Setting Guidelines - ABB REG670 Applications Manual

1MRK 502 071-UEN -
17.10.2
Generator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062
Application manual
contributions to insulation deterioration can be minimized, leaving insulation
temperature as the controlling parameter.
Temperature distribution is not uniform in transformers, the part that is operating at
the highest temperature normally undergoes the greatest deterioration. Therefore, in
aging studies it is usual to consider the aging effects produced by the highest (hottest-
spot) temperature. Since many factors influences the cumulative effect of temperature
over time which causes transformer insulation deterioration, it is difficult to predict
the useful life of the insulation in a transformer with great degree of accuracy.
However, this function will help in reducing the accelerated aging of power
transformers during overload conditions and thus maximize the transformer operating
life.

Setting guidelines

The parameters for the estimation of transformer insulation life function LOLSPTR
are set via the local HMI or PCM600.
Minimum information about the transformer parameters which are required to decide
the transformer insulation life are:
1. Top oil temperature rise over ambient temperature at rated load
2. Average conductor temperature rise over ambient temperature at rated load
3. Winding hot spot temperature rise over ambient temperature
4. Load losses at rated load
5. No-Load (core) loss
6. Oil flow design (Directed or non-directed)
7. Weight of core and coil assembly
8. Weight of tank and fittings
9. Weight of oil in the tank and cooling equipment (excluding load tap changer, oil
expansion tanks)
For information about 1 to 5, the conditions (load, ambient temperature, tap, etc.)
under which the measurements are made should be known. In order to have more
precise calculations, load loss at rated and tap extremes or all possible tap connection
combinations are required.
Operation: Off or On.
TrafoRating: Rated transformer power in MVA.
TrafoType: This setting is used to set the number of phases in the transformer. The
options are:
• Three Phase Trafo: The function considers the given transformer as three phase
transformer.
• Single Phase Trafo: The function considers the given transformer as single phase
transformer.
Section 17
Monitoring
657