Research On Slip Frequency Vector Control Of Synchronous Motor In Electric Vehicle

The emergence of new energy vehicles has brought new directions to the energy crisis and environmental protection.As an important part of new energy vehicles,motors,electronic controls,and batteries are attracting attention.With the mature development of control technology and the advantages of simple structure,low cost,reliable operation and low noise of asynchronous motors,asynchronous motors and their control systems are often used in the field of electric vehicles.In terms of the motor,the system uses three-phase asynchronous AC motors.Compared with other control systems,the vector control technology based slip frequency vector control system is used.The simple control model has static and dynamic performance,and the speed range is wide,the noise is low.Less harmonics can meet the needs of electric vehicles.The article first introduced the development status of electric vehicles at home and abroad,and used three-phase asynchronous AC motors according to the requirements of electric vehicles for drive motors.Then,it elaborated the control scheme of asynchronous motors and selected the slip frequency vector control algorithm based on the demand of electric vehicles.The preconditions of stator voltage compensation propose a linear scalar compensation optimization scheme,and details the basic principles of vector control and the principle of slip frequency vector control.Introduces the SVPWM principle and its implementation method,and builds a control system model under MATLAB/Simulink to verify its feasibility.The system adopts TMS320F28335 as the core control chip,the main work is to design and debug the hardware circuit,and software programming implements the control algorithm.Mainly introduces the main control circuit in the hardware,MOSFET power switch circuit,stator current signal acquisition to achieve current loop control,acquisition of voltage,temperature signal protection circuit with the motor real-time protection,chip eQEP function with speed measurement circuit to complete the speed acquisition speed loop control The serial communication circuit mainly communicates important parameters.In terms of software,the slip frequency vector control is used as the core control algorithm.The timer interrupt completes the detection of the gear signal,voltage,current,and temperature signal acquisition and failure analysis.The PWM interrupt program completes vector coordinate transformation,double closed-loop control,current-voltage model conversion,SVPWM algorithm,angle calculation,and elaborates on the speed measurement method and PI regulation respectively.At the end of the article,physical photos were displayed and a comprehensive analysis of the experimental results was conducted.