500kV 250MVA Single-phase Three-winding Auto-Transformer

500kV Single-phase Three-winding Auto-Transformer Product Introduction 

The 500kV Single-phase Three-winding Auto-Transformer, as a core energy conversion equipment in ultra-high voltage power systems, with a rated capacity of 250MVA, accurately meets the requirements of large-capacity and long-distance power transmission. It is a preferred core equipment for national hub substations and external power transmission projects of large energy bases. This 500kV Single-phase Three-winding Auto-Transformer realizes efficient conversion and dispatching of multi-voltage level electric energy relying on its core structure of single-phase three-winding autotransformer, perfectly connecting the 500kV high-voltage power grid with medium and low-voltage distribution networks, and providing stable support for inter-regional power grid interconnection.

500kV Single-phase Three-winding Auto-Transformer Advantages

• High power conversion efficiency & low-loss energy saving:The structural characteristics of the autotransformer enable direct power transmission through its common winding section. Compared with conventional two-winding transformers of the same capacity, it significantly reduces copper and iron losses by 10%–20% in both no-load and load conditions. Long-term operation can greatly cut power grid energy consumption, aligning with the requirements of green and low-carbon power grid construction.
• Single-phase structure facilitates transportation and on-site deployment:Compared with integral three-phase transformers, single-phase units are smaller in size and lighter in weight, making them adaptable to transportation conditions in complex terrains such as mountainous and hilly areas, and solving the transportation restrictions of ultra-high voltage three-phase transformers. Meanwhile, single-phase equipment can be transported in batches and assembled on site, which greatly lowers engineering construction difficulty and transportation costs, and is especially suitable for external power transmission projects of large energy bases.
• Strong short-circuit withstand capacity & high operational reliability:The windings are made of oxygen-free copper conductors, combined with rigid binding structures and precision insulation design, which can withstand the huge electromagnetic force impact during grid short-circuit faults. The iron core is made of high-quality grain-oriented silicon steel sheets, and its multi-step structure effectively reduces hysteresis loss and noise. It ensures long-term stable operation of the equipment under 500kV ultra-high voltage conditions with a low failure rate.

500kV Single-phase Three-winding Auto-Transformer Technical Parameters

(1) 500kV 100MVA~484MVA Single-phase, Double-winding Power Transformer with Off-circuit Tap-changer

Note: Transformers with various special parameters and performance can be manufactured according to customer requirements.

(2) 500kV 120MVA~1170MVA Three-phase, Double-winding Power Transformer with Off-circuit Tap-changer

Note: Transformers with various special parameters and performance can be manufactured according to customer requirements.