Proposed Power System Stabilizer Research Articles

A new-fangled adaptive mutation breeder genetic optimization of global multi-machine power system stabilizer

This paper presents the design and implementation of Power System Stabilizers in a multimachine power system based on innovative evolutionary algorithm overtly as Breeder Genetic Algorithm with Adaptive Mutation. For the analysis purpose a Conventional Power System Stabilizer was also designed and implemented in the same system. Simulation results on multimachine systems subjected to small perturbation and three phase fault radiates the effectiveness and robustness of the proposed Power System Stabilizers over a wide range of operating conditions and system configurations. The results have shown that Adaptive Mutation Breeder Genetic Algorithms are well suited for optimal tuning of Power System Stabilizers and they work better than conventional Genetic Algorithm, since they have been designed to work on continuous domain. This proposed Power System Stabilizer is demonstrated through a weakly connected three multi-machine test systems.

Optimal tuning of multi-machine power system stabilizers by the Queen-Bee Evolution technique

A Queen-Bee Evolution-based tuning of a multi-machine power system stabilizer, which aims at enhancing the damping of the system over a wide range of operating conditions, is introduced in this paper. The basic components of this study are modeled by IEEE Model 1.1 and Heffron–Philips constants, considering the external resistance but neglecting the armature resistance. The problem is then formulated as a constrained multi-objective optimization problem. For investigation purposes, two different test systems are considered. The non-linear time domain simulations of the proposed power system stabilizer are compared with that based on the conventional approach power system stabilizer. The overall transfer function and the characteristic equation of the compensated system are derived from the single equivalent block diagram, and the nature of stability is verified by both frequency response analysis and Routh-Hurwitz (RH) criterion. Simulation results show that the proposed method motivates faster damping and leads to minimal overshoots in both speed and power angle deviations.

A Novel Algorithm to Minimize the Excitation of Undesirable Oscillations-State Space

A new state-space type stabilizer to minimize low frequency oscillation is proposed. The proposed Power System Stabilizer (PSS) design not only damps the oscillations by moving the Eigen-values to desired left hand plane locations but additionally reduces the excitation of the mode itself through optimization of the left eigenvector of the poorly damped electro-mechanical mode. The stabilizer is implemented as a State-Space (SS) type controller which is optimized using a constrained optimization procedure. Two possible inputs, speed and electrical power are considered as candidate inputs to the stabilizers. The state-space design is also compared with one based on traditional lead-lag compensation. The SS type stabilizer with electrical power input is shown to perform better compared to any other type of PSS by minimizing low frequency oscillations.

Design of robust electric power system stabilizers using Kharitonov’s theorem

A robust power system stabilizer (PSS) is proposed as an effective way to damp-out oscillations in electric power systems. Oscillations of small magnitude and low frequency, linked with the electromechanical models in power systems, often persist for long periods of time and in some cases present limitations on the power transfer capability. The proposed PSS is designed according to Kharitonov’s extremal gain margin theory. It has the following advantages: (i) it is based on simultaneous stabilization of limited number of extreme plants, (ii) the control design can be based on frequency response analysis techniques (root locus diagrams or Nyquist plots) and (iii) the resulting controller is a low-order phase-lead compensator, which is robust to the change of operating points. The proposed power system stabilizer is tested through simulation experiments.

Design of Model-reference Discrete-time Sliding-mode Power System Stabilizer

Power system stabilizers improve the dynamic stability of power systems by increasing the damping torque of the synchronous machines in the system. Over the last four decades, various approaches for the design of power system stabilizers have been reported in the literature. The sliding-mode controller is one of these approaches that has some advantages, such as parameter insensitivity and realization simplicity, over other approaches. In this article, as a first and new approach for the design of the power system stabilizer in the literature, a model-reference discrete-time sliding-mode controller is presented. The effectiveness and the robustness of the proposed model-reference discrete-time sliding-mode controller based power system stabilizer is demonstrated by a number of studies. Simulation results show that the proposed power system stabilizer performs better for less overshoot and less settling time compared with the conventional and linear quadratic regulator based stabilizers under normal load operation and significant system parameter variation conditions.

Power System Stabilizer Design for Minimal Overshoot and Control Constraint Using Swarm Optimization

Power systems are subjected to severe repetitive oscillations that might cause generator shaft fatigue and, consequently, breakdown. In this article, we consider the problem of designing a power system stabilizer that alleviates generator shaft fatigue through the minimization of the maximum overshoot. Moreover, through our design, the levels of control signal, as well as controller parameters, have to be maintained within certain bounds imposed by physical and practical considerations. In this respect, a technique based on the particle swarm approach is proposed to identify the parameters of a fixed structure lead compensator through the solution of a min-max problem while satisfying systems constraints. To enhance the overall performance of the system under wide loading conditions, a set of operating points is considered within our approach. The proposed power system stabilizer is applied to a single-machine infinite-bus system at different loading conditions, and the results showed the effectiveness of the developed approach.

Power System Reliable Stabilization with Actuator Failure

This article presents a new approach to design reliable controllers acting on the excitation and governor of a synchronous alternator. The usage of a power system stabilizer is inevitable for the enhancement of dynamic stability of power grids. The suggested reliable power system stabilizer ensures stability either when both controllers are sound or when one of them fails. A redundant feedback controller is designed using particle swarm optimization to achieve a desired degree of stability whether or not the main controller is responding. The design of the redundant controller is based on minimizing an eigenvalue-based objective function using particle swarm optimization. A single-machine infinite-bus system is considered to demonstrate the functionality of the proposed fault-tolerant controller. Results of the eigenvalue analysis reported in the present article show the effectiveness of the proposed power system stabilizer under different loading conditions. The approach is extended to consider reliable stabilization for multi-machine systems where the designed controller could successfully stabilize the system with sound operation as well as under control channel failure.

Discrete-time adaptive sliding mode power system stabilizer with only input/output measurements

In this paper a discrete-time adaptive sliding mode control method is newly developed and applied to the power system stabilization problem. A controllable canonical form of state space realization is constructed using the parameters identified by the on-line recursive least squares method and the system state is estimated from the input/output measurements and the simple state transformations. The identified parameters and the estimated state are then used by the discrete-time sliding mode control, which is suitable for the digital equipment. The most important advantage of the proposed power system stabilizer (PSS) is that it is able to maintain its regulating performance with a slower sampling period than that of the conventional sliding mode PSS because it is developed in a pure discrete-time domain. Another advantage of the proposed PSS is that it needs neither a mathematical model of the power system nor the full-state measurements because they are identified through on-line identifications. Several computer simulations for the linear power system are performed to verify the performance of the proposed PSS. In the computer simulations for various circumstances which are probable in a power system are considered, such as transitions of the active and reactive powers, change of parameters of the synchronous machine, line-to-ground faults and measurement noise. As a result, a new power system stabilizer which can operate in a wide range of operating conditions and can overcome various disturbances and measurement noises is proposed.

Evaluation of advanced fuzzy logic PSS on analog network simulator and actual installation on hydro generators

This paper presents the experimental evaluation of an advanced fuzzy logic PSS on the analog network simulator at the Research Laboratory of Kyushu Electric Power Co., Inc. The proposed power system stabilizer (PSS) is set up by using a personal computer with A/D and D/A conversion interfaces. The personal computer based PSS was set on the analog network simulator to evaluate the effectiveness of the advanced fuzzy logic control scheme, and to provide sufficient data for the actual installation of the proposed PSS on hydro-units in the Kyushu Electric Power System. This paper also describes the actual installation of the proposed PSS on hydro-units in the Kyushu Electric Power System for the long term evaluation of the proposed PSS using its prototypes.