| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a protective relay exhibiting a good operating time even in case of an input state of operation level from an input voltage/current state too low to establish the power supply voltage. <P>SOLUTION: Input current/voltage are inputted to an input analog circuit 2 through an input transformer 1 and converted into an analog signal of a predetermined level, which is then inputted to an A/D conversion circuit 3 and converted into a predetermined digital signal before being taken into a processing circuit 4 and processed. A power supply circuit 5 supplies a stabilized voltage as the power supply voltage in the protective relay to each circuit from the input current/voltage. Processing results from the processing circuit 4 are outputted to a relay circuit 6 and a contact output is outputted therefrom. At the time of transition to an input state of instantaneous operation level from an input current/voltage state too low to establish the internal power supply voltage, delay time is taken into account and operation is judged by peak level processing only after initialization processing immediately after operation of the processing circuit 4. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
