Performance Of Power System Stabilizer Research Articles

Impact of load variation on power system stability and performance of power system stabilizers: A case study of Peerdawd gas power station, Iraq

<span lang="EN-US">Variable load on the station refers to the fluctuating load on a power plant due to erratic consumer demands. It is known to have an effect on the performance of power system stabilizers, particularly in damping inter-area oscillation. This paper examines how two power system stabilizer (PSS) models and various load conditions affect a power system's voltage and power stability. A dynamic model of the power system station, based on the real case study of the Peerdawd gas power station in north Iraq (PPGS), is utilized to investigate the response of both steady-state and transient-state models: the aggregated excitation control system (Ex2100) and the power system stabilizer (PSS2B). The impact of load variation on voltage stability under normal situations and during disturbances is discussed. Furthermore, the effect of reactive power support from the power plant on the input of the two PSS models is analyzed and discussed. The paper employs a MATLABTM/Simulink-based simulation program, and the results contribute to understanding how load variation influences system damping based on PSS.</span>

Optimization of Power System Stabilizers Using Proportional-Integral-Derivative Controller-Based Antlion Algorithm: Experimental Validation via Electronics Environment

A robust, optimized power system stabilizer (PSS) is crucial for oscillation damping, and thus improving electrical network stability. Additionally, real-time testing methods are required to significantly reduce the likelihood of software failure in a real-world setting at the user location. This paper presents an Antlion-based proportional integral derivative (PID) PSS to improve power system stability during real-time constraints. The Antlion optimization (ALO) is developed with real-time testing methodology, using hardware-in-the-loop (HIL) that can communicate multiple digital control schemes with real-time signals. The dynamic power system model runs on the dSPACE DS1104, and the proposed PSS runs on the field programmable gate arrays (FPGA) (NI SbRIO-9636 board). The optimized PSS performance was compared with a modified particle swarm optimization (MPSO)-based PID-PSS, through different performance indices. The test cases include other step load perturbations and several short circuit faults at various locations. Twelve different test cases have been applied, through real-time constraints, to prove the robustness of the proposed PSS. These include 5 and 10% step changes through 3 different operating conditions and single, double, and triple lines to ground short circuits through 3 different operating conditions, and at various locations of the system transmission lines. The analysis demonstrates the effectiveness of ALO and MPSO in regaining the system’s stability under the three loading conditions. The integral square of the error (ISE), integral absolute of the error (IAE), integral time square of the error (ITSE), and integral time absolute of the error (ITAE) are used as performance indices in the analysis stage. The simulation results demonstrate the effectiveness of the proposed PSS, based on the ALO algorithm. It provides a robust performance, compared to the traditional PSS. Regarding the applied indices, the proposed PSS, based on the ALO algorithm, obtains significant improvement percentages in ISE, IAE, ITSE, and ITAE with 30.919%, 23.295%, 51.073%, and 53.624%, respectively.

Model predictive control stabilization of a power system including a wind power plant

The conventional generators are equipped with power system stabilizers (PSS) to damp oscillations that follow disturbances. The inclusion of renewable energy sources within the existing power systems requires further investigations to enhance the performance of PSS. Several control strategies have been being used to design the PSS. In this paper, model predictive control (MPC) is investigated to be used as a PSS. It uses numerical optimization algorithms to get an optimal control output considering the system’s constraints. Therefore, It is designed and applied to a multi-machine power system with a wind power plant (WPP). Three disturbances are used to test the controllers including three-phase fault, transmission line outage, and voltage reference sudden change. MATLAB/SIMULINK is used in the simulation. Then, the results are compared to conventional multi-band controller (MB) and linear quadratic regulator (LQR). MPC shows efficient performance in handling the constraints and damping types of oscillations with the existence of the WPP in the case of partial power-sharing.

Multi-Mode Damping Control Approach for the Optimal Resilience of Renewable-Rich Power Systems

The integration of power-electronics-based power plants is developing significantly due to the proliferation of renewable energy sources. Although this type of power plant could positively affect society in terms of clean and sustainable energy, it also brings adverse effects, especially with the stability of the power system. The lack of inertia and different dynamic characteristics are the main issues associated with power-electronics-based power plants that could affect the oscillatory behaviour of the power system. Hence, it is important to design a comprehensive damping controller to damp oscillations due to the integration of a power-electronics-based power plant. This paper proposes a damping method for enhancing the oscillatory stability performance of power systems with high penetration of renewable energy systems. A resilient wide-area multimodal controller is proposed and used in conjunction with a battery energy storage system (BESS) to enhance the damping of critical modes. The proposed control also addresses resiliency issues associated with control signals and controllers. The optimal tuning of the control parameters for this proposed controller is challenging. Hence, the firefly algorithm was considered to be the optimisation method to design the wide-area multimodal controllers for BESS, wind, and photovoltaic (PV) systems. The performance of the proposed approach was assessed using a modified version of the Java Indonesian power system under various operating conditions. Both eigenvalue analysis and time-domain simulations are considered in the analysis. A comparison with other well-known metaheuristic methods was also carried out to show the proposed method’s efficacy. Obtained results confirmed the superior performance of the proposed approach in enhancing the small-signal stability of renewable-rich power systems. They also revealed that the proposed multimodal controller could enhance the penetration of renewable energy sources in the Javan power system by up to 50%.

