An Adaptive Excitation System Controller in a Stochastic Environment

A digital, adaptive excitation system controller for synchronous machines is proposed in this paper. The controller design objectives include both reactive power flow control ( for voltage regulation ) and power system stabilization. The performance of the excitation controller is illustrated and evaluated in a stochastic environment. The dynamics of the system to which the machine is connected are modeled by a stochastic process. The adaptive controller is subjected to stochastic disturbances of constant variance and is affected primarily in the parameter identification process rendering instability of the system in some cases. The findings are relevant because the stability of the system is sensitive to the variance of the noise but stability is not otherwise sensitive to the probability density function of the environment parameters.