1000 kVA photovoltaic transformer-13.2/0.48 kV | USA 2025

01 General

1.1 Photovoltaic Transformers

In modern solar power projects, solar photovoltaic transformers play a crucial role in connecting PV arrays to the utility grid while managing local loads. These specialized photovoltaic transformers are not just “solar compatible”; they are built around the unique electrical behavior of PV plants.

Solar generation is inherently discontinuous – day and night cycles, cloud cover, and weather variations all affect the power output. This cyclical nature demands transformers that can handle rapid load swings, voltage fluctuations, and inverter-induced harmonics without compromising efficiency or safety.

Our 1000 kVA PV step-up transformer is specifically designed for this application, stepping voltage up from 480Y/277 V on the low-voltage side to 13,200 GRDY/7,620 V on the high-voltage side for efficient grid interconnection. It supports bidirectional operation, allowing power to flow from the solar inverters to the grid during generation peaks, and from the grid to local loads when needed. This dual-use capability makes it a reliable backbone for any PV plant looking to stabilize voltage, maintain safety, and optimize energy delivery.

1.2 Technical Specification

1000kVA three phase pad mounted transformer specification and data sheet

1.3 Drawings

1000KVA three phase pad mounted photovoltaic transformer drawing and nameplate

02 Solar Power And Electrical Performance

2.1 Discontinuous Solar Power & Cyclical Load

Solar generation is inherently intermittent. Panels only generate full power during peak daylight, and environmental factors like clouds, temperature, and shading affect output. Consequently, the photovoltaic transformer doesn’t run at full load 24/7 – in many cases, it may see full load for just 6–8 hours a day. Our transformer is designed for these conditions. The 480V LV side matches standard PV inverter outputs, stepping up to 13,200V HV, while handling the daily load ramps without thermal stress. DOE-level efficiency ensures losses remain low during fluctuating power cycles, keeping operational costs down and minimizing heat buildup.

2.2 Inverter Interaction

Inverters convert DC from solar arrays to AC, stabilize voltage, and often introduce switching transients. These can create harmonics, DC bias, and short-duration output spikes.

This transformer tackles those challenges through:

5-Legged Shell-Type Core: Improves harmonic handling, reduces zero-sequence effects, and lowers noise in grid-tied applications.
	• FR3 Natural Ester Oil: Enhances thermal endurance, resists frequent temperature swings, and stabilizes insulation aging under daily load ramps.
• NLTC ±2×2.5% Taps: Provides limited but reliable voltage trimming for grid coordination without the mechanical complexity of an on-load changer-ideal for solar sites where voltage needs seasonal or commissioning-stage adjustment rather than continuous tap movement.

2.3 Overload & Transformer Sizing

2.4 Electrostatic Shield (E-Shield)

A dedicated electrostatic shield between primary and secondary windings quietly but crucially manages transient voltages. It prevents inverter-generated harmonics from reaching the utility grid and protects the inverter from grid-side transients. High-frequency noise is minimized, and fault currents are directed safely through a defined, low-impedance path. This is particularly critical for solar plants, where unusual harmonics, DC bias, and ground faults can circulate unpredictably. Combined with the external grounding pad, the system simplifies commissioning, improves lightning performance, and reduces touch potential – stabilizing the transformer as a well-mannered grid asset rather than a wildcard.

2.5 Winding Configuration & Anti-Islanding

Most solar applications require wye-wye connection for proper grounding and anti-islanding detection. This pad mount transformer adopts YNyn0 vector group, compatible with standard PV inverter outputs and grounded utility distribution systems. This ensures:
• Grid faults are recognized by the inverter.
• Proper phase detection prevents backfeeding during islanding.
• Voltage and current behavior remain predictable for both utility protection schemes and local PV operations.

03 Mechanical & Structural Features

Designed for long-term outdoor duty, the pad mounted transformer is fully pad-mounted with tamper-proof enclosure to withstand rain, snow, heat, and mechanical stress. Key features include: • Sealed Pad-Mount Enclosure: Keeps moisture and dust out, maintains safety, and prevents unauthorized access. • High-Strength Tank Construction: Resists vibration, thermal cycling, and long-term stress. Epoxy primer plus polyurethane topcoat ensures corrosion protection for North American outdoor environments. • Side-Mounted Instrument Cabinet: Convenient, standard layout for gauges and monitoring devices. • Separate H0 and X0 Terminals: Simplifies grounding checks and integration with utility protection schemes. • FR3-Compatible Insulation: Maintains dielectric strength and extends service life.

04 Utility-Grade Controls & Protection

4.1 Monitoring & Standard Accessories

Remote monitoring is critical for solar transformers. This unit comes equipped with: • Temperature, oil level, and pressure relief gauges (“three meters and one valve”) • Side-mounted instrument cabinet for easy inspection • ANSI-standard pad-mount fittings and hardware These features allow operators to track performance, detect overload, and prevent downtime, even at remote solar sites.

4.2 Protection & Switching Equipment

The pad mounted transformer meets utility-grade pad-mount requirements: • Four-position loadbreak switch • Elbow-type surge arresters • Full fuse protection package • LV 12-hole spade terminals • External 12-hole ground bar for rapid and secure site grounding This ensures safety and regulatory compliance while supporting bidirectional operation.

05 Packing and transportation