Can I select transformer MVA directly from solar plant MW?

Not without the apparent-power and reactive-power requirements. Check inverter current, power factor/reactive duty, losses and operating conditions. The transformer rating must follow the electrical study, not a fixed universal percentage above PV MW.

Can the same design serve battery storage?

It needs a duty review. Storage can involve sustained charging and discharging as well as reactive operation. Confirm bidirectional duty, PCS waveform, grounding and thermal loading rather than assuming the PV operating profile applies.

Why do the inverter’s harmonic and DC-injection data matter?

They help assess additional heating and the transformer’s magnetic/insulation duty. Obtain the converter manufacturer’s data and operating cases; a generic “inverter-duty” label is not a substitute for interface verification.

Does IEEE 1547 approval of an inverter approve the transformer too?

No. Interconnection approval, inverter certification and transformer design/test requirements are distinct. Agree the utility’s connection conditions and the applicable transformer specification, with IEEE C57.159 considered where relevant to PV duty.

Power Transformers

Solar Inverter-Duty Transformer

Representative configuration. The offered model, dimensions and interfaces are confirmed with the technical proposal.

Overview

Entogo supplies inverter-duty transformers for PV and battery-storage interconnection. Match the inverter/PCS voltage, winding arrangement, grounding, harmonics and thermal duty to the collector network and connection study.

Entogo supplies this project equipment through manufacturing partners. Entogo Inc. in Toronto coordinates technical selection, supply scope and order support.

Specification	Value
Equipment scope	Transformer alone; switchgear/skid integration quoted separately
Power rating	MVA based on inverter/PCS apparent power and required reactive duty
Voltage ratio	Inverter-side AC voltage to collector-network voltage
Winding arrangement	Number of LV windings, vector group and phase displacement as required
Waveform duty	Harmonic spectrum, switching effects and any DC component reviewed
Grounding	Neutral availability and zero-sequence path coordinated with protection
Thermal envelope	PV cycle or bidirectional storage duty, ambient and cooling
Design reference	IEEE C57.159 for applicable PV duty; agreed IEC/utility basis otherwise

Reference configurations and selection criteria are shown together. The technical offer defines the matched ratings, tests and guaranteed performance for the ordered unit.

Match the converter and the grid interface

Active power in MW alone does not establish transformer MVA. Include reactive-power requirements, converter current limits and the expected operating cycle. A PV generation profile and a storage charge/discharge profile can create different thermal duties.

For multiple inverter outputs, define the required LV windings and phase displacement. Keep the transformer scope distinct from a complete skid substation containing switching, auxiliaries and structural integration.

Applications

Solar PV plants
Battery storage interconnection
Renewable energy projects

Selection & project requirements

Can I select transformer MVA directly from solar plant MW?: Not without the apparent-power and reactive-power requirements. Check inverter current, power factor/reactive duty, losses and operating conditions. The transformer rating must follow the electrical study, not a fixed universal percentage above PV MW.
Can the same design serve battery storage?: It needs a duty review. Storage can involve sustained charging and discharging as well as reactive operation. Confirm bidirectional duty, PCS waveform, grounding and thermal loading rather than assuming the PV operating profile applies.
Why do the inverter’s harmonic and DC-injection data matter?: They help assess additional heating and the transformer’s magnetic/insulation duty. Obtain the converter manufacturer’s data and operating cases; a generic “inverter-duty” label is not a substitute for interface verification.
Does IEEE 1547 approval of an inverter approve the transformer too?: No. Interconnection approval, inverter certification and transformer design/test requirements are distinct. Agree the utility’s connection conditions and the applicable transformer specification, with IEEE C57.159 considered where relevant to PV duty.

For Canadian and US projects, include the utility specification, service frequency and required approvals. State whether the order is for the transformer alone or an integrated equipment package.

Discuss your equipment requirements

Send your single-line diagram, load or process data, target market and required schedule. We will identify the configuration and documents needed for a technical quotation.

Design references

Distribution substation and grid interconnection point for solar and battery energy storage

Renewable Grid Connection

Interconnecting solar and storage to the grid: what IEEE 1547-2018 requires

Connecting solar or battery storage to the North American grid means meeting IEEE 1547-2018 for DER behavior, using a UL 1741 SB certified inverter, and passing a utility interconnection review that scales from a fast-track screen to a full study. Here is how the pieces fit.

View

Energy Storage

How to size a battery storage interconnection: inverter kVA, transformer kVA and %Z

A 2 MW battery inverter holding IEEE 1547 reactive capability is a 2222 kVA source, so it needs a 2500 kVA transformer, 2673 A of conductor under NEC 705.28, and 65 kA gear once the 600 V bus fault duty reaches 44,403 A.

View

Commercial rooftop solar array paired with a battery energy storage system, illustrating DC-coupled versus AC-coupled solar-plus-storage architecture

Solar-Storage-Charging

DC-coupled vs. AC-coupled solar-plus-storage: how to choose

DC coupling ties the battery to the array's DC bus behind one hybrid inverter and recaptures clipped energy; AC coupling gives solar and storage their own inverters and easier retrofits. The right choice depends on whether the two are built together.

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Related equipment

Entogo 36 kV class three-phase oil-immersed power transformer for substations

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View

Representative outline drawing of an Entogo three-phase dead-front pad-mounted transformer — front and side elevations, not a photograph

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Three-Phase Pad-Mounted Distribution Transformer

Three-phase pad-mounted distribution transformer for North American utility, commercial and industrial service — 75–2500 kVA, 12.47–34.5 kV class primary to 480Y/277 or 208Y/120 secondary, dead-front loop/radial-feed, NEMA 3R. Designed to IEEE C57.12.34 and DOE 10 CFR 431; UL/CSA certifiable.

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Scott-Connected Transformer

Entogo supplies Scott-connected transformers for conversion between three-phase and two-phase circuits. Define the two output loads, 90° phase relationship, voltage ratio and operating cycle before selecting the winding design.

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36 kV Outdoor Compact Unit Substation

A factory-assembled outdoor unit substation — incoming 34.5 / 35 kV switchgear, liquid-filled step-up or step-down transformer (1,000–10,000 kVA) and a low-voltage section in one weather-tight enclosure — for solar PV, wind and industrial interconnection. Built to IEEE C37.121, ANSI C57.12.34 and IEC 62271-202.

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Match the converter and the grid interface

Discuss your equipment requirements

Interconnecting solar and storage to the grid: what IEEE 1547-2018 requires

How to size a battery storage interconnection: inverter kVA, transformer kVA and %Z

DC-coupled vs. AC-coupled solar-plus-storage: how to choose

36 kV Oil-Immersed Power Transformer

Three-Phase Pad-Mounted Distribution Transformer

Scott-Connected Transformer

36 kV Outdoor Compact Unit Substation

Customer support