Immersed Transformer

The Immersed Transformer is a high-efficiency oil-immersed power transformer designed for medium and high-voltage power systems. Featuring advanced electromagnetic design, high-permeability silicon steel cores, and oxygen-free copper windings, it delivers ultra-low losses, high reliability, and long service life. The transformer supports on-load voltage regulation, ensuring stable voltage output under fluctuating grid and renewable energy conditions. With a hermetically sealed structure, low noise operation, and smart monitoring capability, it is widely used in substations, power plants, renewable energy stations, industrial facilities, and urban power distribution networks where efficiency, stability, and long-term performance are essential.

I. Model Meaning

· S: Three-phase oil-immersed

· Z: On-load tap changing

· 22: Design series (new generation high-efficiency energy-saving type)

II. Key Parameters (Typical for 110kV Class)

· Capacity range: 6300kVA–63000kVA

· Voltage combination: 110±8×1.25%/10.5kV (common)

· Cooling mode: ONAN/ONAF

· Connection group: YNd11

· Energy efficiency class: GB20052-2020 Level 1

· Design life: ≥40 years

III. Product Features

1. Ultra-high energy efficiency, cost reduction & efficiency improvement

Adopts high-permeability silicon steel sheet, oxygen-free copper winding and optimized electromagnetic design. No-load and load losses are significantly lower than national standards, greatly reducing long-term operating electricity costs. The extra investment can be recovered in 3–5 years.

2. On-load voltage regulation, stable voltage

Supports on-load voltage regulation of ±8×1.25% or ±3×2.5% without power interruption. Adapts to new energy fluctuations and precision loads, ensuring power supply quality.

3. High reliability, strong impact resistance

Reinforced winding structure with uniform ampere-turn distribution, strong resistance to short-circuit and lightning impulse. Hermetically sealed oil tank, low partial discharge (≤50pC), leak-proof design, suitable for harsh environments.

4. Low noise & eco-friendly

Lap-jointed core with solidification treatment, noise level better than national standards. Hermetic sealing reduces oil pollution; low loss helps achieve carbon peaking and carbon neutrality goals.

5. Smart operation & maintenance, lower cost

Standard monitoring of oil temperature, oil level, gas relay and winding temperature, supports remote monitoring. Hermetically sealed structure requires no frequent oil refilling and features long maintenance intervals.

IV. Application Scenarios

· Substations of State Grid, China Southern Power Grid, large power plants

· New energy power stations (photovoltaic, wind power)

· Petrochemical, metallurgical and large industrial & mining enterprises

· Urban power grids, data centers, hospitals and other places requiring stable voltage and low noise

Core Parameters (Typical for 110kV Class)（customizable）

III. Typical Parameters for 35kV Class SZ22

IV. Loss Parameters (Typical for 110kV Class, Level 1 Efficiency)

· No-load Loss (P₀): Significantly lower than the national standard Level 1 limit (15%–20% lower than SZ20)

· Load Loss (Pₖ): 10%–15% lower than the national standard Level 1 limit

· Total Loss: Meets GB20052-2020 Level 1 efficiency requirements

V. Ambient and Operating Conditions

· Ambient Temperature: -40℃～+40℃

· Altitude: ≤1000m (Customizable for higher altitude)

· Cooling Medium: 25# Transformer Oil

· Protection Class: Hermetically sealed, IP68 (Tank)

VI. Structure and Materials

· Core: High-permeability silicon steel sheet, step-lap joint + curing treatment

· Winding: Oxygen-free copper conductor, high short-circuit withstand structure

· Tank: Hermetically sealed corrugated / panel radiator, leak-proof design

· Monitoring: Standard oil temperature, oil level, gas relay, winding temperature sensors

Key Features

·  High Energy Efficiency & Cost Saving

Adopts high-permeability silicon steel sheet and oxygen-free copper winding. No-load and load losses are much lower than national standards, achieving obvious power saving.

·  On-load Voltage Regulation

Supports on-load voltage regulation without power cut, ensuring stable voltage and high-quality power supply for new energy and precision loads.

·  High Reliability & Strong Short-circuit Withstand

Reinforced winding structure, strong resistance to short-circuit and lightning impulse; low partial discharge, hermetically sealed and leak-proof.

·  Low Noise & Environmentally Friendly

Low noise level, hermetic structure reduces oil pollution, in line with low-carbon and environmental protection requirements.

·  Smart Operation & Low Maintenance

Equipped with standard monitoring points, supports remote monitoring; long service life and low maintenance cost.

Application Scenario

·  State Grid, China Southern Power Grid and various substations

·  Large power plants, new energy power stations (photovoltaic, wind power)

·  Large industrial and mining enterprises such as petroleum, chemical, metallurgy and mining

·  Urban power grids, data centers, hospitals, commercial complexes

·  Places with strict requirements for voltage stability, low noise and high reliability

About Us

Xinda Transformer Co., Ltd. is located at No. 38, Jinsan Road, Fenghuang Industrial Park, Dongchangfu District, Liaocheng City, Shandong Province, China. The company has a registered capital of RMB 150 million and covers an area of approximately 186,667 square meters (280 mu). It is recognized as a National High-Tech Enterprise, a Shandong Province Technology Innovation Demonstration Enterprise, an Excellent Private Technology Enterprise of Shandong Province, a Shandong Model Base for Employment of the Disabled, a Shandong Province Contract-Honoring and Trustworthy Enterprise, a Liaocheng Municipal Enterprise Technology Center, an Excellent Industrial Enterprise of Dongchangfu District, a Science and Technology Innovation Demonstration Enterprise of Dongchangfu District, and a Key Backbone Enterprise of Dongchangfu District.

The annual production capacity is 9,000 MVA. The total construction area of office buildings, R&D facilities, and standardized workshops is 53,000 square meters. Equipped with over 470 sets of advanced production equipment, the company possesses a manufacturing capacity of 10,000 MVA for transformers up to 220 kV, along with complementary switchgear systems. With qualifications in Power Engineering General Contracting and a dedicated technical construction team, Xinda ranks among the leading power transformer manufacturers in China, excelling in R&D, manufacturing, and integrated engineering services.