【正文】 nds, generally, on the windmill technology and in the wind farms and is influenced by the windmill electrical and mechanical parameters. In other countries, similar specifications may be found as the result of large incorporation of wind power into the local power system. farm model The windmill technology in offshore settings has to be robust, developed and known practical applications. The wind turbine concept with conventional induction generators has been in operation in onland settings in Denmark during many years, which is why it may be considered that this technology will be used offshore as well. The wind turbines are equipped with blade angle control systempitch or active stall that make it possible to 3 adjust the setpoints of the wind turbines by the blade by the blade angle adjustments. The plete representation of the wind farm is chosen because the monly asked question concerning large wind farms is whether there can be electromechanical interaction between a large number of the closely placed windmills excited by disturbances in the power system when the windmills are working at different setpoints, equipped with relatively soft shafts and even having different mechanical data, and equipped with control systems, for instance pitch. The model of the offshore wind farm is implemented in the dynamic simulation tool PSS/E and consists of 80 wind turbines of 2MW power capacity each, see . Each wind turbine is simulated by a physical windmill model consisting of : 1. the induction generator model with representation of the stator transients, 2. the windmill shaft system model, 3. the aerodynamic model of the wind turbine, 4. the pitch control system given by the control logic and the blade servo. For putation of wind turbine aerodynamics there are used airfoil data for a 2 MW pitch windmill equipped with an induction generator. Each wind turbine is via its KV/30KV connected to the wind farm internal work. The internal work is anised in eight rows with 10 wind turbines in each row. Within the rows, the wind turbines are connected through the 30 KV sea cables. The distance between two wind turbines in the same row is 500 m and the distance between two rows is 850 m. The rows are through the 30 KV sea cables connected to the offshore platform with 30 KV/132 KV transformer and, then, through the 132 KV sea/underground cable to the connection point in the transmission system onland. There is chosen an acconnection of the offshore wind farm to the transmission work. An irregular wind distribution over the wind farm area there is assumed since the wind turbines are shadowing each other for ining wind. The efficiency of the wind farm is 93%at the given wind distribution and the power production pattern is shown in . Furthermore, the windmill induction generators have a little different short circuit capacities viewed from their terminals into the internal work and this is why the wind turbine initial setpoints are different. 4 The short circuit capacity from the wind farm connection point into the transmission work is 1800 MVA. In all the simulating examples, the failure event is a short circuit fault in the transmission system of 150 ms of duration. When the fault is cleared, the faulted line is tripped and the short circuit capacity is reduced to 1000MVA. Only the line tripping and, then, reducing of the short circuit capacity to 1000MVA does not lead to voltage instability. This ensures that possible voltage instability is only the result of the short circuit fault with the following windmill overspeeding. 4. Dynamic reactive pensation In this work, the dynamic reactive pensation of the large offshore wind farm is a SVC of the capacity that will be necessary for maintaining the shortterm voltage stability. The model of the SVC is as in Ref. 5 5． When operating as stall windmills Blade angle control is primarily used for optim