Design Of The PMSM Control System For Drum Washing Machines

Permanent magnet synchronous motor has advantages of simple structure,low heat,high power density and torque inertia ratio.Meanwhile,the development of power electronics technology and modern control theory has greatly expanded the application of PMSM,making it the mainstream driving motor of the drum washing machine.Based on the mathematical model of PMSM,as well as the design and application of control algorithms,combined with the working condition analysis of the drum washing machine,this paper has designed a control system for PMSM with certain superiorities such as wide speed range,strong robustness,quick response,low overshoot and effective anti-vibration.Firstly,the mathematical model of PMSM has been established and the space vector control has been introduced in this paper.Thereafter,to meet the requirement of wide speed range,the i_d=0 control strategy has been applied in the constant torque area,as the single current regulation strategy has been implemented in the constant power area.Based on the wide range speed regulation scheme described above which has a variable structure,the characteristic current and voltage of the flux weakening entry and exit point have been analyzed in detail,and the switching gist has been given at the same time.Secondly,the cause of vibration during the washing operation has been explained and the current vibration reduction methods have been introduced.When the machine is running at high speed for dehydration,the vibration resulted in the unbalanced load,which caused by the unevenly distributed clothes in the washing drum,is the most violent and detrimental.Therefore,the following research would focus on this problem.The influence of unbalanced load on the motor control system has been analyzed,a transmission model from the washing drum to the motor rotor has been established,the detailed analysis of the dynamics has been given,according to which the PMSM anti-vibration algorithm has been designed and series of the simulation experiments have been carried out to prove the feasibility and effectiveness of the proposed scheme.Thirdly,there exists parameter perturbation,load disturbance,unmodeled dynamics and unknown uncertainties in the process of washing.To adapt to the complex working condition mentioned above,the current controller of the PMSM drive system is required to have high anti-interference and self-adapting capability.This paper has proposed a robust current controller based on the model-free adaptive control strategy.The full format dynamic linearization current model of PMSM has been established.The parameter matrix update algorithm and the output voltage update algorithm have been designed according to the two essential control goal:system convergence and fluctuation reduction.Meanwhile,an algorithm reset mechanism has been proposed to guarantee the quick convergence of the current controller.The simulation results demonstrate that the model-free adaptive current controller can overcome parameter perturbation and load disturbance,steadily operates in various of the complex working conditions and achieve quick response and small overshoot.Finally,an experiment platform for the drum washing machine based on the SC32F5832chip has been built,and the hardware design of the PMSM drive circuit has been completed.The motor control utility software has been programmed and optimized on this basis.Experiments of the drum washing machine in a variety of working conditions,including lavation and dehydration,have been carried out.The experiment results illustrate that proposed PMSM control system can satisfy presupposed performance index and achieve favor steady and dynamic performance.