变压器油流继电器动板频繁摆动故障机理分析

摘要

油流继电器动板频繁摆动是电力变压器最常见的故障之一，该故障会导致动板轴承磨损、碎屑浸入油中威胁主绝缘等一系列故障隐患。本文通过建立基于流体力学的仿真模型，分析了变压器油流继电器动板频繁周期性摆动的故障机理及其影响因素，分析结果与现场测试数据吻合。实验结果表明，油流继电器动板的状态主要由油流的状态决定。当油流处在层流状态时，其施加给动板的压力为恒定力，动板在弹簧回复力和流体恒定力作用下保持稳定；当油流处在湍流状态，其施加给动板的压力为非恒定力，在出现卡门涡街时表现为周期性变化压力，继电器动板在流体周期性变化压力的作用下出现周期性摆动现象，其摆动的频率与油流的流量以及联结管结构有关。%Frequently oscillation on movable plate of oil-flow relay is one of the most common failure occurred in power transformer .It will cause bearing wearing , metal powder and other hidden troubles which are harmful to insulation . The article analyses the fault reason and influencing factors of frequent , periodic oscillation by building simulation model based on fluid mechanics , occurred in movable plate of oil-flow relay on power transformer .The analysis results are identical with the data obtained from onsite test .The results show that state of oil-flow relay’ s movable plate is mainly determined by oil-flow state.When the oil-flow is laminar, the pressure on movable plate is stable , the movable plate keep stable under the restoring force of torsional spring and stable applied force of oil flow .When the oil-flow is turbulent, the pressure on movable plate is unsteady , which is a periodically pressure as the Karman vortex street appears .Movable plate of oil-flow relay has a periodic oscillation under the pressure varied periodically of fluid .The frequency relates to the flow rate and the structure of connecting pipe .