Transformers help reduce noise pollution in urban areas

Advanced technology used to design ultra low noise transformers for cities around the world

Anyone familiar with the world of electricity knows that transformers make a humming noise. Population growth and environmental awareness are promoting a closer look at the noise levels produced by transformers in cities and large metropolitan areas.

ABB researchers have spent many years studying ways to reduce transformer noise. They have studied the electrical, mechanical, and acoustic aspects of transformer noise in this effort. The research has focused on the three major sources of transformer noise: core noise, cooling equipment noise, and load noise. This effort led to optimized designs of the core, windings, and tank.

In early 2000, New York updated its Noise Code to reflect the changing landscape and advances in acoustic technology. Simply put, the Noise Code was created to reduce: “The making, creation or maintenance of excessive and unreasonable and prohibited noises within the city affects and is a menace to public health, comfort, convenience, safety, welfare and the prosperity of the people of the city.” To put it into perspective, a power transformer’s maximum allowable noise level in New York City is in the 50 dB (A)* range when fully loaded. In comparison, transformers of this size would typically have noise levels in the 70 dB (A) range when energized – even before loading. Moreover, the city’s strict noise ordinance requires power transformers to have ultra low levels at each of the tones of transformer sound when they are fully loaded.

The evolution of the technology used to design and build these transformers is best shown with Consolidated Edison of New York who has deployed three successive generations of ABB’s quiet power transformers since 2005. The technology of the latest 3rd generation of these transformers is now being used worldwide to design ultra low noise transformers for urban areas around the world.

Read more:
ABB Review special report Transformers, 2012: The quiet life. ABB’s ultralow-noise transformers