Abstract: Provided are a wind turbine, and a control method, a controller and a control system for the same. The control method includes: monitoring wind resource data at the location of a wind turbine and operation data of the wind turbine; identifying a complicated wind condition based on the wind resource data and the operation data; determining an accumulative proportion of time periods in which the complicated wind condition occurs within a first predetermined time period; and controlling the wind turbine to perform a protection operation, in response to the accumulative proportion of the time periods exceeding a first preset threshold.

Abstract: In a testing apparatus used to observe the effects of positive pressure and vacuum pressure on a test specimen, such as the effects resulting from forces created by wind, explosions and water, a clamp system is provided for holding the test specimen against the apparatus in a manner which creates an airtight cavity between the test apparatus and the specimen. The clamp system includes one or more rolling clamp assemblies which are selectively movable in relation to the test apparatus in order to accommodate a range of sizes of specimens to be clamped at various locations on the test apparatus. Each clamp assembly includes an elongate track formed by spaced, parallel rails supported on a rolling trolley. One or more clamp members slidably carried on the track each include a threaded rod extending between the rails and a pivoting foot on the distal end of the rod for engaging the specimen.