Learn Electrical Engineering
Explore high voltage cables — construction, insulation types, testing methods, and installation practices for reliable power transmission.
Conductor of an EHV Cable This is the main part of the cable. The one and only purpose of a cable is to carry electric current. The conductor performs that task. The conductor of an EHV XLPE cable is normally stranded. It is needless to say that the stranding is done to reduce the skin … Read more
XLPE stands for Cross Linked Polyethylene. This is a type of polymer insulation widely used in electrical power cables, especially in high voltage (HV) and extra-high voltage (EHV) applications. It is derived from polyethylene but has been chemically modified to improve its thermal, mechanical, and electrical properties. Key Features of XLPE Cross-Linking Process: In standard … Read more
Type Tests for above 33KV up to 220KV XLPE Copper Cable Tests on Conductor Tests on Insulation 3. Measurement of Thickness of Insulation4. Measurement of tensile strength and elongation at break5. Thermal ageing in air oven6. Hot set test7. Shrinkage test8. Void and contaminants test Tests on semiconductive layers of the insulation 9. Resistivity test … Read more
A Milliken conductor is a specialized type of stranded electrical conductor. We primarily use this type of conductor in high-voltage (HV) and extra-high-voltage (EHV) power cables. Its design reduces the skin effect and, the proximity effect. Therefore, it improves current distribution in large cross-sectional conductors, typically those exceeding 800 mm² (e.g., 1000, 1200, 1600, 2000, … Read more
Before discussing the types of sheath bonding used in high voltage cable let us recall our knowledge regarding sheath and cause of induced voltage and current in the sheath of a HV cable. Actually, all types of bonding are used to limit the unwanted, induced voltage and current in a cable sheath. What is a … Read more
Sheath Voltage Limiters (SVL) As I have already told, in high-voltage cables, the metallic sheath plays an important role in protecting the conductor from external physical, environmental and electromagnetic influences. But due to electromagnetic induction of the current flowing through the main conductor, a voltage is developed along the sheath, especially in long cable runs. … Read more
The Earth Continuity Conductor or ECC provides an alternate fault current path in EHV installations, limiting dangerous sheath voltage and safeguarding cable insulation. Sometimes, we also call it Earth Continuity Cable. We most commonly use single-core cables for underground high-voltage transmission systems. This is because 3-core high-voltage transmission cables, mainly above 33kV, are not easily … Read more
Type Tests for XLPE Copper Cable Tests on Conductor Tests on Insulation Tests on Semiconductor Layer on the Insulation Tests on Metallic Screen Tests on Metallic Sheath Tests on Armours Tests on Outer Sheath Tests on Complete Cable Specimen Routine Tests on XLPE HV Cables Acceptance Tests on XLPE HV Cables