The 110kV / 115kV Power Transformer can be fully customized according to the electrical, environmental, installation and transportation requirements of different utility, EPC, industrial and renewable energy projects.

1. Electrical Parameter Customization

• Rated Capacity: 10–240 MVA or customized
• Primary Voltage: 110kV / 115kV
• Secondary Voltage: 6.3kV / 10kV / 10.5kV / 11kV / 13.8kV / 33kV / 34.5kV
• Three-Winding Configuration: Available
• Frequency: 50Hz / 60Hz
• Phase: Three-phase
• Rated Current: According to transformer capacity and voltage
• Short-Circuit Impedance: Customized
• No-Load Loss: Optimized according to efficiency requirements
• Load Loss: Customized according to project requirements
• Vector Group: Dyn11 / YNd11 / YNd1 / customized
• Neutral Connection: Neutral brought out / grounded / customized

2. Tap Changer Options

The transformer can be equipped with different voltage regulation solutions.

On-Load Tap Changer (OLTC)

• Automatic voltage regulation
• Manual / automatic control
• Remote control capability
• Multiple tap positions
• Typical range: ±8 × 1.25% or ±10 × 1.25%
• Customized tap range available

Off-Circuit Tap Changer

• Suitable for applications where voltage adjustment is not required under load
• Simple and economical configuration

3. Cooling System Customization

Different cooling systems can be selected according to transformer capacity and load profile.

Optional cooling components include:

• High-efficiency radiators
• Cooling fans
• Oil pumps
• Automatic fan control
• Oil flow indicators
• Cooling system control cabinet
• Standby cooling equipment

4. Insulation Level Customization

The insulation system can be designed according to the required system voltage, grounding method and insulation coordination.

Customization may include:

• Power-frequency withstand voltage
• Lightning impulse withstand level
• Switching impulse withstand level where applicable
• External insulation clearance
• Creepage distance
• Neutral insulation level
• Bushing insulation level
• Internal insulation structure

For 110kV/115kV applications, insulation coordination should be confirmed according to the applicable standard and project specification.

5. Winding Customization

The winding system can be customized according to load current, short-circuit requirements and project conditions.

Available options include:

• Copper winding
• Aluminum winding
• Disc winding
• Continuous disc winding
• Helical winding
• Interleaved winding
• Optimized axial and radial insulation
• Enhanced short-circuit mechanical strength

The winding structure can be engineered to improve:

• Short-circuit withstand capability
• Voltage distribution
• Thermal performance
• Insulation reliability
• Long-term operating stability

6. Core Customization

The magnetic core can be optimized according to loss, noise and efficiency requirements.

Options include:

• High-grade grain-oriented silicon steel
• Step-lap core construction
• Low-loss core design
• Optimized magnetic flux density
• Noise-reduction design
• Core grounding arrangement

The core design can be optimized to reduce no-load loss, excitation current and operating noise.

7. Tank & Mechanical Design

The transformer tank can be customized according to installation and transportation conditions.

Options include:

• Conservator tank
• Sealed tank
• Corrugated tank where applicable
• Detachable radiators
• Stainless-steel components
• Customized bushing positions
• Cable box
• Lifting lugs
• Jacking pads
• Grounding terminals
• Inspection covers
• Manholes
• Oil filling and draining connections

The tank structure can be designed to withstand vacuum treatment, internal pressure and transportation loads.

8. Bushing Configuration

Different bushing solutions can be selected according to system voltage and installation requirements.

Available options:

• Porcelain bushings
• Composite bushings
• Condenser bushings
• Oil-impregnated paper (OIP) bushings
• Resin-impregnated paper (RIP) bushings

Bushing arrangement can be customized for:

• HV terminals
• MV terminals
• LV terminals
• Neutral terminal
• CT integration

9. Protection & Monitoring Options

The transformer can be equipped with a comprehensive protection and monitoring system.

Protection Devices

• Buchholz relay
• Pressure relief device
• Sudden pressure relay
• Oil level protection
• Over-temperature protection
• Winding temperature protection
• OLTC protection
• Cooling failure alarm

Monitoring Devices

• Oil temperature indicator
• Winding temperature indicator
• Magnetic oil level gauge
• Online dissolved gas analysis (DGA)
• Moisture monitoring
• Bushing monitoring
• Partial discharge monitoring
• Fiber-optic temperature monitoring
• Transformer condition monitoring system

10. Control System Customization

The control system can be configured according to the customer's substation automation requirements.

Options include:

• Local control cabinet
• Remote control
• Automatic voltage regulation
• OLTC control
• Cooling system automatic control
• Alarm and trip circuits
• Digital temperature display
• RS485 communication
• Modbus communication
• IEC 61850 integration where specified
• SCADA interface

11. Environmental Customization

The transformer can be designed for different operating environments.

Available adaptations include:

• High-temperature environments
• Low-temperature environments
• High-altitude installations
• High-humidity environments
• Coastal environments
• Salt-fog environments
• Dusty environments
• Desert environments
• Mining environments
• Industrial pollution areas

Additional protection may include:

• Enhanced anti-corrosion coating
• Stainless-steel components
• Special sealing systems
• Increased creepage distance
• Special transformer oil
• High-temperature insulation materials

12. Transformer Oil Options

Different insulating media can be selected according to project requirements.

• Mineral transformer oil
• Natural ester fluid
• Synthetic ester fluid
• Low-flammability insulating fluid

Oil specifications can be selected according to applicable IEC, ASTM, GB or customer standards.

13. Three-Winding Transformer

For complex substation applications, a three-winding 110kV/115kV transformer can be supplied.

Typical configurations include:

• 110 / 33 / 11 kV
• 110 / 33 / 13.8 kV
• 115 / 34.5 / 13.8 kV
• Other customized combinations

Three-winding transformers can reduce equipment footprint and provide flexible power distribution between different voltage levels.

