发电厂起备变冷备用技术及问题探讨-电气技术.PDF

发电厂起备变冷备用技术及问题探讨 兀鹏越 孙钢虎 邵云鹏 杨胜林 郭 琳 （西安热工研究院有限责任公司，西安 710061 ） 摘要 介绍了发电厂起备变冷备用运行方式下厂用电切换的过程及控制原理，对影响起备变 冷备用运行的变压器空投时差动保护误动作、母线失压时间增加导致快切失败、冷备用时设备带 故障投入、对电压跌落敏感的厂用负荷跳闸等问题进行分析，结合实例介绍了起备变冷备用技术 的应用情况，并对采用此运行方式导致的厂用电切换失败后果进行了分析，指出该技术的可行性。 关键词：起备变；冷备用；快切；励磁涌流 The Investigation of Standby Transformer as Cold Reserve in Power Plant Wu Pengyue Sun Ganghu Shao Yunpeng Yang Shenglin Guo Lin (Xi’an Thermal Power Research Institute, Xi’an 710032) Abstract For standby transformer working as cold reserve, this paper is not only focus on the operation process and basic principle of its service power switching, but also try to work out the problems which influenced its normal work. So it analyzed the reason of differential protection malfunction when transformer input with no-load and discussed the failure action of fast switching device under the long time voltage-losing in bus. Besides, the troubles like cold reserve put into system with fault and the switches tripping by some sensitive devices when the bus voltage dropped down had also been talked here. After the consideration of real situation in power plant and the judgments for problems above, this paper made an assessment of feasibility if the standby transformer could working as a cold reserve in power plant. Keywords ：standby transformer; cold reserve; fast switching device; inrush current 火力发电厂都设置有一台或多台起动/ 备用变 1 起备变的运行方式 压器（简称起备变），除了作为起停机过程中的厂用 电源外，还在机组并网发电后作为厂用电的热备用 1.1 运行方式简介 电源，以保证机组事故跳机时可以立即带厂用电负 图 1