Design and Speed Control of Permanent-Magnet Synchronous Motors

• Main Authors: De-Chang Jin, 金德昌
• Other Authors: Jonq-Chin Hwang
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/62853178088159049887

碩士 === 國立臺灣科技大學 === 電機工程系 === 96 === 　　This thesis is concerned with the design and speed control of permanent-magnet synchronous motors. An auxiliary generator is used to estimate rotor position and speed to facilitate speed and torque controls. The flux analysis software Maxwell 2D is used to analyze characteristics of flux density distribution, cogging and pulsation torques, equivalent rotor flux linkage, quadrature- and direct-axis inductances, and no-load induced voltage of the designed motor. Besides, the phase-shift, half-thickness interior permanent-magnet embedded in oblique slot of rotor is implemented to yield less torque fluctuation and current ripple. The quadrature and direct-axis dynamic models of the motor in rotor frame are derived to facilitate the speed and current closed-loop control using rotor flux orientation as well as the measurement of motor parameters. 　　In this thesis, the digital signal processor TMS320F2808 is used for the speed and current closed-loop controls as well as the system integration of the three-phase permanent-magnet synchronous motor. The control of motor and inverter is accomplished by software for cost reduction. The implementation of the 14-pole , 12-slot permanent-magnet synchronous motor with the linear relationship between the peak electromotive-force and speed is also given. The electromotive-force harmonic distortion measured is 1.03 %, which agrees with the analytic result of 0.95% and thus validates the software accuracy. A prototype of inverter for permanent-magnet synchronous motor with 100 W, 200 rpm, 5 N-m torque output is developed. Specifically, Hall-effect sensors are applied as rotor position feedback when rotor speed is lower than 50 rpm, whereas the auxiliary generator is given when rotor speed is greater than 50 rpm. The current harmonic distortion measured is 2.84 %, which justifies the analysis.