An optimization method of power quality monitoring network considering the severity of substation voltage sags and the difference of power quality monitors are put forward. Firstly

the lightning density

pollution level

cable rate

and rated capacity are introduced to measure the severity of substation voltage sags. The objective and subjective combined weighting methods are used to assess the severity of substation voltage sags and its level is classified. Based on the newest power industry standard of China

the existing power quality monitors are classified into four different levels

i. e.

A

B

C

and D. The design of power quality monitoring network is presented in stages. In the first stage

the severity of substation is introduced and the conventional monitor reach area(MRA)matrix method is improved. A-type monitors are installed in some substations to ensure the voltage sags can be observed. In the second stage

different types of power quality monitors are configured based on the severity level of substations. In this way

mainly voltage sags are monitored while attending to other power quality problems. Finally

the results of simulation show the designed method has good validity and feasibility.