三相晶闸管投切电容器动态参数的研究

Research of Dynamic Parameters in Capacitors Controlled by Three-phase Thyristor

控制晶闸管使其具有软开关特性,可实现快速、无涌流冲击的投切电容。由于晶闸管承受电压和电流的能力有限,所以在晶闸管投切时刻和三相投切顺序上必须有所选择。本文根据三相无功补偿的实际容量,利用拉氏变换和波形图分析得出了晶闸管投切三相电容的最佳时机和顺序、同步信号、晶闸管电压与电容残压等主要参数之间的关系,并在实际应用中得到了验证。

Three-phase thyristor controls capacitors to switch on or cut off so as to compensate reactive power. Control thyristor have soft-switch characteristics that enable thyristor to void impact made by inrush current and to control capacitors quickly. Considering voltage and current thyristor could undertake are limited,so the correct time when thyristor can be switched on or cut off and sequence by which three-phase thyristors can be switched on or cut off should be carefully selected. The paper deduces to the equation of reactive power compensation capacity of three-phase capacitors and analyzes the perfect time and sequence of switching on or cutting off capacitors by the means of Laplace translation. The paper also analyzes important parameters such as synchronous signal,capacitors residual voltage and thyristor voltage by the means of waveform graphs. The conclusions and equations are proved by practical application.