ABB Relion 670 Series Applications Manual page 512

Section 18
Monitoring
WdgTmConstMode : This setting is used to select the winding time constant mode of input to
the function. It has three options:
Standard : Winding time constant is taken from the IEEE or IEC standard as selected for
•
the temperature calculations.
• User defined : Winding time constant is provided by the user through setting. The value
may be given by the transformer manufacturer.
Calculated : Winding time constant is calculated by the function based on the transformer
•
parameters given by the user.
WdgTimeConst1 : This setting is used to get the winding time constant for winding 1. This is
used when the
WdgTimeConst2 : This setting is used to get the winding time constant for winding 2. This is
used when the
WdgTimeConst3 : This setting is used to get the winding time constant for winding 3. This is
used when the
The winding time constant is likely to be in the order of 5 to 20 minutes.
ConductorType : This setting is used to select the winding material between copper and
aluminum. This setting is useful when setting
This setting has two options:
Copper : Winding material is selected as copper.
•
Aluminum : Winding material is selected as aluminum.
•
Winding to oil temperature gradient differs from winding to winding depending on current
density in the winding, physical dimensions, cooling system etc., This value can be between 10
to 20 ̊ C for both distribution and power transformers. For low current density winding it can
be 10 ̊ C and for high current density winding it can be 20 ̊ C. The settings given below are also
used for the calculation of winding time constant.
WdgToOilGrad1 : Winding to oil temperature gradient for the winding 1 at rated load.
WdgToOilGrad2 : Winding to oil temperature gradient for the winding 2 at rated load.
WdgToOilGrad3 : Winding to oil temperature gradient for the winding 3 at rated load.
CuLossW1 : This setting is used to set the winding loss at rated load for the winding 1.
CuLossW2 : This setting is used to set the winding loss at rated load for the winding 2.
CuLossW3 : This setting is used to set the winding loss at rated load for the winding 3.
MassW1 : This setting is used to set the mass of the winding 1.
MassW2 : This setting is used to set the mass of the winding 2.
MassW3 : This setting is used to set the mass of the winding 3.
Loss ratios at different tap positions are required for the calculation of top oil temperature,
especially when the transformer is using online tap changer. This loss ratio is the ratio
between load losses to no-load loss. It may vary from 6 -7 for distribution transformer and 4-8
for power transformer. Normally it varies from 3 to 11. The function has the following settings
related to loss ratio calculation.
RLRated : This setting is used to set the ratio of load losses to no-load loss at principal tapping
position.
RLHighRated : This setting is used to set the ratio of load losses to no-load loss at principal
tapping +1 position.
506
WdgTmConstMode setting is selected as User defined .
WdgTmConstMode setting is selected as User defined .
WdgTmConstMode setting is selected as User defined .
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WdgTmConstMode is selected for calculation.
1MRK 511 401-UEN Rev. K
GUID-5832E7AF-0A4F-4B50-8045-94BF9433A1BF v1
GUID-8A9D8886-8EE5-4B02-80B8-BDDA95164BFF v1
Bay control REC670
Application manual