LY-LXQ Series Nonlinear Resistor Harmonic Damping Device for Neutral Point of 6-35kV Voltage Transformers (Primary Harmonic Eliminator for short)
This device is installed between the neutral point of the primary winding (Y₀ connection) and ground of 6-35kV voltage transformers (hereinafter referred to as PTs). It functions as a nonlinear resistor harmonic damping component specifically designed for neutral point applications.

Material & Manufacturing Process:
The harmonic eliminator utilizes ultra-fine particle silicon carbide (SiC) with superior electrical properties as its base material. The manufacturing involves:

1. High-density compaction of SiC powder using multi-ton presses to form rectangular or disc-shaped blanks
2. High-temperature sintering (>1,000°C) under reducing atmosphere to achieve optimal material density
3. Special surface treatment of exposed resistors for weather resistance, enabling direct outdoor/indoor installation without enclosure

Technical Advantages:

• Compact Design: 40-60% smaller footprint than traditional solutions
• Lightweight Construction: 30-50% weight reduction vs. equivalent porcelain-type devices
• Enhanced Thermal Performance:
  • Thermal conductivity: ≥80 W/(m·K)
  • Maximum operating temperature: 155°C (IEC 60068-2-2)
• Mechanical Robustness:
  • Compressive strength: ≥200 MPa
  • Impact resistance: IK10 (IEC 62262)

Application Features:

• Effective Harmonic Suppression:
  • Damping range: 50Hz-2kHz
  • Resonance attenuation: ≥30dB @ 3rd harmonic
• Environmental Adaptability:
  • IP67 rated (IEC 60529)
  • UV resistance: QUV-B 3000h (ASTM G154)
• Maintenance-Free Operation:
  • MTBF: >200,000 hours (MIL-HDBK-217F)
  • Self-cleaning surface design

Typical Applications:

• Neutral point grounding of 6/10/20/35kV PTs in substations
• Ferroresonance suppression in ungrounded/compensated systems
• Overvoltage protection for capacitor voltage transformers (CVTs)

Compliance Standards:

• IEC 61869-1:2020 (Instrument transformers - General requirements)
• GB/T 20840.7-2007 (Mutual inductors - Part 7: Electronic voltage transformers)
• DL/T 866-2015 (Technical conditions for voltage transformers)