Effectiveness Of Power System Stabilizer Research Articles

Improving Interarea Mode Oscillation Damping in Multi-Machine Energy Systems through a Coordinated PSS and FACTS Controller Framework

Power system stability is of paramount importance in the context of energy sustainability. The reliable and efficient operation of power systems is crucial for supporting modern societies, economies, and the growing demand for electricity while minimizing environmental impact and increasing sustainability. Due to the insufficient effect of power system stabilizers (PSSs) on damping the inter-area mode oscillations, Flexible AC Transmission System (FACTS) devices are utilized for damping this mode and stabilizing power systems. In the present study, a novel optimization framework considering different and variable weight coefficients based on eigenvalue locations is presented, and the parameters of PSS and variable impedance devices, including static Volt-Ampere Reactive (VAR) compensator (SVC) and Thyristor-Controlled Series Compensator (TCSC) (comprising amplifying gain factor and time constants of phase-compensating blocks), are optimized in a coordinated manner using the proposed optimization framework built based on genetic algorithm (GA). Moreover, in the suggested optimization framework, the locations of FACTS devices and control signals are considered optimization parameters. Numerical results for the IEEE 69-bus power system demonstrated an effective improvement in the damping of inter-area modes utilizing the offered approach.

System Frequency Response Model Considering the Influence of Power System Stabilizers

Frequency stability analysis of large power systems are extremely time consuming, laborious and may even exceed the computational capacity of modern computers. Hence, simplified power system models have being developed in the literature. These models are usually called System Frequency Response (SFR). In SFR models, generators are represented by transfer functions, nonlinearities are generally neglected and the grid is not taken into account. Conventional SFR models only contemplate the mechanical behavior of speed governors, turbines and synchronous machines of generators. This is because, a common simplification is to consider that frequency and voltage can be controlled independently. However, it is demonstrated that there is an interaction between them, so frequency can be affected by the effect of power system stabilizers (PSSs) over excitation system controllers. In this work, a modified SFR model is proposed, considering the influence of generators excitation control on frequency. Simulation results show an improvement of the accuracy in the estimation of frequency response of the power system.

Comprehensive small-signal stability analysis of islanded synchronous generator-based microgrids

This paper presents a comprehensive small-signal stability analysis for synchronous generator (SG)-based microgrids (MGs) considering the control type of SGs and wide range of loading condition. The original aim is to evaluate the effect of loading conditions on the small-signal stability of droop-controlled and PQ-controlled SGs which has not been adequately addressed in the literature. To this purpose, complete state–space small-signal model of a typical medium voltage AC MG involving both droop-controlled and PQ-controlled SGs is developed. This facilitates stability studies by means of eigenvalue analysis. Results show that the small-signal stability behavior of droop-controlled SGs is different from that of PQ-controlled SGs. It is found that droop-controlled SGs show weaker stability or even instability in light loading condition. It is found that operation of PQ-controlled SGs in the presence of droop-controlled SGs can result in better stability of SG-based MG at light loading conditions. Effect of reference powers of PQ-controlled SGs on small-signal stability is also investigated. Moreover, the effect of Power System Stabilizer (PSS) on the damping of the weak stability or instability observed in low loading conditions of droop-controlled SG-based MGs is investigated. Time-domain simulations are used in order to verify the proposed theoretical analysis. • Droop and PQ-controlled synchronous generators (SGs) are modeled in state-space. • Stability of droop and PQ-controlled SGs is investigated in wide range of loadings. • Droop-controlled SGs show weaker stability or even instability in light loadings. • Operation of some SGs in PQ mode instead of droop results in better stability.

Effect of different membership functions on fuzzy power system stabilizer for synchronous machine connected to infinite bus

The effectiveness of power system stabilizer (PSS) in providing damping and improving the dynamic response is well established. In this paper focuses, the performance of single machine infinite bus is studied with fuzzy power system stabilizer (FPSS). The generator is represented by the standard K-coefficients as second order system. The mechanism to discuss the rules is described and the performance is investigated for trapezoidal, triangular and Gaussiam membership functions of input and output variables. For FPSS, speed deviation and acceleration deviation are taken as input. The system is simulated in SIMULINK environment and performance is investigated for transients due to change in input of varying magnitude.

