electrical transformer
SZ18 three‑phase oil‑immersed on‑load tap‑changing power transformer
1.Level 3 energy efficiency, up to standard for loss: Compliant with national standard GB20052-2020 Level 3 energy efficiency, with no-load/load loss better than SZ11/SZ13
2.On-load voltage regulation, voltage stabilization without power outage: Automatic/manual voltage regulation with load, stable voltage and reliable power supply
3.Strong short-circuit resistance, safe and reliable: Firm structure, passed short-circuit test, multiple protections
4.Fully sealed, maintenance-free: Anti-leakage, slow oil aging, less core lifting, simple operation and maintenance
5.Wide coverage of capacity/voltage: 30kVA~25000kVA, 10kV/35kV/110kV universal
6.Strong overload capacity: Can withstand 1.2 times overload for a short time, suitable for fluctuating loads
I. Product Introduction
SZ18 three‑phase oil‑immersed on‑load tap‑changing power transformer is a new generation of high‑efficiency and energy‑saving core equipment for power transmission and distribution. It covers voltage classes of 10kV, 35kV, 66kV and 110kV, with a capacity range from 6300 kVA to 63000 kVA.
Adopting high‑quality silicon steel core and full‑copper windings, combined with on‑load voltage regulation and fully sealed oil‑immersed structure, the transformer features low loss, low noise, high reliability and strong short‑circuit withstand capability. It meets the demand of stable power supply and real‑time voltage regulation for power grids, industries, stadiums and other scenarios.
This product complies with the national standard GB 1094 series, and is suitable for newly built substations and energy‑saving renovation of old equipment.
II. Technical Parameters (Take SZ18‑12500kVA/35kV as an example)（customizable）
Rated capacity: 12500 kVA
Voltage combination: High voltage 35 kV, low voltage 0.4 kV
Voltage regulation: On‑load tap‑changing
Connection group: Dyn11
Insulation level: High voltage 95 kV, low voltage 4 kV
Overload capacity: 1.2 times rated capacity, sustainable for 4 hours
Cooling mode: ONAN / ONAF
Protection class: IP00
Operating temperature: -40℃ ~ +40℃
Energy efficiency level: National standard Level 3 and above
III. Main Features
High efficiency and energy saving
Optimized core and winding design significantly reduce no‑load and load losses, lowering electricity cost for long‑term operation.
On‑load voltage stabilization
Automatic voltage regulation under live load, resisting load fluctuation to ensure stable voltage and equipment safety.
High reliability
Full‑copper windings with high‑quality insulating oil feature strong short‑circuit and impact resistance, suitable for long‑term continuous operation.
Easy maintenance
Sealed structure equipped with oil level / oil temperature monitoring and safety protection devices, enabling visible status and simple operation & maintenance.
Low noise and low partial discharge
Structural shock absorption and noise reduction design, low partial discharge and vibration, suitable for indoor and densely populated areas.
Strong environmental adaptability
Stable operation in high/low temperature, humid, dusty and other industrial and outdoor environments.
IV. Application Scenarios
Power grid system: Urban / park substations, regional distribution stations, grid step‑up / step‑down nodes.
Energy & power: Auxiliary power for power plants, new energy grid‑connection stations, supporting transformers for energy storage stations.
Large‑scale industry: High‑power load power supply for metallurgy, petrochemical, mining, manufacturing and other industries.
Public buildings: Convention centers, stadiums, airports, hospitals, data centers (applied in venues of major events).
Infrastructure renovation: Energy‑saving replacement of old transformers, power grid upgrading, load center capacity expansion.
