Evaluation of the maximum allowable generation capacity after offshore wind farms are integrated into the existing taipower system-A case study in Taiwan

Abstract
This research aimed to explore the maximum connection capacity that distribution substations can withstand as well as the distribution status of the system's power flow when offshore wind farms are connected into the power grid in the Changbin area, and then make analyses into the transient stability of the system. It mainly used PSS/E power software to analyze the off-peak system of Taiwan Power Company in 2018, put forward the average and disperse grid connection methods and the grid connection method based on the loading rate of the line, and compared the maximum connection capacity of the area under the circumstance in which the power grid fails to establish (expand) lines, and then adopted the N-1 planning guideline when offshore wind farms are connected to different substations. In addition, this research also analyzed voltage regulation, low voltage right through analysis, and three-phase short circuit current in view of the power grid connected into the maximum capacity of wind farms, conducted fault simulation of different voltage grades and distances in view of the power grid, and observed the ability of the system to reply stably in the face of accidents. It was shown from the research results that offshore wind farms could allow the grid connection capacity of the Changbin area to reach 1.9GW after adopting the proposed grid connection methods. In addition, it was found through the analysis into transient stability, power flow, and other system impacts that the system could restore stable operations after removal of the fault, which complies with the provisions of the Planning Guideline for Power Transmission System and Technical Points for Parallel Connection of Renewable Energy Power Generation System of Taiwan Power Company.