Incorporation of static phase shifter in power systems using variable structure and state feedback control

This paper presents a new approach to static phase shifter (SPS) control. A general model of SPS has been adopted that allows the control of both the magnitude as well as the phase angle of the injected voltage. The SPS is incorporated as an integral part of the system being studied and the overall equations to model the steady state and dynamic behavior of the system are derived. A new control approach is developed where variable structure control (VSC) and state variable feedback are applied together to obtain various controller inputs. Simulation studies are carried out to investigate the effectiveness of the proposed technique under various control modes of SPS in a single machine infinite bus system when subjected to small as well as large system disturbances. Simulation results are presented to demonstrate the impact of controlling the (i) the magnitude of injected voltage, (ii) the phase angle of the injected voltage, and (iii) the magnitude as well as the phase angle of the SPS. The effectiveness of the developed control strategy as well as the nature of coordination required under various modes of SPS control are presented and discussed.