|
|
| (11 intermediate revisions by 4 users not shown) |
| Line 1: |
Line 1: |
| {{Menu_Characteristics_of_particular_sources_and_loads}}
| | #REDIRECT[[Protection of LV/LV transformers]] |
| <br>
| |
| __TOC__
| |
| | |
| At the moment of energizing a transformer, high values of transient current (which includes a significant DC component) occur, and must be taken into account when considering protection schemes (see '''Fig. N31''').
| |
| | |
| ----
| |
| | |
| <br>[[Image:FigN31.jpg|left]]<br><br><br><br><br><br><br><br><br><br><br><br><br><br>
| |
| '''''Fig N31:''' Transformer-energizing inrush current''
| |
| | |
| ----
| |
| | |
| The magnitude of the current peak depends on:
| |
| | |
| *The value of voltage at the instant of energization
| |
| *The magnitude and polarity of the residual flux existing in the core of the transformer
| |
| *Characteristics of the load connected to the transformer
| |
| | |
| The first current peak can reach a value equal to 10 to 15 times the full-load r.m.s. current, but for small transformers (< 50 kVA) may reach values of 20 to 25 times the nominal full-load current. This transient current decreases rapidly, with a time constant θ of the order of several ms to severals tens of ms.
| |
| | |
| [[ru:Ток намагничивания трансформатора при включении]]
| |
| [[zh:变压器励磁涌流]]
| |
