Vector Control Of Load Torque Observation Tsmc Driven By Tractor Based On Kalman Filter

Two-stage matrix converter is a new type of energy saving and environmentally-friendly power converter with excellent input/output performance,no large storage capacitor on DC side and bidirectional energy flow.Gearless permanent magnet synchronous traction machine is widely used in elevator and other lifting fields because of its compact structure,high transmission efficiency,fast dynamic response,high positioning accuracy and low noise.In order to solve the problems such as poor sinusoidal degree of current on the power grid side,large electrolytic capacitance on the DC side,and energy unable to flow bidirectionally in the drive system of traditional traction machine,two-stage matrix converter is used to drive the tractor to improve the above mentioned performance.In order to solve the problem of matrix converter with no continuous current loop,the current mode four step converter strategy is adopted to ensure the safe operation of the system.Aiming at the backsliding problem of sensorless towing machine during startup,in this paper,a load torque observer based on Kalman filter is studied in order to improve the start-up performance of the traction machine.In this paper,the modulation strategy principle of rectifier stage and inverter stage of two-stage matrix converter is analyzed and the expression of duty ratio of each vector is derived.In order to ensure the safe operation of the two-stage matrix converter,the four-step current converter strategy is studied.By changing the order of the driving pulses of the bidirectional switch,the safe commutation of the rectifier stage is realized.A vector control system with id=0 was built for the traction mechanism driven by a two-stage matrix converter.In order to improve the startup backsliding problem of the traction machine,The load torque observer algorithm with Kalman filter is introduced.Based on the mathematical model of the traction machine in dq coordinate system,a load torque observer based on Kalman filter was constructed.Through the process of state prediction and state update,the optimal load torque value is estimated online and the compensation current is calculated,which is compensated to the control loop by feedforward,so as to improve the backsliding phenomenon.The experimental platform of two-stage matrix converter system with DSP+CPLD as the core is built,the software and hardware parts of the system have been designed.The hardware part mainly includes input filter,main circuit and driver,sampling and conditioning,protection circuit,encoder conditioning circuit and D/A,etc.The software includes DSP main program,rectifier stage and inverter stage interrupt program,Kalman filter load torque observation program and CPLD program.The four-step current converter strategy and the load torque observation algorithm based on Kalman filter are verified on the experimental platform.The experimental results show that the vector control system of the traction machine driven by the two-stage matrix converter has good dynamic and steady-state variable frequency speed regulation performance.The current mode four-step converter strategy provides a continuous current loop for the commutation stage bidirectional switch,which has effectively suppressed the commutation peak of the input current.The load torque observer based on Kalman filter has improved the anti-load disturbance performance of the tractor.