Patent ID: 8647047

Claim:
A method for controlling at least two turbocompressors ( 1 . 1 , 2 . 1 ), each having a control device ( 1 . 2 , 2 . 2 ) for maintaining a distance of an operating point (B 1 . 1 , B 2 . 1 ) relative to a surge limit curve (P 1 , P 2 ) of the respective turbocompressor, said method comprising: (a) determining a first distance (A 1 . 1 , A 2 . 1 ) of an operating point for each turbocompressor from its respective surge limit curve (P 1 , P 2 ); (b) trimming the first distance of the operating point (B 1 . 1 ) of a first turbocompressor to arrive at a desired distance (A 1 . 2 ) of an operating point (B 1 . 2 ) relative to the surge limit curve; and (c) trimming the first distance of the operating point (B 2 . 1 ) of at least a second turbocompressor based on the trimming of the first turbocompressor so that a total process variable remains substantially constant, wherein step (a) is performed so that the first distance is substantially identical for all turbocompressors.