Stage with Dependent Characteristic Curve (Thermal Stage)
Function Description
Logic
[lothchuf-080513-01.tif, 1, en_US]
Figure 6-239
Logic of the Overexcitation Protection with Thermal Characteristic Curve
(1) Heating
(2) Cooling
V/f Method of Measurement
The input values of the protection function are the continuously measured voltage and the frequency. The
phase-to-phase voltage is used to process the voltage. The angle difference method (see 6.32 Overfrequency
Protection) is used to determine the frequency. Both values form the V/f ratio. In order to arrive at an absolute
value, standardized data is applied.
Thus, the ratio is derived from:
[foverufn-080523-01.tif, 1, en_US]
with
6.39.3
6.39.3.1
Protection and Automation Functions
6.39 Overexcitation Protection
818 SIPROTEC 5, Overcurrent Protection, Manual
C53000-G5040-C017-8, Edition 07.2017