Hot Topic: Phase Domain Synchronous Machine with Internal Fault

Hot Topic: Phase Domain Synchronous Machine with Internal Fault

Phase Domain Synchronous Machine with Internal Fault: _rtds_PDSM_FLT_v3

A new phase domain synchronous machine model (_rtds_PDSM_FLT_v3) is available in the RSCAD library. Figure 1 shows the three-phase and single-phase view of the machine model.

Figure 1: phase domain synchronous machine model (_rtds_PDSM_FLT_v3)

Figure 1: phase domain synchronous machine model (_rtds_PDSM_FLT_v3)

The phase domain feature of this model makes it capable of simulating synchronous machine internal faults. In order to do so, the self and mutual inductances of machine windings, including faulted windings, must be computed as functions of rotor position and saturation. In this approach, which is called “DQ−Based Method” in this document, it is assumed that not only the healthy windings create a perfect sinusoidally distributed magneto−motive force (MMF), but also, the MMF due to the faulted windings will be sinusoidal. The advantage of this method is that the users do not need to know the information about the distribution of the windings and rotor geometry, and the dq data required for utilizing the component ”lf_sharc_sld_MACV31” is adequate for utilizing this component as well.

Like the other available phase domain synchronous machine model (rtds_PDSM_FLT_v3), this model is capable of simulation of the stator to ground faults. However, as Figure 2 shows, there are more capabilities in model v3 for simulation stator internal faults.  By selecting the proper choice of the fault, the user will be able to simulate different types of machine internal faults.

The user may apply the following types of faults anywhere between 1% and 99% of the windings:

  • Turn-to-turn faults in individual phases
  • Turn-to-ground faults in individual phases
  • Phase-to-phase faults
  • Turn-to-turn faults in the field winding
  • Turn-to-ground faults in the field winding

 

Figure 2: Comparison of the models v2 and v3 for internal stator faults capabilities.

Figure 2: Comparison of the models v2 and v3 for internal stator faults capabilities.

 

Note that the 1st and 2nd point of fault connection can be selected to be on different points of the winding. As an example, Figure 3 shows the percentage of the 1st and 2nd points of fault to be 50 and 30 percent of the winding from the neutral, respectively.

Figure 3: Selecting of the position of faults on the stator winding

Figure 3: Selecting of the position of faults on the stator winding

Some examples of the fault analysis which are possible to perform with the faulted synchronous machine model “_rtds_PDSM_FLT_v3” are mentioned below:

  • Applying internal faults in all of the stator winding phases. Figure 4 shows an internal fault on phase C. Note that both CJ1 and CJ2 can be used for this aim.
Figure 4: An internal fault on phase C of the stator winding

Figure 4: An internal fault on phase C of the stator winding

 

  • Providing two fault point connections in each stator winding phase, this makes it possible to apply turn-to-turn faults in the same phase, by connecting these two connections together. Figure 5 shows a stator winding turn-to-turn fault on phase B.
Figure 5: A turn-to-turn fault on phase B of the stator winding

Figure 5: A turn-to-turn fault on phase B of the stator winding

  • Applying internal fault and turn-to-turn faults on the field winding, since two internal points of the field winding are available for connection. Figure 6 shows a turn-to-turn fault on the field winding. Note that, to see the external field connections, the field excitation type (parameter “fextyp” in General Model Configuration menu) should be set to “Power System Nodes”.
Figure 6: A turn-to-turn fault on field winding

Figure 6: A turn-to-turn fault on field winding

  • Applying internal phase to phase stator faults and phase to field faults Figure 7 shows an internal phase A to phase C stator fault.
Figure 7: An internal phase A to phase C stator fault

Figure 7: An internal phase A to phase C stator fault

Should you have any questions, please do not hesitate to contact us at support@rtds.com.

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Author: Mayssam Amiri, November 2017