Relationship between performance indexes and offset angles of virtual phasor measurement algorithm based on DFT.

Phasor measurement unit can monitor the variation of phase angle of power grid in real time, which is of great significance to ensure the safe and stable operation of power grid. Among them, the virtual phasor measurement algorithm based on discrete Fourier transform (DFT) has been widely used because of its simple principle and relatively easy implementation. However, the existing virtual phasor measurement algorithm only gives the dynamic error reduction effect under the fixed offset angle, and does not give the rule of the reduction effect with the different offset angle. The relationship between anti-harmonic interference capability and response speed with the different offset angles is not analysed. Therefore, this study deduces the pattern of dynamic error reduction effect, anti-harmonic interference ability and response speed with the different offset angles. The dynamic error reduction effect of the algorithm is the best when the offset angle is π/2, and the anti-harmonic interference ability of the algorithm is the strongest when the offset angle is π/3. The response speed of the algorithm increases linearly with the increase of the offset angle. On this basis, the correctness of the algorithm is verified by numerical simulation experiments. [ABSTRACT FROM AUTHOR]