The twin projects are currently consented to have a capacity of 525MW apiece – a 1,050MW total.
But Seagreen Wind Energy — the joint venture (JV) of SSE and Fluor — has written to seabed landlord Marine Scotland, asking it to remove this limit and enable it to use more powerful turbines.
"This would have no implications for the environmental effects of the project," the JV argued.
"It would, however, allow larger capacity WTGs (wind turbine generators) to be constructed under the existing consent parameters."
The partners argued wind turbine technology has "advanced considerably" since 2014 when consent was first given.
With a 1,050MW combined capacity limit, the Seagreen projects would use 7MW turbines, but since 2014 more powerful machines have come on to the market.
They also revealed they intend to participate in the next UK Contracts for Difference (CfD) auction in spring 2019.
Seagreen said the auction will be "extremely competitive" and therefore it is "essential that the Seagreen consents maximise the chances of success in the auction by taking advantage of the developments in Wind Turbine Generator (WTG) technology, which have occurred since the applications were made to increase the maximum generating capacity of the wind farms".
The JV did not apply to alter any of the other existing parameters Marine Scotland consented four years ago.
Seagreen Alpha and Bravo would still include up to 75 turbines each with a maximum blade tip height of 209.7 metres and a rotor diameter between 122 and 167 metres.
Substructure and foundation design would consist of: a four-leg steel jacket with driven piles; a four-leg steel jacket with suction piles; or a gravity-base structure.
The two projects are part of a cluster off the east coast of Scotland that were subject to a lengthy appeal process by the Scottish department of the Royal Society for the Protection of Birds (RSPB) animal protection charity.
The conservation group claimed the projects would adversely affect some migratory bird species and that the Scottish government failed to fully evaluate the impact on wildlife, prior to granting consent in October 2014.
In November 2017, the UK’s Supreme Court rejected the last of the RSPB’s appeals.