Tuning Of Power System Stabilizers Research Articles

Pole placement by coordinated tuning of Power System Stabilizers and FACTS-POD stabilizers

This work presents the application of the Decentralized Modal Control method for pole placement in multimachine power systems utilizing FACTS (Flexible AC Transmission Systems), STATCOM (Static Synchronous Compensator) and UPFC (Unified Power Flow Controller) devices. For this, these devices are equipped with supplementary damping controllers, denominated POD (Power Oscillation Damping), achieving a coordinated project with local controllers (Power System Stabilizers – PSS). Comparative analysis on the function of damping of the FACTS, STATCOM and UPFC is performed using the New England System that has 10 generators, 39 buses and 46 transmission lines.

Wide-area Power System Oscillation Damping using Model Predictive Control Technique

This paper presents a new approach to deal with the problem of robust tuning of power system stabilizer (PSS) and automatic voltage regulator (AVR) in multi-machine power systems. The proposed method is based on a model predic- tive control (MPC) technique, for improvement stability of the wide-area power system with multiple generators and distribution systems including dispersed generations. The proposed method provides better damping of power system oscillations under small and large disturbances even with the inclusion of local PSSs. The effectiveness of the proposed approach is demonstrated through a two areas, four machines power system. A performance comparison between the proposed controller and some of other controllers is carried out confirming the superiority of the proposed technique. It has also been observed that the proposed algorithm can be successfully applied to larger multiarea power systems and do not suffer with computational difficulties. The proposed algorithm carried out using MATLAB/SIMULINK software package.

A Practical Power System Stabilizer Tuning Method and its Verification in Field Test

This paper deals with parameter tuning of the Power System Stabilizer (PSS) for 612 MVA thermal power plants in the KEPCO system and its validation in a field test. In this paper, the selection of parameters, such as lead-lag time constants for phase compensation and system gain, is optimized using linear and eigenvalue analyses. This is then verified through the time-domain transient stability analysis. In the next step, the performance of PSS is finally verified by the generator's on-line field test. After the field test, measured and simulated data are also compared to prove the effectiveness of the models used in the simulations.

Simultaneous Tuning of Power System Stabilizers for Enhancing the Damping Performance in Multi-Machine Power Systems

Simultaneous Tuning of Power System Stabilizers for Enhancing the Damping Performance in Multi-Machine Power Systems

Optimisation, localisation et réduction des stabilisateurs de puissance par algorithmes génétiques

The choice of Power System Stabilizer (PSS) parameters and PSS number as well as their location in power systems are an essential feature in small signal stability. This paper presents genetic algorithms based technique that improves PSS tuning and optimizes location with a reduced number of PSSs devices in a multimachine power system. To validate the performance of this approach in enhancing power system stability, a 16 generators power system model has been studied. The results found are compared with ones of conventional methods.

PSO Algorithm-Based Optimal Tuning of PSS for Damping Improvement of Power Systems

In this paper a method based on the Particle Swarm Optimization (PSO) algorithm is presented for tuning Power System Stabilizer (PSS) parameters. In the proposed method, based on the optimization of a suitable objective function, optimal values for PSS controlling parameters including lead-lag compensator time constants as well as the controller gain are calculated. The employed objective function is the damping ratio of eigenvalues corresponding to system critical modes obtained from the analysis of the linearized model of system around the operating point. Controllable and critical modes of the system are identified using modal controllability and observability criteria. The proposed algorithm is applied to a single machine power system and for various operating conditions. Simulation results prove the capability of the proposed algorithm in damping improvement of power system.

Coordinated control of low-frequency oscillations using real immune algorithm with population management

This paper proposes a modified version of real immune algorithm (RIA) using population management, namely, RIAPM, to simultaneous coordinated tuning of power system stabilizers (PSSs) in a power system. A conventional lead-lag structure is considered for the controllers. Since, the parameters of lead-lag controllers are continuous variables to be found and an infinite number of candidate solutions will exist, therefore a modification will be considered to RIA to reduce the search space gradually, in order to get a more detailed investigation in a smaller region. Using the RIAPM, the parameters of the damping controllers are optimized simultaneously and the interactions among the controllers are considered. The numerical results are presented on a 2-area 4-machine system to illustrate the feasibility of the proposed method. To show the effectiveness of the designed controllers, a three-phase fault is applied at a bus. The simulation study shows that the RIAPM performs better than RIA.

An algorithm for computerized automatic tuning of power system stabilizers

The main objective of this paper is to relieve the power system engineers from the burden of the complex and time-consuming process of power system stabilizer (PSS) tuning. To achieve this goal, the paper proposes an automatic process for computerized tuning of PSSs, which is based on an iterative process that uses a linear matrix inequality (LMI) solver to find the PSS parameters. It is shown in the paper that PSS tuning can be written as a search problem over a non-convex feasible set. The proposed algorithm solves this feasibility problem using an iterative LMI approach and a suitable initial condition, corresponding to a PSS designed for nominal operating conditions only (which is a quite simple task, since the required phase compensation is uniquely defined). Some knowledge about the PSS tuning is also incorporated in the algorithm through the specification of bounds defining the allowable PSS parameters. The application of the proposed algorithm to a benchmark test system and the nonlinear simulation of the resulting closed-loop models demonstrate the efficiency of this algorithm.

