Conventional Power System Stabilizer Research Articles

Transient Stability and Voltage Regulation in Multimachine Power Systems Vis-à-Vis STATCOM and Battery Energy Storage

This paper examines the application of STATCOM and battery energy storage to enhance the transient stability of large-scale multimachine power systems with synchronous and doubly-fed induction generators (DFIGs). A passivity-based control design method [interconnection and damping assignment passivity-based control (IDA-PBC)] is developed for multimachine power systems and its performance is evaluated on a two-area system consisting of two synchronous generators (SGs) and two DFIG along with STATCOM/battery energy storage system. The main contributions of this paper are threefold: 1) use of a STATCOM and battery energy storage system to enhance transient stability and provide voltage regulation with SG and DFIG; 2) demonstrating the application of nonlinear control theory (specifically the IDA-PBC methodology) for the design of a stabilizing feedback controller in large-scale power systems to improve transient system performance; and 3) developing a methodology that can use the additional degrees of freedom in large-scale power systems in order to further improve system performance, in particular the transient stability margin [measured through critical clearing time (CCT)] and the dynamic transient performance of the system. In order to achieve power angle stability along with the simultaneous regulation of frequency and voltage, the performance of the proposed control scheme after the occurrence of large disturbances is evaluated and compared with a conventional power system stabilizer and a feedback linearizing controller.

A Developed Graphical User Interface for Power System Stability and Robustness Studies

This paper present the realization and development of a graphical user interface (GUI) to studied the stability and robustness of power systems (analysis and synthesis), using Conventional Power System Stabilizers (CPSS - realized on PID scheme) or advanced controllers (based on adaptive and robust control), and applied on automatic excitation control of powerful synchronous generators, to improve dynamic performances and robustness. The GUI is a useful average to facilitate stability study of power system with the analysis and synthesis of regulators, and resolution of the compromise: results precision / calculation speed. The obtained Simulation results exploiting our developed GUI realized under MATLAB shown considerable improvements in static and dynamic performances, a great stability and enhancing the robustness of power system, with best precision and minimum operating time. This study was performed for different types of powerful synchronous generators.

A new method for detection of fake data and adaptive fuzzy PI control for power system stability

This paper presents a fuzzy PI controller as a power system stabilizer. The fuzzy PI controller has been designed in order to prepare an auxiliary signal for the excitation system of the synchronous generator. The proposed controller utilizes a combination of a fuzzy logic controller (FLC) and a PI controller, which are the most recent researches in the problem at hand. In comparison with the conventional fuzzy controllers, the proposed fuzzy PI controller takes advantage of both FLC and conventional PI controller to overcome all kind of disturbances. The damping of oscillations local modes in a power system will substantially be controlled by employing this controller as a replacement for conventional PSS. Furthermore, the presented paper considers the conventional PSS and compares its performance with respect to three proposed types of fuzzy PI controller. Correspondingly, the effects of the supplementary signals in damping oscillation have been shown. Finally, to scrutinize the effectiveness of the proposed controller in damping oscillations, a three-phase short circuit condition is studied in order to clarify the application of the developed methodology. The achieved outcomes show that the proposed controller for stabilizing power system can provide very good damping characteristic.

Self-Tuning Control for Synchronous Machine Stabilization

A small-signal stability problem of a synchronous generator influencing a power grid was studied. A thorough theoretical analysis of a simplified linearized model of the synchronous generator connected to an infinite bus was carried out. The described analysis pointed out disadvantages of the conventional linear power system stabilizer. In contrast to the conventional, an original self-tuning power system stabilizer was developed. This stabilizer compacts a linear quadratic regulator and a recursive least square identification method. The study involving numerical simulations and laboratory experiments reveals encouraging results with displayed advantages and feasibility of this novel approach in considered applications. DOI: http://dx.doi.org/10.5755/j01.eee.21.4.12773

Optimal Parameters Tuning of Power System Stabilizer via Bees Algorithm<sup></sup>

