关于A电厂大功率低压电机RCD装置换型改造的经验总结  

Summary of Experience on the Transformation of RCD Device for High Power and Low Voltage Motors in A Power Plant

作　　者：李冲 陈良甲 LI Chong;CHEN Liangjia

机构地区：[1]台山核电合营有限公司,广东江门529000

出　　处：《今日自动化》2023年第12期47-49,共3页Automation Today

摘　　要：大功率低压电动机(200kW及以上电机)一般用在发电厂的给水、疏水相关回路中,这些低压电动机起动电流高达上千安培。在供配电环节,配套的开关容量通常很大,此外,在电机保护配置上,除了常见的过流速断、过载长延时之外,为保护电缆在发生单相接地故障时能承受热稳定冲击,还会单独配备零序保护甚至是RCD(剩余电流保护装置)。由于RCD可调定值小,配套的CT二次侧输出是mV/mA级信号,易受现场其他设备产生的电磁干扰,因此对安装要求极高。文章主要对A发电厂400kW以上大型电动机配备的RCD装置换型改造过程中遇到的问题进行分析和处理,归纳和总结改造相关经验,以期为业内人员提供参考。High power low-voltage motors(200 kW and above motors)are generally used in the water supply and drainage related circuits of power plants,and the starting current of these low-voltage motors can reach thousands of amperes.In the power supply and distribution process,the supporting switch capacity is usually large.In addition to the common overcurrent and overload long delay,in the motor protection configuration,in order to protect the cable from thermal stability shock in the event of a single-phase ground fault,zero sequence protection or even RCD(residual current protection device)will be separately equipped.Due to the small adjustable value of RCD and the fact that the secondary output of the matched CT is a millivolt/milliampere level signal,it is susceptible to electromagnetic interference generated by other equipment on site,thus requiring extremely high installation requirements.The article mainly analyzes and deals with the problems encountered during the transformation process of the RCD device equipped with large motors above 400 kW in Power Plant A,summarizes and summarizes the relevant experience of the transformation,in order to provide reference for industry personnel.

关 键 词：大功率 低压电动机 RCD装置 

分 类 号：TM7[电气工程—电力系统及自动化]