The phrase "have been prevailing" is correct and usable in written English.
You can use it to indicate that a certain state or condition has been present or in place for a long time. Example: The opinions of the experts have been prevailing since the issue first surfaced.
Recently, computer simulations have been prevailing for the evaluation of formability.
Sampled-data control systems have been prevailing in various applications, in parallel with the development of digital computers and its applications in control activities.
That rate is far below the prices that have been prevailing on the wholesale market; in some instances prices have jumped to 30 cents a kilowatt hour and more.
For a long time, and surely in part thanks to Big Night, the Primos have been prevailing, not just in the form of authentic cuisine but with lengthy tasting menus and an overall sense that diners should submit themselves to a chef's vision, rather than requiring a kitchen to live up to their own tastes and expectations.
It is thus quite plausible to state that similar mechanisms must have been prevailing in the present GaSe thin films.
High labor costs and globalization have been prevailing in the stage of economic development in Taiwan in the late twentieth.
They are free-trade deals and therefore they go completely against the development logic that had been prevailing in our relationship with those countries".
Nationwide's chief economist, Robert Gardner, said: "This slowdown returns the annual pace of house price growth to the fairly narrow range between 3% and 5% that had been prevailing since the summer of 2015.
The "extreme tension that has been prevailing in the financial markets, especially concerning the ability of Ireland to achieve a sustainable fiscal path by going it alone," meant that recourse to European Union loans "would, in our view, represent a sensible outturn," Julian Callow and Antonio Garcia Pascual of Barclays Capital wrote in a research note on Friday evening.
And the Liberal Democrats have been the prevailing voice of people's concerns and anxieties.
