| Permanent magnet synchronous motors have the benefits of advanced control efficiency,light weight,small space occupation,low failure probability,and low control cost.It is widely used in the fields of CNC machine tools,aerospace and industrial production design.Traditional mechanical sensors not only increase the bulk of the control system and increase the entire manufacturing cost,but also require regular maintenance,increasing manpower and material resources.In order to solve the above problems,this paper focuses on the permanent magnet synchronous motor position-sensorless control strategy.In this dissertation,the mathematical model of permanent magnet synchronous motor is established,and the vector control strategy of permanent magnet synchronous motor is modeled.The voltage space pulse width modulation technology of permanent magnet synchronous motor is selected as the basis of the control strategy.Aiming at a series of shortcomings of sensors in the permanent magnet synchronous motor control system,an extended Kalman filter control strategy is designed at medium and high speeds,and the mathematical model of the permanent magnet synchronous motor is discretized.The simulation verifies the rotor position of this algorithm at medium and high speeds.Both speed and speed have good tracking performance,but this algorithm has poor tracking effect at zero speed and low speed.Aiming at the problem of the poor tracking effect of the extended Kalman filter at zero speed and low speed,the high-frequency signal injection method is designed,and the mathematical model of the permanent magnet synchronous motor under the high-frequency signal injection method is constructed,and the simulation is set up to verify that the algorithm works at zero speed and It has good tracking performance at low speeds.To sum up,the two control strategies of extended Kalman filter and high-frequency signal injection have their own speed ranges,and they complement each other in speed,but neither of the two control strategies can achieve a smooth transition between speeds alone.Aiming at this problem,a weighted average algorithm under the compound controller is designed.In order to verify the feasibility of the motor compound control strategy,an experiment platform was built with TMS320F28335 as the main control chip,and the hardware circuit and software system control flowchart were designed.The simulation and experimental results show that the control method can achieve good performance at low speed,medium and high speed.The control effect and high precision further verify the validity of the theoretical analysis. |
