Research On Control System Of Permanent Magnet Synchronous Motor Based On Low Resolution Position Sensor

In the Permanent Magnet Synchronous Machine control system,in order to accurately obtain the rotor speed and position information required by the closed-loop speed and space vector pulse modulation,it is necessary to introduce a high-precision position sensor to ensure a better control effect of the motor,but At the same time,it also causes problems such as reduced system reliability and increased control costs.Therefore,the development of a low-cost,high-reliability,and simple-maintenance permanent magnet synchronous motor rotor position information estimation algorithm has gradually become one of the main directions in the field of motor control.The use of low-resolution position sensors such as switch-type Hall position sensors in permanent magnet synchronous motor control systems can replace high-cost,more accurate resolvers,mechanical encoders and other position sensors.Although the low-cost low-resolution position sensor is less affected by external environmental factors,it is easy to install and maintain.However,it is difficult to complete the high-precision rotor position estimation of the permanent magnet synchronous motor in the system only relying on the signals output by these low-resolution position sensors,so these signals must be processed to obtain the precise permanent magnet synchronization used in high-performance control Motor rotor position information.This paper proposes a new rotor position observation algorithm based on the switch-type Hall position sensor.When the motor is running at low speed,the improved first-order acceleration algorithm is used to introduce the speed and cross-axis current to estimate the rotor position;when the motor is running at high speed,the output value of the Hall position sensor is used to piecewise linearly estimate the value estimated by the sliding mode observer algorithm Correction,combined with an improved first-order acceleration algorithm for weighted average processing,to obtain the estimated speed and rotor position.At the same time,in order to increase the reliability of the operation of the permanent magnet synchronous motor system,based on the switch-type Hall position sensor to estimate the rotor position observation algorithm,this paper proposes a new permanent magnet synchronous motor with multiple fault diagnosis and fault tolerance control.In order to solve the problem of Hall position sensor failure,resulting in inaccurate rotor position estimation and unable to drive normally.During the operation of the motor,the output statusof the three-phase Hall sensor is detected online to determine whether there is a sensor failure during the sensor operation,and it is defined as no Hall failure,single,double,three-phase failure.Based on the traditional first-order acceleration algorithm to estimate the rotor position,a sliding mode observer is established,and the rotor position is extracted through a phase-locked loop.According to the different states of the motor operation,the weights and sliding mode observations of the first-order acceleration algorithm are output in coordination.Finally,the experiment proves that the new fault judgment and fault-tolerant control is better than other traditional fault-tolerant control algorithms under the single-phase Hall position sensor fault type,which improves the reliability and stability of the system.