| 摘要 |
<p>PURPOSE:To continue a safe operation by gate-shifting positive and negative side thyristor converters connected in anti-parallel with secondary side phases of a generator motor when the converters are not, even if gate-blocked, arc- extinguished. CONSTITUTION:The secondary side of a variable speed generator motor (variable speed) 1 is connected to a main transformer 4 by a cycloconverter (CYC) 3i (i=1-3) and an exciting transformer 7i, and a converter current Ifbi is detected by a CT. A voltage detector 14i detects a voltage between the anode and the cathode of a thyristor of the CYC3i, and a voltage establishment signal VFD is detected by its logic product. Phase exciting current commands Iref-i of a secondary winding is calculated by a phase signal theta from a phase detector 6 coupled directly to the motor 1 and a slip frequency Sf. The pulse phase shifter 10 of a control circuit 9a calculates and outputs a gate control signal with signals VFD, Ifb-i and Iref-i, and shifts the gate pulse of the CYC 3i failed in arc extinguishing. Thus, a stable operation is continued.</p> |
