Voltage Waveform During Inrush Condition

Discussion in 'The Projects Forum' started by azadeh, Sep 15, 2008.

  1. azadeh

    Thread Starter New Member

    Sep 15, 2008
    Dear friends

    I am trying to simulate the inrush condition of a three-phase transformer for a research project. In this project, I also need to have the VOLTAGE waveforms during the inrush condition. The software that I use is PSCAD/EMTDC. In my simulation in PSCAD the voltage waveform is a completely sinusoidal waveform during inrush condition.

    Some days ago, I faced a demo in MATLAB/Simulink (power_transfosat demo). In this demo, the inrush condition has been simulated and voltage waveform and its 4th harmonic component have been sketched. At this demo, although the voltage scope has been put at the terminals of the three phase sinusoidal source, but the voltage waveform is a completely distorted waveform.

    I tried searching the literature to find an answer. I found only two papers which had plotted the voltage during inrush condition:

    1- Yabe K.: “Power Differential Method For Discrimination Between Fault And Magnetizing Inrush Current In Transformers”, IEEE Transactions on Power Delivery, Vol.12, No.3, July 1997, pp.1109-1118.

    2- Kitayama M., Nakabayashi M.: “A new approach to fast inrush current discrimination based on transformer magnetizing characteristics” 14th PSCC Conference, Sevilla, June 2003

    In the first paper, page 3, figure 1, the voltage waveform of the primary winding (not the tertiary) is an undistorted sinusoidal. In the second paper, page 3, figure 3-a, the voltage is a distorted sinusoidal.

    In the first attachment, I have put the MATLAB demo and the plotted voltage.
    In the second attachment, I have put the first paper (Yabe)
    In the second attachment, I have put the second paper (Kitayama)

    Now, I really do not know how the voltage waveform is, during inrush conditions. I should be grateful if you share your knowledge with me in this regard.