碩士 / 國立成功大學 / 工程科學系碩博士班 / 91 / The fish coordinate transformation is mainly investigated in this thesis. The detailed calculation and inspection insight reveal that the current and torque ripples are directly related to the variations of the fish coordinates of and , respectively. The harmonic effects on the motor can be thereby obtained by observing the shape of the flux fish. On the other hand, if the starting angle r in the fish coordinate transformation is chosen appropriately, the fish transformation technique can be applied to the various PWMs. The intact and symmetric flux fish can be obtained. It can be used to calculate the harmonic figure F and judge the merits of the various switching patterns.
In this thesis, the fish coordinate transformation is originally applied to the voltage-space vector pulsewidth modulation (VSV-PWM). On the basis of the same conditions of fixed switching and the electric frequency of the stator, it shows that the performance of VSV-PWM is superior to that of S-PWM from a viewpoint of the figure of the quality measure F and the total harmonic distortion THD. To reduce the switching losses, a switching table of voltage vector is derived for VSV-PWM. Its flowchart completely illustrates the design procedure.
In addition, the direct torque control theory is also reviewed in this thesis. It includes the flux and torque hysteresis controls. By virtue of the principle of alignment of the flux and voltage vectors of the stator, the vector switching table can be derived. The flux hysteresis control is treated as one kind of PWM in the thesis so that the shape of flux fish can be used to evaluate its figure of merit. Unfortunately, the symmetry of the flux fish can be not maintained due to the variable frequency switching.
The key point of the switching pattern of the fish method is included in this thesis. By analyzing the merits and faults, the differences among various switching patterns are revealed. In the end, comparison results verified by simulation and experiments are also presented.
| Identifer | oai:union.ndltd.org:TW/091NCKU5028077 |
| Date | January 2003 |
| Creators | Yi-Hao Yeh, 葉玴豪 |
| Contributors | Jong-Lick Lin, 林鐘烲 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 151 |
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