nikhilgupta10
commented
7 years ago nikhilgupta10 imported these comments from Sourceforge: "ftuffner": * status changed from new to accepted
Current belief is this is related to the nature of how the losses are being calculated. In a Delta-GWye, in particular, what is \phase A. Technically, we're probably computing the power_in as across the various delta-connected windings, and the power_out across the Wye. As a result, power_in is not really \power_A_in\ so much as \power_AB_in\, and probably isn't really correct in that regards.
Ideally, the losses should be computed as \power out along phase A\ - \power in along phase A\, which will involve additional calculations or mappings to the parent devices.
Item to figure out and possibly fix. May get rolled into forthcoming powerflow revamp.
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"ftuffner":Committed fix to 3.0 as part of r4651. Will migrate to others here later this weekend.
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"jcfuller":- Description has changed:
Diff:
- Resolution: --> none
- Component: Powerflow --> none
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Priority: major --> critical ,
"ftuffner":- status: accepted --> closed
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Resolution: none --> fixed ,
"ftuffner":Committed back in 3.0 and all values still appear correct. Validated and numbers are still calculating correctly.,
It appears that loss calculations in some transformers are not properly calculated. Most likely in one of the delta configurations.
It should be noted that powerflow calculations (current and voltage) are correct. For example, when adding all loads and subtracting from power out at swing node it ~= 300 kW (confirmed in commercial tools), however, sum of all transformer losses is >1MW.
See kevinschneider for model that demonstrates this.
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