Robust decentralized turbine/governor control using linear matrix inequalities (original) (raw)

Decentralized robust guaranteed cost control for multimachine power systems

14th International Conference on Sciences and Techniques of Automatic Control & Computer Engineering - STA'2013, 2013

In this paper, we investigate the problem of the decentralized robust stabilizing control approach and mainly the decentralized robust guaranteed cost control for robust stabilization of interconnected multimachine power systems. The proposed feedback control schemes are developed to ensure the asymptotic stability of the nonlinear uncertain large scale system and formulated in a minimization problem within the framework of linear matrix inequalities (LMIs) which resolution yields the decentralized control gain matrices. The effectiveness of the proposed control techniques are demonstrated through numerical simulations on a nonlinear uncertain power system with three interconnected machines, for different cases of perturbations. Index Terms-Decentralized control; Robust control; Guaranteed cost control; Interconnected power systems; LMI;

Decentralised control of multimachine power systems with guaranteed performance

IEE Proceedings - Control Theory and Applications, 2000

The paper focuses on a robust dcccntralised excitation control of inultimachine power systems. The authors are concerned with the design of a decentralised state feedback controller for the powcr system to enhance its transient stability and ensure a guaranteed level of performance when there exist variations of generator parameters due to changing load and/or network topology. It is shown that the power system can be modelled as a class of interconnected systems with uncertain parameters and interconnections. The authors develop a guaranteed cost control technique for the interconnected system using a linear matrix inequality (LMI) approach. A procedure is given for the minimisation of the cost by employing the powerful LMI tool. The proposed controller design is simulated for a three-machine power system example. Simulation results show that the decentralised guaranteed cost control greatly enhances thc transient stability of the power system in the face of various operating points, faults in different locations or changing network parameters.

Decentralized stabilization of large electric power systems

Computers & Electrical Engineering, 1984

This paper considers the problem of stabilizing the dynamics of a large electric power system, represented by a linear time invariant system of equations, by using several decentralized (or local) state feedback control laws. The stabilization problem is formulated into a functional minimization problem which implicitly controls the closed-loop eigenvalues of the controlled system. The constraint of decentralization is tackled in the minimization algorithm by using the method of feasible directions. To illustrate the application of the algorithm, it is used to stabilize a three machine electric power system.

Decentralized constrained optimal control of the multimachine power system stability improvement

Indonesian Journal of Electrical Engineering and Computer Science, 2020

This paper proposes a decentralized constrained optimal control of the multimachine power system stability. Today's power networks operate closer to their maximum limits. Alternative Current power grids are more vulnerable and subject to instability than ever before. A three machine power system and four machines, power system connected with a lossy transmission line, is investigated. The linearized dynamical equations of the multimachine power system are obtained near to an equilibrium point, and it can be stabilized by using a decentralized constrained controller based on optimal control. The feedback controller, which comprises independent control stations, receives the measurement data and influences the control input of the machine attached to it the subsystems. State feedback controller guarantees that the closed-loop system is stable and can guarantee the performance index. The designed controlled systems are based on the Algebraic Riccati Equations, and all its poles are in the closed left half-plane. Decentralized constrained optimal control of the multimachine power system is achieved through simulation results. The following results are proposed by improving power system stability.

Nonlinear decentralized control of large-scale power systems

Automatica, 2000

This paper describes an application of nonlinear decentralized robust control to large-scale power systems. Decentralized power controllers are designed explicitly to maintain transient stable closed-loop systems. For the "rst time, nonlinear bounds of generator interconnections are used which achieves less-conservative control gains. The proposed controllers are robust with regard to uncertain network parameters and attenuate the persistent disturbances in the sense that the¸-gain from the disturbance to the power frequency is reduced to a certain level. Simulations on a two-generator in"nite bus power system exhibit enhancement of system transient stability at di!erent conditions of operation points, fault locations and network parameters.

Decentralized Nonlinear Controller Design for Multimachine Power Systems via Backstepping

In this paper, a backstepping-based decentralized control scheme is proposed for transient stability enhancement of multi-machine power systems. The design is based on two stages: First, an equivalent single-machine infinite-bus model (SMIB) is developed with respect to each machine. Then, apart from each SMIB model, a decentralized nonlinear control scheme based on a backstepping technique is designed which guarantees asymptotic stability of the overall interconnected power system. Some simulation results demonstrate the effectiveness of this approach.

Robust decentralised load-frequency control using an iterative linear matrix inequalities algorithm

2004

The load-frequency control (LFC) problem has been one of the major subjects in electric power system design/operation and is becoming much more significant today in accordance with increasing size, changing structure and complexity of interconnected power systems. In practice LFC systems use simple proportional-integral (PI) controllers. However, since the PI controller parameters are usually tuned based on classical or trial-and-error approaches, they are incapable of obtaining good dynamical performance for a wide range of operating conditions and various load changes scenarios in a multi-area power system. For this problem, the decentralised LFC synthesis is formulated as an HN-control problem and is solved using an iterative linear matrix inequalities algorithm to design of robust PI controllers in the multi-area power systems. A three-area power system example with a wide range of load changes is given to illustrate the proposed approach. The resulting controllers are shown to minimise the effect of disturbances and maintain the robust performance.

Robust H∞ Control with Selection of Sites for Application of Decentralized Controllers in Power Systems

2012

Eigenanalysis and frequency domain techniques are used for selection of the best sites for application of controllers in multivariable power systems and to design robust H∞ controllers, which are constrained to be decentralized with reduced order and fixed structure. Parameters of the controllers are tuned by using a reliable optimization method to result into a robust control in damping of the critical oscillation modes. Interactions among controllers are analyzed. A good coordination of control is achieved by simultaneous design and application of all controllers in the selected sites. The proposed techniques are applied to design H∞-PSS in a multimachine power system.