| 摘要 |
PURPOSE:To obtain a digital protective relay to which a highly accurate amplitude calculation method is applied by a method wherein a calculation processing pert which calculates an amplitude value, a synthesized amplitude detection part and a relay setting part which compares the synthesized amplitude value with a set value or the modified set value are provided. CONSTITUTION:A CPU 35 processes calculation in accordance with the program of a ROM 37, data from a RAM 38 and a signal from a setting part 36 and, if a trip signal is necessary, outputs the trip signal through an interface circuit 39. By superposing first frequency characteristics 51 obtained by synthesizing the gains of a first digital filter processing part and a first amplitude value calculation processing part upon a curve S2 obtained by synthesizing the gains of a second digital filter processing part, a gain adjustment part and a second amplitude value calculation processing part, an integrated frequency characteristics curve S is obtained. |
