Performance Analysis And Sensorless Control Of Dual Three-Phase Permanent Magnet Synchronous Motor

In recent years,multi-phase permanent magnet synchronous motors have received extensive attention due to their excellent characteristics.With the continuous renewal of new power electronic devices and the rapid de velopment of microcomputer technology,the modern motor speed control systems are also close to the direction of large capacity,high efficiency and high precision,which also requires higher requirements for the research of multi-phase motor speed control technology.In this paper,dual three-phase permanent magnet synchronous motors are selected as the research object.The comparison and analysis of body performance and optimization of control strategies are carried out on two different winding forms of windings with phase shifts of 30° and 180 °.The sensorless control strategy of the dual three-phase winding phase shift 180 ° permanent magnet synchronous motor under medium and high speed was studied.Firstly,the mathematical model of the dual three-phase winding phase shift 30° and 180° permanent magnet synchronous motors in different coordinate systems is derived in this paper,and the transformation process of the motor model from the natural coordinate system to the static coordinate system is given in detail.The basic principle of SVPWM technology based on vector space decoupling method is introduced,and the advantages and disadvantages of two-vector SVPWM algorithm and four-vector SVPWM algorithm are compared and analyzed.Secondly,taking the surface-mounted dual three-phase permanent magnet synchronous motor as an example,the structural characteristics of the dual three-phase winding phase shift 30° and 180 ° permanent magnet synchronous motor are analyzed.The electromagnetic performance of the mo tor with the winding phase-shifting 30° and 180° are simulated and analyzed under static and transient conditions by Ansoft simulation software.The parameters of no-load back-EMF,no-load flux linkage,air gap flux density,electromagnetic torque and other parameters of motors with different phase shift structures are compared,and the effect of different winding phase shift on motor performance are analyzed.Then,the MATLAB / Simulink software is used to build a four-dimensional current vector control simulation model of two structural motors.The speed loop uses a sliding mode controller to replace the traditional PI controller.In order to solve the sliding mode control chattering problem and the saturation effect caused by the integration link,an improved anti-Windup sliding mode control strategy is proposed to improve the control performance.The improved method was used to simulate and analyze the motors with winding phase shift of 30° and 180 °,and the control effects of the two winding structure mo tors were compared.It is concluded that the motor with 180°phase-shift windings is more conducive to decoupling control.Finally,on the basis of the above research,the sensorless control technology of the permanent magnet synchronous motor with 180 ° phase shift of the dual three-phase windings is studied.A sensorless control system of the motor based on the sliding mode observer method is established.In order to reduce the sliding mode chattering phenomenon,the Sigmoid function is used instead of the symbolic function,and the rotation speed information is extracted using the phase-locked loop technology.Through MATLAB/Simulink simulation and comparative analysis,the effectiveness of the improvement measures is verified.At the same time,a sensorless control strategy based on the load disturbance compensation expansion observer method is proposed.The expansion state observer is combined with the phase-locked loop technology to estimate the motor speed.In order to reduce the impact of load disturbance on the system stability,the disturbance observer is used to estimate load torque,and convert the estimated value to the quadrature-axis current for feedforward compensation,and ultimately improve the accuracy of the sensorless control of the motor and the ability to resist load disturbances.The two observer methods are simulated and analyzed under MATLAB / Simulink,and it is concluded that the strategy proposed in this paper has better control effect.