DIGITAL DYNAMIC IDENTIFICATION OF POWER-SYSTEM SUBHARMONICS BASED ON THE LEAST ABSOLUTE VALUE

This paper presents a novel dynamic technique for identifying and meas uring power system subharmonics. The proposed technique is based on th e weighted least absolute value. The parameters to be measured are the magnitude, the rate of decay and the frequency of these subharmonics. The identification process is split into two subproblems. In the firs t problem, the harmonic contents of the voltage or current waveform ar e identified, after which the reconstructed waveform and the error in the waveform, which is the difference between the actual and the recon structed waveform, can be obtained. In the second problem, this error is analyzed to identify the subharmonics. Finally, the final error is obtained by subtracting the combination of the harmonic and the subhar monic contents, the total reconstructed waveform, from the actual wave form. It has been shown that by identifying these subharmonics the fin al error is reduced greatly. In this paper, the results obtained using the proposed algorithm are compared with that obtained using the well -known Kalman filtering algorithm. The features of the proposed algori thm are also, discussed.