Unveiling soil thermal behavior under ultra-high voltage power cable operations.

Area of Science:

• Electrical Engineering
• Geotechnical Engineering
• Thermal Science

Background:

• High-voltage underground power cables are vital for community power.
• Cable insulation temperature, influenced by joule heating, is critical for optimal operation.
• Soil moisture and power demand fluctuations affect cable thermal performance.

Purpose of the Study:

• To investigate the thermal behavior of underground power cables under various soil conditions and thermal loads.
• To expand on previous research by including static and cyclic thermal loads in dry and saturated sand.
• To provide insights for improving the efficiency and sustainability of power cable infrastructure.

Main Methods:

• Conducted extensive laboratory tests on underground power cable models.
• Applied static and cyclic thermal loads to cables embedded in dry and saturated sand.
• Monitored insulation temperature and analyzed heat dissipation dynamics.

Main Results:

• Cyclic thermal loads in dry sand showed a significant thermal charging effect with shorter relaxation times.
• Saturated sand improved heat dissipation due to higher thermal conductivity under static loads.
• A robust convection cell formed in saturated sand after three days, posing challenges for cables under crop fields.

Conclusions:

• Soil moisture content and thermal load patterns critically influence underground power cable thermal management.
• Understanding soil-cable thermal interactions is essential for sustainable clean energy infrastructure.
• Optimizing cable performance requires considering environmental factors like soil saturation and convection.