Rule of Thumb to calculate voltage Dip for standby Generator

[adindas]

COuld anybody guide me the rule of Thumb to calculate voltage Dip at the standby generator terminals, following load switching.

I have read it is a fuction of subtransient and transient reaxtance of the Generator.
Thank you

Adindas

 

[bphgravity]

The generator manufacturer would likely be able to give you this information.

 

[bob]

C0uld anybody guide me the rule of Thumb to calculate voltage Dip at the standby generator terminals, following load switching.
I have read it is a fuction of subtransient and transient reaxtance of the Generator.
Thank you
Adindas

Xd is the generator’s steady-state synchronous reactance, while Xd' is the generator’s direct-axis transient-reactance! These two parameters should have already been supplied by the machine builder. Starting VD is the LRA of a motor x Xd' or the cold load pickup of the load switched x Xd'.

 

[adindas]

IS there any formula ?

IS there any formula ?

Thank you for all who r taking time to answer my question.
If you could assist me top provid rule of thumb formula.

Let take for instance:
Standby generator Genset Rating: 1250 KVA
Transient Reactance Xd' (pu) = 15%

I use to start a load simultaneously with total of:
Starting KVA (sKVA)= 1300 KVA
Starting KW (sKW)=350 KW

What is likely to VD at the teminal when the generato psick the load?

Thank you again for your time

Adindas

 

[bob]

Thank you for all who r taking time to answer my question.
If you could assist me top provid rule of thumb formula.
Let take for instance:
Standby generator Genset Rating: 1250 KVA
Transient Reactance Xd' (pu) = 15%
I use to start a load simultaneously with total of:
Starting KVA (sKVA)= 1300 KVA
Starting KW (sKW)=350 KW

What is likely to VD at the teminal when the generator picks up the load?

Thank you again for your time

Adindas

There is no rule of thumb. There is only OHM's Law. VD = amps x impedance.
In you example Impedance is 0.15. You will have to get the amps from the
starting KVA.