Research On Attack Detection And Power Supply Restoration Methods For Multi-microgrid-based Active Distribution System

In the power distribution system,with the continuous development of new energy technology,microgrid(MG)has become a feasible user-side power system structure,and the power distribution system has also changed from "passive" to "active".However,with the rapid development of information technology in the power field,information technology also brings its information security threats into the power system.At present,the research on the information security field of multi-microgrid(MMG)-based active distribution system is still in its infancy,and the commonly used static protection framework is difficult to deal with the latent and professional intelligent attack methods.Therefore,this thesis takes the MMG-based active distribution system as the research object,carries out information security protection research from the perspective of dynamic protection,and realizes the attack detection of the decentralized multi-microgrid system and the power recovery of the power distribution system under the attack state.This thesis firstly combines the characteristics of the MMG-based active distribution system and the requirements of information security protection,and considers intrusion detection and intrusion response,and proposes an information security protection framework for the MMG-based active distribution system.The framework mainly consists of two parts: the multi-microgrid collaborative intrusion detection and the power distribution system intrusion response.Then,on the basis of multi-microgrid collaborative intrusion detection,this thesis studies distributed collaborative detection and proposes a distributed multi-microgrid collaborative intrusion detection method based on consensus mechanism.The method includes a collaborative detection proposal generation mode that takes into account both triggering and polling,a distributed intrusion detection model based on one class support vector machine(OCSVM),and a consensus mechanism for distributed collaborative detection proposals based on improved delegated proof of stake(DPo S).Subsequently,on the basis of the intrusion response of the power distribution system,this thesis studies the power supply restoration of the power distribution system,and proposes a power supply restoration method for the power distribution system under the attack state.According to the operating status of the power distribution system and the corresponding security countermeasures,this method constructs a power supply restoration strategy model in the power distribution system under an emergency power outage caused by an attack.And the strategy model is solved by genetic algorithm to find the optimal distribution network topology.Finally,this thesis designs corresponding experimental scenarios to verify the distributed multi-microgrid intrusion detection method based on the consensus mechanism and the power supply restoration method of the power distribution system under the attackoriented state.The collaborative intrusion detection method based on the consensus mechanism not only realizes the consensus of distributed collaborative detection proposals that does not require third-party authentication,but also can better perceive abnormalities between microgrids.For the power supply restoration method of the power distribution system under the attack state,the power supply restoration of the non-attack area is realized to the greatest extent through the method of distribution network reconstruction.