ABNORMALITY DETECTING CIRCUIT FOR THYRISTOR CONVERTER

摘要

PURPOSE:To accomplish detection of voltages and troubles of all thyristors by means of power detection circuits each provided for the thyristor. CONSTITUTION:Voltages of thyristors 1-1 and 1-2 are detected by voltage detection circuits 6-2 and 6-3 and optical signals thereof are converted into electric signals by a photodetection circuit to drive flip-flop circuits 10-1 and 10-2 with the signal. When the flip-flop circuits 10-1 and 10-2 fail to be driven within the given space of the time due to troubles of the thyristors or the like. Timing circuits 11-1 and 11-2 detect the state to determine the occurence of the trouble at a time (t) and output trouble signals 16-1 and 16-2. Thus, the detection of the trouble of eacy thyristor can be done simply by providing an electric detection circuit for each thyristor or each group of thyristors.