Therefore, in the present example the dynamic contribution value and {HEAD ~ active power variation requirement} of {TAIL ~ each wind turbine} is imposed by the grid operator  
Therefore , in the present example the dynamic contribution value and { HEAD ~ active power variation requirement } of { TAIL ~ each wind turbine } is imposed by the grid operator
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH