Inter turn Short Circuit in 3 Phase Induction motor model

Question

I am currently modeling a fault diagnostic method for electric machines. Part of it requires me to create an Inter Turn Short Circuit (ITSC) fault, which is incorporated in the three phase squirrel cage induction machine model in Typhoon. 

The problem is, there is little information as to what it means when a percentage of fault severity created during simulation runs. Knowing the exact number or ratio of fault created with respect to the total number of coils per phase is crucial for comparison between simulation and experimental scenarios. The help tab shows the electrical sub system model for a machine with an ITSC, but it appears the matrices are centered around the fault resistance and fault current, with alpha-beta current and voltage relationships

I would appreciate it if more context if provided as to how the relationship between the fault severity factor and the turns/coils can be established. 

Also I would suggest a standalone fault model based on multiple coupled circuit modeling. That way, each coils/turns can be made as separate circuits and it becomes more useful for fault diagnostics. 

Answer 1

Greetings Daniel,

Typhoon’s ITSC model is based on Alberto Berzoy, Ahmed A. S. Mohamed, Osama Mohammed, Complex-Vector Model of Interturn Failure in Induction Machines for Fault Detection and Identification, IEEE, 2016 (link).

Severity factor µ: the fraction of a phase’s total series turns that are shorted, µ = N_shorted / N_total. It’s a pure turns ratio, not a percentage of resistance or current.

Rf: the resistance of the short-circuit path itself, separate from µ. It represents the fault’s own impedance.

Regarding your idea, we’ll keep it in consideration, but especially for real-time simulation, this level of detail would dramatically increase the computational power the model requires.

Best regards,