Generator subtransient reactance measurement

[simonfr]

We are getting a new generator, and the manufacturer shall be performing a variety of tests including Transient & Subtransient Reactance test.

I do not have the test method references IEEE std. 115, Sec 11.8 or IEC 34-4, sec. 3 par 7&8.

How do they physically test for these reactances and the method employed?

Thanks,

Simon

 

[wolf39]

Simon:

Are you getting a 10 kVA auxiliary generator or a 10 MVA diesel generator or a 100 MVA hydro generator or a 500 MVA steam turbogenerator?

For off-the-shelf auxiliary units such tests are unusual. All turbogenerators are tested in the factory. Reactance tests of most diesel generators and nearly all hydro generators are to be performed in the field.

In practice the generator in question will be excited by separate excitation equipment to, lets say, 25% no-load voltage (excitation to be kept constant) and a three-phase short is to be applied to the generator terminals by use of a suitable breaker.

The resulting oscillogram of all three short-circuit currents will be evaluated for determination of subtransient and transient reactances as well as their time constants.

Your company should be able to purchase the IEEE 115 standard for your information. Why don't you ask the manufacturer for details?

Regards
Wolf

http://www.hydropower-consult.com

 

[simonfr]

Wolf

Thanks for replying.

Its a Solar Centaur 40, 4MVA Gas Turbine Generator.

The generator is a 'one off', and being manufactured by Kato Engineering.
According to their test procedures document, they shall be testing for Subtransient Reactance amongst others.

I do not have the test method references IEEE std. 115, Sec 11.8 or IEC 34-4, sec. 3 par 7&8, nor can i get them from my online 'standards' library which is paid for by the company.

Its out of interest id like to know how they test for this w.r.t. these standards.
I would also like to know the exact Subtransient Reactance figure as i am currently using +/- 15% Subtransient Reactance tolerance within ETAP.

Cheers,

Simon