Research On Adaptive Protection Of Distribution Network With Distributed Generation

As a clean energy source,electric energy has become an indispensable part of modern society.However,thermal power and nuclear power will also cause huge pollution to the environment in the production process,while wind power,solar power and tidal power have been paid more and more attention and developed due to their pollution-free and renewable nature.All these energies are connected to the large power grid in the way of distributed power supply,so it is necessary to conduct research and analysis on distributed power supply.As more and more different types of distributed power supply are connected to the power grid,the single radiant structure of the traditional power grid is changed,and the original trend direction will also change,which means that the traditional system protection will be affected.Therefore,it is of great significance to study the protection of the distribution network with distributed power supply.In this paper,the concept,types and common control strategies of distributed power supply are introduced in detail at first,and the control strategy is modeled and simulated in MATLAB/simulink platform to verify the effectiveness of the control strategy.Then the paper theoretically introduces the influence of distributed power supply connected to power grid.Then a grid model with distributed power is designed,and then the battery energy storage system is taken as an example to analyze its working state and fault characteristics in detail.Then,it is divided into two working modes: discharging as an independent power supply and charging as a load.The impact analysis on the access grid is carried out.The specific analysis is divided into two aspects: access capacity and access location.After theoretical analysis,the model is built on the MATLAB / simulink platform for simulation verification.Finally,the concept and advantages of adaptive current protection are introduced on the basis of the traditional protection configuration of distribution network,and the setting calculation of adaptive protection is mainly introduced.Then,in order to realize adaptive protection,a fault phase selection method based on current mutation is proposed.The relevant criterion is obtained through theoretical derivation,and its effectiveness is verified by modeling and simulation on MATLAB / simulink platform.Finally,for the adaptive current protection,a distribution network model with energy storage was built on the MATLAB / simulink platform,and simulation verification wasconducted from two aspects: working as an independent power supply in the discharge state and working as the load in the charge state,demonstrating the method Effectiveness.