The train-mounted ethylene propylene rubber (EPR) cables of electric locomotive are partly restricted by the body structure and spatial layout and are in a combined environment of strong mechanical bending and thermal ageing. The degradation characteristics of the insulation layer have not yet received sufficient attention. In order to study the ageing characteristics of EPR cables of electric locomotive under the combined action of machine and thermal, this paper designs a bending–thermal combined ageing test platform for cables with a temperature of 135°C, bending diameter of 393.52 mm, 590.28 mm and unbending cables, and tests after ageing. The product has been tested by infrared spectroscopy, scanning electron microscopy, elongation at break and broadband dielectric spectroscopy. The research results show that the bending outer part of the train-mounted EPR cable is a pain point. Under the combined action of bending and thermal, whether it is microstructure or macro performance, the degradation rate and degree of the bending of outer insulation layer are greater than the value under a single thermal ageing condition. Mechanical bending has an accelerating effect on the ageing of the EPR insulation layer. The research results can provide a reference for the ageing characteristics of the train-mounted EPR cable under the bending–thermal synergy and the evaluation of operating state of the train-mounted EPR cable under bending–thermal operating conditions.

中文翻译：

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机车乙丙橡胶电缆在机热联合作用下老化特性试验研究

电力机车车用乙丙橡胶（EPR）电缆部分受限于车身结构和空间布局，处于强烈机械弯曲和热老化的组合环境中。绝缘层的退化特性尚未得到足够的重视。为研究机车EPR电缆在机热联合作用下的老化特性，设计了电缆弯曲-热联合老化试验平台，温度为135℃，弯曲直径为393.52 mm，590.28毫米和不弯曲的电缆，并在老化后进行测试。该产品已通过红外光谱、扫描电子显微镜、断裂伸长率和宽带介电光谱测试。研究结果表明，车载EPR电缆的弯曲外部是一个痛点。在弯曲和热的共同作用下，无论是微观结构还是宏观性能，外绝缘层弯曲的退化率和程度都大于单一热老化条件下的值。机械弯曲对EPR绝缘层的老化有加速作用。研究结果可为车用EPR电缆在弯曲-热协同作用下的老化特性以及车用EPR电缆在弯曲-热工况下的运行状态评价提供参考。外绝缘层的退化率和弯曲程度大于单一热老化条件下的值。机械弯曲对EPR绝缘层的老化有加速作用。研究结果可为车用EPR电缆在弯曲-热协同作用下的老化特性以及车用EPR电缆在弯曲-热工况下的运行状态评价提供参考。外绝缘层的退化率和弯曲程度大于单一热老化条件下的值。机械弯曲对EPR绝缘层的老化有加速作用。研究结果可为车用EPR电缆在弯曲-热协同作用下的老化特性以及车用EPR电缆在弯曲-热工况下的运行状态评价提供参考。