14. Renewable Energy Customization

For solar and wind power projects, the transformer can be customized for:

• Solar power plants
• Wind farms
• Battery energy storage systems
• Hybrid renewable energy plants
• Grid-connected renewable projects

Customization can include:

• Renewable-energy-specific voltage ratios
• OLTC
• High harmonic withstand capability
• Optimized loss performance
• Grid interconnection requirements
• Special cooling configuration
• SCADA communication
• Online monitoring

15. Transportation & Installation Customization

For large 110kV/115kV transformers, transportation dimensions can be considered during engineering.

Available solutions include:

• Detachable radiators
• Removable bushings
• Transport oil filling
• Nitrogen-filled transportation
• Separate accessory shipment
• Customized lifting points
• Jacking points
• Transportation brackets
• Shock monitoring
• Customized foundation interface

The manufacturer can provide GA drawings, transportation dimensions, weight data, center-of-gravity information and foundation drawings for EPC project planning.

16. Testing Customization

In addition to routine factory tests, additional tests can be arranged according to project requirements:

• Temperature-rise test
• Lightning impulse test
• Switching impulse test
• Partial discharge test
• Frequency response analysis (FRA)
• Capacitance and tan delta
• Zero-sequence impedance test
• Sound level test
• Short-circuit withstand test
• Transformer oil analysis
• Insulation resistance test
• Special customer-witnessed tests

17. Standards Customization

The transformer can be designed and tested according to:

IEC 60076
IEEE / ANSI
GB / DL
ASTM
Customer-specific utility standards

For international EPC projects, the complete technical design can be matched to the purchaser's Data Sheet, Technical Specification, Single-Line Diagram (SLD) and Grid Code.

Project-Based Customization

For a 110kV / 115kV transformer project, customers can provide the following information:

Capacity → Voltage Ratio → Frequency → Vector Group → Impedance → Tap Range → OLTC → Cooling → Insulation Level → Environmental Conditions → Protection → Monitoring → Applicable Standard

Zisheng can then prepare a project-specific technical proposal, transformer datasheet, GA drawing and quotation based on the customer's requirements.

The 110kV / 115kV Power Transformer is a large and heavy electrical equipment product. Its packing and transportation require careful engineering to protect the transformer against moisture, vibration, impact, corrosion and mechanical damage throughout inland transportation, port handling and international sea shipment.

Zisheng provides customized packing and shipping solutions according to transformer size, transport weight, destination, shipping method and project requirements.

1. Pre-Shipment Preparation

Before packing, every transformer undergoes a comprehensive pre-shipment inspection.

Typical procedures include:

• Final appearance inspection
• Nameplate verification
• Factory test report confirmation
• Bushing inspection
• Oil leakage inspection
• Sealing inspection
• Valve inspection
• Radiator inspection
• Cooling system inspection
• OLTC inspection
• Protection device inspection
• Terminal inspection
• Grounding inspection
• Accessory inventory
• Packing list verification

All detachable components are identified and recorded before shipment to facilitate installation at the project site.

2. Transportation Configuration

Depending on transformer capacity and transportation conditions, the transformer can be shipped in different configurations.

Option A — Complete Transformer Shipment

Suitable for relatively compact units.

The transformer is shipped with major components assembled, while selected accessories are packed separately.

Option B — Main Tank + Accessories

For large transformers, components such as:

• Radiators
• Bushings
• Conservator
• Cooling fans
• Control cabinet
• OLTC accessories

can be removed and packed separately.

This reduces the overall transport dimensions and facilitates handling.

Option C — Nitrogen-Filled Transportation

For large oil-immersed transformers, the transformer body can be transported under a controlled dry nitrogen atmosphere after draining the required amount of oil.

This helps protect the internal insulation system from:

• Moisture
• Oxygen
• Contamination

A pressure monitoring arrangement can be provided during transportation where required.

Option D — Oil-Filled Transportation

For selected transformer designs and transportation conditions, the main tank can be transported with insulating oil according to the agreed transportation specification.

The appropriate method depends on:

• Transformer size
• Transport distance
• Shipping route
• Transportation regulations
• Customer requirements

3. Transformer Main Body Protection

The main transformer body receives special protection before shipment.

Surface Protection

The painted steel surfaces are inspected and protected against:

• Scratches
• Impact
• Salt spray
• Moisture
• Corrosion

Exposed machined surfaces and connection points can receive temporary anti-corrosion protection.

Sealing Protection

All relevant openings are properly sealed to prevent:

• Rainwater penetration
• Dust contamination
• Moisture ingress
• Foreign material entering the transformer

4. Bushing Packing

High-voltage bushings are sensitive components and require dedicated packaging.

Depending on the design, bushings can be:

• Installed on the transformer
• Removed for transportation
• Packed separately

Separate bushings are normally protected with:

• Shock-resistant internal supports
• Moisture-resistant wrapping
• Protective end covers
• Reinforced wooden crates
• Identification labels

Special care is taken to prevent impact or bending forces during loading and unloading.

5. Radiator Packing

Radiators can be removed from the main transformer body for large units.

Before shipment:

1. Radiators are inspected.
2. Connection openings are sealed.
3. Internal cleanliness is checked.
4. External surfaces are protected.
5. Radiators are securely fixed to prevent movement.

Radiators can be packed individually or bundled according to their dimensions and shipping method.

6. Conservator Tank Packing

The conservator tank and associated accessories can be shipped separately.

Typical protection includes:

• Internal cleanliness inspection
• Sealing of connection ports
• Anti-corrosion protection
• Protective wrapping
• Reinforced wooden or steel support
• Identification marking

The conservator components are clearly labeled for convenient installation at the destination.

7. Control Cabinet Packing

The control cabinet is packed separately when required.

Protection includes:

• Moisture-proof packaging
• Dust protection
• Shock protection
• Corner protection
• Reinforced wooden case
• Cable terminal protection

Control cabinets are kept dry during storage and transportation.

8. OLTC Packing

For transformers equipped with an On-Load Tap Changer (OLTC), the OLTC components and drive mechanism are carefully protected.

Depending on the OLTC design:

• OLTC can remain installed on the transformer
• Motor drive mechanism can be packed separately
• Control components can be shipped separately

All components are identified according to the installation drawings and wiring diagrams.

9. Transformer Oil Transportation

The transportation method for transformer oil depends on transformer capacity and project requirements.

