MR ETOS TD User Manual

9 Visualization
Maschinenfabrik Reinhausen GmbH 2020270 4453918/14 ENETOS
®
TD
9.32 Dynamic Transformer Rating (optional)
NOTICE
Damage to the transformer!
An impermissibly strong or long overload can irreversibly damage the trans-
former's insulation system. This can lead to increased gas formation and
could cause the transformer to fail. Note that the permitted overload is cal-
culated based on a thermal model in accordance with IEEEStdC57.91 or
IEC60076-7 and, as a result, deviations in the transformer's thermal model
can occur.
► Ensure that the transformer's protective devices and equipment are func-
tional.
► During overload operation, also monitor the measured values for temper-
ature, power and gas content.
We recommend determining the design-specific parameters of the trans-
former using a heat test in order to improve the forecast calculation of the
thermal model.
You can use the optional Dynamic Transformer Rating function (DTR) to de-
termine the theoretical overload capacity of the transformer and the loss-of-
life caused by it. The value can either be calculated in accordance with the
IEEEStdC57.91 or IEC60076-7 calculation model.
Two operating modes are distinguished for the Dynamic Transformer Rating.
You can set the limit values for both operating modes:
Emergency mode
In emergency mode, unplanned malfunctions or failures occur in the grid
which require the transformer to take on an increased load. Emergency
mode helps support the grid in this process without damaging the equipment
or triggering protection systems.
Insulation-friendly mode
In insulation-friendly mode, you must adjust the limit values for temperatures
and for the maximum permitted aging for 24hours depending on the
planned duration of use of the transformer. This allows you to ensure a
longer service life for the transformer.
Measurement uncertainties
To calculate the permissible overload, the moisture in oil value of the trans-
former is recorded in addition to the measured temperature of the uppermost
oil layer and the calculated hot-spot temperature. The bubbling temperature
is calculated from the moisture in oil value.
The calculation of the bubbling temperature is only sufficiently accurate if the
transformer was in operation for a time period longer than 60days and
loaded evenly.

MR ETOS TD Specifications

General

Brand	MR
Model	ETOS TD
Category	DC Drives
Language	English