Effect of Different Membership Functions on Fuzzy Power System Stabilizer for Synchronous Machine Connected to Infinite Bus

The effectiveness of power system stabilizer (PSS) in providing damping and improving the dynamic response is well established. In this paper focuses, the performance of single machine infinite bus is studied with fuzzy power system stabilizer (FPSS). The generator is represented by the standard K-coefficients as second order system. The mechanism to discuss the rules is described and the performance is investigated for trapezoidal, triangular and Gaussiam membership functions of input and output variables. For FPSS, speed deviation and acceleration deviation are taken as input. The system is simulated in SIMULINK environment and performance is investigated for transients due to change in input of varying magnitude.

The Effect of Power System Stabilizer on Small Signal Stability in Single-Machine Infinite-Bus

The Effect of Power System Stabilizer on Small Signal Stability in Single-Machine Infinite-Bus

OSCILLATION DAMPING EFFECTS OF POWER SYSTEM STABILIZER WITH EIGENVALUE ANALYSIS METHOD

With the development of power system interconnection, the low-frequency oscillation (LFO) is becoming more and more prominent which may cause the instability of power systems. In this paper, a standard multi-band power system stabilizer will be presented to damp the potential power oscillation with consideration of the local, inter-area, and global mode. Based on the small signal linearized modelling technology and eigenvalue analysis approach, the oscillation damping effects of power system stabilizers are discussed, which are demonstrated on a 4-machine 2-area system and 16-machine 5-area system. Numerical results show that the multi-band power system stabilizer is effective in the power oscillation model analysis and can improve the dynamic performance of the power systems.

Robust PSS design by probabilistic eigenvalue sensitivity analysis

Abstract When a wide range of system operation is taken into account for power system dynamic studies, probabilistic eigenvalue analysis efficiently provides the statistical distributions of concerned eigenvalues. Under the assumption of normal distribution, each eigenvalue can be described by its expectation and variance. To enhance system damping under multi-operating conditions by power system stabilizers (PSSs), effects of PSSs on both eigenvalue expectation and variance should be investigated. In this paper, the conventional eigenvalue sensitivity analysis has been extended to probabilistic environment. Eigenvalue sensitivities for both expectation and variance are determined to form two types of probabilistic sensitivity indices (PSIs). Robust PSS locations are selected by one type of PSI, PSS parameters are tuned by the probabilistic sensitivity analysis using another type of PSI.

The application of power system stabilizers to a multigenerator plant

The effect of power system stabilizers on the oscillatory modes of a generating plant, which consists of a number of equal, identical generators, is discussed. It is shown that the power system stabilizer design and the type of power system stabilizer input may alter the damping produced by the stabilizer on the exciter mode and the intra-plant electromechanical modes. A power system stabilizer which is designed to match the ideal phase lead over a wide frequency range is shown to add damping to plant, inter-area and intra-plant electromechanical modes. The exciter mode damping is shown to be reduced by power system stabilizers having frequency input.

Analysis of power system stabilizers application for controlling poorly damped oscillations in the Alcan/BC hybrid power systems

The study requirements to determine the effect of power system stabilizers in controlling the undamped system oscillations in interconnected power systems are described. This analysis is performed for the planning of excitation systems for new generators at Kemano, BC, Canada as well as excitation upgrade for the existing Kemano units. Available small signal stability and transient stability simulation techniques are used. Application of the trapezoidal rule in analyzing the stabilizer control scheme is also presented. A general approach to determine the optimum setting of power system stabilizers with more than one input by the root locus techniques is developed. The usefulness of the power system stabilizers in the exciters for controlling these oscillations is analyzed. Representative excitation systems with power system stabilizers are obtained from the manufacturer. The analyses of small signal stability are conducted for both an interconnected Alcan Smelters and Chemicals Ltd.-BC Hydro system and separated Alcan system. >

The Field Tests on Power System Stabilizers for Damping Low Frequency Oscillation

The significant effect of power system stabilizer (PSS) in damping the low frequency oscillation and improving the stability of power system by field tests are discribed. At the same time, the conditions of appearance of low frequency oscillation are stated. The negative damping causing the low frequency oscillation are mainly from the excitation system of synchronous generator in power system.

Effect of power system stabilizers and load frequency controllers on power system dynamic stability

Abstract The purpose of this paper is to examine the various factors affecting power system dynamic stability. A characteristic feature of this paper is that the load frequency controller as well as the stabilizing transformer and power system stabilizer are included in the model to examine the interactions between the load frequency controllers and the excitation controllers, which have been neglected in previous studies. Both the eigenvalues and the dynamic responses are calculated as an example in this paper.