VZIMAN Z-type Grounding Transformer Solution: Eliminating Grid Risks in Ungrounded Systems
1. Solution Background
In 6kV~36kV distribution networks, delta-connected transformer windings lack a neutral grounding point. VZIMAN® Grounding Transformer addresses this by creating an artificial neutral through Z-type winding topology. This design prevents critical risks during single-phase ground faults, including:
- Overvoltage hazards(>2.5x line voltage in ungrounded systems)
- Persistent fault currentscausing equipment degradation
- Protection device failuredue to insufficient fault current detection
Grounding Transformer enables:
- System grounding protection with <10Ω zero-sequence impedance
- Overvoltage suppression via low-impedance fault current release
- Neutral voltage measurement (30~70V) for full-cable networks
2 . Core Advantages
2.1 Technical Leadership
- Z-Winding Physics (ZNyn Type):
Each phase splits into two reversely wound coils (Zig-Zag configuration), canceling zero-sequence flux → No-load losses reduced by 40% conventional transformers.
Zero-sequence impedance <10Ω(vs. >600Ω in star-delta transformers), enabling >90% arc suppression coil utilization.
- Flexible Grounding Transformer Configurations:
Dry-type (AN/AF cooling) or oil-immersed (ONAN/ONAF)
Short-time withstand: 10s@3000A(customizable to 60s)
2.2 Multifunctional Integration
- Dual-Purpose Design:
Replaces station service transformers by carrying secondary loads while providing neutral grounding, cutting equipment costs by 25%.
- Adaptive Neutral Control:
Generates 30–70V measurable voltagein full-cable networks (low unbalanced voltage).
Balanced 3-phase windings maintain accuracy under **>15% voltage unbalance**.
2.3 High-Reliability Engineering
- Extreme Environment Resilience:
Operational range: -40℃ ~ +40℃| Altitude: ≤1000m (insulation customizable for 4000m)
100% humidity tolerance with IP54+ protection
3. Grounding Transformer Application Scenarios
|
Scenario |
Grounding Transformer Solution |
|
6kV~10kV Distribution |
Provides low-impedance neutral (<10Ω) for delta systems → Direct arc suppression coil connection |
|
35kV+ Systems |
Cooperates with Y-winding transformers to optimize neutral grounding in hybrid grids |
|
Industrial Sites |
Custom windings for high unbalance/full-cable networks → Neutral voltage stabilization (30~70V) |
|
Smart Substations |
Integrated CT/VT + isolation switches → Real-time ground fault analytics |
4. Grounding Transformer Specifications
|
Parameter |
Value |
|
Type |
Zig-Zag (ZNyn) / Dry or oil-immersed |
|
Rated Voltage |
≤36kV |
|
Zero-Seq Impedance |
<10Ω (vs. industry avg. >600Ω) |
|
Cooling Methods |
ONAN (oil)/ONAF (oil+fan)/AN (dry)/AF (dry+fan) |
Note: All Grounding Transformers include IEC 60076-1/6 certification, de-energized tap changers, and HV/LV bushings.
5. Service Commitment
- Onsite Engineering: Certified engineers support installation, commissioning, and arc suppression coil coordination.
- Rapid Response:
Tel: +86(577) 27869969 (Barry) | Email: support@vziman.com
- Lifecycle Management: IEC-compliant maintenance + fault diagnostics for Grounding Transformer
