Research On Self-healing Control Of Distribution Network Based On Immune Mechanism

As the "last kilometer" of power supply,the operation performance of distribution network has a decisive influence on the reliability of power supply.As the main characteristic of intelligent distribution network,self-healing is the main means to restore power supply after the failure of distribution network.Therefore,it is of great significance to study the self-healing control of distribution network to ensure the reliability of power supply.At present,the self-healing control of distribution network adopts the way of online decision making to generate recovery control scheme.When the same or similar fault occurs,the system needs to make decision again.For the distribution system with complex scale,its decision speed and decision performance need to be improved.The secondary response mechanism of the immune system can provide an effective way to solve the above problems in the self-healing control of the distribution network.By referring to the function realization method of the immune mechanism,an implementation model of the self-healing control of the distribution network for fast immune response is established.The model is implemented by the following steps:Firstly,the operation risks of distribution equipment are perceived during normal operation of the distribution network,and the expected accident sets of the distribution network are formulated in an orderly manner based on the risk ranking results.Secondly,when the power grid failure occurs,based on the similar fault state matching technology,the same or similar accident plan is retrieved from the expected accident set.Finally,judge whether the transfer plan meets the operating constraints of the distribution network,and make rapid adaptive adjustment to the plan.By referring to the learning and memory mechanism of secondary immune response,this model can effectively improve the decision-making speed and performance of self-healing control.Because there are so many kinds and quantities of distribution equipment,it takes a lot of time to anticipate an accident.Based on this,an orderly method of making anticipated accidents based on risk perception results is proposed.Firstly,the operation reliability and failure consequences of distribution equipment are analyzed,and the operation risks of equipment are evaluated.Secondly,the risk ranking of each distribution equipment is carried out through TOPSIS analysis.Finally,according to the ranking result of risk perception and the similarity of fault states,the fault prediction of distribution equipment is carried out.This method can make the expected accident adaptable and representative,and effectively reduce the search dimension when the plan is retrieved.In order to solve the problem of similar operation state matching of distribution network,this paper combines clustering idea in similarity analysis with immune mechanism,and puts forward a similar fault state matching method of distribution network based on artificial immune clustering algorithm.Firstly,based on the analysis of the influencing factors of power supply recovery strategy,the characteristic index system of fault sample set similarity analysis was constructed.Secondly,considering that cluster analysis can classify the sample set according to the characteristics of the samples by some similarity measurement method,an artificial immune clustering algorithm is proposed based on the antibody concentration regulation mechanism and mutation mechanism in the immune system.Finally,the proposed algorithm is applied to similar fault state matching,and the effectiveness of the proposed algorithm is verified by simulation tests.Aiming at the problem of rapid immune response of distribution network recovery control,this paper proposes a method based on basic loop matrix to realize rapid immune response of distribution network recovery control.Firstly,the basic loop matrix is constructed to describe the distribution network topology,the modification rules of the basic loop matrix are formulated,and the adjustment mechanism is established when the topology constraint is not satisfied.Secondly,the heuristic rules of switch pair selection in the adaptive adjustment strategy of electrical constraints were established through network topology analysis,and the adaptive adjustment strategy of electrical constraints was constructed by combining the optimal transfer load and the priority of adaptive adjustment when multiple branches are overloaded.Finally,the two adjustment strategies are coordinated to establish a complete rapid immune response mechanism for distribution network recovery control.This method takes into account the rapidity and effectiveness,and can adjust the control strategy quickly and accurately.