I'm having a problem with the static type excitation system (11kV output) for our hydro power plant. The problem is when the excitation is "on" producing 11Kv output, the field current seems to go up as high as 300A although the unit (generator) is not yet loaded or synchronized to the grid.

Previously the main thyristor unit have been replaced after excitation failed to start up and was working okay up until now that this problem aroused.

I need some help.

 

Hi,

First thing, you are getting required voltage (11KV) at stator side? and what abt the condition of it? is it oscillating or maintaining in the same level? if not oscillating, then excitation doing its job perfect. i think 300A in field side to produce 11KV in stator for 50HZ generator is normal. what was the previous value of exc. current?