A space vector based approach for synchrophasor measurement

This paper proposes a simple technique to estimate the positive sequence synchrophasor and the frequency of three-phase voltages or currents in power systems. The approach is based on the space vector transformation using a reference frame which rotates at the rated angular frequency ω0 of the power system. All the frequency components are shifted by ω0, so that the positive sequence phasor appear as a very low frequency term. The frequency shift also decreases the ratio between the frequency of the positive sequence phasor and those of the disturbances, so that they can be rejected by using a simple IIR filter thus requiring low computational effort. Then, the magnitude and phase of the phasor as well as its frequency can be easily estimated through an ordinary least square optimization. A proper tuning of the parameters allows the approach to comply with P-class or M-class requirements of the standard IEEE C37.118.1.