Application of linearized power system model to selection of PST controller input signal

This paper presents a selection method for phase shift transformer PST controller input signal. Simple conditions of input signal selection are obtained using frequency response analysis. The proposed method requires a suitable modeling of power system including PST device. The two types of power system models described in this paper are the nonlinear equations system model and the linearized model. The linearized model is represented as a block diagram transfer function model and as a state space representation model. The block diagram model presented in this paper has been used for the PST feedback input signal selection. Five locally available measurements at the switching node of the PST are considered. The results of frequency domain tests have confirmed that the block diagram transfer function model is a useful tool for power system analysis. The LQR method is used to achieve the final verification and the choice of input control signal.