Lifetime Evaluation Method for Pole Transformer Based on Transient Temperature Analysis

From the viewpoint of reducing the cost of electric transport, a pole transformer has been operated, for a trial, under a short-time overloaded condition. It is not clear how long it takes a pole transformer to deteriorate under an overloaded condition, therefore, a pole transformer lifetime evaluation method is necessary. To realize this method, we developed a transient temperature calculation method from the load pattern and temperature of the outer section of the temperature, and evaluated its accuracy by comparing measurement results and calculations. We developed an estimation method of the degree of polymerization of insulating paper at varying temperature from the measurement result at various temperatures and times in the pole transformer atmosphere.