| 摘要 |
PURPOSE:To prevent the increase in a reverse leakage current by detecting the voltage across main thyristors, applying said voltages to AND gates in a triggering circuit, and suppressing the output of triggering pulses during the reverse-voltage period of the thyristors. CONSTITUTION:The voltages across the anodes and cathodes of main thyristors TU-TZ in a thyristor converter are detected by a reverse-voltage detector RVD, and said voltage are inputted to AND gates AG in triggering circuit. On the other hand, the outputs from a triggering unit TSU, to which a control signal CS and synchronizng signals SS are inputted, are supplied to the AND gates AG through flip-flops FF, and further supplied to thyristors TP and TQ in an inverting extinction circuit via an OR gate OG. Therefore, the generation of the triggering pulses during the period the reverse voltage in the main thyristors are generating can be suppressed, the increase in the reverse leakage currents can be prevented, thereby the reliability of operation can be enhanced. |
