| 摘要 |
PURPOSE:To acquire high reliability in reducing an operational error in an amplitude value when the frequency is changed by operating the amplitude value of quantity of AC electric state on a high speed by the use of five sampling values. CONSTITUTION:Let the sampling values of times t, t-T, t-2T, t-3T and t-4T be 1, 2, 3, 4 and 5. With a product operation means 6 the product of sampling values 2 and 4 is obtained. With a square operation means 7 the square of the sampling value 3 is obtained. With a difference operation means 8 the difference between both of them is found. Similarly, with a product operation means 9 and a difference operation means 10 the difference between the product of sampling values 1 and 5 and the output of the square operation means 7 is found. The output of the difference operation means 8 is squared and quadrupled by a square operation means 11 and a quadruple operation means 12 respectively and then quadrupled by a quadruple operation means 13. With a difference operation means 14 the difference between the outputs of the quadruple operation means 13 and the difference operation means 10. The ratio of it to the output of the quadruple operation means 12 is found with a division operation means 15. Then, if the square root is found with a square root operation means 16, an amplitude of operation result is obtained to a terminal 17. This value has nothing to do with the frequency of AC current whatever. |
