Based on the application of multi-stage axial fan in continuous high speed wind tunnel

the flow rate condition of surge and flow rate characteristic of changeful wind tunnel test state was analyzed

and an anti-surge model based on inlet flow rate and pressure ratio was established. The fan flow similarity condition and a flow rate calculating method were given

the generalized characteristics and work curves of wind tunnel fan were determined

and the anti-surge cluster curves were set based on rotating speed range and work characteristic of fan. Based on PLC （programmable logic controller） and WinCC automation system

a multi-level redundant anti-surge control strategy was proposed and validated in wind tunnel test. The results show that the anti-surge model has satisfactory effect to reflect the operation situation and safety margin of fan caused by changeful wind tunnel test condition exactly; standard deviation of flow rate and pressure ratio acquired is 0.002 and 0.001

anti-surge control repeatability accuracy is 0.003

realizing real-time discrimination and automatic control of surge come true

and effectively preventing the surge.