Stability of power system using variable structure controller with free chattering

A new technique for improving the dynamic stability of a power system based on variable structure stabilizer is synthesized in this paper. This technique makes use of the variable structure system and employs the generator speed to obtain a stabilizing signal to increase the damping torque of the synchronous machine. Supplementary stabilizing signals are also introduced in the power system to increase the damping torque of the synchronous machine. This improves the transient stability of the power system. The plant augmentation method is used to solve the existing control chattering problem. Augmenting the plant by a pure integrator places control chattering at the augmented plant input instead of the original plant input. The simulation results demonstrate that the proposed technique yields a good dynamic performance with overshoot and shorter settling time in step response. This technique can be used as an effective means of increasing the damping torque and hence improving the dynamic stability of the power system.