| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2005: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2004: ¥2,600,000 (Direct Cost: ¥2,600,000)
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| Research Abstract |
For small capacity rectifier circuits such as those for consumer electronics and appliances, capacitor input type rectifier circuits are generally used. Consequently, various harmonics generated within the power system become a serious problem. Various studies of this effect have been presented previously. However, most of these employ switching devices, such as FETs and the like. The absence of switching devices makes systems more tolerant to over-load, and brings low radio noise benefits. We propose a power factor correction scheme using a LC resonant in commercial frequency without switching devices. In this method, It makes a sinusoidal wave by widening conduction period using the current resonance in commercial frequency, Hence, the harmonic characteristics can be significantly improved, where the lower order harmonics, such as the fifth and seventh orders are much reduced. The results are confirmed by the theoretical and experimental implementations.
In the second place, a novel diode bridge rectifier has been discussed, which is constructed solely from passive elements, and which has an almost sinusoidal input current waveform. Since it is not necessary to use switching devices, it eliminates switching losses and noises due to switching. In addition, since it is also unnecessary to employ a complicated driving circuit, so it is favorable in terms of cost performance. This circuit is most suitable for applications where there are relatively stable and constant loads. A disadvantage of this circuit is that a large alternating current flows through the capacitors in parallel to the diode. If we use electrolytic capacitors as the parallel capacitors, it is necessary to divide in parallel them and to select like recent low loss capacitors.
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