High Voltage Submarine Power Cable Fundamentals
📌 Submarine power cables transfer energy, typically from offshore sources like wind turbines, to land, lying on or under the seabed.
🔌 These cables must possess high flexibility and mechanical strength for deep-water operation, utilizing solid XLPE for excellent electrical insulation without oil cooling.
⚡ They operate across a wide voltage range, from $1 \text{ kV}$ up to $500 \text{ kV}$, and are crucial for powering offshore activities like oil/gas platforms and subsea observatories.

Cable Structure and Design Challenges
🔩 A typical cross-section includes conductors, a lead sheet to block the electric field, twisted outer armor for mechanical strength, all packaged within XLPE insulation.
📊 Key performance characteristics engineers evaluate include capacitance, resistance, voltage carrying capacity (electric field distribution), breakdown voltage, losses (eddy current losses in lead sheets and armor), and temperature distribution.

Simulation of Electrical Characteristics (2D Analysis)
✅ 2D simulation using EMx 2D confirmed analytical calculations for capacitance ($0.166 \mu \text{F/km}$) and inductance ($0.48 \text{ mH/km}$ vs. analytical $0.50 \text{ mH/km}$), aligning closely with IEC standards.
⚡ Electric field simulation confirmed that grounded metallic sheets act as a Faraday cage, confining the field within the XLPE insulator, whose breakdown voltage must exceed the operating electric field.
🔥 Loss analysis in 3D included $I^2R$ losses in conductors, eddy current losses in the lead sheet, and losses in the steel armor, all contributing to temperature rise.

Impact of Armor Material and Geometry on Losses
⚙️ Using steel armor results in significantly higher losses (up to $17$ to $18$ times more per unit length) compared to copper or aluminum, but steel is preferred due to its superior mechanical strength.
➰ Simulating twisted vs. untwisted steel armor showed that twisted armor wires significantly reduce armor losses, decreasing total loss from $1.4 \text{ kW/km}$ to $1.22 \text{ kW/km}$, justifying the complex geometry.

3D Simulation and Thermal Coupling (EMS 3D)
🌡️ EMS 3D, integrated within SolidWorks, allows for simulation over a definite cable length, enabling the calculation of magnetic flux distribution, current density, and quantifying losses in components.
📉 Visualization showed that steel armor provides excellent magnetic flux shielding, and current density plots clearly illustrate skin and proximity effects in the conductors and lead sheets.
📈 Coupling magnetic and thermal solvers computed temperature distribution, ensuring the maximum cable temperature ($33.45^{\circ}\text{C}$ in the example) remains well within design specifications.

Key Points & Insights
➡️ Electromagnetic simulation tools (EMx 2D and EMS 3D) are highly reliable for accurately calculating key cable parameters like capacitance, inductance, and resistance, matching analytical and standard results.
➡️ Engineers must balance the trade-off between the mechanical strength provided by steel armor and the associated increased eddy current losses.
➡️ The use of twisted armor geometry is a critical design feature proven by simulation to substantially mitigate armor losses compared to untwisted designs.
➡️ Integrated simulation within CAD platforms like SolidWorks shortens the learning curve and allows for direct analysis of complex 3D effects like flux shielding and current distribution.

📸 Video summarized with SummaryTube.com on Nov 10, 2025, 13:34 UTC