How to indicate in MATPOWER the use of several substations in the cases of radial distribution systems?

[Andrey Vieira]

Hi All! I have a question about the use of several substation bars in the case 
of radial distribution systems with more than one substation.
Examples:
  A) Case 16 buses : it has 3 substations;
  B) Case 135 buses: it has 2 substations;
  C) Case 84 buses : it has 11 substations.

In the case of 84 buses, for example, can I identify all substation buses with 
different numberings and indicate that all 11 buses are of
type 3 in the mpc.bus matrix? Instead of numbering all 11 with the same number 
(1 for exemplo)?

Can anybody advice on representation these sources in MATPOWER?


Andrey R Vieira