Transformer loss-of-life calculation using a computerized probabilistic method

A personal computer program has been developed to calculate the loss-of-life of distribution transformers. It assists the user in choosing the transformer rating that is appropriate for various loading and temperature conditions. The transformer loss-of-life program (LOSLIF), employs a Monte Carlo technique to calculate the probabilistic distribution of loss-of-life per year, based on inputs which represent realistic changes in ambient temperature and secondary load. The required temperature and load statistics are stored in databases which accompany the program and may be modified by the user. Example calculations have shown that the loss-of-life predictions from this probabilistic program are less conservative and more realistic than those provided by deterministic methods. The LOSLIF program can also be used to determine whether it is acceptable to increase loading on an existing transformer, and thus defer a costly change-out