Dynamic Performance Analysis And Temperature Rise Calculation Of Permanent Magnet Servo Motor For Robot Based On Field-circuit Coupling

Ac servo motor is one of the key components of robot.The permanent magnet servo motor has the advantages of compact structure,small size,light weight and strong overload capacity,so it is widely used in the design and manufacture of medical robots,agricultural robots,industrial robots and other robots.Thanks to the rapid economic development of our country in recent years,although great achievements have been made in the design and manufacture of AC servo motors for robots in our country,the design and manufacture of AC servo motors for robots in our country started relatively late.compared with some foreign motor giants,there is still a big gap.In order to meet the requirements of "made in China 2025" for robot motor,this paper studies the permanent magnet servo motor for robot and applies the field-circuit coupling method to the design of robot servo motor.First of all,this paper describes the background of choosing this topic,as well as the purpose and significance of this topic,and summarizes the research status of permanent magnet servo motor for robot at home and abroad.The current research methods of motor loss and temperature rise and the application of field-circuit coupling method in motor design are summarized.The gap between domestic permanent magnet servo motor and foreign permanent magnet servo motor is summarized in three aspects: overload capacity,torque fluctuation and dynamic response,which leads to the main content of this paper.Secondly,the reasons that affect the overload capacity of the motor are analyzed from the torque equation of the motor,and it is concluded that the main parameters that affect the overload capacity of the motor are back EMF and AC-DC-axis reactance.The effects of different pole slot coordination,stator inner diameter and permanent magnet thickness on the overload capacity of the motor are analyzed by changing the stator and rotor structure parameters.Then,on the basis of ensuring that the motor has 5 times overload capacity,it is analyzed that unequal air gap,pole slot fit and stator slot size are used to reduce the cogging torque of the motor.the effects of different motor structure parameters on mechanical time constant and electromagnetic time constant are analyzed,and the cogging torque,electrical time constant and mechanical time constant are collected to determine the structure of the motor on the basis of ensuring that the motor has 5 times overload.The field-circuit coupling analysis model of permanent magnet motor is established,and the key parameters such as no-load back EMF,air gap flux density and output torque of the prototype are simulated and analyzed.Finally,the field-circuit coupling method is used to analyze the loss of permanent magnet servo motor under the same load,different speed and different load,and the three-dimensional model of the motor is established,and the finite element method is used to analyze the steady-state temperature rise and transient temperature rise under rated operating conditions.