10KV 250KVA Three Phase Low Loss Distribution Transformer

Iron Core (Magnetic Circuit System)
Materials & Fabrication:
Utilizes high-permeability, cold-rolled silicon steel laminations manufactured through an advanced full oblique seam stepped lamination process. This method substantially minimizes no-load losses by eliminating traditional joint discontinuities.
Design Advantages:
The seamless core configuration not only yields a compact, efficient structure but also reduces operational noise by 7–10 dB, making it especially suited for noise-sensitive environments such as residential areas.

Windings (Electrical Circuit System)
High-Voltage Winding (10 kV Side):
Employs a multilayer cylindrical architecture crafted with either copper or aluminum conductors. Each turn is insulated with high-grade DMD insulation paper to bolster short-circuit withstand capability.
Low-Voltage Winding (0.4 kV Side):
Features foil-wound copper conductors specifically designed to lower eddy current losses while enhancing heat dissipation efficiency.

Insulation Process
Technique & Materials:
Integrates Vacuum Pressure Impregnation (VPI) with H-grade insulation materials, ensuring thermal endurance up to 180 °C. The subsequent vacuum oil injection process effectively eradicates internal air bubbles, further enhancing reliability.

Oil Tank & Cooling System
Tank Design:
Incorporates a fully sealed corrugated steel oil tank that omits the need for a separate conservator. The inherent elasticity of the corrugated panels compensates for oil volume fluctuations while isolating the oil from oxygen and moisture. This design significantly delays oil aging, supporting an operational life exceeding 30 years.
Cooling Method:
Utilizes a natural oil cooling (ONAN) approach. The integrated corrugated-panel radiator achieves efficient thermal dissipation without reliance on auxiliary fans, promoting a maintenance-free cooling solution.

Protection Devices
Pressure Relief Valve:
Automatically activates to vent excess pressure when the internal pressure reaches or exceeds 35 kPa, thereby safeguarding against potential tank rupture.
Gas Relay (Fault Gas Detection):
Continuously monitors for fault-generated gases within the enclosure. When abnormal gas accumulation is detected, it promptly triggers alarms or initiates a circuit break—particularly critical for units rated at 315 kVA and above.
Temperature Controller:
Equipped with a PT100 sensor, this device facilitates remote monitoring of oil temperature, ensuring proactive thermal management.

Tap Changer
No-Load Tap Changer (NLTC):
Provides a ±5% voltage adjustment on the high-voltage side to compensate for grid fluctuations. This adjustment is performed under de-energized conditions to maintain operational safety.

Bushings & Terminal Connectors
High-Voltage Bushings:
Constructed from a composite of porcelain and silicone rubber, these bushings offer a creepage distance of at least 25 mm/kV and feature an anti-contamination design to mitigate flashover risks.
Low-Voltage Terminals:
Comprised of tinned copper busbars with robust anti-oxidation treatment, ensuring secure and reliable high-current connections.