Research On Control System Of BLDCM Based On Soft-switching Inverter

The exciting current is not needed for the BLDCM, smooth operation, overload ability, high power density and easy control so as to realize high precision operation, etc. The BLDCM will gradually replaces the traditional induction motor, and will be widely applied in drive system of high performance. In this paper, the soft-switching inverter technology applied in brushless dc motor control system, in order to further enhance the system efficiency.Texas Instruments offers a new DSP controller family referenced TMS320- LF2407A, which is specifically designed for the needs of digital motor control. In a single chip application, this device combines a fixed point DSP core with micro-controller peripherals. This chip is able to perform sophisticated control schemes.A new three-phase soft-switching inverter is presented for permanent magnet brushless DC motor(BLDCM) drive to reduce high turning-on loss, high du/dt, high noise and high EMI. An auxiliary circuit which is used to achieve zero voltage switch (ZVS) of power switches in turning-on period is added based on the conventional three-phase inverter according to soft-switching theory. The experimental results show that the proposed three-phase inverter has achieved ZVS in turning-on period, and some disadvantages, including high turning-on loss, high du/dt, high noise and high EMI,were reduced .So the validity of relative theory was demonstrated.Brushless dc motor control system based on soft-switching inverter is introduced in this design. In this experiment, 150W permanent magnet synchronous motor was used to testing the trigger signal waveform and the current control. Test results show that this control system hardware circuit and software design is reasonable, meet the design requirement, efficiency is good.