The Danish power system is characterized by a large penetration of wind power. As the nature of the wind power is unpredictable, more balancing power is desired for a stable and reliable operation of the power system. The present balancing power in Denmark is provided mostly by the large central power plants followed by a number of decentralised combined heat and power (CHP) units and connections from abroad. The future energy plans in Denmark aims for 50% wind power capacity integration which will replace many conventional large power plant units. The limited control and regulation power capabilities of large power plants in the future, demands for new balancing solutions like Vehicle-to-Grid systems. In this article, aggregated electric vehicle based battery storage representing a Vehicle-to-Grid system is modelled for the use in long term dynamic power system simulations. Further, it is analysed for power system regulation services for typical days with high and low wind production in the Western Danish power system. The results shows that the regulation needs from conventional generators and the power deviations between West Denmark and UCTE (Union for the Coordination of Electricity Transmission) control areas are significantly minimized by the faster up and down regulation characteristics of the electric vehicle battery storage.