Research On Distributed Optimal Economic Dispatch For Microgrids Considering Communication Delays

As environmental pollution and energy depletion become more serious,renewable energy has attracted widespread attention.Distributed generation is an important form of utilization of renewable energy,and has the characteristics of low pollution and flexible configuration.In order to alleviate the impact of distributed generators when they are connected to the main network and improve the utilization of distributed generation,Microgrids system has become a research hotspot today.The economic dispatch problem of Microgrids is an important part of its safe and stable operation.It is essentially an optimization problem that aims at minimizing the total generation cost while satisfying the balance between supply and demand and output constraints of each generator.Traditionally,centralized algorithms are the main tool for the problem.However,centralized algorithms have a series of problems such as poor robustness,low computing efficiency,and high communication requirements,so distributed algorithms have received more and more attention.In addition,in practice,the communication environment is very complicated,and problems such as communication channel congestion,asymmetry of information transmission,and limited information transmission are likely to occur due to limited network transmission bandwidth,which may cause various time delays.With mainly the aforementioned inspirations,under various situations of communication delay networks,this paper takes into account the power loses,renewable generators and demand respond and so on.The major contributions of this paper are as follows:(1)The model of economic dispatch for Microgrids with network losses is established.Considering the communication delays by the transmission of information between distributed generators in Microgrids system and the input delays by disposing of information itself,a distributed algorithm with constant communication delays is designed.Meanwhile,the proposed algorithm takes network losses into consideration and has higher economic benefits.(2)Considering that the distributed algorithm under constant delays can only deal with a relatively single and fixed communication environment,this paper further studies and designs a distributed algorithm under time-varying communication delays.In the case of unpredictability and uncertainty,the system can meet the supply and demand balance of the system and realize the economic dispatch of Microgrids.(3)Aiming at the widespread penetration of flexible loads in Microgrids,the model for economic dispatch of Microgrids that takes into account the load-side demand response is established.In the case of multiple time-varying communication delays,a distributed algorithm based on multi-agent consensus is designed to achieve economic dispatching,and can realize plug and play of generators and flexible loads,reduce investment in communication networks,and effectively cope with complex communication environments.