Detection of systematic errors in PMU measurements by the power system state estimation methods

Abstract

The state estimation is a procedure which determines the current state of a power system. For this purpose synchronized phasor measurements from PMU are used in combination with SCADA measurements. A method of test equations (TE) is used to detect gross errors in both SCADA and PMU measurements. The mathematical expectation of the TE discrepancy is used to identify a systematic error in measurements. The non-zero value of this expectation can only testify to the presence of a systematic error in measurements contained in TE, but cannot be used to detect it. Then, a "sensitivity" coefficient of the TE with respect to the error in each measurement is determined. If the measurement error cannot be detected, the value of the measurement distortion is determined by the state estimation procedure.