Investigation of starting torque in entirely tubular submersible motor with rotor sector piece connected by weldments

Abstract

The starting performance of a large tubular submersible induction motor is affected by welding slots. To accurately calculate the starting performance of the double bar entirely tubular submersible induction motor (DBETSIM), an equivalent circuit diagram of DBETSIM is established, and the calculation formula of the starting torque of the motor under is derived. Then, the finite element analysis method and the equivalent circuit parameter method were used to calculate the starting parameters, respectively. Comparing DBETSIM with the normal tubular submersible motor, it is found that the second bar structure can improve the starting performance of the motor. Finally, the structure and material of the second bar are optimized and analyzed. It is concluded that the starting performance is improved most when the welding material is aluminum alloy with narrow and deep welding slots, which provides a reference for the design and optimization of DBETSIM. © 2019 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.