配电站经济运行方式下备用变压器自动投切原理及影响分析  

Automatic switchover theory of stand-by transformer and its influence on economic operation mode of distribution substation

作　　者：吴绪成[1] 盛戈皞[1] 王闻[1] 徐剑[2] 曾奕[1] 江秀臣[1] 

机构地区：[1]上海交通大学电气工程系.上海200240 [2]上海市电力公司沪西供电分公司,上海200051

出　　处：《电力自动化设备》2010年第4期66-70,75,共6页Electric Power Automation Equipment

摘　　要：对配电变压器低压侧互联以降低配电网损耗的经济运行方式进行了研究。分析了配电站采用经济运行方式时负荷切换的原理,提出了基于损耗最小原理的负荷切换点选取原则并给出了低压侧备用电源自动投切装置的工作原理和动作逻辑。重点对三相变压器的空载合闸及有载合闸暂态过程进行数学建模,并采用Matlab仿真计算与实际分析相结合的方法,分析了三相配电变压器在切换过程中产生的空载合闸励磁涌流以及有载合闸冲击电流。结合配电变压器电流速断保护和反时限过流保护的整定原则,分析了励磁涌流和冲击电流对变压器继电保护动作特性及参数整定的影响,验证了变压器低压侧互联的经济运行方式下的供电可靠性。The economic operation mode of distribution transformers interconnected at low voltage side to reduce distribution network loss is researched.The load switchover principle of distribution substation under economic operation mode is analyzed,the rules of load switchover point selection based on the minimal loss theory are proposed,and the working principle and action logic of the automatic switchover equipment at low-voltage side is presented.The transient process of three-phase transformer switching-on with and without load is mathematically modeled.With Matlab simulative calculation and practical analysis,the inrush excitation current of the switching-on without load and the impact current of switching-on with load are analyzed.Combined with the setting principles of instantaneous overcurrent protection and inverse time overcurrent protection,the influence of inrush current and impact current on the operating characteristics and parameter setting of transformer protections are studied.The reliability of power supply under economic operation mode of distribution transformers interconnected at low voltage side is verified.

关 键 词：配电变压器 经济运行 冲击电流 仿真分析 继电保护 

分 类 号：TM421[电气工程—电器] TM76