Research on Improvement of Voltage Fluctuation in Micro-grid Based on Improved Double Closed Loop Control of Flywheel Battery

Clean power sources such as wind power and PV have great randomness and volatility, and random changes in wind speed and solar irradiance are prone to voltage fluctuations. Considering the influence of wind power and photovoltaic on the power quality of micro-grid, this paper adopts the method of connecting the flywheel battery in parallel with the micro-source AC output side to adjust the output voltage of each micro-source inverter. According to the double closed-loop control principle of voltage outer loop and current inner loop, the improved fuzzy PID controller is used to replace the traditional double-loop PI regulator, so that the flywheel battery can stabilize the output voltage of the micro-source more quickly and effectively. The simulation results of MATLAB/Simulink software show that the improved double closed-loop control strategy is used to realize the fast storage and release of the energy of the flywheel battery, which achieves the purpose of stabilizing the system voltage and improving the power quality.