A Study of Harmonic Reduction Effect in Distribution Line Due to Its Reaction Among Power Semiconductor Circuits

对于小容量整流电路，如消费类电子产品和家用电器，一般采用电容输入型整流电路。因此，电力系统内产生的各种谐波成为一个严重的问题。关于这一效应的各种研究以前已经提出过。然而，其中大多数采用开关器件，如场效应管等。没有开关设备使系统更能容忍过载，并带来低无线电噪声的好处。我们提出了一种在商用频率下不使用开关器件的LC谐振功率因数校正方案。该方法利用商业频率的电流共振，通过加宽传导周期产生正弦波，从而使谐波特性得到明显改善，其中五阶和七阶等低阶谐波大大降低。理论和实验验证了这一结果。其次，讨论了一种新型二极管桥式整流器，它完全由无源元件构成，并且具有几乎正弦的输入电流波形。由于不需要使用开关器件，因此消除了开关损耗和开关噪声。此外，由于也不需要使用复杂的驱动电路，因此在性价比方面是有利的。这种电路最适用于有相对稳定和恒定负载的应用场合。这种电路的缺点是大的交流电平行流过电容器和二极管。如果采用电解电容器作为并联电容器，则必须进行并联划分，并选择与最近的低损耗电容器相似的电容器。

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.