Research On The Sensorless Control Technology For High-power High-speed Magnetic-bearing BLDCM

Energy conservation and environmental protection is listed as the first of seven strategicemerging industries in our country, and highlights the important strategic significance. Inorder to guarantee the rapid development of the economy and achieve the goal of energyconservation and emissions reduction, so it urgently needs green high speed machinery.Among them, raising the level of motor efficiency has great significance to energyconservation and emissions reduction work currently, and using high-power maglev highspeed permanent magnet brushless motor is very remarkable to energy-saving effect.The study is based on high-power magnetic levitation brushless dc motor as controlobject, and designs the sensorless control system with TMS320LF28335, which uses the backEMF zero-crossing signal detection method to achieve reliable and stable operation of themotor. For sensorless brushless dc motor (Brushless Direct Current Motor, for shortBLDCM),paper makes a detailed research with the rotor positioning method in the process ofstarting, the principle of back EMF zero-crossing signal detection and the problem of thefiltering phase shift, spikes, the last design the corresponding control strategy.In part of the system hardware, the main circuit chooses BUCK converter and theintelligent power module (IPM) for phase operation, and designs the necessary protectioncircuit, the whole hardware circuit is compact structure and reliable operation. Softwareincludes initialization module and the way of sensorless operation module, wherein thesensorless control way module achieves two functions with the sensorless closed-loop controland completing motor starting. Use TMS320LF28335A as the control core, at the same time,around the DSP peripheral functions, extend A/D acquisition interface and PWM outputinterface, and build the back EMF zero-crossing signal detection circuit, it provides a good experimental platform for the research of motor control algorithm and application of thecontrol system.The design scheme in this paper is applied to high-power magnetic-bearing brushless dcmachine, the experiment results show that the thesis based on the design of the control systemwith the number of TMS320LF28335A DSP chip can control the motor smoothly reaching therated speed, and achieve the change correct and stable operation of the experimental motorwell, and finally proved the feasibility of the design system.