The partial discharge experiment of insulating materials in laboratory is an important means to reveal the phenomenon of partial discharge

and tracking the specific location of discharge points is helpful to study the growth mechanism of electric trees. The accuracy of boundary electric field measurement results has an important influence on the calculation error of discharge point position. In this paper

the influence rules of measuring electrode diameter (D)

measuring electrode spacing (S)

and measuring electrode distance from ground electrode (H) on the measurement error of two-dimensional measuring electrode array used for boundary electric field measurement are studied. The optimal structural parameters are obtained

that is

D=1.5 mm

S=4 mm

and H=0.154 mm. The correction methods of the systematic errors introduced by the measuring electrode

the divider capacitor and the signal acquisition card

and the random errors introduced by the numerical dispersion of the divider capacitor are given. After error correction

the systematic error and random error are less than 3%

which can ensure that the discharge point positioning error is less than 0.01 mm.