Novel approach for the design of state feedback power system stabilizers

Several researchers have shown in the literature that the state feedback power system stabilizers possess superior control capabilities when compared to the conventional lead-lag power system stabilizers. However, power system state variables are generally not measurable, especially the generator rotor angle measurement is not available in most of the power plants. In multi machine systems full state feedback controllers require feedback of other machine states as well. This makes the state feedback designs impractical. This paper utilizes the recently proposed modified Heffron Phillip´s model, which is derived by taking the secondary bus voltage of the step-up transformer as reference instead of the infinite bus, for the design of state feedback controllers so as to eliminate the drawbacks of existing state feedback designs. Here a linear quadratic regulator has been designed as state feedback controller. The performance of the proposed controller has been evaluated on a single machine infinite bus system over a wide range of system and operating conditions. It has been observed that the performance of the proposed controller is much better than the conventional PSS.