| 摘要 |
PURPOSE:To detect and specify a faulty diode correctly, by a method wherein the secondary coils of a current transformer are connected in series in all phases and secondary coils in which the sum of absolute values of positive and negative output pulses becomes maximum are detected. CONSTITUTION:A 3-phase bridge rectifying device 2 rectifies a 3-phase AC power, outputted from the armature coil of an exciting machine 1, and supplies it to the field coils 3 of a synchronizing machine. Protecting fuses 14a-19a are connected in series to two pieces of diodes 4a-9a, constituting respective phase arms of the rotary type 3-phase bridge rectifying device 2, while these series circuits are provided with current transformers 24a-29a respectively. In this case, a closed circuit is formed in respective arms so that the outputs of the current transformers 24a-29a are inputted into amplitude modulating units 31a-31d from the series circuit of the diode 4a and the fuse 14a and the like respectively. The output signals of the closed circuit are inputted into a frequency modulating unit 33 through an adder 32 to transmit them after effecting principal modulation. According to this method, coils in which the sum of the absolute value of positive and negative pulses becomes maximum are detected to specify the faulty diode.
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