Robust Tuning of Power System Stabilizer Using a Non-iterative Taguchi Design Technique

This article presents a new non-iterative approach to deal with the problem of robust tuning of power system stabilizers. The proposed approach is based on the Taguchi robust design technique, which aims at optimizing the power system stabilizer parameters while simultaneously reducing the influence of variations in system operating conditions. The robust tuning methodology of a single-stage power system stabilizer for the single-machine infinite-bus system is presented to demonstrate the Taguchi-based approach. The robust power system stabilizer parameters are determined using analysis of means. The robustness of the designed power system stabilizer is tested using no-way analysis of means and time domain simulations.

Validity testing of third-order nonlinear models for synchronous generators

Third-order nonlinear models are commonly used in control theory for the analysis of the stability of both open-loop and closed-loop synchronous machines. However, the ability of these models to describe the electrical machine dynamics has not been tested experimentally. This work focuses on this issue by addressing the parameters identification problem for third-order models for synchronous generators. For a third-order model describing the dynamics of power angle δ , rotor speed ω and quadrature axis transient EMF E q ′ , it is shown that the parameters cannot be identified because of the effects of the unknown initial condition of E q ′ . To avoid this situation, a model that incorporates the measured electrical power dynamics is considered, showing that state measurements guarantee the identification of the model parameters. Data obtained from a 7 kVA lab-scale synchronous generator and from a 150 MVA finite-element simulation were used to show that, at least for the worked examples, the estimated parameters display only moderate variations over the operating region. This suggests that third-order models can suffice to describe the main dynamical features of synchronous generators, and that third-order models can be used to design and tune power system stabilizers and voltage regulators.

Bio-inspired fuzzy logic based tuning of power system stabilizer

In this paper, bacteria foraging optimization (BFO) – a bio-inspired technique, is utilized to tune the parameters of both single-input and dual-input power system stabilizers (PSSs). Conventional PSS (CPSS) and the three dual-input IEEE PSSs (PSS2B, PSS3B, and PSS4B) are optimally tuned to obtain the optimal transient performances. A comparative performance study of these four variants of PSSs is also made. It is revealed that the transient performance of dual-input PSS is better than single-input PSS. It is, further, explored that among dual-input PSSs, PSS3B offers superior transient performance. A comparison between the results of the BFO and that of genetic algorithm (GA) is conducted in this study. The comparison reveals that BFO is more effective than GA in finding the optimal transient performance. For on-line, off-nominal operating conditions Sugeno fuzzy logic (SFL) based approach is adopted. On real time measurements of system operating conditions, SFL adaptively and very fast yields on-line, off-nominal optimal stabilizer parameters.

Parameters tuning of power system stabilizers using improved ant direction hybrid differential evolution

The tuning of the PSS parameters for a multi-machine power system is usually formulated as an objective function with constraints consisting of the damping factor and damping ratio. A novel mixed-integer ant direction hybrid differential evolution algorithm, called MIADHDE, is proposed to solve this kind of problem. The MIADHDE is improved from ADHDE by the addition of accelerated phase and real variables. The performances of three different objective functions are compared to the MIADHDE in this paper. Both local and remote feedback signals of machine speed deviation measurements can be selected as input signals to the PSS controllers in the proposed objective function. The New England 10-unit 39-bus standard power system, under various system configurations and loading conditions, is employed to illustrate the performance of the proposed method with the three different objective functions. Eigenvalue analysis and nonlinear time domain simulation results demonstrate the effectiveness of the proposed algorithm and the objective function with a remote signal.

Optimal locations and tuning of robust power system stabilizer using genetic algorithms

Optimal locations and design of robust multimachine power system stabilizers (PSSs) using genetic algorithms (GA) is presented in this paper. The PSS parameters and locations are computed to assure maximum damping performance under different operating conditions. The efficacy of this technique in damping local and inter-area modes of oscillations in multimachine power systems is confirmed through nonlinear simulation results and eigenvalues analysis.

Tuning fuzzy power-system stabilizers in multi-machine systems by global optimization algorithms based on efficient domain partitions

In this paper, the problem of global tuning of fuzzy power-system stabilizers (FPSSs) present in a multi-machine power system in order to damp the power system oscillations is considered. In particular, it is formulated as a problem of global minimization of a multiextremal black-box function over a multidimensional hyperinterval. A global optimization technique, recently proposed, is used for solving the stated problem: the search hyperinterval is partitioned into smaller hyperintervals and the objective function is evaluated only at two vertices corresponding to the main diagonal of the generated hyperintervals, thus avoiding unnecessary ponderous simulations. Then, the performances of this technique are numerically compared with ones of a genetic algorithm (GA).

