1997 Fiscal Year Final Research Report Summary
Step-up/down rectifiers with improved supply current waveform
| Project/Area Number |
08650359
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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 | Oita National College of Technology |
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Principal Investigator |
OISHI Hayato Oita Natinal College of Technology, Engineering, Professor, 電気工学科, 教授 (90044502)
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| Project Period (FY) |
1996 – 1997
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| Keywords | Sinusoidal Current / Sigle-phase Rectifier / Harmonics / IGBT |
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| Research Abstract |
The paper presents novel single-phase rectifiers with step-up/down characteristics. This is fundamentally based on the cascade combination of a diode bridge and dc-dc convertor. To sinusoidally waveshape the supply current with a near-unity power factor independent of the working conditions, buffer capacitor is operated with voltage reversibility for the supply by arranging the auxiliary power switching device and diode. The circuit operation is macroscopically analyzed by state-space averaging method based on a DC equivalent circuit and such an operation is also simulated by rigorous state-space method. Moreover, the tested setup, using two insulated-gate bipolar transistors and a 16-bit microcomputer, is implemented to experimentally investigate the steady-state and transient characteristics. The experimental and simulated results confirm the usefulness of the rectifier presented. From the results, it can be seen that the supply current can be sinusoidally waveshaped with a near-unity power factor over a wide variety of operating conditions and the desired transient responses of the output voltage can easily be obtained by a PID controller. Moreover, in practice, it has been confirmed by the experiments that a switching strategy with a fixed frequency contributes to the suppression of the magnetic noises. Consequently, it is considered that the rectifier presented is suitable for the system with good quality AC current even if that is operated with a large handling power, whereas the conventional one is confined to the small handling power applications because the supply current is distorted in the vicinity of a zero crossing of the supply when operating at heavy load conditions or with high step-up ratios.
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