导电悬浮体对管母-管母相间作业间隙操作冲击放电特性的影响

Influence of Floating Conducting Objects on Switching Impulse Discharge Characteristics of Phase-to-phase Gap Between Tabular Buses

为分析变电站带电作业相间作业间隙放电特性,针对变电站带电作业实际工况,进行了变电站管母相间组合间隙(PPCG)放电试验研究,得到了相间组合间隙的操作冲击放电特性曲线。并在Rizk经验公式基础上,引入气体放电流体动力学模型,考虑流注-先导放电系统空间电荷对悬浮体电势影响,建立了带悬浮体相间组合间隙放电的物理计算模型,计算了相间组合间隙的50%放电电压,分析了相间组合间隙的放电特性。研究表明,相间组合间隙的50%放电电压的理论计算结果与试验数据的误差￡4%;变电站带电作业相间组合间隙中悬浮体距正极性管母约1.55 m(即距离负极性管母0.2 m)处为最低放电位置。因此,所提出的物理模型可用于研究变电站带电作业相间组合间隙放电特性。

In order to understand the discharge characteristics of phase-to-phase working-gap in hot-line-working transformer substations, according to the practical working condition, we carried out discharge tests of phase-to-phase complex gap（PPCG） of tubular bus in transformer substation and obtained the characteristic curves of PPCG discharge driven by switching impulses. In consideration of the influence of space charge generated by streamer-leader discharge on potential of floating conducting objects, we built a computational physical model of PPCG discharge with floating conducting objects based on the Rizk＇s empirical formula and gas discharge fluid dynamics. The model was then used to calculate the 50% discharge voltage of PPCG and analyze the discharge characteristics of PPCG It is shown that the differences between the calculation results and test data of 50% discharge voltage of PPCG are not more than 4%,and the lowest discharge position of floating conducting object is 1.55 m from the positive polarity tubular bus in PPCG（i.e. 0.2 m from the negative polarity tubular bus）. It is concluded that the proposed physical model can be applied to researches of PPCG discharge in hot-line-working transformer substations.