DIGITAL OUTPUT PART CIRCUIT OF DIGITAL PROTECTIVE RELAY

摘要

The subject innovation relates to a digital output circuit of a digital protective relay, since the only photo-coupler when a using the output ports of the central processing unit (CPU) 2 output ports outputting a desired signal to normal operation, the noise there is an effect that can improve the reliability of.; Digital output circuit of a digital protective relay according to the present invention for this purpose is input to the digital signal from the signal input unit and said signal input, the voltage transformer (PT) and current transformers (CT) to step-down the input voltage for receiving the three-phase power receiving a digital input unit for outputting operation and a combined signal received is the output voltage of the signal input, and outputs a signal for determining the driving whether the relay, receiving the signal from the digital input section which outputs an operation and a combined signal a digital protective relay, which comprises a computation and control unit, the third terminal to input a signal output from the first and second output port of the operational and control section to the first and second terminals and input the supply voltage to the fourth terminal photocoupler that outputs an output signal to; A signal amplifier for amplifying and outputting the signal received from the third terminal of the photo coupler; And characterized in that configured to include a relay for inputting the output signal and the power supply voltage of the signal amplifier with a first and a fourth terminal, and outputs an output signal to the second and third terminals.