| 摘要 |
PURPOSE: To suppress influence of high harmonic components contained in fault voltage and fault current of system. CONSTITUTION: This protection relay apparatus has a first filtering means 1 which inputs sampling data of voltage vm and current im of the power system voltage v and current i to a filter having a transfer function f(Z).(1+k.Z¬-1+Z¬-2) and outputs a voltage vsm and a current ism, a second filtering means 2 which inputs the voltage vm and the current im to a filter having a transfer function f(Z).(1-Z¬-2) and outputs a voltage vjm and a current ijm orthogonal to the voltage vsm and the current ism, a reactance calculating means 3 which calculates a reactance Xm from vsm, ism, vjm, ijm at a time tm and vsm-p, ism-p, vjm-p, ijm-p at time tm-p, and an operation discriminating means 4 which makes discriminates operation according to a discriminating formula Xm<=Xs with the reactance Xm derived by the reactance calculating means 3 and a setting value Xs.
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