Fuzzy measurements of power system symmetrical components

The symmetrical components are an effective tool for the analysis of the unsymmetrical fault in the power systems. Also, it can be used as an indication to abnormal normal operation of power systems. This paper presents the application of fuzzy system to measure the symmetrical components of a power system for control and protection. The samples for the symmetrical components are obtained using the symmetrical transformation matrix in the time domain. Then the problem of the symmetrical component parameters is formulated as a linear fuzzy regression problem to estimate the fuzzy parameters of each component from the available samples. Two models are discussed in this paper, while in the first model, we assume that the data samples are non-fuzzy, and the model coefficients are fuzzy. In the second model, we assume the data samples are fuzzy and the model parameters are fuzzy as well. The simplex-based linear programming method is used to solve the resulting problems. Simulated and actual recorded data are presented in the paper.