Transformer Remnant flux modeling by DC current source injection in PSCAD

Transformer Remnant flux modeling by DC current source injection in PSCAD

Mohaned Kamal Mohaned Kamal

Mohaned Kamal

Power System EMT Simulation Analyst | Power system Engineer | PSCAD Professional | ETAP | PSSE

发布日期: 2024年9月3日
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  • In PSCAD to model remnants flux:

·??????? By DC current injection {accurate in my opinion} earlier version.

·??????? By using Hysteresis in saturation page {in newer version}


  • Constraint:

·??????? In a new version like V5, we can use hysteresis {either basic or Jiles_Atherton} but this

method disables Inrush's current decay time constant.

·??????? In Autotransformer No way to enter remnant flux.

From the above constraint, the best way is to use DC current source injection method.


  • Steps:

·??????? Split the circuit into single phase view to inject dc current.

·??????? Based on remnant flux ratio {80%, 60 %…} calculate the value of dc current.

·??????? According to the PSCAD application guide, Phase flux M=V/4.44 fr

·??????? For 220KV,50Hz transformer, and 80% as remnant flux, M=0.4577

·??????? Start DC current from a lower value and increase it until get 0.4577 by measuring the

remnant flux in Tr and validate by the M value calculated above.

·??????? Also, validate above by adding 80% as a remnant flux in hysteresis mode and measure

remnant flux {will find it 0.4577}.



领英推荐

  • Transformer energizing:

·??????? Using the above method for 80% as a remnant flux in phase A, -40% in phase B and

-40% in C-phase.

·??????? Calculate the inrush decay time constant according to the Excel sheet.

·??????? Validate transformer saturation parameter by:

Engineering assumption: connect transformer to ideal source and changing will be in

knee voltage or air core reactance to get inrush current equal to 6 to 8 times

transformer rated current.

·??????? With a remnant flux of 80%, the inrush current almost doubles without remnant value.



  • Validate inrush current value by comparing two methods, DC current injection and hysteresis mode {are the same just the different decay time}.




Suriya kumar S

Power System Engineer | DIgSILENT Powerfactory | Short circuit | Protection coordination | Harmonic | Transient stability | Renewable energy | ETAP

2 个月

Insightful Mohaned Kamal , 1) For validation of transformer do we need to provide the remenent flux because that is where we are getting maximum peak and why not we are using without remement flux in tr validation 2) How to check half peak value is correct and if incase it is not matching which parameters to tune Can you please comment on it, which will be adding more value

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Devender Kumar Saini, Ph.D.

SMIEEE||Power system Planning||Sr. Associate Professor at UPES

2 个月

Useful tips.

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Yosry Mostafa

Senior Power System Studies engineer at Dubia Electricity & Water Authority (DEWA)

2 个月

Great work

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1 次回应
Franz R. Guzmán L.

Ingeniero Civil Eléctrico

2 个月

Thanks for sharing. I could try to do too.

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