Fuzzy adaptive fault detector of power systems based on Riccati equation

The dynamics of power systems contain nonlinearities such as trigonometric functions and parameter uncertainties of reactances of transmission lines caused by short circuit faults. Wang et al. (1993, 1994) employed the feedback linearization technique and proposed the switching control between the power system stabilizer (PSS) and the automatic voltage regulator (AVR) in exciting the generator. The PSS is used in the case of transmission-line faults to attain transient stability enhancement. Therefore, it is important to know when the faults occur in the transmission lines. We design an adaptive fault detector for the transmission lines of Wang´s (1994) power system model. We employ the fuzzy basis function expansion and the adaptive parameter update law with a Riccati equation in designing the adaptive fault detector