Low Voltage Distribution Transformers and the 2016 Efficiency Standard Presenter: Bill Forsythe, Sr. Product Manager Juan Gutierrez, Engineering Manager Date: May 26, 2015

Purpose and Learning Objectives

Purpose of Activity:

To educate the participants on the 2016 Department of Energy (DOE) regulations as they pertain to the energy efficiency level of low-voltage general purpose dry-type transformers

At the end of this presentation, you will understand the following as they pertain to General Purpose Transformers 1. The reason behind the change and who is driving it

2. Timing of the change

3. How the design of the transformer changes

4. Impacts of the change with respect to size, efficiency, in-rush, impedance, cost

5. How the new DOE standard exists with NEMA Premium Efficient/CSL-3

GE Industrial Solutions has met the standards and

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Program. Credit earned on completion of this program will be

reported to RCEP at RCEP.net. A certificate of completion will

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Change To Distribution Transformer Efficiency

• On January 1, 2016 the US Department of Energy (DOE) will require that distribution transformers meet new energy efficiency standards

• Department of Energy (DOE) 10CFR Part 431 Energy Conservation Standards for Distribution Transformers has adopted more stringent energy efficiency standards for transformers

• Distribution transformers include a) liquid-immersed, b) low-voltage dry-type (LVDT) and c) medium voltage dry-type (MVDT)

• A distribution transformer… • Has an input voltage of 34.5 kV or less • Has an output voltage of 600 V or less • Is rated for operation at a frequency of 60 Hz • Has a capacity of 10 kVA to 2500 kVA for liquid-immersed units and 15 kVA

to 2500 kVA for dry-type units

Why is the Department of Energy (DOE) making this change?

Law is designed to achieve the maximum improvement in energy efficiency that DOE determines is technologically feasible and economically justified.

Applies to transformers a) manufactured in and b) imported into the USA after Jan 1, 2016

Reason for the Change

Benefits of the Change

What’s Driving The Change

“Beginning in 2016, newly amended energy efficiency standards for distribution transformers will save up to $12.9 billion in total costs to consumers — ultimately saving families and businesses money while also reducing energy consumption. The new distribution transformer standards will also save 3.63 quadrillion British thermal units of energy for equipment sold over the 30-year period of 2016 to 2045. The new amendments to the existing efficiency standards would further decrease electrical losses by about 8 percent for liquid-immersed transformers, 13 percent for medium-voltage dry-type transformers, and 18 percent for low-voltage dry-type transformers. In addition, about 264.7 million metric tons of carbon dioxide emissions will be avoided, equivalent to the annual greenhouse gas emissions of about 51.75 million automobiles.”

Change to LVDT Transformers

• Manufactures must comply with the new standard by January 1, 2016

• LVDT transformers impacted by the law include: 1-Phase 15-333kVA 3-Phase 15-1000kVA • There is no formal name for the new efficiency standard (i.e.

TP-1). Typical names are DOE 2016 and DOE 2016 Efficiency

• Autotransformers

• Drive isolation transformers (DIT)

• Machine tool (control) transformer

• Non-ventilated transformer

• Regulating transformer,

• Sealed transformer

• Special-impedance transformer

• Testing transformer

• Tap range of 20% or more

• UPS transformer

• Welding transformer

Exclusions from DOE 2016

Some special application transformers are excluded from the new law.

Equipment

Class

2016 Transformer Energy Efficiency Increase

• Test method is NEMA TP-2 • Efficiencies determined at 35% load per NEMA TP-2 • Transformer core is twice as efficient • Look! Some models are over 99% efficient

