In this paper

a method for estimating the line impedance of low-voltage distribution network based on power quality analyzer is proposed.The method uses two units of power quality analyzers fitted with GPS which are installed at the head and end of the line respectively so to realize synchronous timing based on the synchronous clock module（GPS）.Four current and voltage channels of the power quality analyzer are used.The simultaneous measurement of phase value of phase A

B and C to the neutral line at the head and end of the line and fundamental phase current of wire ABCN is proposedand

on this basis

the fundamental impedance parameters of the neutral line and the phase line of the three-phase four-wire low-voltage distribution network are accurately estimated

and the basic parameter data is obtained for the low-voltage distribution network analysis

network loss calculation and power quality status.