Adaptive Control Of Permanent Magnet Synchronous Motor Based On Passive Theory

In industrial servo control system,permanent magnet synchronous motor(PMSM)has been widely used in various situations because of its high power density and ratio of torque to current.However,permanent magnet synchronous motor is not only nonlinear and coupling of each variable,but also suffer varying degrees of disturbance when it is used in actual occation,so the traditional PI controller is difficult to satisfy the high performance control of permanent magnet synchronous motor servo system,in other words we must adopt the corresponding control strategy to achieve high-precision control of permanent magnet synchronous motor.The passivity-based control is a essentially nonlinear control method based on system stability theory,its controller is easy to design and adjust,the control method has no singularity problem and has received widespread attention from many scholars and experts.In this paper,the passivity-based control method of PMSM speed regulation system is studied.Firstly,this paper introduces the physical model and mathematical model of permanent magnet synchronous motor.According to the mathematical model of permanent magnet synchronous motor and the basic theory of vector control system in rotating two-phase coordinate system,the system simulation model is built.Secondly,the traditional passive controller has the problem of steady state error when the load torque is unknown,the Port-Controlled Hamiltonian system with Dissipation(PCHD)model of the motor is constructed,the current controller of permanent magnet synchronous motor is designed by using the interconnection and damping assignment passivity-based control method.At the same time,aiming at the shortcomings of the traditional passivity-based controller that only considers the motor body,the two-inertia system is established,and a speed controller based on the system is designed by using passive theory.The simulation results show that the passivity-based control algorithm designed for the two-inertia motor can track the motor speed commands very well,which makes the dynamic response and steady-state performance of motor speed more superior.Then,aiming at the problem that the traditional passive controller has steady error under the condition of unknown load torque,an integral load torque observer and a proportion and integral load torque observer are proposed respectively.The simulation results show that the two observers can return to the speed setting value when the load changes suddenly,and both have strong robustness.Moreover,the proportional integral observer can detect the load torque more quickly and accurately,so that the motor can track the given value more quickly when the load changes suddenly.Finally,this paper applies the proposed control method to the experimental control platform of permanent magnet synchronous motor with TMS320F2812 DSP as the core,writes C language control program to verify the effectiveness of the proposed passive algorithm based on the load torque observer in the control of permanent magnet synchronous motor.The experimental results show that the proposed control method can make the system stable at the expected equilibrium point and can quickly track the given value when the load changes.