Views: 0 Author: Site Editor Publish Time: 2025-05-06 Origin: Site
Selecting the right high voltage transformer directly impacts equipment lifespan, energy efficiency, and safety. Based on IEC 60076 and GB 1094 standards, this guide outlines five critical metrics industrial users must evaluate to ensure optimal performance and avoid selection pitfalls.
l Rated Voltage: Primary/secondary voltages must match grid connection points (e.g., 10kV/110kV)
l Ratio Tolerance: ≤±0.5% (no-load), ≤±1% (full load) per GB 1094.1
l Renewable Energy: Solar farms require ±10% voltage regulation to accommodate inverter fluctuations
l Industrial Applications: Arc furnace transformers must withstand frequent voltage surges (e.g., 30% transient overvoltage)
l Case Study: A photovoltaic solar farm in Ningxia, China faced grid penalties due to excessive ratio deviation (1.2%).
l Formula: S = √3 × U × I (kVA)
l Load Optimization: Maintain 60-80% long-term loading to extend lifespan
Load Type | Design Focus | Applications |
Continuous | Enhanced cooling (e.g., ONAF) | Chemical plants, Data centers |
Intermittent | High overload capacity (115% for 1hr) | Metallurgy, Steel rolling |
Harmonic-rich | K-Factor≥13 design | VFD-driven equipment |
Common Mistake: Oversizing increases no-load losses (wasting >¥50,000/year in electricity).
Type | Advantages | Limitations | Applications |
Oil-immersed | Low cost, easy maintenance | Fire risk | Outdoor substations |
Dry-type (Cast resin) | Fireproof, maintenance-free | 30% higher cost | Basements, Ships |
SF6 Gas-insulated | Compact, pollution-resistant | Environmental concerns | Urban underground |
l ONAN (Oil Natural Air Natural): <30MVA, ~¥20,000/year maintenance
l OFWF (Oil Forced Water Forced): >100MVA, 8% efficiency gain (requires water circulation)
Tool: Download Insulation-Cooling Selection Matrix
l China GB 20052: Grade 1 (40% lower no-load loss vs. Grade 3)
l EU Tier System: Tier 3 (mandatory from 2025)
l No-load loss: 1.2kW (amorphous core reduces to 0.3kW)
l Load loss: 12kW (transposed conductors cut by 15%)
l Annual cost: ~¥43,000 [(1.2×24×365)+(12×8×300)]
ROI: Premium for high-efficiency models recouped via energy savings in 3 years.
l Outdoor: Minimum IP54 (dust/water resistance)
l Desert: IP55+sand filters (e.g., Middle East solar projects)
l High Altitude: Derate 5%/500m above 1000m
l Corrosive Areas: Stainless steel + triple-coating (≥1000hr salt spray test)
l Failure Case: Offshore platform transformer failed in 6 months without "humidity-resistant" (Class H) design.
1. Prioritize Top Chinese Brands: 20-40% cheaper than imports with equal specs
2. Demand Third-Party Tests: Require CTI/STL reports on temperature rise/short-circuit tests
3. Value-Added Services: Seek free EMC compliance solutions
