Research On Doubly Salient Permanent Magnet Motor Constant Speed System

High-power brushless motor drive is required in one"863 program"project. Based on comparison of several motor candidates, doubly salient permanent magnet (DSPM) motor is a good choice for it's outstanding performance. Similar to conventional drive system, DSPM brushless dc motor (DSPM-BLDCM) is composed of DSPM motor and it's controller. The controller is made up of three-phase full-bridge inverter, driver, DSP control unit and etc. For high power system, every switch of three-phase inverter is actually made up of four MOSFETs in Parallel.The structure and working principle of DSPM motor is first introduced, with detailed analysis on it's electrical performances. A new adjustment method of hall sensor is proposed. Then, through analysis of working principle of the controller, comparison between two current hysteretic control, strategies and design of main circuit parameters are given.The controller includes two control loops which are outer speed loop (variable parameter PI adjustment) and inner current loop (single-chop current delta-control). In order to improve system performances, design of digital control system based on DSP is presented. The proportional parameter and integral parameter can be obtained through the design.Finally, experimental results testify that the design of digital control system given in the paper is feasible and reliable.