| 摘要 |
PURPOSE:To improve the characteristic change by frequency fluctuation and get highly accurate judgment results even against the frequency fluctuation being the object of failure detection by removing the sampling time width and the second harmonic from the sampling values of current and voltage. CONSTITUTION:The principal part comprises a distribution path 1 for current data, a distribution path 2 for voltage data, temporary storage rooms 3-5 for current data, temporary custody rooms 6-9 for voltage data, multiplication circuits 11-14, addition circuits 15 and 16, a multiplication circuit 17, circuits 18 and 19 for deforming the quantities of electricity, a subtraction circuit 20, a division circuit 21, a substitution circuit 22, a part 23 for guiding out quantity for judgment, and others. The integrated quantity of the sampling data of the current and the voltage of a power system is guided out to get first quantity of electricity and the second quantity of electricity, and out of the components of that quantities of electricity, the components related to the sampling time width and the second harmonic are removed from the phase difference component. The quantity of electricity becomes only the components related to the phase difference of current and voltage, and the characteristic not accompanied with against frequency fluctuation can be gotten. |
