SWITCHING CONTROL IMPROVEMENTS FOR FRONT-END CONVERTER AND INVERTER OF PERMANENT MAGNET SYNCHRONOUS MOTOR DRIVE

• Main Authors: Lee-Da Huang, 黃立達
• Other Authors: Chang-Ming Liaw
• Format: Others
• Language: en_US
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/96070220448793242895

碩士 === 國立清華大學 === 電機工程學系 === 94 === This thesis is mainly concerned with the establishment of a digitally controlled permanent magnet synchronous motor (PMSM) drive and the switching control improvements for its front-end converter and inverter. First, the structure, governing equations and equivalent circuit parameter estimation of PMSM are explored. Then an experimental digital signal processor (DSP) based PMSM drive is constructed. In addition to the proper design and implementation of system constituted components, the robust ramp-comparison (RC) current control is applied to yield good winding current tracking and driving characteristics. Secondly, in order to enhance the motor driving performance through adjustable DC-link voltage, this thesis designs and implements an AC-switch based switching- mode rectifier (SMR), and performs its low frequency (LF) and high frequency (HF) switching controls and performance evaluation. In this stage, a standard boost SMR is also formed and used for comparative study. In the vibration and acoustic noise reductions, the three-stage excitation technique using auxiliary narrow pulse is employed for LF SMR. As to the HF SMR, the randomly varying band hysteresis current-controlled PWM (CCPWM) scheme and the random frequency RC CCPWM scheme are proposed. Theoretical basis and performance assessment for each approach are introduced in detail. Finally in the high-speed operation performance improvement study, some operating key issues for a PMSM drive are first comprehended, and some modified PWM schemes for increasing the inverter voltage utilization are introduced, wherein the comparative features in realization and output performance of all schemes are understood. Then accordingly, the control approaches are proposed, which include robust current tracking error elimination, commutation advanced shift, field-weakening and DC-link voltage boosting. And some experimental results are provided to perform the comparisons of winding current and speed dynamic responses between these approaches. Key words: Permanent magnet synchronous motor, robust current control, switching-mode rectifier, low-frequency switching, high-frequency switching, front- end converter, random frequency switching, randomly varying band hysteresis switching, vibration reduction, commutation advanced shift, field-weakening, power quality, driving performance evaluation.