HT Motor Starting

This is indeed a tricky one and i'm sure should best br answered by High voltage experts or practitioners. However you may find useful info here

http://www.lmpforum.com/inforum/Advantages-Ht-Motors6-t2512.html

Best of luck

I guess impedance of the two sources would determine how starting load is divided between the two....but am not sure. I could be way wrong on this.

Just Confirm each generator is around 1500KW in rating. Presently they are Solid State Starters, Soft Starters which are designed for 15KV, 22000 HP which reduces a lot of your starting hi-cups as stated. Its becomes more complicated to set a system on a continuous basis to be started in the above manner.

There is absolutely no problem in starting this HT motor with the set up as explained in the question. I want to what are the factors that decide the division of the starting MVA of the HT motor between CPP and the grid.

The missing ingredient is the Utility short circuit capacity at the 40MVA transformer primary. The 12%Z seems high for the transformer alone. With a robust utility, it may go without the generators. I am assuming the motor is line started. The centrifugal fan does not have a starting torque problem, but the high inertia of the fan will stretch the acceleration time and stress the motor rotor bars. stretch the time between starts. Try to limit the drop in voltage to 10% of motor voltage. I think the division of load will depend on the speed of the generator regulators, and would change the division during acceleration. Off the top of my head. Tony

This is a general practice.The sharing depends on trfo tap settings grid fault level and governor and avr settings.The trafo may support typically 60% starting mva.