ROCKWILL H59 Grounding Transformer Solution: Zig-Zag Winding & Smart Monitoring for Neutral Grounding Systems
ROCKWILL H59 Grounding Transformer Solution: Zig-Zag Winding & Smart Monitoring for Neutral Grounding Systems
Application Scenarios:
Neutral point grounding in ungrounded or resonant grounded systems, limiting single-phase ground fault current, suppressing system overvoltage.
I. Core Design Solutions
- Customized Grounding Transformer
- Built on the H59 oil-immersed transformer platform, with high-voltage side using Zig-Zag windings or Yn-d connection to provide stable neutral grounding impedance.
- Complies with IEC 60076 and NF C52-112 standards, with insulation strength designed to withstand ground fault current surges.
- Key Parameters Configuration
|
Parameter |
Value/Specification |
|
Rated Voltage |
System voltage adaptation (6kV/10kV/20kV/33kV) |
|
Short-Time Overload |
Withstands 10–20× rated current for 10 seconds |
|
Zero-Sequence Impedance |
Customized per system capacitive current (Typical: 40Ω–100Ω) |
|
Connection Method |
Znyn11 or YNd11 |
- Grounding Method Selection
- Resistance Grounding: Secondary side connected to stainless steel grid resistor cabinets, limiting fault current to a safe range (Optional: 200A–2000A).
- Arc Suppression Coil Grounding: Paired with automatic tuning arc suppression coils to extinguish fault-point arcs.
II. Technical Advantages
- Reliable Structure & Protection
- Fully sealed oil tank: IP23 protection rating, suitable for outdoor installation (–25℃ to +50℃).
- Epoxy resin bushings: High-voltage side uses 33kV-grade T-type cable terminations (EPDM material), ensuring insulation reliability in humid environments.
- Intelligent Monitoring System
- Integrated DGPT2/DMCR protection relays for real-time monitoring of:
✓ Neutral point current/voltage
✓ Oil temperature (55℃ max. temperature rise)
✓ Oil level & pressure transients
✓ Fault gases (H₂, CH₄) content. - High Efficiency & Energy Saving
- Copper windings + ONAN cooling: No-load loss ≤0.2% of rated capacity (e.g., 1300W for 630kVA).
- Efficiency >98.5% (at full load, cosφ=1), meeting green grid standards.
III. Engineering Adaptation Services
- Customized Configuration
- Bushings creepage distance customized for altitude (>1000m requires reinforced insulation) and pollution levels.
- Optional add-ons:
- 5-position non-excitation tap changer (±2×2.5%)
- Stainless oil valves & anti-vibration roller bases.
IV. Typical Case Parameters
|
Capacity (kVA) |
System Voltage (kV) |
Zero-Seq. Impedance (Ω) |
Resistor Current (A) |
Protection Device |
|
300 |
20 |
60 |
400 |
DGPT2 + Thermostat |
|
500 |
33 |
85 |
800 |
DMCR + Gas Relay |
V. Service Commitment
- 10-year warranty: Lifelong maintenance for seals and windings.
- 48-hour response: Technical support hotline +86 577 27869969.
- Documentation provided: Grounding calculation reports, type test certificates (including temperature rise & short-circuit tests).
Note: This solution requires user-provided parameters (e.g., system short-circuit capacity, capacitive current) for precision engineering. Rockwill engineers will customize designs accordingly.
