热过负荷保护在牵引变压器保护中的应用

提出了一种应用于牵引变压器的热过负荷保护，具有真实反映变压器热过负荷情况、计算变压器热积累、根据实际的热积累情况决定跳闸或告警时间等特点。此热过负荷保护通过对负荷电流的计算得到变压器的温升情况。理论分析及现场运行表明：该保护性能良好，作为变压器的过热保护，以达到延长绝缘寿命，提高变压器运行效益的目的。

Application of thermal overload Relay in Traction Transformer

This paper develops the technique of thermal overload relay used in electrification railway. The technique is provided with the characteristics that reflect the transformer thermal overload situation, calculate the transformer thermal accumulation, and according to the actual thermal accumulation condition to decide the breaker action or alarm time, The theory is to achieve the changing status of transformer temperature through calculating the load current. Both the academic analyzing and practical running in working site indicate that the performance of thermal overload relay is satisfying. As thermal overload relay for transformer, it can extend the insulation lifetime and improve the running efficiency of transformer.