【正文】 chnology―wind power. In the year to e it will be focusing on maintaining power system stability and voltage stability, for example at a short circuit fault, ensuring power supply safety and other important tasks as amount of wind power is drastically increasing. This situation makes it necessary to find solutions with respect to maintaining dynamic stability of the power system with large amount of wind power and its reliable operation. These solutions are based on a number of requirements that are formulated with respect to operation of the large offshore wind farms and the external power system in case of failure events in the external system. The paper contains separate subjects dealing with design of windmills for large offshore applications and their control that shall be taken into account with respect to improving the shortterm voltage stability. 2. system stability requirements In terms of shortterm voltage stability, the major goal is the voltage reestablishing 2 after failure events in the power system with large amount of wind power. The transmission system operator is responsible for maintaining power system stability and reliable power supply. As the situation is today, the majority of the Danish windmills onland are stall wind turbines equipped with conventional induction generators and acconnected to the power system. In case of a short circuit fault in the power system, those windmills are easily overspeeded and, then, automatically disconnected from the power system and stopped. Such automatic disconnections will be very fast and ordered by the windmill protection system relay settings. When the onland windmills are automatically disconnected, there is no dynamic reactive pensation demands related to them, despite their large power capacity. When the voltage is reestablished, the onland windmills will be automatically reconnected to the power system in 1015 min afterwards and continue their operation, The onland windmill relay settings are decided by the windmill manufacturers or the windmill owners and these, as usual, cannot be changed by the transmission system operator. In case of the large offshore wind farms, the power system operator has formulated the Specifications for Connecting Wind Farm to Transmission Network. In accordance with the Specifications, the voltage stability at failure events in the external power system shall be maintained without any subsequential disconnection of the large offshore wind farms. Establishing dynamic reactive pensation of the large offshore wind farms can be, therefore, necessary. The amount of dynamic reactive pensation depends, 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