Novel structure of phase-locked loop robust against disturbances

Phase-locked loop is a key item to control power converters for power conditioning system and power quality compensator. This paper proposes a novel structure of 3-phase phase-locked loop that is composed of adaptive linear combiner and proportional Integral control. The operational principle was investigated through theoretical approach. The performance was verified through computer simulations with MATLAB and experimental works with TMS320vc33 digital signal processor board. The 3-phase phase-locked loop shows accurate performance under the voltage disturbances such as sag, harmonics, and phase-angle jump.