The analog PID controller has been used for the automatic voltage regulator (AVR) of synchronous generator. However, it can not cope with the dynamic performance of the plant due to the change of reference and the disturbance in operation. Then, it is necessory to change the parameters of the controller corresponding to the dynamic performance.
In this paper, the stability of the controller and the closed-loop system of the self-tuning control (STC) AVR of synchronous generator, which is the important problem in the application of the self-tuning control to the AVR of synchronous generator, is discussed for the realization of the automatic tuning of the parameters of controller. In the first step, the pole assignment for the stable response is discussed from a viewpoint of the root locus. Then, the input weighting polynomial is sellected for the stable closed-loop system and the stable controller. Then, the coefficients of the input weighting polynomial are decided. The least-square identification using the supremum trace gain method is introduced to enhance the flexibility of system. Secondly, the validity of the control system is discussed by the simulation of the step response. Furthermore, the control system is constructed with the micro-processor and the availability of the control system is verified by the experiment of the step response and the closing and breaking of load.