1997 Fiscal Year Final Research Report Summary
Development of very power converters for electric utility applications
| Project/Area Number |
08650327
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
電力工学・電気機器工学
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| Research Institution | IBARAKI UNIVERSITY |
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Principal Investigator |
OGUCHI Kuniomi Ibaraki University, Faculty of Engineering, Professor, 工学部, 教授 (50037868)
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| Project Period (FY) |
1996 – 1997
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| Keywords | Power converter / Ripple injection / Harmonic canceling reactor / Multilevel converter |
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| Research Abstract |
For very high power converter systems, double multilevel voltage-source converters coupled with harmonic canceling reactors have been investigated.
1.Control of double three-level converters.
The specific harmonics canceling PWM technique can control the voltages at lower switching frequencies and can generate much better waveforms.
2.Ripple voltage injection method.
The injection of ripple voltages with a frequency of six-times that of power lines into the dc link has been proposed and it is shown that very low distortion waveforms with 36- or 48-step can be obtained.
3.A novel six-phase voltage-source inverter.
The ripple voltage injection method can successfully apply to a six-phase inverter without using a single-phase transformer and can produce nearly sinusoidal waveforms with 60-step.
4.Future problems.
The leakage inductances of the transformers in the ripple voltage injection circuit will cause an adverse effect on the voltage waveforms. Therefore, we should realize a transformerless injection circuit for three-phase systems.
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