岩滩水电厂3 6万kVA主变压器水冷却方式的控制特点

Controlling Characters of the Water Cooling of 360 Thousand kVA Main Transformer of Yantan Hydropower Plant

岩滩水电厂机组单机容量为30.25万kW·h,主变压器为三相三柱式,容量为36万kVA。因受到当时制造工艺、技术要求以及运输路线的限制,致使大容量的主变压器做成体积小巧的三相三柱式,在运行过程中主变压器油温长期处于高温状态下,特别是夏季大负荷时主变压器油温达到65℃以上,对主变压器的安全运行形成潜在安全隐患。岩滩水电厂的主变压器采用水冷却方式后,主变压器油温降低了近20℃,在夏季最大负荷情况下温度基本保持在47℃左右,达到了改造前的预期目的。

The single-machine capacity of Yantan Hydropower Plant is 302.5 thousand kW·h,and its main transformer is three- phase three- limb.And its capacity is 360 thousand kVA.The restrains of manufacturing techniques,technical requirements and transformation lines lead that main transformer with large capacity was made into small volume three-phase three- limb.This causes some potential safety hazards,as the main transformer operates in high temperature,especially its oil temperature reaching 65℃above under the large load in summer.After the plant adopted the water cooling method for main transformer,its oil temperature lowered down nearly 20℃,and it can keep the oil temperature about 47℃under the largest load in summer,which has achieved the expected goals.