An Improved Immune Clone Selection Algorithm for Parameters Optimization of Marine Electric Power System Stabilizer

In the marine electric power system, the marine generators will be disturbed by the large change of loads or the fault of the power system. The marine generators usually installed power system stabilizers to damp power system oscillations through the excitation control. This paper proposes a novel method to obtain optimal parameter values for Power System Stabilizer (PSS) to suppress low-frequency oscillations in the marine electric power system. In this paper, a newly developed immune clone selection algorithm was improved from the three aspects of the adaptive incentive degree, vaccination, and adaptive mutation strategies. Firstly, the typical PSS implementation type of leader-lag structure was adopted and the objective function was set in the optimization process. The performance of PSS tuned by improved immune clone selection algorithm was compared with PSS tuned by basic immune clone selection algorithm (ICSA) under various operating conditions and disturbances. Then, an improved immune clone selection algorithm (IICSA) optimization technique was implemented on two test systems for test purposes. Based on the simulations, it is found that an improved immune clone selection algorithm demonstrates superiority over the basic immune clone selection algorithm in getting a smaller number of iterations and fast convergence rates to achieve the optimal parameters of the power system stabilizers. Moreover, the proposed approach improves the stability and dynamic performance under various loads conditions and disturbances of the marine electric power system.

Optimal Design of PSS on SMIB Using Particle Swarm Optimization

Dynamic disturbances in the power system are caused by sudden changes in load. This condition causes the stability of the generator to be disturbed, such as the emergence of oscillations in the generator in the form of oscillations of frequency and rotor angle. Power System Stabilizer (PSS) is an additional control that can increase generator stability. To get optimal PSS performance, proper tuning of PSS parameters is needed. Optimal performance of PSS can cause the frequency response and angle of the SMIB rotor to be stable. In this study, PSO is used for optimization of PSS parameters. PSS is able to provide stability so that overshoot oscillations can be suppressed, as well as faster settling time performance for the system to reach steady state conditions. To test the reliability of the SMIB, a case study of adding and subtracting loads was used.

Statistical t-test assessment on performance of power system stabilizer for oscillation damping

Statistical t-test assessment on performance of power system stabilizer for oscillation damping

Statistical t-test assessment on performance of power system stabilizer for oscillation damping

The statistical operation is necessary to validate the analytical procedure since the most important common operation is the comparison of result data to quantify accuracy and precision. In this paper, a statistical process is proposed to ensure the impact of power system stabilizers (PSSs) in 202-bus, 40-machine MEPE test system. The eigenvalue analysis is utilized for detecting the lowest damping modes and evaluating the damping ratio of system oscillation, and these modes are applied as input for statistical analysis. A t-test analysis was performed on the difference of damping performance by proposed designed PSS, tuned PSS, and without PSS to support the hypothesis. The t-test results validated that the MEPE test system with designed PSS is most applicable for the improvement of oscillation damping in the power system.

Design of Velocity PID-Fuzzy Power System Stabilizer Using Particle Swarm Optimization

Power system stabilizer (PSS) is used to damping power system local and interarea modes of oscillation. It will act as additional signal through the generator excitation system which produces a component of electrical torque in phase with speed variation. Fuzzy controller is nonlinear. It is more difficult to set the fuzzy controller gains compared to conventional PID controller. This research proposed velocity (PID-FPSS) its gains are tuned off-line by particle swarm optimization techniques (PSO). The objectives are to damp local-area mode of oscillations that occur following power system disturbances. The effectiveness of the proposed technique is illustrated by applying the velocity PID-FPSS to a single-machine infinite bus power system that is typically used in the literature to test the performance of power system stabilizers. The simulation studies has been tested in MATLAB SIMULINK package . A comparison between the proposed PID-FPSS and a well-tuned and designed robust power system stabilizer (RPSS) confirms the superiority of the PID-FPSS.

