| Autor: |
A.L. Mahmood, I. Badran, M.T. Lazim |
| Rok vydání: |
2008 |
| Předmět: |
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| Zdroj: |
American Journal of Applied Sciences. 5:1580-1587 |
| ISSN: |
1546-9239 |
| DOI: |
10.3844/ajassp.2008.1580.1587 |
| Popis: |
In integral-cycle triggering mode of voltage control, subharmonic as well as higher order harmonic components are generated in the load voltage waveforms of a three-phase system. These harmonic components are found to be unbalanced in phase displacement. The correction of the unbalanced phase displacement angles of a particular subharmonic or higher order harmonic for this type of triggering is investigated to solve the limitation of use of this important type of control as a drive and many other industrial applications. In this research a new phase shifting technique is proposed to correct the unbalanced phase displacement angles in the three-phase system. This technique depends on shifting the waveforms of either phase B or phase C or both by multiples of 2π. A microprocessor-based harmonic phase shifter is designed and tested with three-phase resistive and induction motor loads. It is found that there is a well agreement between the theoretical and experimental results and it is believed that the major problem of harmonics phase unbalances associated with the integral-cycle triggering mode of thyristors when used with three-phase circuits have been solved in the present research. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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