METHOD FOR IMPROVING PMU SYNCHRONOUS PHASOR MEASUREMENT PRECISION

摘要

A method for improving the PMU synchronous phasor measurement precision under the dynamic conditions such as out-of-band interference, system low-frequency oscillation, power oscillation, system out of step, short circuit or broken circuit fault belongs to the technical field of electric power automation. The method comprises the following steps: sampling synchronously with high-precision; calculating and pre-filtering a DFT phasor; measuring the frequency with high-precision and correcting the calculated DFT phasor under the frequency deviation condition; transmitting upward the phasor, the frequency and the frequency change rate which are calculated on the basis of the step SS3 and then are filtered by a post upward-transmitting filter to a back-end data concentrator; and testing and validating. The inhibition on the frequency spectrum leakage and picket fence effect when frequency deviation occurs in DFT algorithm is realized by the method, the frequency spectrum aliasing phenomenon that occurs when the calculated phasor contains the components with the oscillation frequency that is higher than the Nyquist frequency is avoided, and the dynamic measuring performance of the PMU under the conditions of modulation, step, etc. is improved.