Review of accumulative failure of winding insulation subjected to repetitive impulse voltages

Abstract

The premature failure phenomenon that occurs in solid insulation under the application of repetitive impulse voltages is known as the accumulative effect of impulse voltages on a solid dielectric. The accumulative failure of winding insulation is considered to be a core problem resulting from this phenomenon. The main problems include the accumulative failure of motor winding insulation under pulse-width modulation impulses and the accumulative failure of transformer winding insulation under the application of overvoltages, and these problems represent new challenges in the safe and stable operation of power grids. With regards to the above problems, this study reviews the results of recent research on the accumulative failure characteristics and mechanisms of winding insulation when subjected to repetitive impulse voltages. The challenges faced are discussed at the end of this study.

Keywords

• transformer windings
• power grids
• power transformer insulation
• insulation testing
• machine insulation
• failure analysis
• machine windings
• repetitive impulse voltages
• premature failure phenomenon
• solid insulation
• accumulative effect
• motor winding insulation
• pulse-width modulation impulses
• accumulative failure characteristics
• transformer winding insulation