Slow sampling on-line harmonics/interharmonics estimation technique for smart meters

This paper presents a modified gradient search (MGS) technique to estimate harmonics/interharmonics of power system voltages and currents. The proposed technique, which is applied to spectral estimation, consumes very low processing power and needs a few samples per cycle for real-time implementation in smart meters. The computational burden of the proposed technique is lower than the discrete Fourier transform (DFT) and fast Fourier transform (FFT) and can be implemented recursively on digital signal processors (DSPs). In addition, the effects of slow sampling on the accuracy and estimation latency have been investigated. Performance of the proposed method is evaluated by simulations in MATLAB-Simulink and confirmed by experimental results.

► This paper presents a modified gradient search (MGS) technique to estimate harmonics/interharmonics of power system voltages and currents. ► The proposed technique, which is applied to spectral estimation, consumes very low processing power and needs a few samples per cycle for real-time implementation in smart meters. ► The computational burden of the proposed technique is lower than the discrete Fourier transform (DFT) and fast Fourier transform (FFT) and can be implemented recursively on digital signal processors (DSPs). ► The effects of slow sampling on the accuracy and estimation latency have been discussed. ► The performance of the proposed method is evaluated by simulations in MATLAB-Simulink and confirmed by experimental results.