  The increasing use of renewable generation, power electronic devices, and
nonlinear loads in power systems brings more severe interharmonic tones to the
measurand, which can increase estimation errors of P-class PMUs, cause
misoperation of protection relays, and even threaten the stability of the power
systems. Therefore, the performance of the P-class synchrophasor estimator
under interharmonic interference should be evaluated and new estimation schemes
that can improve the operational robustness are needed for various protection
and control applications. In this paper, a synchrophasor estimator design for
P-class PMUs that introduces singular value decomposition to the least square
algorithm based on the Taylor series is proposed. By constructing an
optimization with proposed adjustable parameters, finite impulse response
filters with high transition band attenuation are designed. Numerical and
experimental tests verify the proposed dynamic synchrophasor estimator
performance and show an effective improvement in rejecting interharmonic tones,
especially when a short time window and light computational burden are
required.
