Unbalanced-Load Protection
Overview of Functions
The Unbalanced-load protection function detects unbalanced loads or line interruptions of electrical
machines (generators and motors). Unbalanced loads create a counter-rotating magnetic field at double
frequency in the rotor. The skin effect leads to local overheating on the surface of the rotor bars in the transi-
tion between the slot wedges and the winding bundles. Another effect of unbalanced loads is the overheating
of the damper winding.
Structure of the Function
The Unbalanced-load protection function is used in the protection function group. The Unbalanced-load
protection function is preconfigured with 1 stage. A maximum of 2 stages can operate simultaneously in the
function.
[dwunbla-240913, 1, en_US]
Figure 6-175 Structure/Embedding of the Function
6.22
6.22.1
6.22.2
Protection and Automation Functions
6.22 Unbalanced-Load Protection
686 SIPROTEC 5, Overcurrent Protection, Manual
C53000-G5040-C017-8, Edition 07.2017