220kV Oil-Immersed 3-Phase 2-Winding NLTC Power Transformer

220kV Oil-Immersed 3-Phase 2-Winding NLTC Power Transformer.
Cost-effective and reliable standard transformer designed for 220kV high-voltage grids.
Rated 31.5 to 240 MVA, HV 220/242kV, LV 6.3kV to 13.8kV, with ±2×2.5% off-circuit tapping.
Features YNd11 vector group, 12%~14% short-circuit impedance, and low no-load losses (down to 0.26%) for high operational economy.

Product Overview

This series is a cost-effective, reliable, and structurally straightforward standard two-winding main power transformer designed for 220kV high-voltage grids. With its mature, proven design and excellent operational economy, it is widely used in regional substations, end-user applications, and renewable energy power plants.

Serving as a core and fundamental component, it ensures highly efficient power transmission between high-voltage grids and medium-voltage distribution networks.

Technical Specifications

(MVA) Rated Capacity	Rated Voltage and Tapping Range			Vector Group	No Load Current (%)	Short-circuit Impedance (%)	No load Losses (kW)	On load Losses (kW)
(MVA) Rated Capacity	HV (kv)	Tapping Range	LV (kv)	Vector Group	No Load Current (%)	Short-circuit Impedance (%)	No load Losses (kW)	On load Losses (kW)
31500	220 242	±2×2.5	6.3 6.6	YNd11	0.45	12~14	15	115
40000					0.45		18	134
50000					0.42		21	161
63000					0.42		25	188
75000			10.5 13.8		0.38		29	213
90000					0.35		34	246
120000					0.35		41	304
150000			10.5 13.8		0.32		49	360
160000					0.31		51	378
180000					0.29		56	413
240000					0.26		70	484

Core Advantages

Mature & Economical Design: Classic two-winding, oil-immersed, off-circuit tap-changing structure. Simple to operate and maintain, offering significant advantages in total lifecycle costs.
Flexible Capacity Matching: Standard capacities from 31.5 MVA to 240 MVA. The low-voltage side provides common industrial voltages (6.3kV, 6.6kV, 10.5kV, 13.8kV), precisely matching end-user connection needs.
Optimized Electrical Performance: Standard YNd11 vector group ensures good system compatibility and straightforward protection configuration. 12%~14% short-circuit impedance balances fault current limitation with voltage stability.
High Operational Efficiency: Optimized losses with a no-load current as low as 0.26%, ensuring energy savings during day-to-day operation.

Typical Applications

Main transformers for 220kV regional and end-user substations.
Step-up substations in renewable energy projects such as wind farms and photovoltaic power plants.
Main step-down transformers for large-scale industrial enterprises.
Key nodes in urban power grids responsible for power transmission and distribution.

Hot Tags: 220kv oil-immersed 3-phase 2-winding nltc power transformer, China 220kv oil-immersed 3-phase 2-winding nltc power transformer manufacturers, suppliers, factory, 220kV Oil Immersed 3 Phase 2 Winding NLTC Power Transformer, 220kV Oil Immersed 3 Phase 3 Winding OLTC Power Transformer, 220kv power transformer, 220kV Oil Immersed 3 Phase 2 Winding OLTC Power Transformer, 220kV Oil Immersed 3 Phase 3 Winding NLTC Power Transformer