Contrast aging tests are carried out on twisted pairs simulating inter-turn insulation and insulation to ground of inverter-fed traction motor under AC and square wave pulse conditions.

• 变频牵引调速电机匝间绝缘承受来自逆变器的连续高压脉冲方波的作用,其老化机理与工频正弦电压作用下具有很大差异。