An Optimization of Least-Square Harmonic Phasor Estimators in Presence of Multi-Interference and Harmonic Frequency Variance

The wide application of power electronic devices brings an increasing amount undesired harmonic and interharmonic tones, accurate phasor estimation under a complex signal input is important task for smart grid applications. In this paper, optimization least-square dynamic estimators, considering multi-interference frequency variance, proposed. A comprehensive error index (CEI) composed the fundamental-leakage-led amplitude error, mutual interference, out-of-band deviation employed. largest CEI part algorithms using three different decomposition models analyzed first time, variables to reduce component are then introduced singular value decomposition. With defined variables, minimum-error phasors various interference change discussed. Numerical tests performed, test results show that after proposed applied algorithms, errors considerably reduced, especially low-order harmonics. We also possibility choosing desired optimal filter design by balancing measurement accuracy data latency. For example, when window length set nominal cycles, can yield both good fast speed estimating variance.