Application of DSOGI-SPLL algorithm on shunt active power filter under unbalanced and distorted voltages

On the application of a shunt active power filter (SAPF), the detection accuracy of harmonics is a vital factor to judge the performance of the SAPF, which is indeed strongly depended on the veracity of software phase-locked loop (SPLL). However, phase jump, frequency variation and harmonic accompanied with the voltage sags usually impact the dynamic response and accuracy of SPLL. In this paper, a detailed study of Double Second Order Generalized Integrator SPLL (DSOGI-SPLL) and simulation are performed. Then, a three phase four wire SAPF simulation model based on DSOGI-SPLL was built using MATLAB/SIMULINK programs and a 100A three-phase four-wire SAPF prototype is tested, which proved the validity and correctness of DSOGI-SPLL on the test platform.