Control Strategy of Voltage Compensation with Harmonics for Dynamic Voltage Restore

The widespread use of a large number of distributed power supplies such as photovoltaic, wind power and other equipment may bring power quality problems such as voltage fluctuations to the grid, and may cause damage to a large number of user side equipment, resulting in huge losses. Therefore, in order to ensure the stable operation of the system, how to restore the dynamic voltage to keep the stable voltage without fluctuation on the user side is particularly important. In this article, the dynamic voltage restorer is proposed to take the compensations for voltage fluctuation with harmonics accurately. The fast voltage fluctuation detection and high compensation depth Improved Synchronous Reference Frame (ISRF) method are proposed for handling the grid voltage with amplitude fluctuation and harmonics, to ensure that the user side voltage is not affected. In the aspect of harmonic extraction, the method of Butterworth high-pass filter is proposed. Through this filter, the harmonic is extracted and compensated, and the total harmonic distortion is reduced to values which are far less than the limits defined in IEEE519 Standards. Finally, the system is simulated in MATLAB/SIMULINK to verify the feasibility of the system.