Research On Virtual Power Droop Control Method For Low Voltage Microgrid

As the buffer and link between distributed resources and power grid,microgrid provides an effective way for large-scale application of distributed resources.As an important equipment in microgrid,the inverter's control strategy will directly affect the safe and steady operation of the microgrid.In this paper,the virtual power droop control method for power decoupling in low voltage microgrid is studied.Besides,the experimental platform of single inverter is bulit.Firstly,this paper introduces the background information of the research question and the exsiting microgrid power decoupling control strategies.Secondly,the three phase inverters' mathematical model and the principle of virtual power droop control strategy are introduced.Chapter three mainly aims at the poor power sharing effects of virtual power droop control method.After summaries and comparisons of the existing power sharing control methods,the control strategy based on public quantity is chosen to solve the virtual power droop control's power sharing problem.And MATLAB/Simulink is used to bulid the simulation model for verifiation.Chapter four mainly aims at the frquency and voltage deviation problem of virtual power droop control.A practicle example is given to illustrate the possibility that virtual power droop control method based on fixed droop coefficient will cause excessive frequency or voltage deviation.Thus,a novel virtual power droop control method based on Lagrange interpolation is proposed.The new method can ensure that the system frequency and voltage deviation will meet the requirements of power quality as long as the inverter's output power is within its allowable range.And the proposed control strategy is verified by simulation.In chapter five,the experimental platform of a single inverter is bulit.Through design and debugging of the hardware system and software code,the droop control with resistive load is realized.