In Thailand, there is great potential for large-scale offshore wind farms in the Gulf of Thailand between Koh Tao and Koh Pha-Ngan, with possible installed capacity of up to 432 MW. The integration of large-scale wind farms will significantly impact the stability, security, quality, and operation of the power grid. In this paper, possible interconnection points to the 115- kV distribution grid system of the Provincial Electricity Authority (PEA) are selected for integrating three offshore wind farms. The steady-state analysis of power flows, voltage variations, voltage stability, and fault currents is performed using the DIgSILENT Power Factory program. The simulation results indicate appropriate interconnection points for offshore wind farms to the 115-kV grid. These results will be important for developing offshore wind farms in Thailand.