Research On Analog System Of Open-Winding Permanent Magnet Synchronous Motor Based On CTV Mode

The dual inverter structure of open winding permanent magnet synchronous motor is considered a highly valuable new type of motor due to its high flexibility,high error tolerance,and suitability for high-power applications.In order to test the motor driver performance of open winding permanent magnet synchronous motors more efficiently,a motor simulation system based on VTC(Voltage to Current)mode has emerged.However,this mode is difficult to generalize and use due to its difficulty in sampling and application in closed-loop systems.At the same time,due to the internal zero sequence current generated when the open-winding permanent magnet synchronous motor is powered by a common DC bus,its traditional vector control strategy often has problems such as large torque ripple and harmonic interference.Therefore,it is urgent to optimize its control strategy.Therefore,in order to further promote the application of this new type of motor,this thesis conducts in-depth research on the mode of the motor simulation system and the model predictive torque control applied to open winding permanent magnet synchronous motors.Based on the mathematical model of the open winding permanent magnet synchronous motor in each coordinate system,the second order Adams algorithm is used to construct the VTC mode discretization mathematical model.LCL filter is selected as the interface circuit,and the discretization mathematical model of CTV mode is established.After the characteristics of the two ports of the open winding permanent magnet synchronous motor are simulated based on the vector conversion principle,the design of the simulation system of the open winding permanent magnet synchronous motor based on CTV mode is completed.Finally,simulations were conducted under the input power supply of sine wave and pulse width modulation wave,and the results showed that this mode simulation system can effectively reduce simulation errors.Design a control strategy based on the CTV mode open winding permanent magnet synchronous motor simulation system,and preliminarily verify the practicality of the simulation system.Firstly,the zero sequence characteristics and space composite vector of its dual inverter structure are analyzed,and after the research on the reconstruction of common mode free space vector modulation strategy,a model predictive torque control scheme based on reconstruction of common mode free pulse width modulation is designed by combining the unionization of cost function and deadbeat zero sequence current controller.Finally,a simulation system model was built to compare and analyze with conventional motor simulation models,and steadystate and dynamic performance verification was conducted under different control strategies.The experiment shows that the improved model predictive torque control strategy proposed in this thesis can significantly suppress zero sequence current,reduce torque ripple,and improve speed response performance,further verifying the good simulation performance of this mode simulation system.We have built an experimental platform based on the CTV mode open winding permanent magnet synchronous motor simulation system.After comparison with the physical motor experimental platform,it has been verified that the simulation system proposed in this thesis can be flexibly applied in motor driver testing,and has stronger anti-interference ability compared to physical motors;After further changing the control strategy and conducting experiments,it has been confirmed that the control strategy proposed in this thesis has improved the performance of the motor,with obvious zero sequence current suppression effect,faster response speed,and significantly reduced torque ripple.This thesis is of great significance in promoting the applicability of the testing application of the open winding permanent magnet synchronous motor simulation system and the optimization of the drive control performance of the open winding permanent magnet synchronous motor.