Research On Brushless DC Motor Control System Based On HALL Position Sensor

In a brushless DC motor control system,in order to accurately obtain the closed-loop speed and the modulation of the space vector pulse,the rotor speed and angle information is required,and a high-precision position sensor is required to ensure a better control effect of the motor.It also leads to problems such as decreased system reliability and increased control costs.Therefore,the research and development cost is low,the reliability is good,the maintenance is simple,the easy to maintain the brushless DC motor rotor position information estimation algorithm,has gradually become the main direction in the motor control field.In the brushless DC motor control system,the use of low-resolution position sensors such as switching HALL position sensors can replace position sensors such as higher cost and accurate conversion transformers and mechanical encoders.Although low-cost high-resolution position sensors are not affected by external environmental factors,they are very convenient to install and maintain.However,it is difficult to accurately estimate the rotor position of the brushless DC motor based on the output signals of these lower resolution sensors in the system.Therefore,these signals must be processed to obtain accurate rotor position signals of the brushless DC motor.Used for high performance control.This thesis proposes a new rotor position measurement algorithm based on a switching HALL position sensor.When the motor is running at low speed,an improved first-order acceleration algorithm is adopted,and the rotation speed and quadrature axis current are introduced to estimate the position of the rotor;when the driving motor is running at high speed,the rotation speed output stable value function of the position speed sensor is used to compare The first-order sliding mode motion observer control algorithm meets the estimated value of the speed to carry out the quadratic linear numerical correction,combined with the first-order motion acceleration control algorithm to carry out the second weighted average calculation of the speed,and obtains the speed and motor rotation that meet the estimated value Accurate result of movement position.At the same time,in order to improve the operating reliability of the brushless DC motor system,this paper estimates the rotor observation algorithm based on the HALL position sensor,and proposes a new brushless DC motor fault diagnosis and error control to solve the fault of the HALL position sensor.This leads to inaccurate estimation of the rotor position and abnormal driving.When the motor is working,the output status of the three-phase HALL sensor is detected online,and it is judged whether there is a sensor failure during the sensor working process,and it is defined as a non-HALL,single,double,and three-phase sensor failure.On the basis of the traditional first-order acceleration algorithm to estimate the rotor position,a sliding mode observer which completes the rotor position extraction through a phase-locked loop is established.For different motor states,coordinate the output of the weights and sliding mode estimates of the level 1 acceleration algorithm.Finally,through experimental verification,the control effect of the new fault judgment and fault-tolerant control in the single-phase HALL position sensor fault type is better than the traditional fault-tolerant control algorithm,which improves the reliability and stability of the system.The thesis includes 52 figures,6 tables and 71 references.