When load reduced to a certain degree

compressor will produce dramatic surge phenomena.This will seriously damage the machine and lead to a serious consequence.In order to avoid the compressor surge of fluid catalytic cracking unit

high-power compressor is usually chosed to make its stable work

and the same time the problem of high fixed investment and lots of operating cost will bring.Active control can expand the stable work region of the compressor

and make compressor work in high performance areas

so this paper chooses a small-power compressor to work.The result of it maybe the compressor can not work in the steady areas in most time

but through the active control function the idea not only can make the compressor work in steadily

but also achieve the purpose of reducing the investment cost and operating cost.It respectively describes the control scheme and control algorithm. Finally

it proves the effectiveness of the proposed scheme by simulation of the actual cases.