Research On The Application Of Dynamic Voltage Restorer In DC Microgrid

As a way to connect the distributed power supply and the power grid,the DC microgrid is a kind of trend in the future,because of its strong ability of reconfiguration,high power quality,and high efficiency.In the power quality problems and governance,as a new type of low-voltage DC microgrid distribution network has many new features,including voltage sag and swell is the main power often appear in the micro grid power quality problems,affect the daily use of electricity,the need to take effective measures,the normal operation of the micro grid stability to ensure the quality of power supply,load.This paper summarizes the basic characteristics of DC micro grid system structure,voltage level,voltage of DC micro grid in the sag of power quality problems,and the DC low voltage DC power distribution system at home and abroad to the quality standard and power quality control measures.Based on in-depth research of the AC micro grid dynamic voltage restorer,applying DC Dynamic Voltage Restorer in DC microgrid,improve the quality of voltage of DC micro grid.Based on the characteristics of DC system,DC dynamic voltage restorer topology is designed in this paper using isolated high frequency DC / DC structure,can achieve a wide range of voltage sag compensation,improve the security of the system,and reduce the volume of equipment.For the isolation of high frequency DC dynamic voltage restorer DC-AC-DC topology is studied in this paper,DC voltage detection,voltage compensation method,control algorithm and system controller,the voltage detection algorithm using DC voltage detection algorithm based on extrapolation,can improve the system dynamic response speed;voltage compensation method using DC voltage full compensation method;controller with voltage loop and current loop double loop active damping control based on proportional integral,ensure the steady state accuracy of the system response speed and the output of the system,good dynamic and steady state characteristics.To build a simulation model of DC Dynamic Voltage Restorer in the MATLAB/Simulink software platform,and DSPACE1005 controller based on 2kW experimental platform,the simulation and experimental results finally verify the effectiveness of the topology and control algorithm.In the end,this paper improves the DC dynamic voltage restorer topology,proposes bidirectional DC dynamic voltage restorer,solve the problem of DC voltage and voltage swell.Based on the topology design,a compound control algorithm for voltage detection,judgment and system is designed.A simulation case is built in the MATLAB/Simulink software platform to verify the correctness of the topology and the effectiveness of the control algorithm.