1500 kVA Pad-Mounted Transformer for Solar Projects in Mexico

06-09 2026 | By:

Project Overview

A 1500 kVA pad-mounted transformer was designed for a photovoltaic power generation project in Mexico, providing the medium-voltage transformation required between the solar power collection system and the local electrical network.

The transformer adopts a three-phase, oil-immersed, pad-mounted design, suitable for outdoor installation in solar power plants.

For the Mexican market, the transformer can be configured around commonly used medium-voltage levels such as 13.8 kV, with the low-voltage side selected according to the PV inverter output and project interconnection requirements.

Mexican electrical projects commonly use 60 Hz systems, while CFE project documentation also shows 13.8 kV and 34.5 kV applications in distribution and substation systems.

1500 kVA Pad-Mounted Transformer Technical Specifications

Engineering note: The 13.8/0.48 kV configuration above is a representative configuration for a Mexico PV project. Actual voltage ratio, vector group, BIL, impedance, grounding arrangement and protection scheme should be finalized from the CFE interconnection study, inverter output voltage and project single-line diagram.

Designed for Mexico Solar Power Projects

For photovoltaic projects, the transformer operates differently from a conventional distribution transformer because the power flow is generally:

PV Modules → DC Combiner → Inverter → LV AC → Pad-Mounted Transformer → MV Collection System → Grid

The 1500 kVA transformer therefore needs to consider not only the nominal voltage and capacity, but also:

• PV inverter output voltage
• Harmonic current
• Bidirectional power flow
• Grounding method
• Medium-voltage protection
• Transformer impedance
• Continuous outdoor operation
• Solar plant ambient temperature
• Grid interconnection requirements

This makes the pad-mounted transformer a practical solution for decentralized transformer installation throughout a solar field.

Mexican Standards and Engineering Requirements

For the Mexican market, standards should be selected according to the transformer’s capacity and application rather than simply listing every Mexican standard.

NOM-002-SEDE/ENER-2014 establishes safety and energy-efficiency requirements for distribution transformers sold in Mexico. However, its definition of distribution transformers covers 5–500 kVA, so a 1500 kVA unit falls outside that specific capacity definition.

For 1500 kVA equipment, the engineering specification should therefore be established based on the project owner’s requirements, CFE requirements where applicable, Mexican NMX standards, and internationally recognized transformer standards such as IEEE/IEC.

Relevant Mexican transformer standards include NMX-J-116-ANCE for distribution and power transformer requirements and NMX-J-169-ANCE for transformer testing. CFE specifications also reference these standards in transformer applications.

For example, CFE documentation demonstrates the use of 34.5/13.8 kV, 60 Hz transformer systems in Mexican grid applications.

Pad-Mounted Design for PV Applications

The transformer enclosure is designed for outdoor solar-farm installation and can integrate:

• Medium-voltage load-break switch
• Bayonet or current-limiting fuses
• LV circuit breaker
• Pressure relief device
• Oil level indicator
• Temperature indicator
• Drain and sampling valve
• Grounding terminals
• HV/LV cable compartments
• Surge arresters
• Removable cabinet panels

The final configuration can be customized according to the PV plant protection coordination and utility interconnection requirements.

Why 1500 kVA Pad-Mounted Transformers for Solar?

A 1500 kVA transformer provides a compact solution for connecting PV inverter blocks to the medium-voltage collection network.

Key Advantages

Compact Installation
Integrated transformer and switching/protection equipment reduce installation footprint.

Outdoor Operation
The pad-mounted enclosure is designed for installation directly within the solar field.

PV-Compatible Configuration
Voltage ratio, impedance, vector group and protection can be customized according to inverter and grid requirements.

Reliable Grid Connection
The transformer provides the required voltage transformation between the inverter output and the MV collection network.

Easy Maintenance
The integrated cabinet arrangement provides convenient access to switching, protection and transformer components.

Quality Control and Factory Testing

Each transformer should undergo routine testing before shipment. Depending on the project specification, testing may include:

• Winding resistance test
• Transformer ratio test
• Polarity and vector group test
• No-load loss and current test
• Load loss and impedance test
• Applied voltage test
• Induced voltage test
• Insulation resistance test
• Oil leakage / tank sealing test
• Functional inspection of accessories

For Mexican projects, the required factory test reports and documentation should be agreed with the customer and utility before production.

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