SZ□-35KV Oil-Immersed Transformer for Power Systems | Transformer Solution

Overview

The SZ□-35KV Oil-Immersed Transformer is a highly efficient, on-load voltage regulating transformer designed for power systems operating at 35kV and below. Operating under a frequency of 50Hz, this transformer is a key component in medium and small-sized substations. It provides reliable power distribution for industrial, agricultural, and lighting applications.

Manufactured with precision and built using advanced domestic and international technology, the SZ□-35KV transformer incorporates optimized design techniques and modern materials. This results in a more compact structure, enhanced electric and mechanical strength, and superior heat dissipation performance.

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Standards Compliance

This transformer complies with national and international quality standards ensuring safety, durability, and efficient operation.

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Operating Conditions

• Altitude: ≤1000m
• Ambient Temperature:
  • Maximum: +40℃
  • Monthly Average: +30℃
  • Yearly Average: +20℃
• Installation Conditions:
  • Maximum inclination: <3°
  • Free from significant dust, corrosive gases, and flammable vapors

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Structural Features

1. Iron Core

The iron core is fabricated using high-grade cold-rolled silicon steel sheets. The core design incorporates:

• Fully biased multi-stage joints
• Non-punch hole wind cores
• Stainless steel stays and epoxy glass tape reinforcement

This structure minimizes energy losses and reduces operational noise, ensuring long-term performance.

2. Coil Design

The winding conductors are manufactured from high-purity oxygen-free copper wires, available as enameled wire or paper-wrapped flat copper wire. The coil structures include:

• Drum type
• Spiral type
• Improved spiral
• Continuous winding
• Staggered layout

This design ensures uniform distribution of magnetic flux and prevents hot-spot formation.

3. Oil Tank

The oil tank is available in:

• Barrel-type or shielded construction
• Corrugated plates or electroplated radiators for cooling

Instead of wheels, the base is welded to meet national gauge standards for stable, fixed installation.

4. Safety & Protection Devices

Based on customer and standard requirements, the transformer can be equipped with:

• Pressure relief valve
• Gas relay
• Signal thermometer
• Oil conservator
• Oil sample valve
• Oil filter system

These features ensure system integrity during overvoltage or fault conditions.

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Technical Specifications

SZ9-35KV Transformer Technical Data

Rated Capacity (kVA)	H.V (kV)	Tapping Range	L.V (kV)	Connection	No-load Loss (W)	Load Loss (W)	No-load Current (%)	Impedance (%)
2000	35	±3×2.5	6.3/10.5	Yd11	2900	20200	0.9	6.5
2500					3400	22700	0.9
3150	35-38.5				4100	26000	0.8	7
4000					4900	30700	0.8
5000					5800	36000	0.75
6300					7000	38700	0.75	8
8000				Ynd11	9900	43000	0.7
10000					11600	50600	0.7
12500					13800	59900	0.7
16000					16200	73000	0.7
20000					19500	84600	0.7
25000					22500	100200	0.7	10
31500					26400	124000	0.6

SZ11-35KV Transformer Technical Data

Rated Capacity (kVA)	H.V (kV)	Tapping Range	L.V (kV)	Connection	No-load Loss (W)	Load Loss (W)	No-load Current (%)	Impedance (%)
2000	35	±3×2.5	6.3/10.5	Yd11	2300	19240	0.8	6.5
2500					2720	20640	0.8
3150	35-38.5				3230	24710	0.72	7
4000					3870	29160	0.72
5000					4640	31200	0.68
6300			6.3/6.6/10.5	Ynd11	5630	36770	0.68	7.5
8000					7870	40610	0.6
10000					9280	48050	0.6
12500					10940	56860	0.56	8
16000					13170	70320	0.54
20000					15570	82780	0.54

SZ13-35KV Transformer Technical Data

Rated Capacity (kVA)	H.V (kV)	Tapping Range	L.V (kV)	Connection	No-load Loss (W)	Load Loss (W)	No-load Current (%)	Impedance (%)
2000	35	±3×2.5	6.3/10.5	Yd11	2300	19200	0.5	6.5
2500					2720	20600	0.5
3150	35-38.5				3230	24700	0.5	7
4000					3870	29100	0.5
5000					4640	34200	0.5
6300					5630	36700	0.5	8
8000			6.3/6.6/10.5	Ynd11	7870	40600	0.4
10000					9280	48000	0.4
12500					1090	56800	0.35
16000					1310	70300	0.35
20000					1550	82100	0.35
25000					1830	97800	0.3	10
31500					2180	716000	0.3

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Frequently Asked Questions

1. What is the purpose of an oil-immersed transformer in modern power systems?

Oil-immersed transformers provide efficient insulation and superior heat dissipation, making them suitable for medium-voltage networks and industrial applications.

2. How does the SZ□-35KV transformer support voltage regulation?

The SZ□-35KV transformer features on-load voltage regulation capability, allowing it to adapt to grid voltage fluctuations in real time without service interruption.

3. What makes this transformer energy-efficient?

With advanced materials, optimized coil and core designs, and reduced no-load and load losses, this transformer significantly improves overall energy efficiency.