Oil Filled

The transformer is transported with insulating oil.

Partially Drained

A specified oil level is maintained during transportation.

Oil Drained + Nitrogen Filled

The transformer is drained and filled with dry nitrogen to protect the internal insulation system.

If the transformer is shipped under nitrogen, the nitrogen pressure should be monitored throughout transportation and storage.

Additional oil can be shipped separately in:

• Steel drums
• Oil tanks
• ISO tanks
• Customer-specified containers

10. Moisture Protection

Moisture protection is particularly important for oil-immersed high-voltage transformers because the insulation system must remain dry and clean.

Protection measures may include:

• Sealed openings
• Moisture-proof film
• Desiccant
• Dry nitrogen
• Sealed control cabinets
• Waterproof covers
• Moisture indicators
• Temporary anti-corrosion protection

For long-distance ocean transportation, additional waterproof protection can be applied according to the shipping environment.

11. Export Seaworthy Packing

For international projects, Zisheng can provide export seaworthy packing suitable for:

• Sea freight
• Container transportation
• Breakbulk shipping
• Heavy-lift vessels
• Project cargo transportation

Packing materials may include:

• Heavy-duty plastic film
• Waterproof membrane
• Moisture barrier
• Reinforced wooden cases
• Steel frames
• Shock-absorbing materials
• Protective covers

The packaging method is selected according to the actual transportation route.

12. Heavy Cargo Transportation

110kV/115kV transformers can have significant dimensions and weight.

Before shipment, transportation information can be provided, including:

• Total weight
• Transport weight
• Overall dimensions
• Center of gravity
• Lifting points
• Jacking points
• Loading points
• Securing points
• Transportation drawings

For oversized transformers, transportation may involve:

Factory → Heavy Truck → Port → Heavy-Lift Vessel / Breakbulk Vessel → Destination Port → Special Transport Vehicle → Project Site

Transportation engineering can be coordinated with the customer's EPC contractor or logistics company.

13. Container & Breakbulk Shipping

Container Shipping

Suitable for accessories and components within container dimensions.

Typical separately shipped items include:

• Bushings
• Radiators
• Control cabinets
• Cooling fans
• Conservator
• OLTC components
• Transformer accessories

Breakbulk / Project Cargo

For large 110kV/115kV transformers exceeding standard container dimensions, breakbulk or project cargo transportation may be more suitable.

This allows the transformer main body to be transported as heavy-lift cargo.

14. Loading & Securing

Professional loading procedures are used to minimize transportation risks.

The transformer and accessories are secured using suitable:

• Steel brackets
• Chains
• Tie-down systems
• Wooden supports
• Shock-absorbing materials
• Anti-slip materials

The securing method is designed to reduce movement caused by:

• Sudden braking
• Road vibration
• Ship movement
• Crane handling
• Port loading and unloading

15. Shock & Vibration Protection

High-voltage transformer components are protected against excessive mechanical shock.

Special attention is given to:

• Bushings
• Radiators
• Control cabinets
• OLTC mechanisms
• Instrumentation
• Internal active parts

For high-value projects, shock and tilt indicators can be installed to record abnormal transportation events.

16. Shipping Marks

Each package is clearly marked with relevant shipping information.

Typical markings include:

PRODUCT NAME

TRANSFORMER MODEL

SERIAL NUMBER

PACKAGE NUMBER

GROSS WEIGHT

NET WEIGHT

DIMENSIONS

CENTER OF GRAVITY

LIFTING POINT

THIS SIDE UP

KEEP DRY

FRAGILE

DO NOT STACK

Customized shipping marks can be provided according to the customer's logistics requirements.

17. Shipping Documents

The shipment can be supplied with complete export documentation.

Typical documents include:

• Commercial Invoice
• Packing List
• Bill of Lading
• Certificate of Origin
• Factory Test Report
• Routine Test Report
• Quality Certificate
• Product Certificate
• Technical Specification
• Installation Manual
• Operation Manual
• General Arrangement Drawing
• Foundation Drawing
• Wiring Diagram
• Nameplate Drawing
• Accessory List
• Transportation Drawing
• Insurance documents where required

Additional documents can be prepared according to the EPC contract or destination-country requirements.

18. Installation at Destination

For large transformer projects, installation support documents can be provided to assist the customer's site team.

Typical installation procedures include:

1. Unloading and positioning
2. Inspection after transportation
3. Installation of radiators
4. Installation of bushings
5. Installation of conservator
6. Installation of cooling equipment
7. OLTC connection
8. Control cabinet installation
9. Vacuum treatment where required
10. Transformer oil filling
11. Oil filtration
12. Electrical testing
13. Protection system testing
14. Commissioning
15. Energization

The exact procedure must follow the manufacturer's installation manual and project-specific requirements.

19. Long-Term Storage

If the transformer cannot be installed immediately after arrival, suitable storage conditions should be maintained.

Recommended storage measures include:

• Keep equipment in a dry environment
• Prevent rainwater accumulation
• Maintain required nitrogen pressure where applicable
• Protect bushings from moisture
• Keep control cabinets sealed
• Periodically inspect package integrity
• Check oil or nitrogen condition
• Monitor moisture indicators
• Protect accessories from corrosion

Long-term storage requirements should be confirmed according to the actual transportation configuration.

20. Global Delivery Support

Zisheng can coordinate packing and shipping requirements for international utility, EPC, industrial, mining and renewable energy projects.

Shipping Support

Factory Inspection → Final Testing → Packing → Loading → Port Transportation → Export Customs → Ocean Freight → Destination Port → Project Site

For each project, the packing and shipping method can be customized according to:

• Transformer capacity
• Transformer dimensions
• Total transport weight
• Destination country
• Port conditions
• Shipping route
• Incoterms
• Customer installation requirements

Custom export packing and project cargo transportation solutions are available for 110kV and 115kV power transformers.

The 110kV / 115kV Power Transformer is subjected to comprehensive manufacturer testing before shipment to verify its electrical performance, insulation integrity, mechanical strength, protection functions and overall manufacturing quality.