Damping of Low-Frequency Oscillations in Power Systems by Large-Scale PV Farms: A Comprehensive Review of Control Methods

Global warming and the desire to increase the use of clean energy have led to increasing the installation and operation of renewable energy power plants (REPPs), especially large-scale photovoltaic (PV) farms (LPFs). Given that the LPFs are added to power system or replace conventional power plants, they must be able to perform the basic tasks of synchronous generators (SGs). One of these tasks is the ability to mitigate the low-frequency oscillation (LFO) risk. Also, one of the LPFs problems is reducing the power system inertia and increasing the risk of LFOs. Therefore, these types of power plants must damp the LFOs through a power oscillation damping controller (PODC), similar to the performance of power system stabilizers (PSSs) in the SGs. This paper represents an overview of the different PODCs and control methods for LFOs damping by LPF. It seems that it can be a driver for future studies. Different studies show that the application of PODCs for LPFs can play an effective role to damp the LFOs and increase the power system stability.

Transient Stability Performance of Power Systems with High Share of Wind Generators Equipped with Power-Angle Modulation Controllers or Fast Local Voltage Controllers

The decommissioning of synchronous generators, and their replacement by decoupled renewable power plants, has a significant impact on the transient stability performance of a power system. This paper concerns with an investigation of the degree of transient stability enhancement that can be achieved in power systems with high shares (e.g., around 75%) of wind generation. It is considered that the wind generators can work either under the principle of current control or under the principle of fast local voltage control. In both cases, a power–angle modulation (PAM) controller is superimposed on the current control loops of the grid side converters of the wind generators. The investigation of the degree of enhancement takes into account different approaches of the tuning of PAM. It considers a simple approach in the form of parametric sensitivity, and also a sophisticated approach in the form of a formal optimization problem. Besides, the paper gives insight on what is a suitable objective function of the optimization problem, which entails the best performance of PAM. The whole investigation is conducted based on a synthetic model of the Great Britain (GB) system

Improvement of Small Signal Stability of SMIB System with Optimized Power System Stabilizer

As electrical power system is a complex system, there are more chances of stability issues may arise. One of the stability issues is Low Frequency Oscillations (LFOs) which makes the system unstable. As these oscillations are having low frequency i.e. large time constant with slowly increasing magnitude, they are referred to small signal stability. The main reason of these oscillations is due to lack of sufficient damping torque. Automatic Voltage Regulator (AVR) action in generator is providing sufficient synchronizing torque for system stability. This is possible with high gain and low time constant AVR which results in reduction of damping torque. Power System Stabilizer (PSS) is used together with AVR for providing necessary damping torque to minimize the LFOs. For effective damping, the PSS performance is improved by optimizing its parameters. In this paper, Single Machine Infinite Bus (SMIB) system is considered for studying the effect of LFOs. The SMIB system is simulated for a step disturbance in reference voltage and the results are carried out for different optimizing techniques Particle Swarm Optimization (PSO), Cat Swarm Optimization (CSO), Teaching and Learning based Optimization (TLBO).

Optimization based Design of Dual Input PSS for Improving Small Signal Stability of Power System with RESs

This paper proposes a method to enhance the small signal stability performance of power system considering high RESs penetration. A hybrid differential evolution-particle swarm optimization (DE-PSO) is used to design and tune DIPSS parameters. Eigenvalue, damping performance, and time domain simulation are thoroughly investigated to analyze the system performance using DIPSS based on hybrid DE-PSO and find how much RESs penetration level can be considered. From the simulation results, it is found that by utilizing DIPSS based on hybrid DE-PSO can enhance the small signal stability performance of power system with significant penetration of RESs.

Roust Power System Stabilizer Design Using Kharitonov’s Theorem: A Case Study

This paper proposes a robust power system stabilizer(PSS) for a steam synchronous generator in Barka II power station. The PSS should be capable of damping small-disturbance oscillations (inherently existing in power systems due to e.g. load changes, lines switching...etc.) within a certain settling time for different load conditions. Also, the proposed PSS must have the conventional structure and its parameters must not be violated. To achieve this goal, robust control provides many advantages. The suggested controller is tuned by the Kharitonov’s theorem and uses the standard structure employed in industry. The problem is cast into a nonlinear constrained optimization problem to achieve the desired settling time without violating the practical values of the controller parameters. Performance of the robust PSS is evaluated by several simulations in the presence of system uncertainty due to load changes.

Artificial Neural Network Control of Battery Energy Storage System to Damp-Out Inter-Area Oscillations in Power Systems

This paper proposed an ANN (Artificial Neural Network) controller to damp out inter-area oscillation of a power system using BESS (Battery Energy Storage System). The conventional lead-lag controller-based PSSs (Power System Stabilizer) have been designed using linear models usually linearized at heavy load conditions. This paper proposes a non-linear ANN based BESS controller as the ANN can emulate nonlinear dynamics. To prove the performance of this nonlinear PSS, two linear PSS are introduced at first which are linearized at the heavy load and light load conditions, respectively. It is then verified that each controller can damp out inter-area oscillations at its own condition but not satisfactorily at the other condition. Finally, an ANN controller, that learned the dynamics of these two controllers, is proposed. Case studies are performed using PSCAD/EMTDC and MATLAB. As a result, the proposed ANN PSS shows a promising robust nonlinear performance.

