Home » Topics » English riddles » Switchgear » Switchgear Riddle No.12 – Drive fault

Switchgear Riddle No.12 – Drive fault

  • Creator
    Topic
  • #651
    Manirul islam

      A 11 Kw drive having no I/C and O/G choke, at full load, measured current before drive and after drive are 2A and 30A respectively, why this abnormality? …
      A 11 Kw drive having no I/C and O/G choke, at full load, measured current before drive and after drive are 2A and 30A respectively, why this abnormality? drive feeder is the outgoing feeder of a PMCC, incommer of this PMCC having capacitor bank for PF correction, is this because of capacitor bank or no choke, please discussed the matter.

    Viewing 1 replies (of 1 total)
    • Author
      Replies
    • #2328
      Hamid

        The flow of current to a variable speed motor is controlled by the converter. The current is non-sinusoidal due to the non-linearity of the converter and the generation of harmonic currents. Generally forming of sneak circuit in power system including semiconductor devices such as diode and thyristor especially with higher harmonics is possible. Please note to form of tuned sneak circuit probability making with C1,C2 and L in following figure. You can check harmonic content of that leakage current (2A) with an oscilloscope and influence of external capacitor bank with temporary remove it.

      Viewing 1 replies (of 1 total)
      • You must be logged in to reply to this topic.