My post was an explanation to your query;
"Is it not the opposite i.e. the turbine that provides the mechanical energy to drive the alternator?"
The train of thought started before I realized that this was a steam turbine and not an aero-derivative turbine.
Aero-derivative turbines or gas turbines take a lot of power to start.
Typically the alternator is motored to spin up the turbine to start it.
This puts a lot of current through the damper winding and if the start-up time is extended may damage the damper winding.
The alternator is started as a...
I had assumed a steam turbine. (You know what they say about that. My bad.)
Will the 46 MVA alternator be able to start the turbine without badly overheating the damper winding?
When faced with a low insulation resistance (often below 1 Meg Ohm) I calculate the losses and make a judgement call as to the severity of the losses and the associated heating.
Phase to phase = 15 MΩ.
15 MΩ at 400 Volts = 0.027 mA
0.027 mA at 400 Volts = 0.0107 Watts per phase.
Total heating =...
Years ago I was hanging out in a hotel in the Yukon territory. That's east of a cold part of Alaska, but colder.
An exploration helicopter crew was stationed at the hotel.
One day I was sitting in the coffee shop when a helicopter landed.
The pilot was watching the rotors slow down.
That was...
I would be more worried about increasing the speed of the turbine if it is a steam turbine.
As I understand your post, the reduction gear remains the same and yet the gear ratio increases?
With a 40 Hz signal, switching faster than 40 Hz or possibly 80 Hz seems needless.
I suspect that the solid state relays will depend on zero crossing switching.
8 Volts DC from rectified 6 VAC is to be expected. The DC volts will peak at 8.49. The actual voltage will depend on the filtering and the load.
Your transformers may be a type of constant voltage transformer. In that case high no-load current is normal.
By the way, how did you determine that...
With corner grounding, there will be leakage currents through the insulation resistance and capacitive currents from the two ungrounded phases to ground.
These are insignificant and may generally be ignored.
If your inverter feeds are ungrounded or have no ground reference you should have no...
In low voltage cables, 300 Volt rated or 600/1000 Volt rated, a concentric neutral would be used with a three conductor cable for single phase, (two hots and the neutral, or a four conductor cable for three phase, three hots and the neutral.
As the neutral carries only the unbalanced current...
A couple of issues here;
The code specifies the ampacity of the ECG.
It is doubtful if the shield meets the ampacity requirement.
A shield on a single conductor cable will have a voltage induced.
If the shield is grounded at both ends, a current will flow.
The code generally requires the cable...
As the current increases, the magnetic flux increases.
When the thin section saturates, The magnetic flux is forced across the air gap.
Flux is the product of the Amp Turns over the length of the magnetic path.
The ratio of air path to iron path may be over 1000:1
That is 0.001 inches of air...
The directed current in the secondary will cause a directed current in the primary determined by the primary/secondary ratio.
The directed current in the tertiary will cause a directed current in the primary determined by the primary/tertiary ratio.
The directed sum of these currents will be the...