Testing is performed according to the applicable IEC 60076, IEEE/ANSI, GB standards and customer-approved technical specifications. For utility and EPC projects, additional type and special tests can be arranged according to the purchase specification.

1. Factory Testing Overview

Manufacturer testing generally includes:

Routine Tests

Performed on each transformer before delivery.

Type Tests

Performed to verify the design performance of a transformer type.

Special Tests

Performed when required by the purchaser, utility, EPC contractor or project specification.

For a 110kV/115kV transformer, the factory testing program can be expanded according to the required insulation level, capacity, grid requirements and contractual technical specification.

2. Visual & Mechanical Inspection

Before electrical testing, the completed transformer undergoes a detailed mechanical inspection.

The inspection includes:

• Overall transformer dimensions
• Tank construction
• Paint and surface condition
• Radiator installation
• Bushing installation
• Conservator installation
• Valve arrangement
• Grounding terminals
• Lifting lugs
• Jacking points
• Nameplate information
• Cable connections
• Control cabinet
• Cooling system
• OLTC mechanism
• Oil level indicators
• Temperature indicators
• Pressure relief devices

The inspection verifies that the manufactured transformer conforms to the approved General Arrangement (GA) Drawing and technical specification.

3. Winding Resistance Test

The resistance of each transformer winding is measured to verify:

• Winding conductor integrity
• Internal connections
• Soldered/jointed connections
• Tap changer contacts
• Phase consistency

Measurements are normally performed on all phases and tap positions as required.

The measured values are compared with the manufacturer's design calculations and applicable acceptance criteria.

4. Voltage Ratio Test

The transformation ratio is measured between the high-voltage and low-/medium-voltage windings.

The test verifies:

• Correct winding ratio
• Correct tap positions
• Correct winding connections
• Correct phase relationship
• OLTC operation

All applicable tap positions can be checked for transformers equipped with an OLTC.

5. Vector Group & Phase Displacement Test

The phase relationship between HV, MV and LV windings is verified.

The test confirms:

• Correct vector group
• Correct winding polarity
• Correct phase sequence
• Correct phase displacement

Typical configurations may include:

Dyn11

YNd11

YNd1

or a project-specific vector group.

6. No-Load Loss & No-Load Current Test

The transformer is energized at rated frequency and voltage without external load.

The manufacturer measures:

• No-load loss
• No-load current
• Excitation current

This test evaluates the magnetic performance of the transformer core.

The results are compared with the guaranteed values specified in the transformer technical datasheet.

7. Short-Circuit Impedance & Load Loss Test

The transformer is tested to determine:

• Short-circuit impedance
• Load loss
• Winding losses

The test provides important information about transformer efficiency and impedance characteristics.

The results are evaluated against the guaranteed values and applicable standards.

For utility transformers, the specified impedance is particularly important because it affects:

• Fault current
• Voltage regulation
• Parallel operation
• System stability

8. Applied Voltage Test

The applied-voltage test verifies the insulation between:

• HV winding and ground
• MV/LV winding and ground
• Other winding insulation systems

A specified power-frequency test voltage is applied for the required duration.

The purpose is to verify that the main insulation system can withstand the specified electrical stress without breakdown or abnormal discharge.

9. Induced Voltage Test

The induced-voltage test evaluates the insulation between turns, layers and winding sections.

The transformer is energized at an increased frequency and appropriate voltage level according to the applicable test procedure.

The test helps verify:

• Inter-turn insulation
• Inter-layer insulation
• Longitudinal insulation
• Winding insulation integrity

10. Lightning Impulse Test

For 110kV/115kV transformers, lightning impulse testing is an important part of high-voltage insulation verification when required by the applicable standard or project specification.

The test simulates transient overvoltages caused by lightning and verifies the transformer's ability to withstand the specified impulse stress.

Testing may include:

• Full-wave lightning impulse
• Chopped-wave impulse where specified
• HV terminal testing
• Neutral terminal testing where applicable

The applicable impulse withstand level is determined by the specified insulation coordination.

11. Switching Impulse Test

For applicable high-voltage transformer designs, switching impulse testing can be performed according to the required insulation level and project specification.

The test simulates transient overvoltages associated with:

• Circuit breaker operation
• Line energization
• Fault clearing
• Switching operations

This is particularly relevant to high-voltage transmission and substation applications.

12. Partial Discharge Test

Partial discharge (PD) testing can be performed to assess the quality of the transformer insulation system.

The test can detect localized electrical discharges caused by defects such as:

• Voids
• Contamination
• Poor insulation interfaces
• Localized electric-field concentration
• Manufacturing defects

For high-voltage transformers, PD testing can provide additional confidence in the long-term reliability of the insulation system.

The acceptance level is determined according to the applicable standard and project specification.

13. Temperature-Rise Test

A temperature-rise test can be performed as a type test or special test.

The test verifies the thermal performance of the transformer under specified loading conditions.

Measurements can include:

• Top oil temperature rise
• Average winding temperature rise
• Hot-spot temperature where applicable
• Cooling system performance

The results verify that the transformer operates within the specified temperature limits.

14. Short-Circuit Withstand Test

For major utility and EPC projects, a short-circuit withstand test may be specified.

The test verifies the transformer's ability to withstand the:

• Electromagnetic forces
• Mechanical stress
• Thermal stress

generated during external short-circuit conditions.

The test evaluates the mechanical integrity of:

• HV windings
• MV/LV windings
• Clamping structures
• Axial supports
• Radial supports
• Internal connections

This is especially important for large-capacity 110kV/115kV transformers.

15. Frequency Response Analysis — FRA

Frequency Response Analysis can be performed before shipment to establish a reference fingerprint of the transformer.

The FRA results can later be compared with measurements taken after:

• Transportation
• Installation
• Major fault events
• Maintenance

Changes in the response may indicate possible movement or deformation of internal active parts.

FRA is particularly useful for large transformers that will undergo long-distance transportation.

16. Capacitance & Tan Delta Test

Capacitance and dielectric dissipation factor (tan delta) measurements can be performed on:

• Transformer windings
• Bushings
• Insulation system

The test helps evaluate insulation condition and detect abnormalities such as:

• Moisture
• Contamination
• Aging
• Insulation deterioration

17. Transformer Oil Testing

Transformer insulating oil is tested before filling and/or after final filling according to project requirements.

