A Multi-Timescale Schedule Strategy For Multi-Microgrids: A Distributed Approach

Multi-microgrids (MMGs) interconnect microgirds (MGs) with geographical adjacency and improve the overall efficiency, stability, and reliability of a regional energy system. The uncertainty brought by renewable energy resources (RESs) is one of the challenges facing the schedule of MMGs. To cope with it, a multi-timescale schedule strategy is proposed. Specifically, in day-ahead schedule, the on/off states of the units are determined. Then, based on the day-ahead plan and the more accurate estimation of RESs, the refined schedule is achieved in the intraday. And to enhance the flexibility of the MMGs system, multienergy complementarity is considered in this work. Moreover, how to achieve the coordinated schedule between MGs owned by different parties is another problem facing the MMGs system operation. To solve this, a distributed algorithm, namely predictor corrector proximal multiplier, is introduced. During the solution process, each MG only needs to reveal the exchange power to the virtual controller, which protects the privacy and reduces communication burden. Numerical simulation of an MMGs system with four MGs is carried out. The results show that the proposed distributed method has good convergence performance. Besides, the absolute relative differences of objective function results obtained using the proposed method with the centralized counterpart are less than 2% in the day-ahead timescale and which can be less than 0.08% in the intraday timescale. Therefore, the economy and flexibility of the system can be achieved.