Switchgear Connectors and Terminals for Harsh Offshore Installations

This is the third article in a 6-part series featuring topics on Connectivity and Sensing in Harsh Environments. The series will showcase how highly engineered connectivity, and sensing solutions enable advancements in manufacturing, transportation, construction, healthcare, energy generation, and consumer products. This series is sponsored by Mouser Electronics. Through the sponsorship, Mouser Electronics shares its passion for technologies that enable smarter and connected applications.

The marine industry has moved from the ‘Sail Age’ through the ‘Steam Age’ to the ‘Electricity Age’ now. With the rapid developments in the shipbuilding and offshore industry, we can now reflect on some key trends that have emerged in power systems. ^[1]

1. Rapid electrification has resulted in electricity becoming the main source of power for the industry.

2. High-voltage and high-power systems are becoming a necessity for operations.

3. The scale at which projects are implemented is getting bigger.

This article presents three case studies wherein highly engineered electrical connectors, and terminations by TE, a company specializing in connectivity technologies, enabled the construction and operations of offshore installations in harsh environments.

Case 1: Robust and Reliable Switchgear Connectors For Offshore Wind Farms

Over 10% of global electricity is generated by wind energy. ^[2] Windmills are harnessing an enormous amount of energy already.  But in reality, this is just a tiny fraction of their true potential. Wind, as we know it, is a phenomenon that sweeps the entire earth, including all the landmasses and oceans. Constructing wind farms in the oceans can help us tap into the true potential of wind energy. Such projects are referred to as offshore wind farms and have emerged as interesting alternatives to the onshore wind farms. But being positioned in the middle of an ocean, the development of such projects becomes an engineering challenge.

Three leading renewable energy companies initiated the construction of one of the world´s largest offshore wind farms. With an area of approximately 100 km², the wind farm would supply power for nearly half a million homes a year and significantly decrease the CO₂ emissions in the region. ^[3]

Fig. 1: Offshore wind farms have to endure harsh climatic conditions present in the ocean 

For this project, the engineers in charge of the energy supply structure requested screened separable connectors that would enable them to connect large cross-section cables in their unique and very compact switchgear. Because of the challenging environmental conditions of the offshore wind farm, they required connectors that could withstand extreme temperatures in an environment characterized by its high humidity and salinity.

Case 2: Improving Power Density and Efficiency in Offshore Manufacturing Industry 

As a leader in the construction of marine and offshore equipment, South Korea is home to some of the world's largest manufacturers of bulk carriers, tankers, rigs, and platforms. The country's marine designers and engineers face tough operating environments. Depleting oil reserves makes it necessary to drill even deeper and wider. ^[4]

This has led to a dramatic increase in demand for power.  To cater to this surge in power requirements, higher-density installations with an ability to operate in tough operating environments are required. 

The solution was to introduce a low-profile, short, and high-performance Medium Voltage (MV) termination to ensure ease and simplicity of installation and resistance to humid environments.

To deliver increased power density, new designs of cable accessories that facilitate simpler, faster, and more reliable installations were required. An example of this is the low-profile MV termination that allows several cables to be successfully terminated into a small space.

To ensure an even smaller, more compact, and robust solution that outperforms the competition, design engineers had to incorporate a radically new stress control system. and a total seal to the cable insulation, sheath, and lug barrel.

Case 3: Harsh Environmental Resistant Connectors and Cable Joints for Shipbuilding

The North Sea presents some of the harshest operating conditions for marine installations and products. The average temperature in the North Sea, Atlantic Ocean during the summer months is 17 °C while in winter, a season of frequent gales and storms, the normal temperature is 6 °C while salinity averages 34 g to 35 g of salt per liter of water. The North Sea is also prone to storm surges, an offshore rise of water associated with a low-pressure weather system caused primarily by high winds pushing the ocean’s surface. ^[5]

Fig. 2: Connectors used in shipyards should be resilient to several environmental hazards including fire.

The early days of exploration and recovery of North Sea offshore oil in the 1970s called for exceptionally enduring products that would meet the exacting requirements of the companies operating in this harsh environment. A British oil and gas company was looking for high-performance Low Voltage (LV) and MV joints and terminations for their innovatively constructed platforms.

The challenge was to design, test, and manufacture several fire-resistant cable joints in a limited time that could be quickly and easily installed.

Engineering components of marine power systems for reliability 

The increased complexity of offshore landscapes has led to an increase in power demands and a range of other technological challenges for the marine industry. Reliability is critical in the supply and distribution of power in offshore environments. 

Faults in electrical systems have a direct effect on the operation, control, monitoring, efficiency, and safety of the entire unit. This is why uttermost care is required when picking the components for the development of the project. The power system components need to be resilient to salinity, humidity, and a wide range of temperatures that the marine environment offers. 

Power connections and components must also have effective moisture sealing, electrical insulation, and electrical/mechanical protection. This calls for high-performance products and materials that are proven to withstand the harshest operating environments.