Typical parameters include:

• Breakdown voltage
• Water content
• Acidity
• Dielectric dissipation factor
• Resistivity
• Interfacial tension
• Appearance
• Dissolved gas analysis where specified

The oil test confirms that the insulating medium meets the specified quality requirements.

18. Bushing Testing

High-voltage bushings are inspected and tested according to the applicable requirements.

Testing may include:

• Capacitance measurement
• Tan delta measurement
• Insulation resistance
• Dielectric tests
• Visual inspection
• Terminal inspection

For condenser bushings, capacitance and dielectric loss measurements are particularly important.

19. OLTC Testing

For transformers equipped with an On-Load Tap Changer, the complete tap-changing system is tested.

The manufacturer verifies:

• All tap positions
• Tap position indication
• Motor drive operation
• Electrical interlocks
• Manual operation
• Remote operation
• Limit switches
• Control circuit
• Emergency stop
• Tap position feedback

The OLTC operation is checked repeatedly to ensure smooth and reliable switching.

20. Cooling System Testing

The cooling system is tested before shipment.

Testing includes:

• Cooling fan operation
• Oil pump operation
• Automatic start/stop
• Temperature control
• Alarm functions
• Standby cooling function
• Control cabinet operation
• Fan rotation direction
• Pump operation
• Electrical interlocks

For ONAF, OFAF or ODAF transformers, the cooling system is verified under the specified control logic.

21. Protection Device Testing

The protection system can include:

Buchholz Relay

Tested for:

• Gas alarm
• Oil surge trip
• Contact operation

Pressure Relief Device

Checked for:

• Mechanical operation
• Alarm/trip contacts
• Pressure relief function

Oil Level Indicator

Verified for:

• Normal level indication
• Low-level alarm
• Contact operation

Temperature Indicators

Checked for:

• Temperature indication
• Alarm
• Trip
• Cooling control

22. Control Cabinet Testing

The transformer control cabinet is tested before delivery.

Testing includes:

• Wiring inspection
• Terminal verification
• Insulation resistance
• Control circuit operation
• Alarm circuits
• Trip circuits
• Cooling control
• OLTC control
• Local/remote switching
• Interlock functions
• Communication interface where applicable

The wiring is checked against the approved electrical drawings.

23. Leak & Pressure Testing

The transformer tank and associated oil systems undergo leakage inspection.

Testing may include:

• Tank leakage test
• Vacuum tightness test
• Pressure test
• Radiator leakage test
• Valve inspection
• Bushing connection inspection

The purpose is to ensure that the transformer can maintain its required oil and sealing conditions during long-term operation.

24. Noise Level Test

A noise test can be conducted when required.

The test evaluates the acoustic performance of the transformer during operation.

Noise can be affected by:

• Core flux density
• Core construction
• Cooling fans
• Oil pumps
• Tank structure

For projects located near residential, commercial or environmentally sensitive areas, a specific maximum sound level can be included in the technical specification.

25. Final Factory Acceptance Test — FAT

For major EPC and utility projects, customers can participate in a Factory Acceptance Test (FAT).

The FAT may include:

Document Review → Visual Inspection → Routine Tests → Protection Test → OLTC Test → Cooling Test → Special Tests → Test Report Review → Final Acceptance

Customer representatives can witness selected tests according to the approved Inspection & Test Plan (ITP).

26. Test Documentation

After testing, the manufacturer can provide a complete testing dossier.

Typical documents include:

• Routine Test Report
• Type Test Report
• Special Test Report
• Factory Acceptance Test Report
• Transformer Oil Test Report
• Calibration Certificates
• Material Certificates
• Inspection Records
• Dimensional Inspection Report
• Protection Test Records
• OLTC Test Records
• Cooling System Test Records
• Quality Certificate
• Final Inspection Report

The test documentation can be submitted for customer, EPC contractor, consultant or utility approval.

Manufacturer Testing Process

Manufacturing → Internal Inspection → Mechanical Inspection → Routine Electrical Tests → Dielectric Tests → Protection Tests → Special Tests → FAT → Final Inspection → Packing & Shipping

Key Quality Commitment

100% Factory Tested Before Delivery

IEC 60076 Compliant Testing

Customer Witness Testing Available

Complete Test Documentation

FAT Support for EPC & Utility Projects

Project-Specific Inspection & Test Plan (ITP)

The 110kV / 115kV Power Transformer is designed for high-voltage transmission, substation, power generation and large-scale industrial applications. It provides reliable voltage transformation between high-voltage transmission networks and medium-voltage distribution or utilization systems.

With customizable capacity, voltage ratio, impedance, vector group, tap changer, cooling system and insulation level, the transformer can be engineered for utility, EPC, industrial, mining and renewable-energy projects.

1. Utility Power Grid

The 110kV / 115kV transformer is widely used in utility substations for power transmission and distribution.

Typical applications include:

• Transmission substations
• Distribution substations
• Grid interconnection substations
• Regional power networks
• Urban substations
• Rural electrification networks
• Grid reinforcement projects

Typical voltage configurations include:

110/33kV

110/11kV

115/34.5kV

115/13.8kV

The transformer reduces transmission voltage to an appropriate medium-voltage level for downstream distribution.

2. Power Generation Plants

The transformer can be used in conventional and renewable power generation facilities to connect generated electrical energy to the high-voltage grid.

Applications include:

• Hydroelectric power plants
• Thermal power plants
• Gas-fired power plants
• Biomass power plants
• Diesel power plants
• Combined-cycle power plants

Typical configurations may include:

Generator → Generator Transformer → 110kV / 115kV Grid

The transformer can be customized according to generator voltage, grid voltage, rated output and system fault requirements.

3. Solar Power Plants

110kV / 115kV transformers are commonly used in large-scale photovoltaic power projects for grid interconnection.

