I'm struggling a bit with learning to use GIMP, so please bare with me for not coming with a drawing just now. I'd reckon you could picture this in your head, while I'm sitting at the drawing table.
We have two diesel generators (and two shaft generators, but irrelevant here) producing power to the main bus bar. 690 volts, max. 1000 kW each. For everything I am saying here, only one diesel generator is online.
We also have an azimuth thruster 880 kW, which has a frequency converter, which receives power from the main bus bar. Before the DC link of the frequency converter, there is a LCL filter (don't know the values, but the inductors are pretty big! So are the caps..) I think I read somewhere, that the LCL filter is to protect the DC link and give it a stable feed of AC current, but also to protect the main bus bar from all the noise the DC link does. But today I could only find articles saying it's to protect the main bus bar (where everything on the ship is somehow connected to), and not the DC link. Thoughts?
And another thing. I've noticed, that if we give almost full power to the the azimuth, and all of a sudden take all the power off, we get a kVAR effect error on the diesel generator on line. Is this because the propeller is now still spinning at full speed and thus acting as a generator feeding into the main bus bar, which the generator voltage controller can't figure out to handle?
We have two diesel generators (and two shaft generators, but irrelevant here) producing power to the main bus bar. 690 volts, max. 1000 kW each. For everything I am saying here, only one diesel generator is online.
We also have an azimuth thruster 880 kW, which has a frequency converter, which receives power from the main bus bar. Before the DC link of the frequency converter, there is a LCL filter (don't know the values, but the inductors are pretty big! So are the caps..) I think I read somewhere, that the LCL filter is to protect the DC link and give it a stable feed of AC current, but also to protect the main bus bar from all the noise the DC link does. But today I could only find articles saying it's to protect the main bus bar (where everything on the ship is somehow connected to), and not the DC link. Thoughts?
And another thing. I've noticed, that if we give almost full power to the the azimuth, and all of a sudden take all the power off, we get a kVAR effect error on the diesel generator on line. Is this because the propeller is now still spinning at full speed and thus acting as a generator feeding into the main bus bar, which the generator voltage controller can't figure out to handle?