局部热源对电力变压器内部温度分布的影响分析

Influence analysis of local heat source on internal temperature distribution of power transformer

油浸式电力变压器是电力系统的主要电气设备,其运行可靠性对电力系统的安全运行有重要的影响,在生产、安装及运行等过程中可能会破坏其绝缘结构,导致变压器内部产生局部放电现象甚至击穿。本文以S9-M-100/10型号的油浸式配电变压器为研究对象,仿真分析变压器正常运行、匝间短路及层间短路三种状态下变压器内部电磁场及温度场的分布规律。仿真结果表明,正常状态下变压器铁芯、高低压绕组之间的油隙撑条帘处及高压绕组中间位置的温度较高;存在匝间及层间短路故障时,变压器故障部位的电磁损耗加剧,温度骤升;两种故障对变压器内部温度场的影响不同,且匝间短路故障对其附近温度的影响较明显。分析结果可为解释变压器热性故障及故障分类提供参考。

Oil immersed power transformer is the main electrical equipment in power system.Its operation reliability has an important impact on the safe operation of power system.In the process of production,installation and operation,its insulation structure may be damaged,resulting in partial discharge and even breakdown inside the transformer.In this paper,S9-M-100/10 oil immersed distribution transformer is taken as the research object,and the distribution laws of electromagnetic field and temperature field in transformer under normal operation,inter turn short circuit and inter layer short circuit are simulated and analyzed.The simulation results show that under normal conditions,the temperatures at the oil gap between the transformer core and the high and low voltage windings and the middle position of the high-voltage winding are high.When there are inter turn and inter layer short circuit faults,the electromagnetic loss of the fault part of the transformer increases,and the temperature rises suddenly.The influence of the two faults on the internal temperature field of the transformer is different,and the influence of the inter turn short circuit fault on the temperature nearby is obvious.The analysis results can provide reference for the thermal fault interpretation and fault classification of transformer.