Research on Influence of Eccentricity on Submersible Motor and its Solution

The working efficiency and stability of submersible motor are very important for energy utilization, and dynamic eccentricity is the main factor affecting its efficiency and fatigue life. This paper takes a 2-pole 60kW vertical three-phase cage induction motor with static eccentricity as the research object. Through finite element analysis, the mechanical structure and coordination of submersible motor shaft and spiral pump are analyzed. The influence caused by motor shaft eccentricity is regarded as external interference received by the system. The idea of auto disturbance rejection controller to eliminate this disturbance, thereby restraining the negative effects caused by motor shaft eccentricity. By using the state expansion observer of the active disturbance rejection model to estimate and compensate the internal disturbance and uncertainty of the system in real time, the rotation error of the shaft of the submersible motor is eliminated, and the motion inconsistency between the rotor of the screw pump and the shaft of the submersible motor caused by shaft eccentricity is suppressed.