A typical solar power transmission system can be configured as:

PV Modules → Inverter → Step-Up Transformer → MV Collector System → 110/115kV Substation → Grid

Applications include:

• Utility-scale solar farms
• Ground-mounted PV plants
• Desert solar projects
• Floating solar projects
• Industrial solar power plants
• Hybrid solar + energy storage projects

Customization can include:

• 33kV / 34.5kV input
• 110kV / 115kV output
• OLTC
• High-efficiency design
• Harmonic considerations
• Remote monitoring
• SCADA integration

4. Wind Power Projects

The transformer can be used in wind farms to collect and transmit generated electricity to the high-voltage grid.

Typical system:

Wind Turbine → Wind Transformer → MV Collector Network → 110/115kV Main Transformer → Grid

Applications include:

• Onshore wind farms
• Large wind power bases
• Coastal wind projects
• Renewable energy parks
• Hybrid wind + solar projects

The transformer can be customized according to the wind farm's:

• Total installed capacity
• Collector voltage
• Grid connection voltage
• Reactive power requirements
• Harmonic characteristics
• Voltage regulation requirements

5. Mining Projects

Large mining operations require high-capacity and reliable power supply systems.

The 110kV / 115kV transformer can be used for:

• Gold mines
• Copper mines
• Iron ore mines
• Coal mines
• Lithium mines
• Mineral processing plants
• Mining camps

A typical system may be:

Utility Grid → 110/115kV Transformer → 33kV / 11kV Distribution → Mining Equipment

It can supply power to:

• Crushers
• Mills
• Conveyors
• Pumps
• Ventilation systems
• Processing equipment
• Heavy machinery

For mining environments, additional customization can include enhanced corrosion protection, high-temperature design, dust protection and special cooling configurations.

6. Oil & Gas Projects

110kV / 115kV power transformers can be used in large oil and gas facilities where high-capacity and continuous power supply are required.

Typical applications include:

• Oil refineries
• Petrochemical plants
• LNG facilities
• Natural gas processing plants
• Oil terminals
• Pumping stations
• Offshore/onshore energy facilities

The transformer can be integrated with:

• High-voltage substations
• MV switchgear
• Protection systems
• SCADA
• Emergency power systems

Special environmental and corrosion-resistant designs can be provided for demanding installations.

7. Industrial Plants

The transformer provides high-voltage power supply for large industrial facilities.

Applications include:

Steel Plants

• Electric arc furnaces
• Rolling mills
• Steel processing

Cement Plants

• Cement production
• Grinding systems
• Kilns
• Material handling

Chemical Plants

• Chemical processing
• Industrial production lines
• Large motor loads

Manufacturing Facilities

• Automotive plants
• Machinery factories
• Heavy manufacturing
• Large industrial parks

A typical configuration is:

110/115kV Grid → Main Transformer → 33kV / 11kV Distribution → Industrial Loads

8. Industrial Parks

The transformer can serve as the main power supply transformer for large industrial parks.

Applications include:

• Manufacturing parks
• Technology parks
• Logistics parks
• Export processing zones
• Economic development zones

A centralized high-voltage substation can distribute power to multiple industrial users through medium-voltage networks.

Typical configurations:

110/33kV

110/11kV

115/34.5kV

9. Data Centers

Large data centers require highly reliable electrical infrastructure.

110kV / 115kV transformers can be used as part of the primary electrical supply system.

Typical architecture:

Utility Grid → 110/115kV Substation → MV Switchgear → UPS → Data Center Loads

Applications include:

• Hyperscale data centers
• Cloud computing centers
• AI data centers
• Internet data centers
• Enterprise data centers

The transformer can be customized for:

• High reliability
• Low losses
• Low noise
• Redundant cooling
• Online monitoring
• Dual power supply configurations

10. Railway & Transportation Infrastructure

High-voltage transformers can be used to supply large transportation infrastructure.

Applications include:

• High-speed railway systems
• Metro systems
• Railway substations
• Railway maintenance facilities
• Airport infrastructure
• Port facilities

The transformer can be integrated with the project's high-voltage receiving substation and downstream distribution network.

11. Battery Energy Storage Systems

110kV / 115kV transformers can be used in large-scale battery energy storage projects.

Typical configuration:

Battery System → PCS → MV Transformer → 110/115kV Substation → Grid

Applications include:

• Utility-scale BESS
• Renewable energy storage
• Grid peak shaving
• Frequency regulation
• Renewable energy integration
• Grid stabilization

The transformer can be designed according to the project's:

• MV voltage
• Grid voltage
• Bidirectional power flow
• Loading profile
• Harmonic characteristics
• Grid-code requirements

12. Hybrid Renewable Energy Projects

The transformer can serve as the main grid-interconnection transformer for combined renewable energy projects.

For example:

Solar + Wind + BESS → MV Collection System → 110/115kV Transformer → Utility Grid

This configuration is suitable for large renewable-energy parks where multiple power sources share a common high-voltage grid connection point.

13. Commercial & Infrastructure Projects

For large infrastructure projects, the transformer can provide high-voltage power supply to centralized substations.

Applications include:

• Airports
• Ports
• Large commercial complexes
• Convention centers
• Universities
• Hospitals
• Government infrastructure
• Large residential developments

For these applications, transformer design can prioritize:

• High reliability
• Low noise
• Low losses
• Compact installation
• Automatic voltage regulation

14. Utility Substation Expansion

The 110kV / 115kV transformer can also be used to expand the capacity of existing substations.

Applications include:

• Increasing substation capacity
• Replacing aging transformers
• Adding new transmission capacity
• Supporting increasing electricity demand
• Improving grid reliability

The replacement transformer can be engineered to match the existing:

• HV voltage
• MV voltage
• Busbar configuration
• Protection system
• OLTC control
• Foundation
• Cable arrangement

15. Grid Interconnection Projects

The transformer can be used to connect new power-generation or industrial facilities to existing transmission networks.

