Abstract: To analyze the impact of correlation between wind speed, illumination intensity and load demand, this paper proposes a new reliability evaluation model for distribution system with distributed generation （DG） considering correlation. Firstly, we adopt the correlation coefficient matrix, Latin hypercube sampling and Cholesky decomposition to establish a sampling method, which can effectively deal with the correlations between the non-normal distribution random variables and the nonlinear relationship. Then we propose the method of correcting the traditional reliability index based on island stable operation probability, which effectively combines the traditional distribution reliability assessment with the distribution reliability assessment containing DG to improve the assessment efficiency. Finally, through the quantitative analysis on examples, we analyze the influences of correlation intensity between the same type DG, different types of DG, DG and load on island stable operation and distribution system reliability index, whose results verify the feasibility of the proposed model and method.

Key words: distribution system, distributed generation（DG）, correlations, island operation, reliability assessment