Rearch On The Speed Control Of PMSM With A Wide Speed Regulation

Industrial robots are widely used in the fields of industry as an electromechanical device with high integration degree.As one of the most important components of the industrial robots,multiple motor servo systems are integrated into a single industrial robot to achieve the needs of each joint movement.Therefore,the motor servo systems have a large market value with the development of industrial robots.The industrial robot requires servo drive motors having good dynamic performance,strong anti-disturbance ability and wide speed range regulation.However,in the course of the operation the motor servo systems affect by the disturbance torque caused by the air gap between the motor gear change,the friction disturbance and so on.It causes great damage to the control performance while the motor is running at low speed,and the motor speed may fluctuate greatly.In addition,the back electromotive force of permanent magnet synchronous motor winding lifts with the increase of the motor speed,and the motor speed cannot rise as the motor back electromotive force increases to the maximum voltage that the DC inverter can provide.At this point if not using a special control method,the motor servo systems will not be able to meet the wide speed range requirements.In this paper,the vector control of permanent magnet synchronous motor is analyzed,and a motor control system is modeled with the build of the voltage equations and the torque equations.The SVPWM modulation algorithm is deduced in particular.To solve the problem that the sum of the two adjacent fundamental voltage vectors turns on the PWM control period time,we insert an empty vector in the form of the system to re-follow the seven-stage modulation to avoid the situation of multiple switch action and reduce the inverter overcurrent.Secondly,by analyzing the disturbance torque of the motor in the low speed region,the disturbance torque of the motor is observed by designing the minimum dimension perturbation observer algorithm,and the feedforward compensation of the control system is carried out by using the observation torque to improve the steady-state performance and anti-disturbance capability in the low-speed operation of motor.And we set the compensation coefficient to control the disturbance observer compensation amount,which reduces the overshoot in the disturbance observer adjustment process.Then,the principle of field weakening control of permanent magnet synchronous motor is analyzed.The current trajectory in the process of field weakening is analyzed from the perspective of steady-state.And the advanced angle weak magnetic control method is designed on the theoretical analysis.Then,an improved single current control of flux-weakening control algorithm is proposed for the surface permanent magnet synchronous motor(PMSM),which is used to solve the problem of the control lag and current oscillation in the advanced angle weak magnetic control.Finally,this paper designed the motor drive hardware circuit,so that the drive circuit is more suitable for high-speed control occasion.Designed the drive control software architecture,and a faulty program is designed for faults in the process of motor control to avoid damage caused by improper control.Finally,the SCARA robot servo drive platform is designed,and the actual performance of the algorithm and hardware circuit is verified by the actual test of SCARA robot.