Rated Voltage 110 kV XLPE Insulated (Flame Retardant) Power Cable

Executive Standards
The design, manufacture, and testing of the product strictly comply with the following standards:
- GB/T 11017-2014: "Power cables with cross-linked polyethylene insulation and their accessories for rated voltage of 110 kV (Um = 126 kV)" (core national execution standard).
- Q/320481SS356-2021: Enterprise-specific technical standard formulated for cables with flame retardant characteristics.
- GB/T 19666: General rules for flame retardant wires and cables.

Model Code Definitions
The extra-high voltage cable model reflects its material and protective construction through specific combinations:
- YJ: Cross-linked polyethylene (XLPE) insulation.
- LW: Metal sheath (usually aluminium sheath), providing sound radial water resistance and mechanical protection.
- 02: Polyvinyl chloride (PVC) outer sheath.
- 03: Polyethylene (PE) outer sheath.
- -Z: Longitudinal water blocking construction (preventing water penetration along the interior of the cable).
- Z(A/B/C): Flame retardant characteristic code (Class A/B/C flame retardant).

Product Specification Range
The cable adopts a single-core construction, with specifications covering requirements from high-voltage distribution to high-capacity backbone networks:
- Rated voltage: 64/110 kV.
- Conductor cross-sections:
  - Standard round conductor: 240, 300, 400, 500, 630, 800 mm².
  - Segmented conductor: 800, 1000, 1200, 1400, 1600, 1800, 2000, 2500 mm².
  - Note: The segmented conductor design effectively reduces skin effect and proximity effect during transmission in large cross-section cables, lowering operating losses.

Core Technical Parameters
1. Conductor operating temperature: The maximum continuous permissible operating temperature is 90 °C; during a short circuit (max. 5 s), the maximum conductor temperature is 250 °C.
2. Partial discharge requirements: Under stringent test voltages, the partial discharge magnitude is very small, ensuring long-term insulation reliability of the cable under extra-high voltage electric fields.
3. Water resistance: A metal sheath (such as an aluminium sheath) combined with a longitudinal water blocking layer (-Z) forms a complete sealing system, preventing the "water tree" phenomenon that leads to insulation ageing.

Product Structural Characteristics
- Triple-layer co-extrusion process: The conductor shield, XLPE insulation, and insulation shield are applied using a triple-layer co-extrusion process. The interfaces are tightly bonded, eliminating air gaps and greatly improving dielectric strength.
- High-performance metal sheath: The aluminium sheath can not only withstand high short-circuit current impact but also acts as a mechanical protective layer against external impact and provides 100% radial water blocking.
- Large cross-section process: For specifications of 1000 mm² and above, a segmented conductor construction is adopted, maintaining current-carrying capacity while preserving cable flexibility.

Applicable Scenarios
- Urban power grid backbone: Serving as underground extra-high voltage main lines in high-rise building dense areas or core urban districts.
- Energy transmission channels: Outgoing lines from step-up substations of large thermal, hydroelectric, or nuclear power plants.
- Industrial giant power supply: Dedicated high-voltage distribution systems for steel, chemical, and heavy machinery manufacturing parks.

Selection and Installation Recommendations
- Earthing method consideration: Due to the high induced voltage generated by 110 kV cables, the earthing method of the metal sheath (such as cross-bonding or single-point earthing) must be carefully designed according to line length and load conditions during installation to reduce circulating current losses.
- Bending radius limitation: Extra-high voltage cables have a large overall diameter and tight construction. The minimum bending radius requirement (typically 15–20 times the overall cable diameter) must be strictly observed during installation, and dedicated bending rollers must be used.
- Environmental monitoring recommendation: For critical 110 kV lines, it is recommended to combine distributed fibre optic temperature measurement technology or real-time load monitoring systems to ensure the long-term safe operation of the extra-high voltage power artery.