Global sensitivity analysis of voltage stability in the power system with correlated renewable energy

•Monte Carlo sampling method is proposed to solve the correlation between renewable energy sources.•The sampling accuracy of Monte Carlo method is higher than that of empirical formula.•A simplified Ls-index is proposed. Ls-index can maintain enough calculation accuracy and reduce calculation time.•This article gives a practical calculation formula for GSA. The practical calculation formula solves the problem that the conditional expectation cannot be solved directly. The high penetration of renewable energy in power systems significantly increases the difficulty of system modelling. Adequate attention should be paid to the impact of the correlation between renewable energy sources and voltage stability. In this paper, a global sensitivity analysis method is proposed to analyse the sensitivity of correlated renewable energy generation to voltage stability. The established model fully considers the uncertainty of wind speed and solar irradiance. Moreover, the simplified local voltage stability index is used to evaluate voltage stability. The global sensitivity analysis method is used to identify the sensitivity of random factors. In addition, the Monte Carlo method is proposed to calculate Pearson correlation coefficients in different distribution spaces. The Nataf inverse transform is used to sample correlated renewable energy. Finally, the global sensitivity index of renewable energy generations is obtained. Numerical results on the modified IEEE 30-bus system and modified IEEE 118-bus system show that with the enhancement of correlation between renewable energy sources, the sensitivity of renewable energy generations to voltage stability is also increasing.