ABB delivers ultra-low-noise transformers to New York City
The transformers are the successful result of an intensive research and development effort over a number of years by a team of ABB engineers and scientists in the United States, Sweden, and Germany. Included in the team were experts in the fields of vibrations as well as sound generation, transmission and radiation. The project also involved the development of appropriate measuring methods of ultra-low-noise levels at discrete frequency components, as well as appropriate transformer mounting. The newly developed technology has set new industry benchmarks for transformer noise emissions. The noise requirements of the transformers are not only 20–25 decibels (dB) lower than is typical for these sizes of transformer (65 MVA and 93 MVA), but limits were also set on the level of each frequency tone when the transformers are at full load.
In addition to meeting ConEd’s stringent standards for noise, ABB had to ensure that the transformers meet tight limits on weight, width and height to permit transportation in Manhattan. The transformers also have to comply with technical requirements like overload of up to 200 percent and extremely tight limits on the range of transformer impedance.
ABB delivered the first ultra-low-noise transformer to ConEd in 2005. This transformer had to be provided with a sound enclosure. As the technology developed further, subsequent transformers delivered to ConEd did not need these enclosures and in fact were much smaller in size and weight. Six of these transformers have been delivered to ConEd and several are already in operation. Four additional transformers of even lower noise levels are scheduled for delivery later this year and in early 2009.
The ultra-low-noise transformer technology resulting from this development is now being used to produce optimum designs for low and ultra-low-noise transformers for other noise-sensitive metropolitan areas around the world.
The above accomplishment would not have been possible without the support that the ABB technical team received from ABB management in St. Louis, USA and globally. The challenge given and cooperation received from the ConEd technical team, headed by Donald Chu and Harold Moore, throughout the technology development process have been pivotal.