Electromagnetic Performance Analysis And Control Strategy Research Of Pumping Unit Motor

With the continuous development of the oil industry,the pumping unit is widely used as the common pumping equipment in the oil field.In the process of oil exploitation,the motor plays a very important role,and it is the most important part of the pumping unit.Three-phase AC asynchronous motor has the characteristics of simple structure,reliable operation and easy maintenance,and is suitable for use as the driving motor of the pumping unit.With the advent of the intelligent era,the requirements for the control of the pumping unit motor are also raise.Therefore,According to the electromagnetic performance requirements of the pumping unit motor,a three-phase AC asynchronous motor with a power of 45 KW is designed and its control strategy is studied in this thesis.First,the electromagnetic design of three-phase AC asynchronous motor for oil pumping units is carried out to determine the length and material of each part(stator outer diameter,stator inner diameter,rotor outer diameter,rotor inner diameter,etc.).The motor designed in this article increases the number of stator slots to improve the heat dissipation ability of the motor and thus improve the electromagnetic performance of the motor while ensuring the utilization rate of the number of stator slots.Using SOLIDWORKS to conduct a three-dimensional modeling of the motor body,import the motor model into MAXWELL 3D,conduct an overall analysis of the magnetic field line distribution,magnetic density distribution,and current density distribution of the motor under stable operating conditions,and conduct a detailed analysis of the magnetic density of the main components of the motor(stator and rotor magnetic density,air gap magnetic density),as well as other important factors affecting electromagnetic performance,to summarize the electromagnetic field distribution rules,Verify that the electromagnetic performance of the designed motor meets the requirements of being a pumping unit motor.Then,According to the characteristics of the pumping unit motor,the rotor magnetic field oriented vector control and SVPWM technology are introduced to regulate the speed of the motor.According to the characteristics of the controlled object and different control requirements,the MATLAB/SIMULINK software is used to complete the construction of a PID control model for the current loop and speed loop double closed loop motor speed control.In order to solve the current problem of slow down speed and poor stability of the pumping unit motor in PID control,an intelligent control algorithm,adaptive fuzzy PID control,was introduced.An attempt was made to introduce fuzzy PID control into the rotational speed loop of the pumping unit motor dual closed-loop speed regulation system.Through analysis and design of a fuzzy PID controller,a dual closed-loop motor speed regulation model based on fuzzy PID control was established.The simulation and comparison of two different algorithms for speed regulation systems are conducted,and the speed,torque,and three-phase current curves under different operating conditions such as no-load,variable speed,and load are analyzed to verify the advantages of the fuzzy PID intelligent algorithm.Finally,the high-performance digital signal processor TMS320F28335 is selected as the core controller to complete the design of the hardware part of the control system.According to the speed regulation strategy based on fuzzy PID vector control,the software part of the control system is designed and verified by experiments.