This paper presents a new approach for designing the Power System Stabilizer. As in power system network, low frequency oscillation always occurs for a long period of time that will decrease the power transfer capability. Power System Stabilizer known as PSS is being installed as one of the control devices in a generating unit. The conventional PSS (CPSS) is the most commonly used in power system, which uses lead-lag compensation. The lack in CPSS has drawn an interest of designing the new approach of PSS to outperform the conventional one. Thus, Bees Algorithm (BA) which is known as one of the numerous intelligent optimization methods is proposed in this paper. It is appears to aid the system stability by optimizing the PSS parameters tuning. The PSS with the BA approach is labelled as BA-PSS and being tested on single machine infinite bus system (SMIB) in Matlab/Simulink environment. BA-PSS performance is compared with CPSS as to validate the ability of the proposed method to achieve great performance in power system stability enhancement. Different type of mechanical input is being injected into the system and the result shows that BA-PSS is capable to optimize the parameters tuning of PSS. BA-PSS also improved the unstable or poorly stable modes as the system achieve the stability with lower overshoot and less time settling. The superior response of BA-PSS controller proved the ability of BA approach in which is capable to solve the lack in CPSS with better performance in enhancing the system stability.

Lead Lag Controller of TCSC Optimized by Bees Algorithm for Damping Low Frequency Oscillation Enhancement in SMIB

Power system is often vulnerable to low frequency electromechanical oscillations due to the interconnected configuration. A common lead-lag controller is used for one of the FACTS devices known as Thyristor Controlled Series Compensator (TCSC) as supplementary controller for damping purpose in order to improve transient stability and power oscillation damping of the system. As Bees Algorithm (BA) optimized the parameters of the TCSC lead-lag controller, thus its named is TCSC-BALL. In this study, the optimization problem is formulated as a constrained optimization with the main objective is to move the system eigenvalues to the left as far as possible in order to improve the system stability. Then, the system is simulated in MATLAB by using The Phillips-Heffron model for single machine infinite bus (SMIB) with responses of increases in mechanical power at t=1 second. The performance is observed in terms of electromechanical eigenvalues position on s-plane and damping responses of low-frequency oscillations where the system implemented with the TCSC-BALL controller given better results as compared to the system without and with the inclusion of conventional Power System Stabilizer (CPSS).

Fuzzy Logic PSS Assisted by Neighboring Signals to Mitigate the Electromechanical Wave Propagation in Power Systems

This paper deals with the mitigation of electromechanical wave propagation in power systems. Different conventional controllers addressed this problem, such as the conventional PSS and the conventional fuzzy logic PSS. In this paper, the fuzzy logic PSS is assisted by auxiliary signals from the fuzzy logic PSS of the interconnected machines to augment the damping of electromechanical wave propagation and the associated oscillations. The neighboring machines speed deviation and its derivatives signals are exploited through the fuzzy logic PSS to assist the local fuzzy logic PSS. The disturbance propagation and reflection phenomena are considered in the design of the adopted strategy. The efficacy of the proposed assistance of the conventional fuzzy logic PSS are examined through different simulation results. DOI: http://dx.doi.org/10.11591/telkomnika.v14i3.7837

A New Meta-heuristic Technique Based on Robust Power System Stabilizer with Wind Power Penetrations

In this paper a robust Power System Stabilizer (PSS) is proposed based on inverse additive perturbation in a power system with wind farms. The proposed controller designed by new Improve Bacteria Foraging Algorithm (IBFA) to achieve robustness of this strategy where the optimization process is formulated based on an enhancement of system robust stability margin. The designed optimal PSS is based on Fuzzy Logic Controller (FLC). The effectiveness of the proposed technique is tested over ten macine 39 buses New England power system. Obtained results demonstrate the superiority of proposed technique over conventional PSS.

Improvement of the dynamic behavior of large-scale power systems by using robust power system stabilizers based on fuzzy logic

In this paper, the effect of fuzzy logic-based robust power system stabilizers on the improvement of the dynamics of a large-scale power system is investigated. The study is particularly focused on the Mexican Interconnected System and on adding damping to two critical inter-area system oscillation modes: The north-south mode and the western-peninsular mode. The fuzzy power system stabilizers (FPSSs) applied here are based on a significantly reduced rule base, small number of tuning parameters, and simple control algorithm and architecture, which makes their design and implementation easier and suitable for practical applications. Non-linear time-domain simulations for a set of test cases and results from Prony Analysis verify the robustness of the designed FPSSs, as compared to conventional PSSs.

