How to understand Isc( short circuit current) ?

iser Zhang

Hi Chris,

I try to find some tips in forum to help me to understand this formula: Isc = Flux/Ls (Wb/H), but still have some questions need your help;

1, Because the Flux is measured under no load condition, refer to below diagram, the "Flux" in formula is λaf, or λm?

2, About Flux=V/(Hz*2Pi), the parameter of "V" means Voltage P-N or Voltage P-P? RMS or amplitude?

3, I know how to dervie the formula of ψ=L*I, if the "Flux" means λaf, or λm, why λaf, or λm=L*I?

λaf: Armature flux linkages due to rotor magnets

λds: Stator flux linkages in d-axes

λm: Reference or command mutual air gap fl ux linkages

λqs: Stator flux linkages in q-axes

tks,

over 10 years ago

0 ChrisClearman over 10 years ago

TI__Guru** 119680 points

Iser,
I'll post something later this week. Currently traveling which makes it hard to give detailed answers.

0 ChrisClearman over 10 years ago

TI__Guru** 119680 points

AdvancedElectricalDrives_Isc.pdfattached is a pdf of workshop sheets out of the book 'Applied Control of Electrical Drives' (one of the authors is Duco Pulle with whom we work) which explains the short-circuit current and a salient model that is linked with the equations

For non salient PM the Lsd and Lsg are equal to Ls.

These models are much easier to use then the mutually coupled models which have traditionally been used.

0 iser Zhang over 10 years ago in reply to ChrisClearman

Prodigy 30 points

Hi Chris,

Thanks for you kindly help, your ppt solved my problem.

iser 5/17

C2000™︎ microcontrollers

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How to understand Isc( short circuit current) ?