To investigate the effect of m-aminobenzoic acid-functionalized fullerene(fC

60

)doping on the space charge and dielectric properties of cross-linked polyethylene(XLPE)composites

500 kV DC cable-grade XLPE was selected as the matrix. Three XLPE specimens were prepared by solution blending and hot

pressing. Space charge tests under room-temperature and high-temperature conditions

broadband dielectric spectroscopy

and quantum chemical calculations were carried out to analyze the space charge and dielectric properties of XLPE before and after modification. The results show that the addition of fC

60

effectively enhances the space charge suppression ability of XLPE. After polarization at 70 鈩?and 20 kV/mm for 1 800 s

the average charge density of fC

60

/XLPE is 1.21 C/m

3

which is 48.1% lower than that of pure XLPE

2.33 C/m

3

and 18.8% lower than that of m-aminobenzoic acid/XLPE

1.49 C/m

3

. The characteristic trap energy level of fC

60

/XLPE reaches 0.94 eV at 70 鈩? and the trap density is 4.1810

23

m

-3

鈥V

-1

which is beneficial for restricting charge migration. The composite also exhibits a lower dielectric loss at power frequency. At 90 鈩? the dielectric loss factor of fC

60

/XLPE is 2.4610

-5

lower than those of pure XLPE and m-aminobenzoic acid/XLPE

which are 4.6910

-5

and 4.2510

-5

respectively. Quantum chemical calculations show that the dipole moment of fC

60

increases from 3.71 D to 7.42 D under an external electric field. This indicates that fC

60

can introduce electric-field-sensitive deep traps into the XLPE matrix

enhance charge trapping

and reduce space charge accumulation and dielectric loss in fC

60

/XLPE composites.