Search

Offshore substations are important sustainable power infrastructures subjected to strong vibrations induced by complex environmental excitations such as wind, waves, and currents. To protect the structures and expensive facilities, lightweight vibration control devices are highly desirable in offshore substations. With a high-performance energy dissipation device, the inerter, the conventional Tuned Mass Damper (TMD) is upgraded for lightweight vibration control. The optimal parametric design and performance evaluation of single- and double-tuned vibration control devices is performed based on the H-norm criteria. The corresponding equivalent mass ratios of both single- and double-tuned vibration control devices are summarized and formulated in a systematical manner. Finally, the presented optimal design formulas, equivalent mass ratios, and control performances are validated by vibration control analyses on a practical offshore substation. The results show that inerter-based vibration control devices can be effectively equivalent to a TMD, with the equivalent mass ratio. The double-tuned inerter-based device could save 25% mass compared to a TMD. With a Tuned Mass Damper Inerter (TMDI), the responsibility for the mass could be shared with dual-end connected inerters. Meanwhile, the Tuned Viscous Mass Damper (TVMD) completely replaces the mass block with an inerter, which has a superior lightweight vibration control performance. [ABSTRACT FROM AUTHOR]

Condition-based maintenance is very desirable for minimizing the maintenance and failure costs of power systems without sacrificing reliability. A systematic approach including an adaptive maintenance advisor and a system maintenance optimizer is proposed here for effectively handling the operational variations and uncertainties for condition-based maintenance. First, the maintenance advisor receives and implements the maintenance plans for its key components from the system maintenance optimizer, which optimizes the maintenance schedules with multi-objective evolutionary algorithm, considering only major system variables and the overall system performance. During operation, the offshore substation will experience continuing ageing and shifts in control, weather and load factors, measurement and human judgment detected from the connected grid and all other equipments with uncertainties. Then, the advisor estimates the changes of reliability indices due to operational variations and uncertainties of its key components by hierarchical fuzzy logic and sends the changes back to the maintenance optimizer. The maintenance optimizer will upgrade the load-point reliability and report any drastic deterioration of reliability within each substation, which may lead to re-optimization of the substation's maintenance activities for meeting its desired reliability. The offshore substation connected to a medium-sized onshore grid will be studied here to demonstrate the ability of this proposed approach in dealing with uncertainties in the implementation of maintenance with significant reduction of computational complexity and rule base.

[Introduction] Sea transportation is one of the governing conditions for the structural design of topside modules, the accuracy of load input directly affects the structural design of the topside. At present, domestic sea transportation design generally ignored the influence of hull deformation in topside design, which considers the hull as a rigid body, this assumption is not in line with the actual situation, it is necessary to analyze the influence of hull deformation on sea transportation design of the topside module. [Method] Firstly, the domestic sea transportation analysis methods were introduced. Then, combined with the classification society specification, the hull deformation was theoretically expounded, and how some multinational companies consider the influence of hull deformation on sea transportation design of topside module was introduced, the current sea transportation design method was improved. [Result] Based on real project calculation, it proves that structural stress is seriously small without considering the hull deformation load. With the development of marine engineering, we need to pay more attention to the influence of hull deformation on sea transportation design. [Conclusion] This paper explains the risk of traditional sea transportation design and provides an important basis for improving sea transportation design methods.

[Introduction] This paper aims to reduce the risk of shutdown or heavy loss of regional oil fields caused by platform fire in offshore substation. [Method] Taking an offshore substation as an example, the adaptability and application scope of high pressure water mist fire extinguishing system were analyzed. Through the benchmarking analysis and calculation of domestic and foreign specifications and equipment parameter characteristics, the parameter selection and application methods of different fire extinguishing types of electrical equipment in offshore substations were proposed. [Result] The study shows that the local application system of high pressure water mist is suitable for the oil-containing electrical primary equipment and large room, and the spray intensity shall be not less than 1.5 L/(min·m2). When taking into account the equipment waterproof grade and equipment heat dissipation is not economical, heptafluoropropane fire extinguishing system should be used for electrical secondary equipment. [Conclusion] The research results can provide reference for the construction of fire extinguishing system in offshore substation.

Copyright of Southern Energy Construction is the property of Southern Energy Construction Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Southern Energy Construction is the property of Southern Energy Construction Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Introduction] In this paper, strength and toughness analysis under earthquake for the whole model of offshore substation is presented, performance of offshore substation is analyzed under effect of earthquake in the design reference period different exceedance probabilities. [Method] The seismic performance was evaluated by the results from response spectrum method for strength analysis and the pushover analysis method for toughness analysis. [Result] By analyzing performance of substation jacket platform and accessory structures, the seismic performance of the structure meets the requirement of "No damage under minor earthquake, Repairable under moderate earthquake, No collapsing under major earthquake" considering sufficient safety factor. [Conclusion] It shows that the offshore substation has good seismic performance.

