Power measurement under wide-range frequency deviations

XV Xi-qiong， ZHU Hong-wei
（Institute of Very Large Scale Integrate Circuit Design， Zhejiang University， Hangzhou 310027， China）

Abstract： Aiming at the power measurement under wide-range frequency deviations，a simple algorithm for measurement of the frequency and both the fundamental active and apparent power of a power system was presented. The input voltage and current signals were filtered to be fundamental components and the noise effects were minimized，adaptive finite-impulse-response（FIR） filters were used to measure fundamental active power，Prony-based algorithm was carried out to measure the frequency and fundamental apparent power. Weighted-least-square（WLS）algorithm was employed to improve the precision of both the fundamental active and apparent power. The results indicate that the measurement with proposed algorithm has a high accuracy over a wide range of frequency changes. Thus，the proposed algorithm really meets the needs of online applications.
Key words： adaptive finite-impulse-response（FIR） filters；apparent power；active power；fundamental wave；Prony-based algorithm；weighted-least-square（WLS）