A New Software Phase-locked Loops

Abstract

A new type software phase-locked loops is proposed. The amplitude integral and selective characteristic of frequency are used to form the positive frequency fundamental filter. The K is derived, the principle of the variable sampling period phase-locked loops is further analyzed, it’s mathematical is established, and the regulators parameters is optimize designed. Simulation and experiment show that the proposed phase-locked loops can lock the phase and frequency of the positive sequence fundamental voltage quickly and accurately, So it can provides a reliable base for grid-connected system.