Current Harmonics Improvement of Three-phase Permanent-magnet Synchronous Motor Drives
| Autor: | Jia-Huei Lin, 林家輝 |
|---|---|
| Rok vydání: | 2015 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 104 The thesis focuses on the development of low total harmonic distortion (THD) of current for a six-leg inverter for three-phase permanent-magnet synchronous motor (PMSM) drives. The power circuit of six-leg three-phase inverter will provide independent operation for each phase of PMSM to raise the utilization factor of dc-link voltage. In addition, two types of current harmonics mitigation control are proposed: one for normal operation and the other for the case when single phase winding fault occurs. The former uses current prediction to suppress the zero-axis current, while for the latter, adjusting the phase angle difference of the other two windings to 60 degrees and introducing zero-axis back electro-motive-force compensation will reduce THD of current as well as torque ripple under unbalanced condition. Finally, an auxiliary generator is used to measure the position and speed of the rotor to facilitate the coordinate transformation of feedback current for current and speed closed-loop control. In this thesis, Matlab/Simulink is used to simulate the proposed PMSM drive including current and speed closed-loop control, fault tolerance control as well as harmonic mitigation. The digital signal processor, TMS320F28069, is adopted as the control core and the program is compiled by C language, thereby reducing the circuit components and enhancing the reliability. Experimental evaluation for current harmonics mitigation control is conducted at 180 rpm with a load of 2 N-m. Under normal operation, the THD of current is reduced from 10.43% to 1.81%. Whereas, when single phase winding fault occurs, the THD of current is reduced from 4.46 % to 2.96 %. Besides, peak to peak value of torque is dropped from 0.68 N-m to 0.66 N-m. The experimental results show the feasibility of the proposed current harmonic control strategy. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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