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.
