What is a composite pin insulator?

I. Core Definition: The Intelligent Insulation Pillar of Distribution Networks

Composite Pin Insulator is a rigid insulating device made of organic composite materials, specifically designed for 10-35kV distribution lines. It combines traditional porcelain insulator technology with modern polymer materials, using an epoxy fiberglass core rod for mechanical strength andsilicone rubber sheds for electrical insulation, achieving a lightweight, high-reliability line support solution.

The term “Pin” comes from its unique pillar-type mounting structure – the insulator base is directly fixed to the crossarm via threads or flange, forming a stable support point, while the top secures the conductor through a clamp.

II. Structural Features: Three-Layer Composite Engineering Wisdom

1. Load-bearing core:

   • Epoxy fiberglass pultruded rod: Tensile strength ≥600MPa

   • Diameter range: φ18-φ36mm (depending on voltage level)

   • Elastic modulus: ≥40GPa

2. External insulation:

   • High-temperature vulcanized silicone rubber (HTV)

   • Hydrophobicity: HC1-HC2 class

   • Shed design: Alternate large/small sheds for optimal rain washing

3. Metal fittings:

   • Top: Aluminum alloy clamp with ball-joint adjustment

   • Bottom: Hot-dip galvanized steel base with GB/T 97 standard threads

   • Connection interface: Crimping process ensuring mechanical strength

Table: Performance Comparison Between Composite and Porcelain Pin Insulators

III. Technical Advantages: Breakthrough Innovations in Distribution Insulation

1. Excellent pollution flashover resistance:

   • Strong hydrophobicity maintains high insulation even when polluted

   • Operational data from Zhejiang coastal areas shows 90% reduction in pollution flashover failures

2. Outstanding mechanical performance:

   • Bending resistance up to 12kN, withstands level 10 winds

   • Good toughness, 5-7 times better seismic performance than porcelain

3. Easy installation and maintenance:

   • Weight only 1/3 of porcelain insulators, no heavy equipment needed

   • Maintenance-free design reduces maintenance workload by 70%

4. High safety and reliability:

   • No zero-value insulator issues

• • No explosive damage when failing

IV. Applications: Multi-Sector Coverage in Distribution Networks

1. Urban distribution networks:

   • Compact design suitable for confined spaces

   • Aesthetic appearance blends with urban environment

2. Rural power grids:

   • Excellent pollution resistance adapts to rural conditions

   • Reduced maintenance needs lower operational costs

3. Special environments:

   • Coastal areas: Special anti-corrosion treatment

   • Industrial zones: Chemical corrosion resistant design

   • High altitude: Increased creepage distance design

4. Renewable energy integration:

   • Distributed PV access points

   • Wind farm collection lines

V. Technical Parameters: Precision-Engineered Performance

• Electrical performance:
• • Rated voltage: 10kV/20kV/35kV

  • Dry flashover voltage: ≥110kV (10kV)

  • Wet flashover voltage: ≥65kV (10kV)

  • Lightning impulse withstand: ≥125kV (10kV)

• Mechanical performance:

• • Rated bending load: 8kN/10kN/12kN

  • Failure load: ≥16kN/20kN/24kN

  • Torsional strength: ≥100N·m

• Environmental adaptability:

• • Operating temperature: -40℃～+40℃

  • UV resistance: No aging after 1000 hours

  • Pollution class: Level IV (highest)

VI. Selection Guide: Scientific Choices Ensure Optimal Performance

• By voltage level:

• • 10kV lines: 280-320mm height
  • 20kV lines: 380-420mm height
  • 35kV lines: 480-520mm height

• By environmental conditions:

• • Clean areas: Standard creepage distance
  • Polluted areas: Increased creepage distance
  • Coastal areas: Special anti-corrosion type

• By mechanical load:

• • Normal lines: 8kN specification
  • Long span lines: 12kN specification

• Special requirements:

• • Bird protection type: Added bird deterrent devices
  • Ice/snow resistance type: Special shed design