变压器油流带电数学模型的研究及其应用第一部分:数学模型的推导

Study on the Mathematical Model for the Static Electrification in Transformers and Its Application Part 1:Development of the Mathematical Model

由油流带电引发的变压器事故或故障引起了各国电力部门的广泛关注，许多国家纷纷开展变压器油流带电的研究，大量的油流带电的机理模型也就应运而生。本文在国外学者提出的流动作用机理和电动作用机理两种机理模型的基础上，推导出变压器油流带电的数学模型，与目前存在的几种典型的油流带电计算模型相比，本模型的特点在于它可综合反映起电的流动作用和电动作用，并可基本反映油流流速、油品电导率、外加交流电场强度和系统温度等因素对油流带电的影响。关于本模型的应用实例及与实验的比较见第二部分。

Electrical breakdown due to static electrification in forced oil cooled EHV power transformer has caused great concern and been widely investigated by the manufacturers and researchers all over the world.Many mathematical models have been suggested to explain the electrification phenomenon.In this paper a combined model based on both flow induced charge effect and AC field induced charge effect is proposed.Compared with existing models,this model has the advantages of taking the above two effects into consideration.By this model,the influences of oil velocity,oil conductivity,the stress of applied AC filed and system temperature on streaming electrification can be easily investigated.An application of the model and comparison with experiments will be described in a companion paper.