Power system stabilization control based on the wide area phasor measurement

AbstractThis paper presents a method of tuning power system stabilizers (PSS) in order to damp low‐frequency oscillations in a multimachine power system based on wide area phasor measurements. The authors have developed a method for detecting interarea low‐frequency modes from measured small oscillations associated with load fluctuations by approximating the oscillations as a coupled vibration model. In this paper, the coupled vibration model is extended to include the effect of PSS. PSS are tuned directly by using the extended model, since the model includes parameters of PSS. The advantage of this method is that steady state phasor fluctuations are available for tuning PSS and assessing the effect of the tuning control. That is, a large disturbance like a line fault is not necessary since the stability of major modes can be investigated directly by using eigenvalues of the extended model. The identification process does not require information on the input to the system for perturbation. Some numerical analyses demonstrate the effectiveness of the method by using phasor dynamical data obtained by a power system simulation package. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 163(1): 16–24, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20640

Optimal tunning of lead-lag and fuzzy logic power system stabilizers using particle swarm optimization

In this paper, the problem of simultaneous and coordinated tuning of brushless exciter and lead-lag power system stabilizer parameters of a single infinite bus power system is considered. This problem is formulated as an optimization problem, which is solved using particle swarm optimization technique. Also in this paper, the optimal tuning of a fuzzy logic power system stabilizer using particle swarm optimization method is carried out.Simulation results show the effectiveness of the proposed particle swarm optimization-based lead-lag power system stabilizer and particle swarm optimization-based fuzzy logic power system stabilizer to damp the oscillation of multimachine system and work effectively under variable loading and fault conditions.

Optimal Power System Stabilizer Tuning in Multi-machine System via an Improved Differential Evolution

Power system stabilizer (PSS) is one of the most important controllers in modern power systems for damping low frequency oscillations. Many efforts have been dedicated to design the tuning methodologies and allocation techniques to obtain optimal damping behaviors of the system. Traditionally, it is tuned mostly for local damping performance, however, in order to obtain a globally optimal performance, the tuning of PSS needs to be done considering more variables. Furthermore, with the enhancement of system interconnection and the increase of system complexity, new tools are required to achieve global tuning and coordination of PSS to achieve optimal solution in a global meaning.Differential evolution (DE) is a recognized as a simple and powerful global optimum technique, which can gain fast convergence speed as well as high computational efficiency. However, as many other evolutionary algorithms (EA), the premature of population restricts optimization capacity of DE. In this paper, a modified DE is proposed and applied for optimal PSS tuning of 39-Bus New-England system. New operators are introduced to reduce the probability of getting premature. To investigate the impact of system conditions on PSS tuning, multiple operating points will be studied. Simulation result is compared with standard DE and particle swarm optimization (PSO).

Application of a Stability-Constrained Optimal Power Flow to Tuning of Oscillation Controls in Competitive Electricity Markets

A novel technique based on a stability-constrained Optimum Power Flow (OPF) algorithm that properly captures important rotor angle and voltage stability conditions is proposed and described. The application of this technique to the optimal tuning of both Power System Stabilizers (PSS) and thyristor controlled series compensators (TCSC) to damp power system oscillations within the context of competitive electricity markets is proposed and discussed as well. The proposed technique is tested on the IEEE 14-bus benchmark system and compared with a "standard" OPF algorithm. The results obtained demonstrate the advantages of the proposed technique over existent dispatching techniques from the point of view of power dispatch and system stability conditions, and especially locational marginal prices.

Neural Network Based Assessment of Small-Signal Stability

This paper presents a neural network (NN) based approach for the assessment of small-signal stability of single-machine infinite bus power system by predicting the modal components of the local mode. Two types of feedforward NNs were examined, namely, the radial basis function neural network (RBFNN) and back propagation neural network (BPNN). The input patterns of the generator real and reactive power, over a wide range of operating conditions, were associated with the corresponding output patterns of the damping factor and damped frequency of the local mode of oscillation. The performance of the NNs was evaluated in terms of the training and generalization simulation results. The performance comparison between the NNs shows that the RBFNN is much faster in training and more accurate in approximation than the BPNN. The simulation results also show that the proposed approach can be used as an effective tool by power system operators to predict the local mode and assess the small-signal stability of the system and take the appropriate action to enhance the system stability over a wide range of operating conditions by tuning power system stabilizers, etc.

06/02187 Use of power system stabilizers for damping inter-area oscillations in the south systems of the Mexican electrical grid: Castellanos, R. B. et al. Electric Power Systems Research, 2006, 76, (4), 169–179.

This paper documents research conducted to investigate the use and tuning of power system stabilizers (PSSs) to improve small-signal dynamic performance of the Mexican interconnected system (MIS). The analysis focuses on the control of a critical inter-area mode associated with the interaction between the southeastern and western regions of the system and a critical local mode. Study results include the determination of critical system modes more controllable by existing PSSs and the use of supplementary control actions to damp low-frequency inter-area modes of oscillation. Results for both, small and large perturbations are presented to illustrate the placement and tuning of PSSs at several appropriate locations throughout the system. © 2005 Elsevier B.V. All rights reserved.