Credible Capacity Evaluation Method for Wind Farms Considering Output Correlation

After wind farms are integrated into the power system, they not only inject renewable energy, but also improve the power supply capability. However, the output of wind turbines has strong volatility, and the installed capacity of wind turbines cannot represent the increase in system power supply capability. Indicators such as credible capacity have been proposed one after another. The sequential output of wind farms is an important input parameter for credible capacity evaluation. Therefore, how to consider the correlation of wind farms’ output is a major challenge. This paper proposes a credible capacity evaluation method for wind farms considering output correlation by Johnson distribution system. Firstly, based on first-order Markov chains, statistical analysis is conducted on the fluctuation of wind farm output to generate random sequential wind speed. Then, Johnson distribution system is used to generate correlated sequential wind speed and convert it into wind farm output as the input parameter of Sequential Monte Carlo simulation. Finally, load increment that enable the system meet equal power supply reliability criteria is the credible capacity of the wind farms.