励磁功率柜智能均流暂态过程分析

Analysis of transient process of intelligent load sharing in excitation power units

分析和研究了智能均流时晶闸管换流的暂态过程,重点对并联整流桥同号桥臂晶闸管间的换流过程进行了理论分析和实验研究.结果表明,触发在先的晶闸管会率先完成相间换流,触发在后的晶闸管则会在已经导通的同臂号晶闸管之间进行分流;相间换流速度快,幅度大,同臂号晶闸管间的分流速度慢,幅度小;无论导通时刻是否一致,同臂号晶闸管的关断截止时刻总是相同的.得出了智能均流是通过改变同臂号晶闸管的触发时刻,进而改变其导通初期的电流幅度和通流宽度来实现均流目的的.指出了智能均流技术在励磁功率柜中应用时需注意的问题.

In this paper, the transient process of the thyristor during intelligent load sharing was studied, and the commutation process between the same bridge arms of the parallel rectifiers were analyzed theoretically and experimentally. The results showed that the thyristor with leading firing angle would firstly finish interphase commutation while the one with delay firing angle would bring the second commutation process which arose between parallel thyristors. The second commutation process was much longer than the first one. Whether the turn-on time of the same arm thyristors was uniform or not, the turn-off time was always identical. So it was concluded that intelligent load sharing was realized through changing triggering time to change the current amplitude and width of the thyristor. Finally it was pointed out that some problems must be paid more attentions to for parallel excitation power units.