This paper proposes a method of frequency estimation based on multiple-consecutive-samples (MCS) frequency estimation (MCS-FE) for a three-phase grid, which can estimate the grid frequency quickly and accurately. In particular, the proposed method shows strong robustness against dc-offsets. On the basis of the relationship of distorted grid voltage and four consecutive sampling signals, the model of MCS-FE is established. According to this, estimated frequency, positive-sequence and negative-sequence components can be obtained at the same. Compared with traditional SOGI-PLLs (second-order eneralized integrator (SOGI) based frequency locked loops), MCS-FE shows fast response, high accuracy and good capability of rejecting dc-offsets, and simulation results confirm that.

multiple-consecutive-sample;dc-offstes;positive-sequence component;negative-sequence component;frequency estimation