Resonant Calculations Hand / EMTP - Please Help.

[Los123]

I have a Question. It is about resonant condition(s).
Is it possible to do quick calculation to see if resonance is the problem, or do I have to run EMTP?

My case: New feeder, 138 kV to 27 kV, energized (from 138kV) for the first time - tripped upon being energized. The cause of the trip was a cable fault.

I ruled out Ferranti Rise.

I do not know how to do quick hand calculation (if it possible for this case)
Line data:
Z 1 = 0.392 + j 0.656 ( percentage impedance, 100 MVA base)
3 Phase Charging = 9.8 MVAR
Transformer data:
Z = 0.322 + J 18.499 ( Percentage impedance, 100 MVA ).
Fault 11% distance from 138 kV

Thank you.

 

[wareagle]

Check this information. It may help

http://ecmweb.com/powerquality/electric_power_factor_correction_3/index.html

 

[jghrist]

IEEE Std 519-1992, IEEE recommended practices and requirements for harmonic control in electrical power systems has some hand calculation methods for harmonic resonance. These concern a non-linear load and an inductive source with a shunt capacitor. Your situation sounds like you are worried about distributed cable capacitance becoming resonant with a load transformer.

What makes you suspect that the line fault was caused by resonance instead of more mundain things like faulty cable? If the cable capacitance were in parallel resonance with the transformer reactance, and there was a source of harmonic current, then a high harmonic voltage could appear at the transformer. Did any arresters flash over?