The secondary voltage method using potential transformers (PTs) is widely used for on-site measurement of resistive current in metal-oxide surge arresters (MOAs).However

phase-to-phase stray current interference and temperature effects are the primary factors affecting the accuracy of resistive current measurements for linearly arranged MOAs.In such configurations

the measured resistive current of phase A is usually higher than its true value

while that of phase C is lower.Moreover

the MOA resistive current increases with rising temperature

yet an effective temperature compensation method is still lacking.To address these issues

this study proposes two improvements:One is measuring the MOA resistive current under factory test temperature to minimize thermal effects

and the other is employing a fixed induction plate method

where a reference position is determined to eliminate phase to phase interference

and subsequent measurements are conducted with the plate fixed at this position.Field tests on MOA samples demonstrate that the fixed induction plate method effectively eliminates stray current interference and thermal effects

thereby reducing misjudgment of MOA operational status.