Online Tracking of Reactive Power Reserve For Wind Farms

Effective monitoring of VAR capability and reactive power reserve (RPR) of wind farms is an essential approach to assess stability performance of power systems with high wind penetration. However, such information is essentially difficult to obtain because it is not only impacted by many factors like wind conditions and external power grid approximation, but also subject to internal operation constraints of wind farms. An optimal sensitivity based online tracking scheme and its algorithm is proposed in this paper to obtain accurate RPR of wind farms and adapt to impacting factors and internal constraints aforementioned. The simulation results based on an actual wind farm system in China further confirm the effectiveness of the proposed approach.

Rotor angle stability control for DFIG‐integrated power system considering phase‐amplitude characteristics of transient‐grid voltage

The rotor angle stability of power systems under the influence of doubly fed induction generator (DFIG)-based wind turbines has elicited increasing attention as the penetration of wind power increases. The flexible and controllable power capability of DFIG makes it feasible to improve the stability performance of power systems. However, the effects of DFIG on rotor angle stability are not accurate because the phase angle variation of grid voltage has not been considered in existing studies. Current stability control methods may not be effective. This study proposes a rotor angle stability control method considering phase-amplitude characteristics of transient-grid voltage. Variations in both amplitude and phase angle of grid voltage are considered to analyse the effect of DFIG on the rotor angle stability of the DFIG-integrated power system. An evaluation index, which represents the accelerating area variation of the synchronous generator (SGs), is defined to quantise the effect of DFIG. In addition, the controllable power region of DFIG is established by considering DFIG's power constraints and effects on system stability. The control method of rotor angle stability is proposed based on the controllable power region and the evaluation index. Simulation results verify that the effectiveness of proposed method.

TLBO Tuned SSSC Controller for Improvement of Power System Stability Performance

TLBO Tuned SSSC Controller for Improvement of Power System Stability Performance

A synchrophasor measurement based wide-area power system stabilizer design for inter-area oscillation damping considering variable time-delays

Owing to the everlasting growth of power demand and continual change in configuration of modern power system, the role of electric utility in supplying secure and reliable power has become more prominent. Presently, the ongoing interconnections of existing power system are adding more complexity to the system and consequently, making it exposed to small-signal stability issues related to inter-area oscillations. If these issues are not adhered efficiently then it may lead to system voltage collapse and even blackouts. However, incorporation of a properly designed power system stabilizer (PSS) based on information received from wide-area measurements can solve the problem. Moreover, design of such PSS is still a challenging task as the network uncertainties are highly unpredictable. The remote signals obtained through wide-area measurement system (WAMS) are needed to be transferred to control center via communication channel. However, this process makes the system subjected to inherent communication time-delays. Consequently, the performance of PSS using these signals may deteriorate if these delays are not compensated appropriately. This motivated the present work of the design of wide-area power system stabilizer (WAPSS) utilizing information contained in synchrophasor measurements for inter-area oscillation damping considering variable communication time-delays. To obtain wide-area synchrophasor measurements, phasor measurement units (PMUs) compliant to IEEE C37.118.1 principles are adopted. The variability in communication time-delays are compensated by a time-delay compensator (TDC) designed using Simevents toolbox available with MATLAB. Based on geometric measures of controllability and observability, the choice of location of WAPSSs and the selection of their respective input signal are obtained. The parameters of WAPSSs are tuned by recently proposed, simple yet efficient, Jaya algorithm (JA). Different case studies of small-signal analysis and nonlinear time-domain simulations are carried out on New England 39-bus test system operating under diverse conditions. The obtained results establish the achievement of desired performance by the JA based WAPSSs regarding inter-area oscillation damping under consideration of variable communication time-delays.

Tuning of Velocity PID-Fuzzy Power System Stabilizer by Particle Swarm Optimization

Power system stabilizer (PSS) is used to damping power system oscillation. It will act as supplementary feedback through the generator excitation system, which produce a component of electrical torque in phase with speed variation. Fuzzy controllers are nonlinear. It is more difficult to set the fuzzy controller gains compared to conventional PID controller. This research proposed velocity (PID-FPSS) its gains are tuned by particle swarm optimization technique (PSO). The objective is to damp local-area oscillation that occur following power system small or large disturbances. The effectiveness of the proposed technique is illustrated by applying the velocity PID-FPSS to a single-machine infinite bus power system that is typically used in the literature to test the performance of power system stabilizers. The simulation has been conducted in MATLAB, SIMULINK (R2013a) package. A comparison between the proposed PID-FPSS and a well-designed robust power system stabilizer (RPSS) confirms the superiority of the proposed technique.