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Transformer Regulation & Losses Calcualation (As per Transformer Name Plate)
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:Three Phase Transformer Detail::I²R Losses Calculation:
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Transformer MakeHV Full load current :0.84Amps
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Transformer Serial NoLV Full load current :21.33Amps
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KVA rating of Transformer16000VAHV Side I2R losses 227.800Watts
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Primary voltage 11000VoltsLV Side I²R losses 149.63Watts
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Secondary voltage433VoltsTotal I² R lossses @ Amb temp377.43Watts
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Primary side ConnectionTotal Stray losses @ Amb temp 16.57Watts
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Scondary side ConnectionI² R lossses @75° c temp 441.52Watts
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No load losses72WattsStray losses @ 75° c temp 14.16Watts
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No load current0.59AmpsTotal Full load losses at @75° c 455.69Watts
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Full load losses394WattsTotal Impedance at ambient temp 989.94Ohms
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Impedance voltage480VoltsTotal Resistance at amb temp 535.15Ohms
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Lv resistance in milli ohms219.16M OhmsTotal Reactance (X) : 832.82Ohms
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Hv resistance in ohms 215.33OhmsResistance at@ 75° c626.03Ohms
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Amb temperature 30Deg c Impedance at 75° c 1041.88Ohms
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Total Connected Load on Transformer10000VAPercentage Impedance 4.59%
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% Loading of Transformer63%Percentage Resistance 2.76%
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Percentage Reactance 3.67%
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Jignesh.Parmar:Regulation Calculation:
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jiguparmar@yahoo.comRegulation at Unity P.F2.76
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www.electricalnotes.wordpress.comRegulation at P.F of0.84.430.6
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:Efficiency Calculation:
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Efficiency at P.F of UnityEfficiency
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At Transformer Loading 125%96.80%
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At Transformer Loading 100%97.27%
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At Transformer Loading 75%97.69%
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At Transformer Loading 50%97.96%
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At Transformer Loading 25%97.67%
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Efficiency at P.F of 0.8Efficiency
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At Transformer Loading 125%99.52%
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At Transformer Loading 100%96.61%
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At Transformer Loading 75%97.12%
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At Transformer Loading 50%97.47%
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At Transformer Loading 25%97.10%
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Formulas
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HV Full load current = VA / (1.732xVolt)
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LV Full load current = VA / (1.732xVolt)
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HV Side I2R losses = I²R x1.5
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LV Side I²R losses = I²R x0.5x3
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Total I² R lossses @ Amb temp = Hv losses+ Lv losses
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Total Stray losses @ Amb temp =Measured losses -I² R losses
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I² R lossses @75° c temp = ((225+75) x losses) / (225+ Amb temp)
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Stray losses @ 75° c temp=((225+Amb temp)(Stray losses at amb)) / 300
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Total Full load losses at @75° c = I²R losses at 75°c+Stray losses at 75°c
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Total Impedance at ambient temp =(Imp voltage x1.732) / Full load current
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Total Resistance at amb temp = I²R losses / I²
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Total Reactance (X) =SQRT(Impedance ²- Resitance ²)
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Resistance at@ 75° c =(300 x resistance at amb ) /(225+Amb temp)
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Impedance at 75° c =SQRT(R² at 75 + X²)
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Percentage Impedance =(Z at 75° c x I x 100)/V1
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Percentage Resistance =( R 75° c x I x 100)/V1
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Percentage Reactance =(X x I x 100) / V1
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Regulation at Unity P.F =(%R cosø+%Xsinø).
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Regulation at 0.8 p.f.= (%R cosø+%Xsinø)+1/200(%R sinø-%Xcosø)2"
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Efficiency at Unity P.F
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At 125 % of Transformer Loading =(Kva x 1.25 x 100)/((kva x 1.25)+(I²R losses x 1.25²)+(No Load Losses))
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Efficiency at 0.8 P.F
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At 125 % of Transformer Loading =(Kva x 1.25xp.f x 100)/((kva xp.fx 1.25)+(I²R losses x 1.25²)+(No Load Losses))
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