Digital measurements of symmetrical components of a multiphase power system

The paper presents a digital algorithm method for measurements of symmetrical components of a multiphase power system, four phases. The models for symmetrical components of the multiphase system are first developed, and the algorithm of solution is introduced. The proposed algorithm uses the samples of the phase voltages; the least error squares algorithm is the estimation algorithm to identify the magnitude and phase angle of each component. In this paper, the voltage signals are assumed to be polluted with noise and/or harmonics. Identifying the symmetrical components can be used to analyzing the fault in the system. Effects of critical parameters on the estimated components are discussed.