一种电机保护器缺相误动原因分析及对策

An Open-phase Protection Misoperation Analysis and Solution for the Oil-pump Machine Motor Protector

抽油机负载的特殊性导致油田电网功率因数普遍偏低,一般采用固定无功补偿或者无功动态补偿方法提高功率因数。但抽油机装配无功补偿装置后,若补偿装置接入位置不当,电机保护器将会因缺相保护而误动作,造成抽油机频繁停止运行。本文结合电机保护器工作原理,给出了补偿接入位置不当而导致误动作原因,并给出了正确的补偿接入位置。实践证明,该方法有效解决了该类缺相误动作的问题。

Because of particularity of the load, the power factor is generally low in oil-field .And some oil-fields usually assemble fixed reactive power compensation or dynamic reactive power compensation to raise the power factor. But after Pumping Units assembled Reactive Power Compensation Devices, if the position of these devices is not suitable, these protectors will cause Open-phase Protection misoperation and cause the oil-pump machines to stop working frequently. In this paper, one reason proposed for misoperation is the wrong access position of the Reactive Power Compensation Device by studying the working principle of motor protector and present the correct position of these devices. Practice shows thatthis method can resolve Open-phase Protection misoperation of this type effectively.