Design of power system stabilizers based on μ-controller for power system stability enhancement

The problem of the poorly damped low-frequency (0.1-0.4 Hz) oscillations of power systems has been a matter of concern to power engineers for a long time, because they limit the power transfer capability in power systems. The power systems stability is also affected by these poorly damped oscillations and can lead to the system instability. The paper presents a design PSSs based on μ-controller to enhance power systems stability and improve power transfer capability. MATLAB dynamic model was developed for a power system and lead-lag PSS structure is considered in the model. Damping torque technique is applied to tune the PSS parameters. The results of this technique have been verified by eigenvalue analysis and time-domain simulations. The optimal sampling time was determined for transferring the s-domain of PSS model to digital (z-domain) model and then it was implemented on μ-controller chip. The peripheral interface controller (PIC) μ-controller type was used and the developed MATLAB model was interfaced with the μ-controller. The simulations results show that the system time responses under different operating conditions are well damped with the designed PSS. Moreover, the proposed PSS based μ-controller is relatively simple and suitable for real-time applications in the future smart power grid where the stabilizing signals to the PSSs will be provided by wide-area measurement signals using the new technology of synchrophasors.