Fabrication of oxide-based nano-patterned sapphire substrate to improve the efficiency of GaN-based of LED

In this study, an oxide-based nano-patterned sapphire substrate (ONPSS) was used as the substrate for a nitride-based light emitting diode (LED) in order to enhance the LED’s internal quantum efficiency and light extraction efficiency. The ONPSS was fabricated by a direct spin-on-glass printing technique, which is simple, easy, and relatively low-cost technique. Conventional PSSs are generally fabricated by photolithography and a sapphire etching process. However, the process reported here, it is possible to fabricate an oxide-based PSS without the sapphire etching process. After a GaN-based blue LED device was grown on the ONPSS, we measured the photoluminescence and electroluminescence intensity to confirm the light extraction efficiency and internal quantum efficiency of the LED. Compared to a GaN LED grown on an unpatterned sapphire, the ONPSS-based LED exhibited a 100% increase in light output power without electrical degradation.

Improved synergetic excitation control for transient stability enhancement and voltage regulation of power systems

Abstract This paper proposes decentralized improved synergetic excitation controllers (ISEC) for synchronous generators to enhance transient stability and obtain satisfactory voltage regulation performance of power systems. Each generator is considered as a subsystem, for which an ISEC is designed. According to the control objectives, a manifold, which is a linear combination of the deviation of generator terminal voltage, rotor speed and active power, is chosen for the design of ISEC. Compared with the conventional synergetic excitation controller (CSEC), a parameter adaptation scheme is proposed for updating the controller parameter online in order to improve the transient stability and voltage regulation performance simultaneously under various operating conditions. Case studies are undertaken on a single-machine infinite-bus power system and a two-area four-machine power system, respectively. Simulation results show the ISEC can provide better damping and voltage regulation performance, compared with the CSEC without parameter adaptation scheme and the conventional power system stabilizer.

Online Tuning of Power System Stabilizers using Fuzzy Logic Network with Fuzzy C-Means Clustering

Power system stabilizers (PSS) have been widely used to enhance damping due to the electromechanical low frequency oscillations occurrence in power systems. In this paper, a new method is used for the online tuning of parameters of conventional power system stabilizers (CPSS) using fuzzy logic. Fuzzy logic enables mathematical modeling and computation of some nonlinear parameters of the system, which are usually, derived empirically by utilization of expert knowledge rules. Various literatures has shown that fuzzy logic controller is one of the most useful methods for expert knowledge utilization. This type of controller is adaptive in nature and can be used successfully as a power system stabilizer. The design of fuzzy logic controllers is mainly based on fuzzy rules and input/output membership functions. Simple and efficient clustering algorithms allow data classification in distinct groups using distance and/or similarity functions. In the present paper, the optimum generation of fuzzy rules base using Fuzzy C-means (FCM) clustering technique is used. In fact, data are classified and the number of fuzzy rules which depends on convergence radius is determined. Finally, the performance of proposed FCM controller is compared with that of conventional controller. The active power, reactive power and bus voltages used as inputs to the fuzzy logic network based power system stabilizer and the parameters of the optimum stabilizer , i.e. gain factor as well as time constants of the lead/lag compensator, are the outputs of the proposed system. The design method has been successfully implemented on a single machine power system connected to an infinite bus over various operating conditions.