TE’s switchgear connectors, terminations, and other connectivity solutions for harsh offshore environments

TE offers complete switchgear solutions to empower offshore establishments like wind farms, manufacturing facilities, shipbuilding units, and more.  TE’s broad-screened separable connectors portfolio makes the projects less challenging.

LV and MV Terminations

Sealing of all interfaces is considered essential for the marine/offshore environment. MV terminations are widely used for connecting cables to equipment such as motors, generators, switchgear, and transformers together.

Fig. 3: MV terminations by TE. Source: TE Connectivity

Fig. 3: MV terminations by TE. Source: TE Connectivity

The terminations by TE have multiple advantages including: 

• Short length

• Small profile (sheds not required on wire cores)

• Easily installed in confined spaces, and even on cables that are not straight

• Total sealing of termination to cable and lug substrate

• Heat-shrink installation technology that ensures no moisture is captured or retained under the termination, even when installed in very wet or present in humid environments

• High robustness and toughness of materials used

• Precise electrical performance

• No shelf life limitations

Screened Separable Connectors

TE’s Screened Separable Connectors feature a compact design to fit in tight installation spaces, are fully shielded, submersible, and available with optional test points. Over 6 million separable connectors are in use worldwide.

Screened Separable Power Connectors by TE. Source: TE Connectivity

TE´s Screened Separable Connectors adapt easily to a variety of different cable types and sizes. Their compact design and the flexibility of silicone components facilitate the installation of the connectors, saving time and reducing errors.

TE’s power connectors undergo rigorous performance testing to meet stringent safety standards. The brand pioneered terminations and connectivity solutions in the 1940s. TE connectivity solutions from the 1970s are still in operation more than 40 years after they were installed.

Conclusion

Marine and offshore environments are among the toughest testing grounds for cable accessories, because of the harsh conditions they offer. In any marine or offshore operating environment, the reliability of the products is crucial. In addition to selecting the cable accessory with the correct voltage, size, and construction, it is also vital to choose products that are proven to perform and deliver the expected full-service life.

This article was initially published by Mouser and Amphenol in an e-magazine. It has been substantially edited by the Wevolver team and Electrical Engineer Ravi Y Rao. It's the third article of a 6-part series examining connectivity and sensing technologies for harsh environments. Future articles will introduce readers to some more interesting applications of the technologies in various industries.

• The introductory article provided an overview of the different harsh environments that electronic circuits and systems are put through.
• The first article showcased how improvements in connectors, terminals, splices, relays, and heat shrink tubing enable connected applications
• The second article was focused on some key trends and design considerations for automotive connectivity systems.
• The third article presented three case studies on how connectors and terminals enable massive power handling in offshore installations. 
• The fourth article shifted the focus back to the transport industry to explain the necessity of reliable connectors that withstand harsh environments.
• The fifth article was about the theory of sensor design for harsh environments.
• The final article examined the principles, design, manufacturing, and applications of heat shrink cable accessories in depth.

About the sponsor: Mouser Electronics

Mouser Electronics is a worldwide leading authorized distributor of semiconductors and electronic components for over 1,100 manufacturer brands. They specialize in the rapid introduction of new products and technologies for design engineers and buyers. Their extensive product offering includes semiconductors, interconnects, passives, and electromechanical components.

References

[1] R. Zheng, John Duhig, ‘TE’s connectivity solution for MV power connections in harsh offshore environments, TE Connectivity, [Online], Available from: https://www.te.com/content/dam/te-com/documents/energy/global/productdocuments/Shipbuilding/energy-shipbuilding-wp-MV-en.pdf

[2] Wind Market Reports: 2021 Edition, Office of Energy Efficiency and Renewable Energy, US Dept. of Energy, [Online], Available from: https://www.energy.gov/eere/wind/wind-market-reports-2021-edition

[3] A case study on Switchgear connectors in harsh environments, TE Connectivity, [Online], Available from: https://www.te.com/content/dam/te-com/documents/energy/global/productdocuments/RSTI/energy-RSTI-case_study.pdf

[4] A case study on Improving Power Density and Efficiency in South Korea, TE Connectivity, [Online], Available from: https://www.te.com/usa-en/industries/oil-gas-marine/insights/shipbuilding-and-offshore-case-study-korea.html

[5] A case study on Harsh Environmental Resistant Cable Joints for Shipbuilding and Offshore, TE Connectivity, [Online], Available from: https://www.te.com/usa-en/industries/oil-gas-marine/insights/shipbuilding-and-offshore-case-study-britain.html

[6] Advanced Separable Connector Technology, TE Connectivity, [Online], Available from: https://www.te.com/content/dam/te-com/documents/private/Energy/energy-cable%20accessories-ssht-epp%202922-separable%20connectors-en.pdf

[7] Raychem screened separable connectors for switchgear and transformers in medium voltage distribution networks, TE Connectivity, [Online], Available from: https://www.te.com/content/dam/te-com/documents/energy/global/productdocuments/RSTI/energy-switchgear-br-epp2566-en.pdf