Research On Microgrid Vulnerability Assessment And Reconfiguration After Fault

The large power grid has been rapid development for its advantage of energyconservation in recent years. But it has undergone several blackouts in the world, thatits shortcoming of centralized power supply is increasingly obvious. It is difficult tomeet the user’s requirements for safety and reliability. So the distributed powergeneration technology has been paid more and more attention. Microgrid as a smallcapacity distributed power becomes a research hotspot. It can parallel operate withthe large power grid and disconnect from the network to separate operate in the largepower grid fault. This solves the problems that the large power grid is difficult toguarantee the reliability and security of the power system. But there are also someproblems in Microgrid, that is the fragility itself and the complexity of the system.The paper mainly introduces the vulnerability assessment and malfunctionreconstruction of the current research situation and the main problems in theMicrogrid, and studies the vulnerability and reconstruction of the Microgrid.Analytic hierarchy process is adopted to establish the five indicators of vulnerability,and fully assesses the micro grid from circuit overload resistance and voltageinstability and so on. This paper also proposed the system comprehensivevulnerability to evaluate the Microgrid on the basis of the above method. Take theant colony algorithm as the optimization algorithm of the microgrid to search theglobal Microgrid, this algorithm doesn’t depend on the setting of the initialparameters. This paper improves the updating rules of the ant colony algorithm andgreatly improves the searching efficiency for the drawback of traditional algorithmwhich blindly selects its initial values. And puts forward a method which takes thesystem comprehensive vulnerability and network loss minimum as the objectivefunction to translate the multi-objective optimization problem into single objectiveoptimization, this method improves the efficiency of the algorithm and gets thescheme of Microgrid reconstruction and operation. This also provides the reference for the Microgrid safety and operation maintenance and renovation. The experimentresults show that this method can accurately get the best solution for the Microgridreconstruction after the Microgrid malfunctioned.Thirty-three standard nodes of Microgrid was built in MATLAB/SIMULINKplatform. The simulation of vulnerability evaluation index of the micro power gridand reconstruction after fault verifies the feasibility of the approach used in thispaper.