To calculate the lightning induced over voltage on overhead distribution lines

by adopting the lightning return stroke model (MTLE model) proposed by Nucci C A

the paper calculates the electromagnetic field generated by the lightning return strokeThe horizontal electric field with ground conductivity affection is calculated by using the Corray Rubinstein formula

and an Agrawal model is improved as the coupling of field to line model to establish the lightning induced over voltage equation on overhead distribution linesBased on finite difference time domain (FDTD) method

values of the lightning induced over voltage on 10 kV overhead lines are calculated

which shows that calculation results is affected notably with or without considering the ground conductivity

which would reduce the amplitude of voltage on the line to nearly 20 kVDifferent return stroke velocities also affect the value of over voltageQuantitative calculation of such induced over voltages needs analysis of various factors influencing lightning induced over voltage calculation

perfection of calculation methods and ensurance of the calculation accuracy

so as to make the theory and calculation methods suitable for the power distribution lines lightning protection design

and provides valuable reference