Basic Info.
Our H59-1250kVA oil immersed transformer is designed for medium-voltage power distribution systems requiring reliable voltage transformation and flexible voltage regulation.
The transformer has a rated capacity of 1250kVA and a voltage ratio of 33/0.4kV, allowing 33kV medium-voltage power to be stepped down to 0.4kV for low-voltage distribution and electrical loads.
Unlike a conventional off-circuit tap transformer, this unit is equipped with an On-Load Tap Changer (OLTC), allowing the transformer voltage ratio to be adjusted while the transformer remains energized and supplying the load. This helps compensate for fluctuations in the incoming grid voltage and maintain a more stable low-voltage output.
The transformer uses a Dyn11 vector group, which is widely used in three-phase distribution systems. The winding configuration provides a suitable solution for medium-voltage distribution networks and commercial or industrial power supply applications.
The transformer is configured with 21 tap positions,33kV, +4 /-16 taps, each tap 2.5%, providing flexible voltage regulation according to the project requirements and local grid conditions.
Cooper windings are used to provide a cost-effective transformer configuration while maintaining the required electrical and thermal performance. The oil-immersed construction provides effective insulation and heat dissipation for continuous operation.
Application
1. Remote-area power grids in Africa and other regions
Severe grid voltage fluctuations occur; the high-side voltage is prone to sharp drop under heavy-load conditions.
2.Mining camps, processing plants & large quarry projects
Long-distance power is fed from main substations to mine sites, featuring heavy and drastically fluctuating mining loads.
3. Large-scale solar / PV power plants
33kV / 36kV collector-network step-down substations compensate voltage deviations resulting from generation fluctuations and long-distance transmission.
4. Rural & suburban electrification projects
Long overhead distribution lines together with variable loads ensure stable 400V LV output for end-users.
5. Isolated industrial parks & off-grid / weak-grid industrial projects
Upstream grid fails to sustain voltage at rated levels continuously.
6. Highway, water conservancy and large-scale infrastructure construction sites
Sites supplied via long-distance high-voltage power transmission.
