Consideration of Active Resistances Temperature Dependency of Power Transformers when Calculating Power Losses in Grids

An analytical method for calculating power losses is developed taking into account the temperature dependence of the active resistances in power transformers. The proposed mathematical model is based on the transformation of the nonlinear function of the power loss versus linear dependence. This transformation is based on the integral least-squares method. For the power transformer TMN 6300/35, the power losses are calculated taking into account the temperature dependence of the load losses. The results of comparison of power losses in transformers with power losses in power transmission lines show the need to take into account the temperature dependence of the resistance in transformers.