ABB RELION REX640 Technical Manual page 1285

1MRS759142 C
REX640
Technical Manual
If transformer insulation paper is not upgraded, that is, if setting Insul paper type is set
to "Normal", the setting Ageing rate method selects between the IEC and IEEE
methods of calculation. If Ageing rate method is set to "IEC", the relative ageing rate
is calculated as shown in the
98
( θ )
−
h
V 2 6
=
IEC
GUID-6BBB42B9-75A3-4726-AF11-C32594F370AB V1 EN
If the setting Ageing rate method is set to "IEEE", the ageing rate is calculated as
shown in the Equation 300.
15000 15000
−
110 273 273
θ
V e + +
h
=
IEEE
GUID-A5C22C49-7562-47D8-8446-0A633E4E25A4 V1 EN
Where
V
IEC
V
IEEE
θ
h
If the setting Insul paper type is set to "Upgraded", the IEEE method
is used for calculating the ageing rate irrespective of the value of
Ageing rate method setting.
The calculated value of the relative ageing rate, AGEING_RATE is given as an output
in the Monitored data view.
The module also calculates the average ageing rate, AVG_AGE_RATE, over a
specified time period given by the Avg Age rate period setting. The setting Avg Age
rate period can be set to "DAY", "WEEK", "MONTH" or "YEAR".
For example, if the Avg Age rate period is set to "MONTH", the output
AVG_AGE_RATE is updated every day with the average ageing rate since the day the
calculation started. Once a month is completed, the AVG_AGE_RATE is calculated
over the previous 30 days. That is, after the 31st day, the average ageing rate is
calculated from day 2 to day 31 and so on.
If the Avg Age rate period is set to "DAY", "WEEK" or "MONTH", the calculated
AVG_AGE_RATE is refreshed every day at 12:00 hours, but if it is set to "YEAR", the
AVG_AGE_RATE is refreshed once in 30 days.
The calculated AVG_AGE_RATE is given as an output in the Monitored data view.
The function considers month as 30 days and correspondingly a year
as 12 months or 360 days.
Condition monitoring functions
Equation 299.
Momentary ageing rate as per IEC method
Momentary ageing rate as per IEEE method
The calculated hot-spot temperature
Section 7
(Equation 299)
(Equation 300)
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