Abstract: With the high penetration rate of new energy power generation in microgrids and the application of

high proportion of power electronic equipment，coupled with the access of a wide variety of loads such as unbalanced and non-linear loads and energy storage device，the power quality problems in microgrids have become increasingly serious and has certain particularities：on the one hand，traditional problems such as voltage fluctuations are more prominent in the microgrid；on the other hand，the high degree of power electronics and the increase in switching frequency lead to some new problems such as inter-harmonics and ultra-high harmonics. Firstly，the causes，characteristics and hazards of traditional power quality problems in microgrids and comprehensive curing measures were introduced. Secondly，according to the current research status at home and abroad，the treatment of voltage and frequency deviations at point of common coupling in new energy grids were summarized. Moreover，new technologies such as power springs and multi-function grid-connected inverters were introduced. Finally，combined with the development of Chinese smart grid，the comprehensive management of microgrid power quality problems was prospected.

      Key words: microgrid ；new energy penetration ；power electronics ；power quality ；smart grid（SG）