Performance of a phase locked loop as affected by power system dynamics

摘要

Implementation of vector control for a VSC-based equipment installed in a power system relies on the accurate and fast tracking of the phase of voltage at the point of common coupling (PCC) by a phase locked loop (PLL). This paper investigates the influence of power system dynamics on the performance of the PLL by connecting the PLL to a power system. Results of power system simulation demonstrate that the PLL's performance is significantly affected by power system dynamics, which is not observable under the normal test condition with the PLL being connected to a three-phase voltage source. In the paper, three representative design schemes of the PLL are examined and tested with various simulation results presented.