Research On Micro-grid And Its Inverter Control Technology

Micro-grid, referred to micro electric network, this is another new definition tothe public grid in recent years，it contains a variety of distributed micro-power notonly through the inverter generates electricity supply power to the local load, but alsothrough electronic devices output the power to the public grid.Inverter as interface between the micro-grid and the public grid, is an importantdevice for various distributed micro-power output the power to the local load andmake the micro-grid connected to the public grid. The control of micro-grid inverterpower is essentially a control of the inverter, the inverter output power is not only toprovide for the local load, but also can guarantee the inverter output voltage meet theinterconnection standards to the public grid, at the same time when the micro-gridwork in off-grid mode, the inverter should be able to adjust the output power in timely,and reallocate the required power of the local load so as to maintain the micro-gridstable reliable and continuous work.This article focuses on the micro-grid inverter control technology research, andintroduces the micro-grid and distributed generation systems on the basis of thestructure and operation mode, control mode of the inverter smooth switching inmicro-grid on-grid and off-grid and under two different operating conditions as theresearch target. First analyzes the three kinds of control methods to the single inverter:PQ control, V/f control and Droop control, then construct the simulation model of themicro-grid system in MATLAB/Simulink software platform, Analysis of theperformance of micro-grid under various conditions, to verify the rationality of thedesigned control methods. On this basis, then the traditional droop control to theinverter has been appropriately modified so that it can be effective applied in thelow-voltage micro-grid. Finally, this paper designed two integrated control methodsto the multiple inverters in micro-grid: master-slave control and peer-peer control,and through a variety of simulation scenarios with integrated control method to verifythe applicable and stability of the two methods in the micro-grid.