Power systems are crucial for low-carbon energy applications. Condition maintenance plays a vital role in reducing the maintenance cost of renewable power systems without sacrificing system reliability. This paper proposes a hybrid method to effectively deal with the operational changes and uncertainties of state maintenance within the power system of renewable energy applications. Specifically, a multi-objective evolutionary algorithm is first adopted to maintain key components when only considering system variables and overall performance. During operation, numerous variations in offshore substations are detected from power grids and other equipment, such as continuous aging, weather, load factors, measurement, and human-judgment factors. Then, the advisor implements a system optimization maintenance plan in the substation, which can predict changes in load reliability based on the type 2 fuzzy logic and hidden Markov model technology. The reliability of the load point of each substation would also be obtained. Illustrative results indicate that these serious deteriorations would cause substation for the re-optimization maintenance and optimization activities to meet expected reliability. Through connecting an offshore substation to a medium-sized offshore substation, the uncertainties in condition-based maintenance of renewable energy applications can be well handled.

The current development of electric power industry in Poland, especially in the field of renewable energy sources, including wind power, brings about the need to introduce legislation on new work environment. The development of occupational safety and health (OSH) regulations that must be met by new workplaces, such as offshore substations becomes necessary in view of the construction of modern offshore wind power plants – offshore wind farms. Staying on offshore substation is associated with an increased exposure to harmful health factors: physical, chemical, biological and psychophysical. The main sources of health risks on offshore substations are: temperature, electromagnetic field, noise from operating wind turbines, direct and alternating current, chemicals, Legionella bacteria and social isolation of people. The aim of this article is to draw attention to the problem of offshore substation workers’ exposure to harmful factors and to present methods of preventing and reducing the risk-related adverse health effects. In this paper, there are identified and described risks occurring on offshore substations (fire, explosion, lightning, accidents at work). Some examples of the means and the methods for reducing the negative impact of exposure on the human health are presented and discussed. The article also highlights the need to develop appropriate laws and health and safety regulations concerning the new working environment at the offshore substations. The review of researches and international standards shows that some of them can be introduced into the Polish labor market. Med Pr 2016;67(1):51–72

Offshore renewable energy, and in particular the offshore wind energy sector, is still developing in many countries around the world. Wind offshore projects are characterized by the need to build offshore electric power transmission infrastructure. Offshore substations are a key element of submarine electric power transmission systems. Due to the environmental conditions, an offshore substation is constructed as an indoor facility located on a platform. Depending on the offshore wind farm capacity, there are various solutions for platform and substructure designs used for the substation. Numerous economic and technical analyses indicate a significant potential for the development of offshore wind energy in Poland. By 2030, this potential is set at 6 GW of installed capacity, taking into account 2.2 GW of power included in the connection agreements being concluded. The main objective of this paper is to present the prospects for the development of offshore wind energy in Poland, and to describe the various offshore substation solutions and the different aspects of substation operation. Offshore wind energy resources and power capacity are also presented. Moreover, solutions for offshore substation platforms, electrical equipment and layout, functions of offshore substations in the power systems and offshore substation designs are described. [ABSTRACT FROM AUTHOR]

The current development of electric power industry in Poland, especially in the field of renewable energy sources, including wind power, brings about the need to introduce legislation on new work environment. The development of occupational safety and health (OSH) regulations that must be met by new workplaces, such as offshore substations becomes necessary in view of the construction of modern offshore wind power plants - offshore wind farms. Staying on offshore substation is associated with an increased exposure to harmful health factors: physical, chemical, biological and psychophysical. The main sources of health risks on offshore substations are: temperature, electromagnetic field, noise from operating wind turbines, direct and alternating current, chemicals, Legionella bacteria and social isolation of people. The aim of this article is to draw attention to the problem of offshore substation workers' exposure to harmful factors and to present methods of preventing and reducing the risk-related adverse health effects. In this paper, there are identified and described risks occurring on offshore substations (fire, explosion, lightning, accidents at work). Some examples of the means and the methods for reducing the negative impact of exposure on the human health are presented and discussed. The article also highlights the need to develop appropriate laws and health and safety regulations concerning the new working environment at the offshore substations. The review of researches and international standards shows that some of them can be introduced into the Polish labor market., (This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.)