Multi-time scale optimal dispatch of microgrid is an effective way to integrate intermittent distributed energy into the bulk system. In light of the problems that the conventional multi-time scale optimization scheme based on power flow is easy to appear not timely unit response

large tracking errors and so on

a multi-time scale coordinated dispatch method based on model predictive control(MPC)is proposed. During the day-ahead scheduling

an optimal economic dispatch model with the aim of minimum operation cost is developed

which takes into account peak-valley difference of electricity price

energy storage life

and the randomness of renewable energy sources(RESs). During the intra-day scheduling

an MPC-based rolling optimization correction strategy is proposed to depress power fluctuations caused by RES forecast errors at tie-line and ensure the daily energy balance of the energy storage. By using the rolling optimization scheduling of limited time window instead of the conventional single section optimization scheduling

the future changes of the renewable energy output and the tie-line plan can be perceived ahead of time so as to adjust the unit generation in advance. At the same time

by combining receding horizon and feedback correction of the real-time state of the system

the influence of uncertainty factors in the microgrid can be eliminate greatly to ensure the rationality of the day-ahead plan and the stability of the system. Finally

a microgrid demonstration project is taken as case study and simulation results verify the effectiveness of the model and algorithm proposed. This work is supported by Knowledge Innovation Important Direction Project of Chinese Academy of Sciences(No. KGCX2-EW-322)and National Natural Science Foundation of China(No. 51277170).