Abstract:Objective: Aiming at the problem that large-scale distributed generation (DG) and electric vehicle (EV) has a certain impact on the reliability of the distribution network after they are connected to the distribution network, a new reliability evaluation method of a distribution network based on DG and EV is proposed. Methods: Firstly, considering the complementary characteristics of wind and solar output in time and space, based on Copula theory, Spearman rank correlation coefficient、Kendall rank correlation coefficient, and Euclidean distance are introduced, the Frank-Copula function with the best fitting is selected, and the wind-solar joint power output probability model is established as the output power model of DG in reliability calculation. Secondly, the behavior characteristics of EV users are analyzed, and an EV orderly charge-discharge control strategy based on dynamic time of use (TOU) price is proposed. Finally, using the main feeder F4 of the improved IEEE-RBTS Bus6 test system, the reliability of the system is calculated and analyzed from three aspects: the type of DG, the number of EVs, and the orderly charging and discharging mode. Results:1) The results show that when connecting with a separate photovoltaic generator (PVG)/wind turbine generator (WTG), the system average interruption frequency index (SAIFI) decreases from 2.7914 times to 2.7586 times. The system average interruption duration index (SAIDI) decreases from 15.0939 h to 14.6790 h. However, when using the wind-solar complementary power generation system established, the average service availability index (ASAI) increases from 99.82% to 99.84%, and expected energy not supplied (EENS) decreases from 79.1722MW to 75.0307MW. 2) The results show that the system, after connecting 200 EVs, SAIFI and SAIDI increased from 2.7745 times and 14.0786 hours to 2.9317 times and 14.9640 hours, respectively; As the number of EVs increased to 1000, the reliability indexes SAIFI and SAIDI significantly increased, and the ASAI decreased from 99.84% to 99.83%. 3) The results show that compared with the disordered charging mode, the SAIDI of the system decreases from 14.9640 to 14.7296h and 14.1118h, and the EENS also decreases from 77.4233 MW to 76.3983 MW and 75.7556 MW. Conclusion: 1) Compared with the situation without DG access, DG can effectively improve the reliability of the distribution network.2) The system's reliability connected with a single WTG is higher than PVG. However, the system's reliability connected with a wind-solar complementary power generation system is higher than that of a single WTG / PVG. 3) EVs connected with disorderly charging will increase the system's peak load and significantly reduce the reliability of the distribution network. With the increase in the number, the deterioration of reliability will intensify. 4) Compared with the disordered charging mode, the orderly charging and discharging mode using TOU price and dynamic TOU price can effectively suppress the peak load and reduce the impact on the system reliability after the EV is connected to the distribution network. Among them, the charging and discharging mode using dynamic TOU price has the most negligible impact on the reliability of the distribution network.