Optimal Tuning of Multimachine Power System Stabilizer using Cuckoo Search Algorithm

In this paper, optimal multiobjective design of robust multimachine Power System Stabilizers (PSS) using Cuckoo Search (CS) optimization algorithm is presented for small-signal stability enhancement. This algorithm is based on the obligate brood parasitic behaviour of some cuckoo species in combination with Lévy flight behaviour of some birds and fruit flies. A conventional speed-based lead-lag PSS is used in this work. The parameters of the Cuckoo Search based Power System Stabilizer (CSPSS) are optimized simultaneously to shift the unstable or poorly damped electromechanical mode eigenvalues of all operating conditions to a D-shape zone in the left half of the s-plane. A multiobjective eigenvalue based objective function is designed to optimize a problem involving the damping factor and damping ratio of the electromechanical modes. To show the effectiveness and the robustness of CSPSS, time domain simulations, eigenvalue analysis and performance indices are presented and compared with Genetic Algorithm based PSSs (GAPSS) and Particle Swarm Optimization based PSO (PSOPSS) under wide range of operating conditions and severe disturbances. It is observed that CSPSS exhibits improved damping performance compare to GAPSS and PSOPSS.

Power System Stabilizer Design Using Compressed Rule Base of Fuzzy Logic Controller

In this paper, the fuzzy logic controller (FLC) based power system stabilizer (PSS) with compressed / reduced rule is presented. The FLC rule base is generally based on empirical control rules. In this method, the fuzzy system with a large number of fuzzy rules is compressed to a fuzzy system with a reduced number of rules by removing the redundant and inconsistent rules from the rule base which doesn’t affect the performance of the fuzzy logic controller. The FLC based PSS has two input signals as speed deviation and derivative of speed deviation with an appropriate number of linguistic variables. The number of compressed rules in the rule base through the proposed dominant rule algorithm is reduced to a number as low in the number of selected linguistic variables to represent input and output signals. The application of the FLC with compressed rules as a power system stabilizer (CR-FPSS) is investigated by simulation studies on a single-machine infinite-bus system (SMIB). The superior performance of this compressed rule based fuzzy PSS (CR-FPSS) as compared to conventional PSS and proves the better efficiency of this new CR-FPSS. The reduced CPU computational time and storage space as compared to the fuzzy power system stabilizer (FPSS), proves its applicability in control.

Direct adaptive power system stabilizer design using fuzzy wavelet neural network with self-recurrent consequent part

This paper aims to propose a stable fuzzy wavelet neural-based adaptive power system stabilizer (SFWNAPSS) for stabilizing the inter-area oscillations in multi-machine power systems. In the proposed approach, a self-recurrent Wavelet Neural Network (SRWNN) is applied with the aim of constructing a self-recurrent consequent part for each fuzzy rule of a Takagi-Sugeno-Kang (TSK) fuzzy model. All parameters of the consequent parts are updated online based on Direct Adaptive Control Theory (DACT) and employing a back-propagation-based approach. The stabilizer initialization is performed using an approach based on genetic algorithm (GA). A Lyapunov-based adaptive learning rates (LALRs) algorithm is also proposed in order to speed up the stabilization rate, as well as to guarantee the convergence of the proposed stabilizer. Therefore, due to having a stable powerful adaptation law, there is no requirement to use any identification process. Kundur's four-machine two-area benchmark power system and six-machine three-area power system are used with the aim of assessing the effectiveness of the proposed stabilizer. The results are promising and show that the inter-area oscillations are successfully damped by the SFWNAPSS. Furthermore, the superiority of the proposed stabilizer is demonstrated over the IEEE standard multi-band power system stabilizer (MB-PSS), and the conventional PSS.

A Novel Fuzzy-based Power System Stabilizer for Damping Power System Enhancement

A Power System Stabilizer (PSS) is the absolute most cost effective approach of increase the system positive damping; enhance the steady-state stability margin. The stability of power electrical networks is really a key factor for the delivery of top quality energy. This study compares the power system stabilizer based on fuzzy logic control with the conventional power system stabilizer for Single Machine Infinite Bus System (SMIB). The objective of designing the fuzzy stabilizer could be the increased stability and improving the dynamic response of the single machine system linked to the infinite bus. A Fuzzy Power System Stabilizer (FPSS) design using discrete inputs is presented. To offer satisfactory behavior in the whole region of operation of the generator, additional signals namely, generator's active and reactive power are utilized as inputs to FPSS. The results of simulations performed on the model of nonlinear system shows good performance of the Fuzzy controller. SMIB system was selected due to the simple structure, that will very useful in understanding the effects and implications of the PSS.

