Fuzzy Phase Locked Loop for Three-phase Power Converters

This paper presents a new structure for a phase locked loop (PLL) that operates based on a fuzzy logic controller. One commonly known fact is that phase jump may deteriorate phase locked loop performance. Accordingly, this paper specifically focuses on designing a fuzzy phase-locked loop (PLL) to track phase jumps in the least possible time. The fuzzy PLL attempts to track phase angle through outputs of the fuzzy logic controller, including angular frequency and phase angle compensation factors. To achieve the best possible performance, an adaptive fuzzy particle swarm optimization (AFPSO) algorithm is considered to optimize parameters of the fuzzy system. Two main advantages of this proposed structure is a) the very fast tracking of phase jumps and b) the ability to integrate the fuzzy PLL into other types of PLLs.