applied to the offshore plant structure module and it improved the work efficiency by more than 50% compared to the existing method.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.37 no.3
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• pp.286-291
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• 2024

Research on aged insulation of cables by stress is constantly being considered for reliable and stable power transmission of offshore wind farms. This study aimed to evaluate the insulation characteristic of aged XLPE (cross-linked polyethylene) insulation for application of offshore wind farms. In this study, The XLPE insulation of cable was set as various mechanical strains. The XLPE insulation is exposed to the mechanical stress below yield strain of 5%, 10%, and 20%. Aged samples were tested by using the method of AC BDV (alternative current breakdown voltage), tensile strength, elongation, and SEM (scanning electron microscope) to obtain insulation characteristics. The experimental results show that the dielectric breakdown of the sample with a strain 20% was 50% lower than the unaged sample; thereby, demonstrating that the mechanical strain that occurred in the submarine cables can weaken the insulation characteristics. Therefore, mechanical strain should be monitored when laying and operating submarine cables for offshore wind farms.

• Journal of Ocean Engineering and Technology
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• v.18 no.6 s.61
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• pp.51-57
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• 2004

In this study, the improved three-dimensional analysis model designed for a more accurate analysis of marine cable-supported structures, is presented. In this improved analysis model, the beam elements, of which the stability function is derived using Taylor's series expansions, are used to model space frame structures, and the truss elements. The equivalent elastic modulus of the truss elements is evaluated on the assumption that the deflection curve of a cable has a catenary function. By using the proposed three-dimensional analysis model, nonlinear static analysis is carried out for some cable-supported structures. The results are compared with previous studies and show good agreement with their findings.

• Journal of Ocean Engineering and Technology
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• v.33 no.3
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• pp.205-213
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• 2019

Recently, because of the global recession of the offshore plant industry and low-cost orders, there has been increasing interest in strengthening the competitiveness of domestic companies for the design and production technologies of offshore plants. However, in the offshore plant design field, the Plant Design Management System (PDMS), which is a 3D CAD program for plant layout developed by AVEVA Marine, is already commonly used as offshore plant design software and widely used in large domestic shipyards and cooperative design companies. Under this background, we have been thinking about ways to design better with the existing software. In this study, we developed a parametric design program to maximize the efficiency and reduce the working time for offshore plant electrical outfit production design based on the Programmable Macro Language (PML) of PDMS. We also examined its performance. By applying the developed program to the offshore plant module selected as an application example, it was confirmed that a 50% improvement in the work efficiency of cable tray design could be obtained compared with the existing method, with work efficiency improvements of 80% or more in other field design work.