Note: Actual rated capacity, voltage ratio, impedance, insulation level, vector group, tap range and cooling method should be determined according to the customer's technical specification.

Typical Voltage Ratios

Depending on the substation design, typical configurations may include:

• 133kV / 33kV

• 133kV / 11kV

• 133kV / 13.8kV

• 135kV / 33kV

• 135kV / 11kV

• 135kV / 13.8kV

• 133/33/11kV

• 135/33/11kV

Three-winding configurations can also be supplied for complex substation applications.

Transformer Configuration

The transformer can be supplied with a comprehensive range of components and accessories.

Main Components

• Transformer tank

• Magnetic core

• HV windings

• LV windings

• Insulation system

• Transformer oil

• Radiators

• Conservator

• Buchholz relay

• Pressure relief device

• Oil level indicator

• Winding temperature indicator

• Oil temperature indicator

• HV/LV bushings

• Earthing terminals

• Lifting lugs

• Oil drain valve

• Sampling valve

Optional Equipment

• OLTC

• Motor drive mechanism

• On-load tap changer controller

• Cooling control cabinet

• Fans

• Oil pumps

• Online temperature monitoring

• Oil level monitoring

• Digital monitoring system

• Surge arresters

• CTs

• Remote monitoring system

Customization Optional

Zisheng can customize the transformer according to the customer's electrical and mechanical requirements.

Electrical Customization

• Rated capacity

• HV voltage

• LV voltage

• Frequency

• Voltage ratio

• Vector group

• Short-circuit impedance

• Tap range

• Tap changer type

• Neutral grounding configuration

• Insulation level

• No-load and load losses

Mechanical Customization

• Tank structure

• Radiator configuration

• Conservator size

• Bushing arrangement

• Cable box

• Terminal configuration

• Dimensions

• Transportation weight

• Lifting arrangement

Environmental Customization

For projects located in challenging environments, the transformer can be engineered for:

• High-temperature regions

• High-altitude locations

• Coastal environments

• High-humidity areas

• Dusty environments

• Mining sites

• Desert regions

• Tropical climates

Each transformer undergoes strict manufacturing quality control and testing before shipment.

Typical manufacturer testing includes:

Electrical Testing

• Winding resistance test

• Voltage ratio test

• Polarity and phase displacement test

• No-load loss and current test

• Load loss and impedance test

• Dielectric tests

• Induced voltage test

• Lightning impulse test when specified

• Partial discharge test when applicable

Mechanical & Oil Testing

• Transformer oil testing

• Leakage test

• Pressure test

• Vacuum test

• Temperature-rise verification

• OLTC functional test

• Accessory functional inspection

All test requirements can be aligned with the customer's technical specification and applicable international standards.

Routine Testing

Before delivery, routine tests are performed according to the applicable standards and project requirements.

Typical routine tests include:

1. Measurement of winding resistance

2. Measurement of voltage ratio and phase displacement

3. Measurement of short-circuit impedance and load loss

4. Measurement of no-load loss and current

5. Dielectric routine tests

6. Insulation resistance verification

7. Transformer oil inspection

8. Tap changer operation test

9. Temperature indicator inspection

10. Protection device inspection

11. Leakage inspection

12. Final dimensional and appearance inspection

Factory test reports can be provided for customer and EPC project documentation.

Applicable Standards

The transformer can be manufactured according to different international standards depending on the target market.

IEC

• IEC 60076 series

• IEC 60076-1

• IEC 60076-2

• IEC 60076-3

• IEC 60076-5

• IEC 60076-10

Other Standards

• ANSI

• IEEE

• CSA

• GOST

• Customer-specific standards

For EPC projects, the manufacturing and testing requirements can be matched to the project's technical specification.

Utility Substations

Used for high-voltage grid transmission and distribution networks, supporting reliable power delivery between transmission and distribution voltage levels.

Industrial Power Systems

Suitable for large industrial facilities requiring high-capacity and stable power supply.

Renewable Energy

Can be integrated into:

• Solar power plants

• Wind farms

• Hybrid renewable energy systems

• Renewable energy substations

Mining Projects

Designed for demanding mining environments where high reliability and robust construction are required.

Infrastructure Projects

Suitable for airports, railways, ports, water treatment facilities, and other large infrastructure projects.

Product Advantages for EPC Projects

For EPC contractors, the product can be supplied as part of a complete transformer solution rather than simply as a standalone transformer.

Engineering Support

• Technical parameter confirmation

• Transformer selection

• Electrical design support

• Drawing preparation

• Technical document support

Manufacturing

• Factory production

• Strict process control

• Electrical testing

• Routine testing

• Customer inspection support

Project Delivery

• Export packaging

• Transportation preparation

• Shipping documentation

• Installation guidance

• Commissioning support

This makes the 133kV / 135kV transformer suitable for utility, EPC, industrial and infrastructure projects requiring customized high-voltage substation equipment.

What is a 133kV / 135kV power transformer?

It is a high-voltage three-phase transformer designed for substations and power transmission/distribution systems operating around the 133kV or 135kV voltage class.

Can the transformer be customized?

Yes. Capacity, voltage ratio, impedance, vector group, tap changer, cooling system, insulation level, accessories, and other parameters can be customized.

Can you supply a 133kV/33kV transformer?

Yes. 133kV/33kV is one of the possible voltage configurations. Other voltage ratios can also be manufactured according to the project requirements.

Can you supply 135kV/33kV?

Yes. A 135kV/33kV three-phase transformer can be designed and manufactured according to the required capacity and technical specification.

Can OLTC be installed?

Yes. An on-load tap changer (OLTC) can be supplied where automatic voltage regulation is required.

What cooling systems are available?

Depending on the capacity and application, options can include ONAN, ONAF and OFAF.

Which standards can be followed?

IEC, ANSI/IEEE, GOST and other customer-specified standards can be supported.

Can you provide factory test reports?

Yes. Routine test reports and other required inspection/test documentation can be provided according to the project requirements.