Starting Prformance And Electromagnetic Noise Analysis Of Submersible Motor With Welded Rotor In Entirely Tubular Eletric Pump

Submersible motor plays an important role in water conservancy and other major livelihood projects.The submersible motor for the entirely tubular pump combines the motor and the pump structure by installing the pump impeller in the rotor cavity,which has a wide application prospect.Due to the constraints of rotor size and working environment,the rotor core of large-scale submersible motor in entirely tubular pump is made up of sector pieces and fixed by welding process.The resulting welded seam will affect the performance of the motor.In this paper,a method of solving the equivalent circuit parameters of the submersible motor with welded rotor used in entirely tubular pump is proposed.The equivalent circuit parameters are used to calculate the electromagnetic torque of the motor,and the optimization scheme is proposed from the perspective of weld structure and material to improve the starting performance.Then from the air gap magnetic field and operation conditions,the influence of welding seam on the electromagnetic noise of the motor is analyzed and the optimization measure is investigated.The research in this paper mainly includes the following aspects:1.The change of equivalent circuit parameters can reflect the influence of weld structure on the motor.In order to solve the problem that the traditional analytical model can't correctly analyze the equivalent circuit of submersible motor with welded rotor used in entirely tubular pump,the finite element method is used to calculate the equivalent circuit parameters.The advantages and disadvantages of the analytical method and the finite element method are compared.The two methods are used to calculate the equivalent circuit parameters.2.The finite element virtual displacement method is used to prove that the weld structure can improve the starting performance of the submersible motor with welded rotor used in entirely tubular pump.Using the analytical method and the finite element equivalent circuit parameter method to calculate the locked rotor torque of the prototype respectively,and comparing with the finite element virtual displacement method,the results show that the finite element equivalent circuit parameter method has a high accuracy in analyzing the torque of the submersible motor with welded rotor used in entirely tubular pump,and is suitable to be used as a tool for starting performance optimization analysis.On this basis,in order to improve the starting performance of the motor,the finite element equivalent circuit parameter method is used to optimize the geometry and material of the weld seam.3.In view of the influence of the weld structure on the electromagnetic noise of the submersible motor with welded rotor used in entirely tubular pump,the electromagnetic force wave structure of the submersible motor with welded rotor is analyzed from the theoretical derivation and the two-dimensional Fourier decomposition,and then the finite element simulation analysis proves that the weld structure increases the electromagnetic noise of the motor.On this basis,the magnitude of electromagnetic noise in different operating conditions is analyzed,and a rubber damping ring is installed at the connection between the two ends of the motor and the water suction chamber to suppress the noise.In this paper,the equivalent circuit parameters,starting performance and electromagnetic noise of the submersible motor with welded rotor used in entirely tubular pump are systematically investigated by combining theoretical analysis and finite element simulation,which provides a reference for the design and manufacture of high-performance submersible motor with welded rotor used in entirely tubular pump.