Machine-translated by Google. Questions are authored in English.
Top

Discussion

The excitation required for unity power factor at a synchronous motor's rated load compared with that at light load is

  • A.larger, since the machine must offset more armature reaction
  • B.smaller, since less flux is needed at heavier loads
  • C.exactly the same, normal excitation being a fixed value
  • D.zero, no excitation being required at rated load at all

Answer: A

As the load grows the demagnetising component of armature reaction grows with it, so the field must be raised to keep the reactive exchange at zero. Normal excitation therefore rises along a locus as the load increases.

No comment is present. Be the first to comment.
Loading…

Post your comment

Please log in or register to post a comment.