Case analysis of abnormal ground current misjudgment of high frequency transformer core
Overview of transformer core
The core is the main magnetic circuit in the high frequency transformer. Usually made of hot rolled or cold rolled silicon steel sheet with high silicon content and coated with insulating paint. A complete electromagnetic induction system consists of an iron core and a coil wound around it. The transmission power of the power transformer depends on the material and cross-sectional area of the iron core.
Key points of transformer core grounding
an iron yoke clamp is set separately to ground the lead wire. Because if there is a core have on a multipoint earthing faults, in core earth current is only internal flow, no current flows through the, the core grounding lead can lead to staff as core is no malfunction; After setting, no matter where the iron core touches the clamp, it will form a loop through two external grounding leads, so that the earth current can be detected correctly on the outside.
the iron core grounding plate is placed in the middle of the cross section of the iron yoke. This place, no matter the iron yoke drawstring insulation bolt in any location and fault location in any position, the biggest induced voltage is only 1/4 turn voltage circuit, then the biggest earth current is also only a few amps, a core ground lug much smaller when placed in other place.
If really because of inconvenient installation problems such as core grounding piece needs to be placed in other place, also should pull iron yoke with the insulation of the bolt and grounding piece diagonal placement, in order to prevent large current is generated.