electrical transformers
1.Class IE efficiency, lower loss, long-term energy saving.
2.On-load tap changer, stable voltage, regulation without power outage.
3.Strong short-circuit withstand capability, more reliable operation.
4.Low noise, low partial discharge, safe and eco-friendly.
5.Compact structure, long service life, low maintenance cost.
Product Introduction
I. Model Meaning
S: Three-phase oil-immersed
Z: On-load tap changing
22: Design series (new-generation high-efficiency & energy-saving type)
II. Key Parameters (Typical for 110kV Class)（customizable）
Capacity range: 6300kVA – 63000kVA
Voltage combination: 110±8×1.25% / 10.5kV (common)
Cooling mode: ONAN / ONAF
Connection group: YNd11
Energy efficiency class: GB20052-2020 Level 1
Design life: ≥ 40 years
III. Product Features
Ultra-high energy efficiency, cost reduction & efficiency improvement
Adopts high-permeability silicon steel sheets, oxygen-free copper windings and optimized electromagnetic design. No-load and load losses are significantly lower than national standards, greatly reducing long-term operating costs. The incremental investment can be recovered within 3–5 years.
On-load voltage regulation, stable voltage
Supports on-load voltage regulation with ±8×1.25% or ±3×2.5% range without power interruption. It adapts to new energy load fluctuations and precision loads, ensuring high-quality power supply.
High reliability, strong impact resistance
Reinforced winding structure with uniform ampere-turn distribution, excellent short-circuit and lightning impulse withstand capability. Hermetically sealed oil tank, low partial discharge (≤ 50pC), leak-proof structure, suitable for harsh environments.
Low noise & eco-friendly
Adopts step-lapped core with solidification treatment, noise level superior to national standards. Hermetic sealing reduces oil pollution; low-loss design contributes to carbon peaking and carbon neutrality goals.
Intelligent operation and maintenance, low O&M cost
Standard monitoring for oil temperature, oil level, gas relay and winding temperature, supporting remote monitoring. Hermetically sealed structure requires no frequent oil replenishment and features long maintenance intervals.
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IV. Application Scenarios
Substations of State Grid, China Southern Power Grid and large power plants
New energy power stations (photovoltaic, wind power)
Petrochemical, metallurgical and large industrial & mining enterprises
Urban power grids, data centers, hospitals and other sites requiring stable voltage and low noise
Core Parameters (Typical for 110kV Class)
| Item | Specification |
Rated Capacity | 6300kVA–63000kVA (Standard series) |
Voltage Combination | 110±8×1.25%/10.5kV (Common) |
Voltage Regulation Range | ±8×1.25% or ±3×2.5% (On-load) |
Cooling Mode | ONAN / ONAF |
Connection Group | YNd11 |
Rated Frequency | 50Hz |
Energy Efficiency Class | GB20052-2020 Level 1 |
Design Life | ≥ 40 years |
Insulation Level | LI480AC200 / LI200AC85 (110/10.5kV) |
Partial Discharge | ≤ 50pC |
Short-circuit Impedance | 10.5%–12% (depending on capacity) |
Insulation Class | Class F (Winding temperature rise ≤ 100K) |
Typical Parameters for 35kV Class SZ22
| Item | Specification |
Rated Capacity | 630kVA–25000kVA |
Voltage Combination | 35±8×1.25%/10kV or 35/10.5kV |
Connection Group | Yd11 / YNd11 |
Short-circuit Impedance | 5.5%–7% |
Cooling Mode | ONAN / ONAF |
Energy Efficiency Class | Level 1 |
Loss Parameters (Typical for 110kV Class, Level 1 Efficiency)
No-load Loss (P₀): Significantly lower than the limit of national standard Level 1 (15%–20% lower than SZ20)
Load Loss (Pk): 10%–15% lower than the limit of national standard Level 1
Total Loss: Complies with GB20052-2020 Level 1 efficiency requirements
Ambient and Operating Conditions
Ambient Temperature: -40℃ ～ +40℃
Altitude: ≤ 1000m (customizable for high-altitude areas)
Cooling Medium: No.25 transformer oil
Protection Class: Hermetically sealed, IP68 (tank)
Structure and Materials
Core: High-permeability silicon steel sheet, step-lap joint with curing treatment
Winding: Oxygen-free copper conductor, high short-circuit withstand structure
Tank: Hermetically sealed corrugated / panel radiator, leak-proof design
Monitoring: Standard oil temperature, oil level, gas relay, winding temperature sensors
Main Features
High Energy Efficiency & Cost Saving
Adopts high-permeability silicon steel sheets and oxygen-free copper windings. No-load and load losses are far below national standards, with obvious energy-saving effects.
On-load Voltage Regulation
Supports on-load voltage regulation without power interruption, ensuring stable voltage and high-quality power supply for new energy and precision loads.
High Reliability & Strong Short-circuit Withstand
Reinforced winding structure with excellent short-circuit and lightning impulse withstand capability; low partial discharge, hermetically sealed and leak-proof.
Low Noise & Environmentally Friendly
Low noise level; hermetic structure reduces oil pollution, meeting low-carbon and environmental protection requirements.
Intelligent Operation & Low Maintenance
Equipped with standard monitoring points and supports remote monitoring; long service life and low operation & maintenance cost.
Application Scenarios
Substations of State Grid, China Southern Power Grid
Large power plants, new energy power stations (PV, wind)
Large industrial and mining enterprises such as petroleum, chemical, metallurgy
Urban power grids, data centers, hospitals, commercial complexes
Sites with strict requirements for voltage stability, low noise and high reliability
