With the increase of the scale of wind farms and the proportion of wind power in energy system

the power grid has higher and higher requirements for the voltage stability of wind farms. The actual operation status of wind farms is focused

and the key issues of the reactive power and voltage control of wind farms are summarized

including how wind turbines adjust the reactive power

how to allocate the reactive power in large scale wind farms

how to maintain the stability of the internal node voltage of wind farms

how to solve the problem of voltage control lag

the transient voltage control strategy under fault conditions

and so on. In view of these issues

the methods and characteristics of reactive power and voltage control technology in wind farms are systematically summarized

and the realization process of reactive power and voltage control technology is expounded from the aspects of the characteristics of wind turbines and reactive power compensation equipment

reactive power and voltage steadystate control

internal node voltage control

model predictive control

and transient control under fault conditions.The research can provide reliable technical means for safe and stable operation of wind farms.