Nomex® Improves Performance of Substation Power Transformers

ABB substation power transformers for nuclear power plants feature improved reliability and higher temperature performance due to the use of DuPont™ Nomex® brand paper.

Application Description

ABB, a global leader in power and automation technologies, manufactures a
generator excitation transformer rated at 5 MVA for use in nuclear power plant substations.  This liquid-immersed substation power transformer features a hybrid insulation system of Nomex® paper and cellulosic pressboard.

Benefits Gained

Increased reliability:   Nomex® paper offers exceptional resistance to shrinkage and compression.  The excellent dynamic mechanical strength of Nomex® paper helps ensure coil structures will remain tight and are able to withstand short-circuit forces, even after years of service.

Improved high-temperature capability:   The use of Nomex® paper as insulation in high-temperature locations allows substation power transformers to be built with higher capacity or increased overload tolerance in a given unit size, improving the capability to operate reliably at high temperatures.

Longer service life:   Increased reliability under demanding conditions, combined with greater overload capacity and reduced load and no-load losses, leads to longer service life for these substation power transformers that are insulated with Nomex® paper.

Materials Selected and Why

Nomex® paper features inherent dielectric strength, excellent mechanical toughness and outstanding thermal stability, making it an ideal choice to meet this application’s needs for higher-temperature performance and increased reliability over a longer service life.

Reliability and High Temperature Performance in Nuclear Power Plants