A novel power calculation method based on second order general integrator

The droop control method has been widely applied in parallel inverters. However, the stability and performance of droop control are strongly influenced by speed and accuracy of the power calculation. The conventional power calculation method has the disadvantages of slow dynamic response, heavy memory burden and one fundamental delay. In this paper, a novel method to calculate the average active and reactive power for single phase systems is proposed. Through taking the advantages of second order general integrator (SOGI), which not only has a rapid transient response, but also insensitive to the output voltage noise, the method can enhance the speed and accuracy of power calculation greatly. Simulation and experiments are developed, the results verify the theory analysis and the validity of the proposed method.