The Research On Digital Control System Of Permanent Magnet Synchronous Elevator Traction Machine

With the development of the modern city,there are higher and higher demands on the safety,efficiency and comfort of elevators,which are the main transportation equipment of high-rise building.In order to satisfy the increasing requirements on the control of elevators,small,comfortable,energy-saving and reliable permanent magnet motor driven technology has already been applied in the elevator traction machine.The elevator traction machine is simple in structure,small in size,stable in operation,accurate in positioning,quick in speed response,strong in carrying ability and it has not crawl in low speed,and can be started and stopped frequently.Consequently,it is quite applicable for the control of elevators.In this paper,the operating mode and characteristics of elevator dragging system is analyzed,the permanent magnet synchronous traction motor model is analyzed,the permanent magnet synchronous traction motor control requirements is presented,mainly to achieve a balance in the fast and comfortable,which acceleration and control requirements of acceleration change are both fast and comfortable in the start process and the deceleration process.Three segment control way of the acceleration and deceleration is raised,the first section is variable acceleration control,control jerk is constant,in order to meet the passenger comfort and taking into account the fast;the second section is the constant acceleration process,mainly to meet the fast and to consider the requirement of comfort,the third section is again transformed into variable acceleration control,and the transition of the static three-phase A,B,C coordinate of the permanent magnet synchronous motor to the two-phase d and q coordinate is discussed in details.As a result,the voltage equation,linkage equation,as well as the torque,power and efficiency equation of the permanent-magnet synchronous motor in coordinate transformation matrix and d and q coordinate is obtained.On that basis,several control strategies and features are discussed and analyzed,and meanwhile,the identification method of electric machine parameters,such as the stator electron an inductance,rotor position,etc.as well as the SVPWM control principle and implementation method is studied.The control system structure is established according to the vector control principle,and the transfer function of electricity closed-loop and revolving speed is derived.The electricity and revolving speed PI adjuster is designed according to the second-order optimal index,and system simulation is conducted with the Matlab/Simulink software.The structure obtained can satisfy the requirements of performance by combining the basic parameters of the permanent magnet traction motor.Eventually,with the DSP as the main control unit,the control,sampling,vector control calculation,duty ratio calculation,PWM wave generation programs are designed with TMS320F2812 chip of American TI Company.Besides,the chip is equipped with PWM interface and applied for the motor control.Moreover,the experiment board is installed on the experimental platform.In the elevator control laboratory of the unit,the main circuit and encoder control circuit of the permanent magnet synchronous traction machine is connected and tested,the elevator control board and the experimental board I/O line is completed.The basic parameters current of the traction machine is the repeated tested by changing the load and operating conditions,in order to verify the feasibility of the control system scheme of permanent magnet elevator traction motor.As a result,the test runs well and receives good effect.