I have a question regarding calculating transformer losses. I report each month on revenue metering variances and one comparison is on our station load which we use the revenue meter from the utility company versus our in house meter - simple enough. The problem I am having is the revenue meter and our in house meter are on the line and load side respectively. This being the case I need to account for the losses across the transformer and add them to our in house meter.
I have the following information from the transformer OEM:
High Voltage - 18000 V Delta
Low Voltage - 4160 V Wye
KVA - 15000
Phase 3
Hertz 60
MEASURED TRANSFORMER DATA
Winding Resistance @ 85 degrees C reference temperature:
-high voltage OHMS = 0.2685
-low voltage OHMS = 0.9946
No load loss @ 100% of rated voltage WATTS = 12760
Exciting current @ 100% of rated voltage % = 0.18
Load Loss @ 85C ref temp WATTS = 58055
Impedance @ 85 degrees C ref temp % = 8.56
CALCULATED DATA
Regulation at reference temp 85 C
and 1.0 PF % = 0.75
and 0.8 PF % = 5.65
Efficiencies @ 100% full load % = 99.53
75% full load % = 99.60
50% full load % = 99.64
25% full load % = 99.56
The load side varies based on plant conditions so what I want to do is calculate the real time losses - ideally I would implement the algorithm in the DCS to provide a corrected measurement.
Do I have enough information to perform such a calculation? I think from what I have I can correct for when the unit is @ 100% full load - can I use the efficiencies to calculate the losses throughout the load profile?
I would appreciate any help with this - my background is process controls so this is not my area of expertise.
I have the following information from the transformer OEM:
High Voltage - 18000 V Delta
Low Voltage - 4160 V Wye
KVA - 15000
Phase 3
Hertz 60
MEASURED TRANSFORMER DATA
Winding Resistance @ 85 degrees C reference temperature:
-high voltage OHMS = 0.2685
-low voltage OHMS = 0.9946
No load loss @ 100% of rated voltage WATTS = 12760
Exciting current @ 100% of rated voltage % = 0.18
Load Loss @ 85C ref temp WATTS = 58055
Impedance @ 85 degrees C ref temp % = 8.56
CALCULATED DATA
Regulation at reference temp 85 C
and 1.0 PF % = 0.75
and 0.8 PF % = 5.65
Efficiencies @ 100% full load % = 99.53
75% full load % = 99.60
50% full load % = 99.64
25% full load % = 99.56
The load side varies based on plant conditions so what I want to do is calculate the real time losses - ideally I would implement the algorithm in the DCS to provide a corrected measurement.
Do I have enough information to perform such a calculation? I think from what I have I can correct for when the unit is @ 100% full load - can I use the efficiencies to calculate the losses throughout the load profile?
I would appreciate any help with this - my background is process controls so this is not my area of expertise.