换相过程对变抽头六相整流电路的影响

在变抽头六相整流系统中,整流换相和变抽头换相对有效抑制交流侧电流波形畸变起到了重要作用.采用分段解析法给出了考虑换相过程时变抽头六相整流系统的数学模型,得出了交流侧电流波形,并对交流电流进行了傅氏级数分解.通过实验研究,查明了电流正弦性畸变率的变化规律和影响因素,给出了抽头换接器的匝数匹配优化值,为该系统的工程设计提供了重要指导.

Influence of commutation on six-phase rectifier system with tap-changer

The commutation process of six-phase rectifier system with tap-changer is very important to the suppression of current distortion. The mathematical model with the influence of commutation is presented via piecewise analytical method, and AC current waveforms which agree with experiments very well are provided. Furthermore, a Fourier series expansion of the AC current is achieved. On the basis of experiments, the regularity and influential factors of total current harmonic distortion (THD) are worked out. It also has been verified that the line-voltage harmonic distortion(VHD) on AC-side and the voltage ripple factor(K) on DC-side are reduced in the six-phase rectifier system with tap-changer. Finally, the engineering practical optimum turn ratio of the tap-changer Interphase reactor is obtained. The results provide a most important guidance.