| 摘要 |
PURPOSE:To improve the efficiency and to prevent a self-distinguishing element from damaging in a power converter for obtaining a variable DC power using the element by flowing a current at commutating time through a thyristor switch to a load. CONSTITUTION:When a gate turn-off thyristor (GTO) GU is commutated to GTO-GV, the GTO-GU is extinguished and thyristors S4, S3, S1 are simultaneously turned ON. Then, the current IU of the U-phase of the power source side continues flowing through a diode D4, a thyristor S4, a capacitor C, the thyristor S3, the thyristor S1 and the GTO-GY. The IU starts reducing from when the charging voltage of the capacitor C becomes equal to the voltage VUC between the power sources U and V, and the IGV increases. At this time, the GTO-GV fires. The load current IL is commutated to the GTO-GU, and the current IL is circulated through the GTO-GY, GV. |
