Research Project Information

Research Project Summary Information

Market and Technology Analysis of Ferroresonant Transformers(ST10242-1)

The Cadmus Group, Inc.


Industrial and to a lesser extent commercial sites employ a variety of technologies to improve the quality of their electricity. One of these technologies is the ferroresonant transformer. This type of transformer is valued for its ability to deliver stable voltages to loads even when the power supply side (primary) of the transformer receives varying voltages. Ferroresonant transformers help many facilities control power quality, but they exact a cost in terms of decreased power conversion efficiency. Depending on how they are loaded, ferroresonant transformers can have efficiencies of 65 percent or lower. This means at least 35 percent of incoming electricity is simply converted to heat and never reaches the load it is intended to serve. There are alternatives to the current purchase, specification, and operation of ferroresonant transformers, including improved ferroresonant transformers, power inversion technologies, and voltage regulators such as the Mini-EVR.

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Project Description

The Contractor will inventory the New York State market of ferroresonant transformers, projecting sales 10 years out; determine typical applications, nominal sizes, efficiencies, and the market barriers of why they are not more prevalent. Based upon findings of the field survey, Contractor will conduct metering at 15 sites to determine actual electrical characteristics of the transformers tied to their installation intended function.


A first-order estimate of the total annual cost of losses in ferroresonant transformers is $20 million per year in New York State. Depending on whether the sites are cooled, an additional 10 to 20 percent can be saved through reduced cooling costs. Potential economic benefit - one maker of a technology alternative to ferroresonant transformers is located in Niskayuna, New York, and a manufacturing office in Watervliet If the study shows that the alternative to ferroresonant transformers is cost-effective; there would likely be job growth in both locations.

Project Results


The Cadmus Group, Inc.
100 5th Ave., Ste 100
Waltham, MA 02451

Principle Investigator

Dave Korn

Universities Involved


Project Type:

Research Study

Technologies Types:

NYSERDA Contact Information

Gregory Pedrick


R&D -Transport & Power Systems

Contract Details

Start Date: 1/11/2010
Project Status: Active
Contract Number: ST10242-1

Last Updated: 2/27/2012