However, Pulse Width Modulation (PWM) which was input from inverter is characterized by steep rising edge and high frequency, resulting in the too early failure of motor insulation.

然而，逆变器输出的PWM(脉冲宽度调制)连续高压脉冲的上升沿很陡、频率很高，导致在脉冲电压下牵引电机绝缘过早失效。

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Features: temperature coefficient of capacitance at a certain temperature range is small and similar to polycarbonate. Low loss at high frequency. Small size. light weight. High insulation.

特点：在一定温度范围内电容量温度系数小，接近于聚碳酸脂介质，高频损耗小，体积小，重量轻，绝缘电。

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The insulation class F or class H . The insulation of open-loop U/f condition of . structure has the adaptability to high carrie frequency voltage supplied by frequency converter .

电动机的绝缘等级为F级或H级，绝缘结构具有对变频器输出高载波频率电压的适应能力。

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