Improved Step Response of Power System Stabilizer using Fuzzy Logic Controller

As every power system is constantly being subjected to disturbances, we should see that these disturbances do not make the system unstable. Therefor additional signals derived from speed deviation, excitation deviation and accelerating power are injected into voltage regulators. The device to provide these signals is referred as power system stabilizer. The use of power system stabilizers has become very common in operation of large electric power systems. The conventional PSS which uses lead-lag compensation, where gain settings designed for specific operating conditions, is giving poor performance under different loading conditions. Therefore, it is very difficult to design a stabilizer that could present good performance in all operating points of electric power systems. In an attempt to cover a wide range of operating conditions, Fuzzy logic control has been suggested as a possible solution to overcome this problem. In this paper, a systematic approach to fuzzy logic control design is proposed. The study of fuzzy logic power system stabilizer for stability enhancement of a single machine infinite bus system is presented. In order to accomplish the stability enhancement, speed deviation and acceleration of the rotor synchronous generator are taken as the inputs to the fuzzy logic controller. These variables take significant effects on damping the generator shaft mechanical oscillations. The stabilizing signals were computed using the fuzzy membership function depending on these variables. The performance of the system with fuzzy logic based power system stabilizer is compared with the system having conventional power system stabilizer and system without power system stabilizer

Optimal location and optimized parameters for robust power system stabilizer using honeybee mating optimization

A honeybee mating optimization technique is used to tune the power system stabilizer (PSS) parameters and find optimal location of PSSs in this article. The PSS parameters and placement are computed to assure maximum damping performance under different operating conditions. One of the main advantages of the proposed approach is its robustness to the initial parameter settings. The effectiveness of the proposed method is demonstrated on two case studies as; 10‐machine 39‐buses New England (NE) power system in comparison with Tabu Search (TS) and 16 machines and 68 buses‐modified reduced order model of the NE New York interconnected system by genetic algorithm through some performance indices under different operating condition. The proposed method of tuning the PSS is an attractive alternative to conventional fixed gain stabilizer design as it retains the simplicity of the conventional PSS and at the same time guarantees a robust acceptable performance over a wide range of operating and system condition. © 2014 Wiley Periodicals, Inc. Complexity 21: 242–258, 2015

Stability Improvement of Single Machine using ANFIS-PSS Based on Feedback-linearization

Electrical power system (EPS) operation always follows load changes which occur within time. Load changes and disturbances cause EPS operation to find a new balance point and before can reach the new balance point, the rotor speed will swing around its synchronous speed. This phenomenon causes the stability of the EPS operation decrease significantly, moreover, when the disturbance is large the machine tend to become unstable. To overcome this problem, it is necessary to add a power system stabilizer (PSS). This research proposes ANFIS-PSS based on feedback-linearization to stabilize the EPS operation. Feedback-linearization is a nonlinear control technique which feedback and limits several outputs in order to make the nonlinear system acts as a linear system. Data from conventional PSS is used to train and to update ANFIS-PSS parameters. Simulation results show an improvement of the stability of single machine model such as decreasing in maximum magnitude of rotor speed at the value of 0.466 rad/s and to reduce the time settling to 5.6 s.

Stability Improvement of Single Machine using ANFIS-PSS Based on Feedback-linearization

Electrical power system (EPS) operation always follows load changes which occur within time. Load changes and disturbances cause EPS operation to find a new balance point and before can reach the new balance point, the rotor speed will swing around its synchronous speed. This phenomenon causes the stability of the EPS operation decrease significantly, moreover, when the disturbance is large the machine tend to become unstable. To overcome this problem, it is necessary to add a power system stabilizer (PSS). This research proposes ANFIS-PSS based on feedback-linearization to stabilize the EPS operation. Feedback-linearization is a nonlinear control technique which feedback and limits several outputs in order to make the nonlinear system acts as a linear system. Data from conventional PSS is used to train and to update ANFIS-PSS parameters. Simulation results show an improvement of the stability of single machine model such as decreasing in maximum magnitude of rotor speed at the value of 0.466 rad/s and to reduce the time settling to 5.6 s.