The structure parameters and operation environment of single-core cable can lead to reactive power loss variation of the cable.In order to explore the influence of structure and operating environment of single-core cable on the reactive power loss of cables

the equivalent circuit model of cable is set up based on the internal structure of cable in this paper.The variation of reactive power loss of single-core cable under special working condition is studied through analyzing the form of reactive power loss inside the cable.The results show that the main internal loss of singleended grounded cable is capacitive reactive power loss.The higher the voltage level of cable is

the shorter the ultimate transmission distance of certain power is

and the ultimate transmission distance of 66 kV

110 kV

220 kV

330 kV and 500 kV cable is given.The capacitive reactive power loss can increase by 10%～30% after penetration of water inside the cable.The higher the voltage level or the larger the cross-section area of the cable is

the greater the increment of reactive power loss after water penetration is.The increment of reactive power loss of cable is proportional to the quadratic square of eccentricity of cable core.Under the same eccentricity

the increment of reactive power loss of cable with large rated carrying capacity is larger.The study results of this paper can be used to calculate the reactive power loss of single-core cable under special working condition and provide reference for reactive power compensation.