A discussion of some concepts in thermal aging test-thermal aging and thermal breakdown

Based on the experimental and analytical research results, the thermal stress preprocess and its performance in a thermal aging test should be divided into two distinct physical phases: thermal aging (TA) and thermal breakdown (TB). This paper presents firstly the definitions of TA, TB, and some related concepts in a thermal aging test for winding insulation systems, then discusses the property and distinction between TA and TB, the two kinds of different physical processes in the aging performance study, by means of an aging test with high accuracy. Finally the significance of this distinction for the research of thermal stress performance as well as for the fault detection and prognosis is explained in the paper.