A study on transformer loading in Manitoba-peak-load ambient temperature

It is shown that the hourly ambient temperature and load of a substation transformer in Manitoba, observed over the three-month winter or summer time window, are governed by the normal distribution, respectively, and they jointly follow the bivariate normal distribution. Based on this, a rigorous model for the peak-load ambient temperature (i.e., the ambient temperature at the time when the winter or summer peak-load of the transformer occurs) is developed. This makes it possible to accurately determine the peak load capability of the transformer if its historical hourly ambient temperature and load data are available.