DC microgrid is a highly efficient form of microgrids. In this paper

the background

the engineering situation

topologies and typical characteristics of DC microgrid are firstly described and analyzed. Power quality problems with the grid-interconnection point

feeder lines and users load bus in DC microgrid are also summarized and expounded

respectively. By drawing on the research experience in AC system power quality

the key problems of power quality in DC microgrid are dealt with

including phenomena mining and analysis

and the assessment and control of power quality

with the assessment and control further discussed. The framework of power quality standardization is also proposed to arouse readers' thinking and exploration.This work is supported by National Natural Science Foundation of China(No. 51207051).