The time skew problem in PMU measurements

In this paper, the time skew problem observed in synchronized phasor measurement unit (PMU) measurements is illustrated and analyzed. The term `time skew' is used to describe the faulty sychronization of measurements from different PMUs which are expected to be synchronized based on the time stamps. The origin of the time skew is presented and a practical example is provided to depict the time skew existing in actual PMU measurements. A Kalman filter model is proposed to compensate for the time skew error.