SAIFI, SAIDI, CAIDI and ASAI are reliability indicators used by electric power utilities worldwide, essentially based on number of customers affected by interruptions. But in Spain and Portugal, you will find TIEPI and NIEPI instead, which are based on the ratings of interrupted transformers. I would like to know if there is a (simple?) way to go from one value to the other, or any meaningful correlation among them. Thank you very much!
Dear Professor Martí,
If you just have the values of TIEPI and NIEPI, I think that are two situations based on the fact that the number of customers in a transformer may have a relationship with the power at each transformer:
First, It can be a linear relationship between power at transformer i ($PI_i$) and the amount of customers connected to such transformer ($N_i$) ($PI_i = \alpha * N_i$), and the values of TIEPI and NIEPI will be the same for SAIDI and SAIFI respectively.
Second, the relation between power at transformers and it number of customers are not linearly related. In such case, you can try to obtain an average proportional value and carry the variation of such average value to SAIDI and SAIFI indices (SAIDI = TIEPI +- variation).
The first scenario is less likely than the second. I hope this helps; we can discuss best if you want.
Thank you.