  The working principle of a electric current transformer is based on
electromagnetic induction, mainly composed of a closed iron core and windings.
Its primary winding has relatively few turns and is connected in series with
the current circuit to be measured. However, due to the frequent occurrence of
full current passing through the current transformer during use, its secondary
winding has relatively more turns. During use, errors may occur in the current
transformer. Therefore, technical personnel can adopt the heterodyne
measurement method to shield interference signals and ensure the accuracy of
measurements during on-site examining and repairing of current transformers.
This article mainly introduces the characteristics of transformers and their
on-site examining and repairing process and errors, and describes the specific
application of heterodyne measurement in on-site examining and repairing of
current transformers.
