Ask Your Question

Calculating centre of inertia frequency, scaling?

asked 2018-03-15 09:35:04 -0500

anonymous user


Hey there,

I have code that acquires all frequencies and is used to find COI frequency to find ROCOF on COI frequency, so I can use the ROCOF to estimate system inertia when certain contingencies occur.

To make COI frequency, I need to scale the machines' frequency contribution. I do not understand what Mbase is. Is it equivalent to inertia constant or rated power? If not, how can I get these two values from PSSE? I've spent so long looking around.

Thank you for your time.

edit retag flag offensive close merge delete

3 answers

Sort by ยป oldest newest most voted

answered 2022-11-16 14:26:41 -0500

From the dyanmic data of the machienes avalilable in you network, you can just multiply the Inertia constant with the MVA rating of the machine. Do the summation of the all the generators to get total inertia of the network,

edit flag offensive delete link more

answered 2022-10-26 22:16:14 -0500

Clarck gravatar image

Depends on the Turbine/Governor model H might be in Turbine rating ( Trat) or in machine rating MBase.

edit flag offensive delete link more


The inertia constant H is given in the generator model in machine base (MBASE).

perolofl gravatar imageperolofl ( 2022-10-27 01:44:05 -0500 )edit

answered 2018-03-20 17:13:48 -0500

perolofl gravatar image

updated 2018-04-05 02:14:01 -0500

Mbase is the rated MVA power of the generator. The inertia constant H is found in the dynamic generator model.

edit flag offensive delete link more

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer

[hide preview]

Question Tools

1 follower


Asked: 2018-03-15 09:35:04 -0500

Seen: 623 times

Last updated: Nov 16 '22