Improvement of the transient stability and voltage regulation of a single-machine-infinite-bus power system under the effects of a symmetrical three-phase short-circuit fault is detailed. The dynamical model of the system is described. A design strategy for nonlinear controllers is considered, and the design of a nonlinear variable-structure excitation controller is described. Simulation results obtained using the nonlinear excitation controller are given, and a new nonlinear coordinated controller is proposed. Simulation results obtained by using the nonlinear coordinated controller are presented. >

Transient stability enhancement and voltage regulation of power systems

https://www.cs.ucf.edu/~yguo/paper/guoy_automatica.pdf

Nonlinear decentralized control of large-scale power systems

The note considers the L/sub 2/-disturbance attenuation of multimachine power systems via dissipative pseudo-Hamiltonian realization of the systems. First, the note expresses multimachine systems as a dissipative Hamiltonian system. Then, the note investigates the energy-based control design of L/sub 2/-disturbance attenuation of multimachine power systems and proposes a decentralized simple control strategy. Simulations on a six-machine system show that the achieved L/sub 2/-disturbance attenuation control strategy is very effective.

/pdf/dissipative-hamiltonian-realization-and-energy-based-l-sub-2-4fvxkftmr2.pdf

Dissipative Hamiltonian realization and energy-based L/sub 2/-disturbance attenuation control of multimachine power systems

A particle-swarm-based approach of power system stability enhancement with unified power flow controller

Robust decentralized nonlinear controller design for multimachine power systems

It is of great importance to improve stability as well as dynamic performances of power systems for both small and large disturbance. Such issues have received a great deal of attention and many contributions have been made to this objective. However, some of the design methods developed previously are based on second-order synchronous generator model, so excitation systems or/and governor systems could hardly be considered by them, the others based on linear models, which are set up by approximate linearizing at an equilibrium point of the system. Since, in fact, a power system is a nonlinear dynamic one, the controller designed by using the approximate linearized model may cause untolerable errors, while the state point of the system is changed away from the equilibrium point at which the linearization is realized. A new approach to nonlinear decoupled optimal control based on the differential geometric control theory for interconnected power systems is proposed. And it is successfully applied to nonlinear steam valving control of multimachine systems. For an m-machine system the optimal steam valving control law of the ith-machine can be expressed as ui= TS; ii(K1-M& 1+ K2 cw-+ K3; | wdt + TsiPei+ (Pmj-Pmjo) (18) where Mi inertia coefficient (in sec.) Tsi, time constant of servomotor and steam (in sec.) wi, speed (in per unit) Di damping coefficient Pei electrical power (in per unit) Pmi mechanical power (in per unit) and K1j, K2j, and K3j are optimal feedback gain coefficients.

Nonlinear stabilizing control of multimachine systems

This paper examines a category of second-order nonlinear systems' predefined-time tracking control issue restricted by the state and input from the control. The safety predefined-time control framework proposed by this work aims at tracking a desired trajectory in a predefined time while maintaining safe system outputs and control inputs. The safety predefined-time controller is specifically created by a safety filter utilizing the control barrier function approach and a predefined-time controller on the basis of the backstepping technique. The predefined-time controller establishes an explicit relation between the controller parameters and the convergence time constraint. Moreover, the safety filter enforces the state and control input constraints by constructing a quadratic programming problem. In an effort to demonstrate the feasibility of the safety predefined-time controller, a second-order practical system is simulated.

Yuan Zhang Sun

Papers

Nonlinear stabilizing control of multimachine systems

Safety Predefined-Time Tracking Control of Second-Order Nonlinear Systems