牵引机车过分相时高频谐波分析及对电缆终端发热问题研究

The analysis of high frequency harmonic and the research of the problem for cable termination during passing natural section of traction locomotive

针对牵引机车在过分相时产生高频谐波以及由此导致应力控制型电缆终端绝缘迅速裂化的问题。文中研究牵引机车在过分相时网压、网流及电压波形畸变率的变化,及由此高频谐波对电缆终端的影响。实验通过搭建高频高压老化实验装置,利用高频高压发生装置对电缆终端施加不同的频率和电压,使用红外热成像分析高频谐波对电缆终端热点的影响。此外,通过电场仿真发现,在高频电压作用下,电缆终端外半导电层截断处的场强要明显大于工频电压下的场强。结果表明:机车在过分相时网压、网流波动比较明显,并由此带来的谐波比较严重,高频谐波含量比较丰富,在高频电压的作用下,应力控制型电缆终端的热点温升要明显高于工频电压下的温度变化。

In allusion to the high frequency harmonic in the excessive phase of traction engine,which results in the quickly degradation of terminal insulation of stress control cables. This paper studied the change of the voltage,the current and the wave form deviation rate of voltage in the excessive phase and the effect of high frequency harmonic on the cable terminal.,which built the high frequency and high voltage aging experiment device,applied different frequency and values of voltage to the cable terminal,meanwhile,it analyzed the effects of high frequency on the hot spots of the cable terminal with the infrared thermal image instrument. In addition,by the electric field simulation,it found that,under the effect of high-frequency voltage the field strength of cable terminal outer semi-conductive layer truncation is significantly stronger than that under power frequency voltage. The results show that the fluctuation of voltage and current is more noticeable in the excessive phase of traction engine,which results in serious harmonic and the high frequency harmonic content is rich,and under the action of high frequency voltage,the temperature rise of hot pot in the terminal of stress control cables is significantly higher than that under power frequency voltage.