What is Transformer Inrush Current?

What is Transformer Inrush Current?

Transformer Inrush Current Definition

Transformer inrush current is defined as the high transient current drawn by a transformer when it is energized.

Initial Flux and Voltage

At startup, there is no initial flux, and the flux wave starts from zero, following the voltage waveform.

Peak Flux and Core Saturation

The flux can peak at double the steady-state maximum value, leading to core saturation and high inrush current.

Transient Nature of Inrush Current

Inrush current is transient, lasting only a few milliseconds, but can be up to 10 times the normal rated current.

Impact on Circuit Operation

High inrush current can cause fuse or breaker interruptions, component failures, and introduce noise and distortion into the electrical system.