A Six-Step Voltage Driving Method for a PMSM with Quasi-Sinusoidal Stator Currents
| Autor: | Chin-Hao Chen, 陳錦豪 |
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| Rok vydání: | 2012 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 100 High efficiency, high power density and wide constant power region are all the required functions of the traction motor and drive in electric vehicle applications. However, these requirements are mainly dependent on the output phase voltage utilization of the motor drives. An over modulation method with fixed dc-link voltage was traditionally proposed to increase the output phase voltages. But this method may yield current harmonics to increase torque ripples. In this thesis, a novel six-step voltage control method is proposed to increase phase voltage utilization and reduce both current harmonics of PMSM and switching loss of its motor drive simultaneously. The proposed method provides two-degree-of-freedom control by adjusting both DC-link voltage and phase angle between applied six-step voltage and back EMF of PMSM. The DC-link voltage is regulated by a bi-directional dc-dc converter according to the no-load back EMF under different speed. Hence one can increase the speed operating range and yield generated torque under MTPA. Moreover, in order to reduce the current harmonics caused by the six-step voltage, the phase angle of applied six-step voltage is adjusted to lead the no-load back EMF to get a nearly sinusoidal stator current. A MATLAB-based simulation environment of the motor drive system is established for developing the proposed control method first. Then, a MCU SH7137-based motor drive is employed to realize the control algorithms. Finally, some experimental results tested on a 6kW/47Nm IPMSM are carried out to verify the effectiveness of the proposed system. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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