The Study Of Power System Transient Stability Control Design Via Energy Shaping

Power system is the pillar industries of modern society, and the transient stability is one of the most important criterions of power system security operation, as well as the main targets of power system automation controls, such as generator-tripping and load shedding, Thyristor Controlled Braking Resistor(TCBR), which are called Direct Energy Controlled Measures(DECMs) in this dissertation. The fundamental reason of transient instability is the destruction of power system energy balance. DECMs can directly eliminate the unbalance power and are regarded as one of the most effective control measures. The design of DECMs controller is a challenge problem both in theory and practical engineering because of its complexity. How to employ the energy-based theory and methods to guide the design the effective DECMs controller is the aim of this dissertation.In this paper, the energy-shaping theory and methods based on Hamiltonian system have been developed and applied into power systems' transient control, including the constant open-loop generator-tripping or load shedding emergency control and continuous close-loop Thyristor controlled braking resistor (TCBR).In modeling methodology aspects, the power injection model is proposed to describe the DECMs. Then by the Hamiltonian formulation of the controlled power system, an explicit energy analysis interpretation of the variables in the power system dynamic and the model of energy-based are provided. As for open-loop generator-tripping and load-shedding emergency control problem, the energy-shaping Casimir function method is applied into constructing a novel Lyapunov function which can integrally stability assess and emergency control design of power system with constant control. The stability judgment criterion, pseudo sensitivity and stability margin of controlled power system is proposed to develop an emergency control decision-making algorithm with relatively high efficient. As for the TCBR close-loop controller, the energy shaping IDA-PBC (Interconnected and Damping Assignment and Passive Based Control) method is applied to design a passive stabilizer, and the close-loop Hamiltonian function is the real energy function for the close-loop system. Also a feasible scheme is propose to employ the control strategy after considering the physical structure of power system. The proposed strategy and methods are proved to be effective by the results of digital simulation research done in this paper. This dissertation has some contributions in stability control design methodology based on Hamiltonian energy shaping theory.