中文摘要：

油流带电对电力变压器造成危害,引起系统故障甚至事故,为此实验测量了油道内的冲流电流,并仿真计算了油道中的电场强度分布。以变压器中典型的并联油道结构为研究对象,分别对油流温度、流速以及外加电场因素影响下的油道内的冲流电流进行了测量,得到了冲流电流的分布规律。试验结果表明冲流电流在外电场作用下呈现随电场强度增大指数增大的现象。基于上述试验研究,对相应的仿真模型施加交流电场与表面静电荷两种载荷,进行了有限元仿真计算,得到了油道内部的场强分布。计算结果表明,在表面静电荷与外电场等2种载荷共同作用下,油道内与电极接触绝缘纸板油纸界面处油侧的电场强度由无表面静电荷作用下的4.9kV/mm上升至10kV/mm,油道内局部电场出现严重畸变并呈现增大的趋势。因此,应当采取有效的措施预防或减少油流带电造成的危害。

英文摘要：

Oil streaming electrification could harm power transformer, it even cause fault and accidents. Thus we measured the streaming current in oil duct experimentally, as well as calculated the electric field distribution in oil duct by simulations. Taking a typical parallel oil duct in transformer as the study object, we measured the streaming current in the duct under different external electric field, temperatures and oil velocities, and consequently obtained the distribution discipline of the streaming current. Experimental results showed that the streaming current exponentially increased with the increasing external electrical field. Based on the results, the geometric model was created, that was exerted the complex electrical field including AC electrical field and surface charge on it. Hence the distribution of electrical field of the oil duct was acquired through simulations on the model. The results showed that under the complex electrical field, the electrical field increased from 4.9 kV/mm, to 10 kV/mm, which was the value affected by no surface charge, and it distorted at some parts of the oil duct with an tendency of increasing. It is concluded that effective measures should be taken to restrain the possible harms caused by the streaming electrification in power transformer.