The SZ18 (S20/S22) series 35kV on-load tap changer (OLTC) energy-efficient power transformer is designed for modern power systems requiring stable voltage regulation and high energy efficiency.

Equipped with an on-load tap changer, this transformer can adjust voltage under load conditions without interrupting power supply, ensuring continuous and stable operation of the grid.

Manufactured with high-quality cold-rolled silicon steel cores and oxygen-free copper windings, the transformer offers excellent electrical performance, safety, and long-term reliability.

It is widely used in:

• Urban and rural power grids
• Industrial and agricultural power systems
• Substations and distribution networks
• Renewable energy integration systems

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🔹 Standards Compliance

This transformer complies with major international and national standards:

• IEC 60076-1 – Power Transformers
• GB/T 1094.1 – Power Transformers
• GB/T 6451 – Technical Requirements for Oil-Immersed Transformers
• JB/T 10088 – Sound Levels of 6kV–500kV Transformers
• GB 20052-2020 – Energy Efficiency Limits and Grades

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🔹 Key Features

✔ On-Load Voltage Regulation (OLTC)

• Adjusts voltage without power interruption
• Ensures stable output voltage under varying load conditions
• Improves grid reliability

✔ High Energy Efficiency

• Meets GB20052-2020 energy efficiency standards
• Reduced losses and operating costs

✔ Advanced Structural Design

• Compact and optimized internal structure
• Improved insulation and cooling system

✔ High Reliability & Safety

• Strong mechanical strength
• Excellent short-circuit resistance
• Stable long-term operation

✔ Remote Monitoring Capability

• Supports real-time monitoring of operating conditions
• Enhances maintenance efficiency and system control

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🔹 Structural Design

🔸 Core

• Made of high-quality cold-rolled silicon steel
• Step-lap core structure (3-step or 5-step joints)
• Surface coated with curing varnish

➡ Reduces:

• Core loss
• Noise level

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🔸 Windings

• High-quality oxygen-free copper conductors
• Advanced winding design with optimized oil ducts
• New insulation structure

➡ Provides:

• High mechanical strength
• Strong short-circuit resistance
• Efficient heat dissipation

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🔸 Oil Tank

• Corrugated (wave-type) oil tank design
• Multiple structural configurations available

➡ Features:

• Efficient heat dissipation
• Compact and aesthetic design
• Enhanced sealing performance

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🔹 Applications

• Substation voltage regulation systems
• Industrial and commercial power distribution
• Smart grid infrastructure
• Renewable energy power plants
• Urban and rural power networks

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🔹 Advantages Summary

• Continuous voltage regulation (OLTC)
• High efficiency and energy saving
• Reliable and safe operation
• Remote monitoring capability
• Suitable for modern intelligent grids

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❓ FAQ

1️⃣ What is an on-load tap changer (OLTC) transformer?

An OLTC transformer can adjust its voltage ratio while operating under load, without interrupting power supply.

👉 This ensures stable voltage output and is essential for modern power grids.

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2️⃣ What are the advantages of SZ18 compared to standard transformers?

Compared to standard transformers:

• Provides real-time voltage regulation
• Improves power quality
• Reduces voltage fluctuation
• Enhances system stability

👉 Ideal for grids with variable load conditions.

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3️⃣ Does this transformer support remote monitoring?

Yes, it can be equipped with remote monitoring systems, allowing:

• Real-time status tracking
• Fault detection
• Predictive maintenance

👉 This helps reduce downtime and maintenance costs.

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4️⃣ Can the transformer be customized?

Yes, customization options include:

• Voltage levels and ratios
• Capacity (MVA)
• OLTC range and steps
• Cooling methods
• Installation environment

👉 Suitable for utility, industrial, and renewable energy projects.