Typical applications:

Power Plant → 110/115kV Transformer → Transmission Grid

or

Industrial Facility → 110/115kV Receiving Substation → Utility Grid

The transformer can be engineered according to the utility's grid-connection requirements, including:

• Short-circuit level
• Voltage regulation
• Protection coordination
• Grounding system
• Insulation coordination
• Reactive power requirements

16. Typical Application Voltage Levels

17. Suitable Project Types

The 110kV / 115kV Power Transformer is suitable for:

Utility Projects

EPC Projects

Power Generation

Transmission & Distribution

Solar Power Plants

Wind Farms

Battery Energy Storage

Mining Projects

Oil & Gas

Steel & Cement Plants

Industrial Parks

Data Centers

Railway Infrastructure

Grid Expansion & Upgrade Projects

Project Solution

For large-scale projects, the transformer can be supplied as part of a complete substation solution:

110kV / 115kV Power Transformer

→ HV Switchgear

→ MV Switchgear

→ Protection & Control

→ SCADA / Monitoring

→ Cooling System

→ Transformer Accessories

→ Factory Testing

→ Export Packing

→ Installation & Commissioning Support

This makes the 110kV/115kV transformer suitable not only as an individual electrical product, but also as part of a complete high-voltage substation and power distribution solution for global EPC and utility projects.

1. What is a 110kV / 115kV Power Transformer?

A 110kV / 115kV Power Transformer is a high-voltage oil-immersed transformer designed to transfer electrical energy between transmission and medium-voltage networks.

It is commonly used in:

• Utility substations
• Power plants
• Solar and wind farms
• Mining projects
• Industrial facilities
• Oil & gas projects
• Data centers
• Large industrial parks
• Grid interconnection projects

The transformer can be customized according to capacity, voltage ratio, impedance, vector group, cooling system, tap range and insulation requirements.

2. What is the difference between a 110kV and 115kV transformer?

The main difference is the rated system voltage for which the transformer is designed.

A 110kV transformer is commonly used in transmission systems based on a 110kV nominal voltage, while a 115kV transformer is commonly used in systems using a 115kV nominal voltage.

The actual design must consider:

• Maximum system voltage
• Insulation level
• Lightning impulse withstand level
• Neutral grounding
• Tap range
• Grid code
• Utility requirements

The final rated voltage should therefore be determined according to the customer's grid specification rather than simply selecting 110kV or 115kV based on nominal voltage.

3. What capacities are available?

Typical capacities include:

• 10 MVA
• 16 MVA
• 20 MVA
• 25 MVA
• 31.5 MVA
• 40 MVA
• 50 MVA
• 63 MVA
• 80 MVA
• 100 MVA
• 120 MVA
• 150 MVA
• 180 MVA
• 200 MVA
• 240 MVA

Higher capacities can also be engineered for large utility and power-generation projects.

Capacity is fully customizable according to the customer's load and grid requirements.

4. What voltage ratios are available?

Common configurations include:

• 110/11kV
• 110/33kV
• 110/13.8kV
• 110/10.5kV
• 115/11kV
• 115/13.8kV
• 115/33kV
• 115/34.5kV

Three-winding configurations are also available, such as:

• 110/33/11kV
• 110/33/13.8kV
• 115/34.5/13.8kV

Other voltage combinations can be customized.

5. Is the transformer oil-immersed?

Yes.

The 110kV / 115kV power transformer is normally supplied as an oil-immersed transformer using an oil-paper insulation system.

Available insulating fluids may include:

• Mineral transformer oil
• Natural ester fluid
• Synthetic ester fluid

The insulating medium can be selected according to project requirements and applicable standards.

6. What cooling systems are available?

Different cooling systems can be supplied according to transformer capacity.

ONAN

Oil Natural Air Natural.

ONAF

Oil Natural Air Forced.

OFAF

Oil Forced Air Forced.

ODAF

Oil Directed Air Forced.

Large-capacity transformers may use forced oil circulation and forced-air cooling to maintain acceptable temperature rise under high loading conditions.

7. Does the transformer support an OLTC?

Yes.

An On-Load Tap Changer (OLTC) can be installed for applications requiring voltage regulation while the transformer is energized.

Typical tap ranges include:

• ±8 × 1.25%
• ±10 × 1.25%
• Customized tap ranges

The OLTC can include:

• Motor drive
• Local control
• Remote control
• Automatic voltage regulation
• Tap position indicator
• Limit switches
• Interlocking
• Protection functions

8. What vector groups are available?

Typical vector groups include:

• Dyn11
• YNd11
• YNd1
• YNyn0
• Customized vector groups

The appropriate vector group depends on the customer's grid configuration, grounding system and parallel-operation requirements.

9. Can the transformer be customized?

Yes.

The transformer can be customized in almost every major electrical and mechanical parameter.

Customization includes:

• Rated capacity
• HV voltage
• MV voltage
• LV voltage
• Frequency
• Vector group
• Impedance
• Tap range
• OLTC
• Cooling system
• Insulation level
• Bushing type
• Winding material
• Transformer oil
• Tank configuration
• Protection devices
• Monitoring system
• Control cabinet
• Communication interface
• Dimensions
• Cable entry
• Painting and corrosion protection

10. What standards can the transformer comply with?

The transformer can be designed and tested according to:

• IEC 60076
• IEEE
• ANSI
• GB
• Customer-specific utility standards
• EPC project specifications

For 110kV/115kV applications, the insulation and dielectric testing requirements are coordinated with the applicable high-voltage transformer standard and project insulation level.

11. What routine tests are performed before shipment?

Each transformer undergoes the required factory routine tests before delivery.

Typical tests include:

• Winding resistance
• Voltage ratio
• Phase displacement
• Vector group
• No-load loss
• No-load current
• Load loss
• Short-circuit impedance
• Applied voltage test
• Induced voltage test
• Insulation resistance
• OLTC operation
• Control circuit testing
• Protection device testing
• Cooling system testing
• Oil leakage inspection

A complete Routine Test Report can be provided to the customer.

12. Are high-voltage dielectric tests available?

Yes.

Depending on the applicable standard and project specification, testing can include:

• Applied voltage test
• Induced voltage test
• Lightning impulse test
• Switching impulse test where applicable
• Partial discharge test

The required test levels are determined by the specified insulation coordination and customer requirements.

13. Can customers witness factory testing?

Yes.

For major utility and EPC projects, Factory Acceptance Testing (FAT) can be arranged.

