Tracking objective controller design for power system stability based on Linearization through Observation

The precision of the voltage phase angle measured by the PMU (Phasor Measurement Unit) can well meet the need of power system analysis and control. A new controller is proposed for power system stability, which can linearize its nonlinear state equations by online tracking of the state variable with the help of PMU, and complete an objective control strategy that forces the system state into a desired objective. The control method is called linearization through observation (LTO) for a tracking objective control, which is proposed in this paper. Application of the LTO method on tracking objective excitation control (TOEC) is also presented in this paper. An example of a single machine infinite bus power system is given to show the effectiveness of the proposed controller. The simulation results show that TOEC is superior to linear optimal excitation control (LOEC) in both enhancing power system stability and improving power system dynamic quality. Meanwhile TOEC has the ability to force operation state into a desired objective, which will be very useful in the coordinating control of a large power system.