Research On Microgrid System Based On H_? And Droop Control

At present,people's demand for electric energy is getting larger and larger.the thermal power generation is often used,pollution of the environment and high cost is its drawback,so the development of new energy is becoming more and more important.As a kind of green economy energy,photovoltaic power microgrid system has become a research hotspot.This paper studies the inverter control method in photovoltaic microgrid system.The main work is as follows:Firstly,the H_?controller design of single-phase grid-connected inverter with disturbance at the output end is studied,and the simulation model of two-stage photovoltaic grid-connected inverter controlled by H_?is built to simulate with traditional PI control.The comparison of the effects shows that the H_?controlled inverter exhibits strong robustness when subjected to external disturbances such as load and grid frequency change.Secondly,the synchronous control method of parallel inverter is studied.The combined control method of droop control and dual PI control is used to realized the stable synchronous operation of two parallel single-phase off-grid inverters.The output voltage and current of the single-phase inverter are collected separately,then the active power and the reactive power are calculated,and the active power and the reactive power are simultaneously input into the droop control module,and the droop control module calculates the voltage reference phase according to the active power.The voltage reference amplitude is calculated according to the reactive power,and the two combine to output the reference voltage,and then the PWM control signal for controlling the inverter is generated by the double PI adjustment.The parallel inverter simulation of the method shows that the load is robust when the load is sudden;The third,micro-grid monitoring system is designed,in which the hardware is built based on the STM32F130C8T6 chip,including parallel inverter module,voltage and current acquisition module,control module,wireless communication module,etc,The host computer interface is designed,it based on the QT platform development and uses C++language,which realize the monitoring of the voltage and current of the off-grid microgrid.The research in this paper has certain reference value for the control design of microgrid.