Customer or third-party inspectors can witness selected tests according to the approved Inspection & Test Plan (ITP).

A typical FAT process is:

Document Review → Visual Inspection → Routine Testing → Functional Testing → Special Testing → Test Report Review → Final Acceptance

14. Can the transformer be used for solar power plants?

Yes.

The transformer can be designed for utility-scale photovoltaic projects.

Typical configuration:

Solar PV → Inverter → MV Collection System → 110/115kV Transformer → Grid

Common configurations include:

33kV / 110kV

34.5kV / 115kV

The transformer can be customized for:

• Renewable-energy loading profiles
• OLTC
• Grid-code requirements
• Harmonic considerations
• SCADA
• Remote monitoring
• High-efficiency operation

15. Can it be used for wind farms?

Yes.

The transformer can be used as the main grid interconnection transformer for wind farms.

Typical system:

Wind Turbines → MV Collector Network → 110/115kV Transformer → Transmission Grid

The design can be customized according to the wind farm's installed capacity, collector voltage and grid-connection requirements.

16. Is it suitable for mining projects?

Yes.

110kV/115kV transformers are suitable for large mining and mineral-processing projects.

Applications include:

• Gold mines
• Copper mines
• Iron ore mines
• Coal mines
• Lithium mines
• Mineral processing facilities

The transformer can supply 33kV, 11kV or other medium-voltage distribution systems within the mining site.

Special designs can be provided for:

• High ambient temperatures
• Dusty environments
• High humidity
• Corrosive environments
• Remote installations

17. Can it be used in desert or high-temperature environments?

Yes.

The transformer can be customized for harsh environmental conditions, including:

• High ambient temperature
• Desert environments
• Dust
• High solar radiation
• Coastal salt fog
• High humidity
• Industrial pollution

Possible adaptations include:

• Enhanced cooling capacity
• Special radiator configuration
• Improved coating system
• Increased creepage distance
• Special sealing
• Environmental protection for control equipment

18. Can the transformer be used at high altitude?

Yes.

High-altitude installation can be accommodated during design.

The design may need to consider:

• Reduced air density
• External insulation
• Cooling performance
• Creepage distance
• Clearance
• Temperature rise

The customer should provide the actual installation altitude so the transformer can be properly engineered.

19. What protection devices can be supplied?

The transformer can be equipped with:

• Buchholz relay
• Pressure relief device
• Sudden pressure relay
• Oil temperature indicator
• Winding temperature indicator
• Magnetic oil level indicator
• OLTC protection
• Cooling failure alarm
• Over-temperature alarm/trip
• Online transformer monitoring

Protection configuration can be customized according to the utility or EPC protection philosophy.

20. Is online monitoring available?

Yes.

Optional online monitoring systems can include:

• Oil temperature monitoring
• Winding temperature monitoring
• Dissolved Gas Analysis (DGA)
• Moisture monitoring
• Bushing monitoring
• Partial discharge monitoring
• OLTC monitoring
• Cooling system monitoring
• Transformer condition monitoring

Communication can be integrated with the customer's control or SCADA system where required.

21. How is a 110kV/115kV transformer shipped?

Large transformers require project-specific transportation planning.

Possible shipping configurations include:

• Complete transformer shipment
• Main tank + separate accessories
• Nitrogen-filled transportation
• Oil-filled transportation where applicable
• Breakbulk shipping
• Heavy-lift project cargo
• Container shipment for accessories

For large units, the manufacturer can provide:

• Transport dimensions
• Transport weight
• Center of gravity
• Lifting points
• Jacking points
• Transportation drawings

22. Can the transformer be shipped internationally?

Yes.

Export packing can be arranged for international projects.

The shipping package can include:

• Waterproof protection
• Moisture protection
• Reinforced packing
• Separate accessory packing
• Shock protection
• Anti-corrosion protection
• Shipping marks
• Export documentation

The shipping method can be coordinated according to the destination country, port and project logistics requirements.

23. What documents are supplied with the transformer?

Depending on the contract, the documentation package can include:

• Technical specification
• General Arrangement Drawing
• Foundation Drawing
• Wiring Diagram
• Nameplate Drawing
• Routine Test Report
• FAT Report
• Oil Test Report
• Quality Certificate
• Inspection Certificate
• Installation Manual
• Operation Manual
• Packing List
• Commercial Invoice
• Certificate of Origin
• Transportation Drawing
• Accessory List

Additional documents can be supplied according to EPC or utility requirements.

24. Can Zisheng provide OEM / ODM service?

Yes.

Zisheng can manufacture transformers according to the customer's:

• Technical specification
• Drawings
• Voltage requirements
• Utility standards
• Brand requirements
• Project-specific datasheet

OEM/ODM services can include customized nameplates, documentation, electrical configuration and mechanical design.

25. What information is required for a quotation?

To prepare an accurate technical proposal and quotation, customers are recommended to provide:

Rated Capacity: ___ MVA
HV Voltage: 110kV / 115kV
MV Voltage: ___ kV
LV Voltage: ___ kV
Frequency: 50Hz / 60Hz
Vector Group: ___
Impedance: ___ %
Tap Range: ___
Tap Changer: OLTC / Off-Circuit
Cooling: ONAN / ONAF / OFAF / ODAF
Insulation Level: ___
Installation Altitude: ___ m
Ambient Temperature: ___ °C
Applicable Standard: IEC / IEEE / ANSI / GB / Other
Quantity: ___ units
Destination: ___

If the customer already has a single-line diagram, transformer datasheet or EPC technical specification, it can be provided for engineering review.

26. Why choose Zisheng for a 110kV / 115kV transformer project?

Zisheng can provide a complete project-oriented service covering:

Engineering Design

→ Customized Manufacturing

→ Factory Routine Testing

→ FAT / Customer Inspection

→ Export Packing

→ Global Shipping

→ Technical Documentation

→ Installation & Commissioning Support

The 110kV / 115kV transformer can be engineered specifically for utility substations, EPC projects, power plants, renewable-energy projects, mining operations and large industrial facilities, rather than being supplied as a one-size-fits-all standard product.