Abstract
In order to control large and complex power system, more flexible decentralized control scheme is desired. Since the system configuration is changing continuously, the system must be controlled based on uncertain and inadequate information. The control scheme should provide robustness.
The sliding mode control based on the variable structure system theory is paid attention as one of the promising robust control scheme. In the sliding mode control, the structure of the control system is changed across the hyperplane (switching plane) in state space so that the state variables of the system are kept on the hyperplane.
In this paper, applications of the sliding mode control to power system stabilization are discussed. The sliding mode control is applied to the control of the thyristor controlled SDR (System Damping Resistor). Since the SDR is operated discretely (on or off), it is impossible to keep the state variables on the switching plane all the time. Therefore, the “partial” sliding mode control is introduced. A new practical switching plane for the sliding mode control is developed. Using the plane, the system can be stabilized effectively.
