Dynamic Phasor Estimation Based on Iterative Symmetric Taylor Weighted Least Squares Method

As power electronic equipment becomes increasingly prevalent, interharmonic disturbances have emerged as a major obstacle to achieving precise synchrophasor measurement. To overcome this limitation, this work introduces a novel dynamic synchrophasor estimation approach utilizing the Iterative Symmetric Taylor Weighted Least Squares (I-STWLS) technique. By employing a Taylor series to represent the dynamic signal and applying iterative estimation through symmetrically weighted least squares, the proposed algorithm is able to mitigate the impact of negative frequency components and substantially enhance phasor estimation precision. Performance validation through simulations-conducted for both steady-state and dynamic conditions as prescribed in IEEE/IEC 60255-118-1, such as tests for frequency deviation and ramping-shows that ISTWLS consistently delivers highly accurate results, maintaining TVE, FE, and RFE well within the required limits. Furthermore, the method demonstrates considerable resistance to interharmonic interference and fully satisfies the criteria for both M-class and Pclass PMUs, indicating its significant promise for practical engineering use.