Design For BLDCM Sensorless Control System Based On DSP

The control system of sensorless BLDCM based on DSP-TMS320F2407A is studied in this thesis, particularly the realization of the third harmonic component sensorless control is emphasized.This thesis firstly introduces the academic background and the research actuality in the field at home and abroad. Particularizing various sensorless control methods and their advantages and disadvantages. Third harmonic detection is one of the back-EMF method, and it's a better method than the three end-voltage crossing zero comparing with simper realization, wider speed-width and less interruption by load. Therefore, it's becoming a new heading using the third harmonic method to make up a digital sensorless control system in order to improve performance.Then the thesis describes the running principle of BLDCM, gives the mathematical model. In the following part, the settlements of several key technical problems applied in sensorless BLDCM control are given out, include the rotor position orientation at the time of starting, BEMF third harmonic method in rotor position checking principle, and some problem met during the commutation, such as filter error, aiguille pulse and torque pulse etc. are discussed particularly, and the is control strategy is designed accordingly.After above is hardware designing, the switch component of the converter is N-MOSFET—IRFZ24N of IR Corporation, according to DC voltage and the power tube's on-off frequency. The driver chip IR2130 has the power that drives 6 N-MOSFET at the same time, which simplifies circuit configuration efficiently. In driver circuit, there are A/D conversion interface,PWM output interface depending on DSP's Extended capability. Build up the third harmonic detection and voltage sharing and filtering circuit designed at first, and then determine the parameters of capacitance and resistance, making the range of detecting signal breadth is consistent with DSP, finally produce accurate waveform. The hardware design supplies one favorable experiment platform used for motor's control algorithm research and control theory application.The software is designed and realized based on the sensorless control theory and the hardware platform in Chapter 5, in which as well as overall design thought of the...