中文摘要：

换流变压器油纸绝缘的沿面放电特性受电场、温度场等多场耦合作用的严重影响,而目前相关研究又极其缺乏。为此使用典型柱–板电极模型,对70、90、100℃下油纸绝缘沿面放电发展过程中放电信号的特征谱图进行了统计分析,探索了温度对交直流复合电场下油纸绝缘沿面放电特性的影响机制。研究结果表明：随着温度的不断升高,油纸绝缘在相同交、直流复合电压作用下相邻2次放电之间的时间间隔快速缩短,放电量快速升高,沿面放电发展速度加快,沿面放电发展4个阶段中小幅值放电量的放电次数逐渐减少,大幅值放电量的放电次数逐渐增多。分析表明随着温度的升高,加速了放电前电荷的积聚和放电后残余电荷的泄放速度,小幅值放电量的“驼峰”区域向放电量增大的方向缓慢移动,大幅值放电量密集出现加剧了对绝缘纸板的表面的烧蚀破坏,加速了油纸绝缘沿面放电发展的速度。

英文摘要：

The characteristics of creepage discharge in paper-oil insulation （POI） was seriously influenced by the coupling effect of temperature and electrical field in converter transformer. However, few studies have focussed on effect of creep- age discharge on temperature in POI under combined AC-DC voltage conditions. Thus, we investigated the characteristic spectra of creepage discharge in POI under combined AC-DC voltage conditions, and explored the mechanism of temperature on characteristics of creepage discharge under different temperaturs of 70 ℃, 90 ℃, and 100℃ using a cylinder-plane electrode configuration. The experimental results show that the interval time between two discharges decreases under same AC-DC voltage stress, whereas the magnitude of discharges increases with a higher temperature. The developing velocity of creepage discharge is accelerated. Meanwhile, the times of high magnitude discharge （HMD） gradually increases at each stage of creepage discharge with a higher temperature during 4 stages. But the times of low magnitude discharge （LMD） decreases and magnitude of LMD increases. The results indicate that the charge carriers can easily accumulate before discharging and quickly migrate directional movement along the electric field after discharging with higher temperature. The residual charge carriers are dissipated easily after discharging. The ＇hump＇ region of LMD moves to the direction of higher discharge magnitude. The HMD intensively appears, resulting in accelerating the devel- opment of creepage discharge in POL