| The application of user-side energy storage in the distribution network is becoming more and more widespread,and its impact on the voltage of the distribution network cannot be ignored.In this thesis,we consider a complex distribution network system composed of user loads,distributed power sources,reactive power compensation devices,etc.,and study the optimization effect of energy storage synergy on the voltage quality of the distribution network.In this thesis,we construct a complex distribution network model to quantify the impact of energy storage access to the distribution network,and construct a PQ node model to study the impact of user-side energy storage capacity,storage access location,storage as load,and storage output power factor on the distribution network voltage.Under the 33-node model,simulations are performed to analyze the effects of different energy storage types and distributed power sources with user-side energy storage on voltage quality.This thesis also constructs a consistent algorithmic process for distribution grid voltage and implements cooperative voltage control of energy storage through an improved multi-objective cone model.Under the 69-node system of PG＆E,we simulate and analyze the optimization effect of cooperative energy storage on distribution grid voltage quality and obtain the conclusion that cooperative energy storage on the user side can effectively improve the voltage quality of distribution grid,which mainly includes.（1）Analysis of the research background and sources of this topic,and summarize the status of domestic and international research on user-side energy storage and voltage quality control technology respectively,determine the research objectives and main research contents of this thesis,and make pre-preparation and plan for the subsequent research.（2）To study the classification of user-side energy storage and its characteristics,analyze the general optimal allocation method of user-side energy storage,construct a cooperative auxiliary system for energy storage,and develop a cooperative control strategy,and construct a network model for system energy storage cooperation.（3）Analyze the operational characteristics of distribution network voltage,develop stable evaluation indexes and analysis methods for distribution network voltage quality,and take voltage deviation,voltage fluctuation and three-phase unbalance as the main evaluation indexes of distribution network voltage.（4）Study the influencing factors of traditional distribution network voltage,construct an equivalent model of distribution network,and analyze the influence of user-side energy storage access to distribution network system tide.（5）Study the voltage quality control strategy of distribution network,analyze the research application of PQ node strategy in energy storage access to distribution network,and analyze the sag control of energy storage.（6）Analyze the impact of user-side energy storage on voltage quality,construct the PQ node model of distribution network,study the impact factors of user-side energy storage on system voltage quality,analyze the impact of different types of energy storage synergy on voltage,and verify through simulation.（7）Implement the voltage control of energy storage synergy by using consistency algorithm,solve the voltage control of energy storage synergy by using multi-objective cone model,and analyze the optimization effect of user-side energy storage on system voltage by example. |