Currently 98.0%

2016 Efficiency Change

TP-1 2016 TP-1 201615 97.7% 97.70% 15 97.0% 97.89%

25 98.0% 98.00% 30 97.5% 98.23%

37.5 98.2% 98.20% 45 97.7% 98.40%

50 98.3% 98.30% 75 98.0% 98.60%

75 98.5% 98.50% 112.5 98.2% 98.74%

100 98.6% 98.60% 150 98.3% 98.83%

167 98.7% 98.70% 225 98.5% 98.94%

250 98.8% 98.80% 300 98.6% 99.02%

333 98.9% 98.90% 500 98.7% 99.14%

750 98.8% 99.23%

1000 98.9% 99.28%

Efficiency %

kVA kVA

Efficiency %

Single-Phase Three-Phase

NEMA Premium 2016 NEMA Premium 201615 98.39% 97.70% 15 97.90% 97.89%

25 98.60% 98.00% 30 98.25% 98.23%

37.5 98.74% 98.20% 45 98.39% 98.40%

50 98.81% 98.30% 75 98.60% 98.60%

75 98.95% 98.50% 112.5 98.74% 98.74%

100 99.02% 98.60% 150 98.81% 98.83%

167 99.09% 98.70% 225 98.95% 98.94%

250 99.16% 98.80% 300 99.02% 99.02%

333 99.23% 98.90% 500 99.09% 99.14%

750 99.16% 99.23%

1000 99.23% 99.28%

Single-Phase Three-Phase

kVA

Efficiency %

kVA

Efficiency %

Comparison to TP-1 Comparison to NEMA Premium

Technical Changes to the Transformer

Core

Coils

Core

The DOE doesn’t tell manufacturers how to meet the efficiency standard

Transformer Efficiency

Input power is energy you are consuming. Output power is used in productive work.

Two main sources of energy loss.

1. No load losses (losses in the core)

2. Load losses (depends on output)

a) I2R losses are produced by resistance of conductors

b) Stray losses are caused by magnetic flux of transformer.

Stray Losses

Input Power

No Load Losses

I2R Losses

Output Power

Load Losses

Methods of Increasing Transformer Efficiency

To Decrease Core Loss Core Loss Coil Loss Cost Impact

Use lower-loss core material Lower No change Higher

Increase cross-section of core Lower Higher Higher

Decrease coil wire CSA Lower Higher Lower

To Decrease Coil Loss Core Loss Coil Loss Cost Impact

Use lower-loss coil material No change Lower Higher

Increase coil cross-sectional area Higher Lower Higher

Decrease core cross-sectional area Higher Lower Lower

Making a Transformer More Energy Efficient

1. Improve the material of the core - Grain oriented vs. non grain oriented

2. Improve the method of core construction - Butt lap and step lap - When combined with grain-oriented material, reduce loss without increasing mass of the core

One approach… improving the design of the core

Transformer Core Laminations

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Efficient Core Construction Methods

Butt Lap Core Construction •No flux flowing in the corners •Not utilizing the full cross-sectional area of the core •Flux density is higher in usable area, thus loss is higher

Step Lap Core Construction •Flux flows in the corners •Utilizing the full cross-sectional area of the core •Flux density is lower •Combine with GO steel

Combined with Grain Oriented Steel • Flux does not need to bend to change direction • Flux is flowing in the rolling direction

Unicore Core Technology StepLap Core Technology

Unicore Core

Step Lap Core

New Core Technologies

Changes You Can Expect

• New core & coil designs from manufacturers

• Similar in size and weight to today’s NEMA Premium transformers.

• Transformer core & coil may be 15% heavier and larger than TP-1

• Some designs may be taller

• Impedance – small increase. NEMA impedance requires designs to be inside a range: 1.5%-5% for small xfmrs, 3.5% to 7% for larger xfmrs

• Inrush may increase approximately 30%

• Price may increase 25%-45%

• Minimal changes to enclosures

• Manufacturer catalog numbers will change

• New 2016 designs will be seismic/OSHPOD tested and certified prior to January 1

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Plan Ahead

• Projects quoted in 2015 that will not ship until 2016 should bid the new high efficiency design. Choose NEMA Premium or DOE 2016 models to ensure availability and price accuracy in 2016

• Shipment of stock TP-1 transformers from manufacturer warehouses after Dec 1 may be subject to availability

• Orders for non-stock TP-1 transformers may be cutoff in mid-November

Thank you for your time!

This concludes the educational content of this activity.

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