scholarly journals Comparative Technical-Economical Analysis of Transient Stability Improvements in a Power System

2021 ◽  
Vol 11 (23) ◽  
pp. 11359
Author(s):  
Giuseppe Marco Tina ◽  
Giovanni Maione ◽  
Sebastiano Licciardello ◽  
Domenico Stefanelli
Keyword(s):  
Stability Analysis ◽  
Power Systems ◽  
Power System ◽  
Transient Stability ◽  
Short Circuit ◽  
Software Tool ◽  
Frequency Stability ◽  
Sensitivity Analyses ◽  
Worst Case ◽  
Rotor Angle

Power systems are rapidly evolving to face the increasing penetration of renewable inverter-based generation units and to improve their reliability and safety. A power system is constantly exposed to sudden changes or disturbances that may affect its stability. In this paper, a comparative analysis of solutions to improve transient stability, both rotor angle and frequency stability, is performed. These solutions are SVC, STATCOM, a fast excitation system, and an additional parallel transmission line. Sensitivity analyses were performed to evaluate the effects of the location of the three-phase fault line and the most effective SVC or STATCOM installation bus. Based on these analyses, the worst-case fault is considered, and the critical fault clearing time is determined as an engineering parameter for comparing the different solutions. For the numerical analysis, the IEEE 9 bus system is considered, and the PowerWorld software tool is used. Rotor angle and frequency stability analyses were performed. Moreover, specifically for SVC and STATCOM, the effects of different values of short-circuit ratios were considered in the context of rotor angle stability analysis. As part of the frequency stability analysis, the use of the remuneration for load shedding service in Italy was considered to perform an economic analysis for SVC and STATCOM.

Transient stability analysis and control of power systems with considering flux decay by energy function approach

2012 ◽  
Vol 60 (1) ◽  
pp. 3-8
Author(s):  
D. Lu ◽  
X. Zhang
Keyword(s):  
Stability Analysis ◽  
Power Systems ◽  
Energy Function ◽  
Transient Stability ◽  
Stability Boundary ◽  
Function Approach ◽  
Fault System ◽  
Rotor Angle ◽  
And Control ◽  
Transient Stability Analysis

Transient stability analysis and control of power systems with considering flux decay by energy function approach In this paper, transient stability of power systems with structure preserving models is considered. A Hamiltonian function which can be regarded as a Lyapunov function for the system is proposed. Based on this, the influence of flux decay dynamics, especially during a fault, on transient stability is analyzed. With the increase of load power, the variation of stability boundary in the rotor angle/E'q plane is shown. The Energy-based excitation control, aiming at injecting additional damping into the post-fault system may reduce the critical clearing time (CCT). This can be demonstrated by the comparison of different flux decay dynamics in the fault-on condition, and the reason is illustrated by the relationship between rotor angle/E'q and the stability boundary. An improved control strategy is proposed and applied to increase the CCT. Simulation results verify that improvement is obtained both in transient stability and dynamic performance.

scholarly journals Parametric Sensitivity Analysis of Rotor Angle Stability Indicators

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5023
Author(s):  
Ashish Shrestha ◽  
Francisco Gonzalez-Longatt
Keyword(s):  
Sensitivity Analysis ◽  
Power Systems ◽  
Power System ◽  
Transient Stability ◽  
Damping Ratio ◽  
Parametric Sensitivity ◽  
Parametric Sensitivity Analysis ◽  
Angle Stability ◽  
Rotor Angle ◽  
Rotor Angle Stability

With the increasing penetration rate of Power Electronic Converter (PEC) based technologies, the electrical power systems are facing the problem of transient stability since the PEC based technologies do not contribute to the system inertia, and the proportion of synchronous generators (i.e., the source of inertia) is in decreasing rate. In addition, PEC based technologies’ components have poor inherent damping. It is very important to analyze the system characteristics of a power system to minimize the potential instabilities during the contingencies. This paper presents the parametric sensitivity analysis of the rotor angle stability indicators for the 39-bus New England power system. The indicators of rotor angle stability analysis such as critical fault clearing time (CCT), Eigenvalue points, damping ratio, frequency deviation, voltage deviation, and generator’s speed deviation are identified and analyzed for three case scenarios; each scenario has six sub-cases with different inertia constants. The results show that the CCTs for each component will be reduced if the inertia reduces at any section of a multi-machine power system. Although the applied three scenarios with six sub-cases are identified to be stable in this analysis, the decreasing inertia constant has significant impact on the power system dynamics.

scholarly journals Area-Based COI-Referred Rotor Angle Index for Transient Stability Assessment and Control of Power Systems

2012 ◽  
Vol 2012 ◽  
pp. 1-23 ◽  
Author(s):  
Noor Izzri Abdul Wahab ◽  
Azah Mohamed
Keyword(s):  
Power Systems ◽  
Power System ◽  
Transient Stability ◽  
Stability Index ◽  
Test System ◽  
Emergency Control ◽  
Control Scheme ◽  
Rotor Angle ◽  
The Stability ◽  
And Control

This paper describes an index for judging the severity of transient events of power systems in simulation. The proposed transient stability index, known as the area-based COI-referred rotor angle index, is developed by considering the fact that a large-sized power system is divided into several areas according to the coherency of generators in a particular area. It can be assumed that an equivalent single large machine can represent all the generators in that area. Thus, the assessment of rotor angles for all generators can be simplified by only assessing the index of areas in a power system. The effectiveness of the proposed index in assessing the stability of power systems and its ability in pinpointing the weakest area in the power system is analyzed. Furthermore, this paper developed an emergency control scheme known as the combined UFLS and generator tripping in order to stabilize the system when unstable faults occurred in a power system. The proposed index is used to identify the generator to be tripped when the developed emergency control scheme operates. The performance of the proposed index and the combined UFLS and generator tripping scheme are evaluated on the IEEE 39-bus test system.

scholarly journals Rotor Angle and Voltage Stability Analysis with Fault Location Identification on the IEEE 9 Bus System

2020 ◽  
Vol 10 (1) ◽  
pp. 5259-5264
Author(s):  
H. F. Khan ◽  
A. H. Hanif ◽  
N. Anwar
Keyword(s):  
Stability Analysis ◽  
Power Systems ◽  
Voltage Stability ◽  
Fault Location ◽  
Transient Stability ◽  
Test System ◽  
Load Flow ◽  
Interconnected Power System ◽  
Rotor Angle ◽  
Bus System

Transient stability is very imperative in multi-machine interconnected power systems in order to scrutinize and analyze the system’s performance and response. Rotor angle stability and voltage stability are studied in this paper. By applying three-phase symmetrical faults, the transient stability of the IEEE 9 bus system is studied. A characteristic double hump is analyzed in the response of the generator, which is nearer to the fault location. By analyzing the characteristic double hump, the fault location in a large interconnected power system can be determined. It is shown that, as the fault is cleared, the system takes some finite time to return to its prior state. IEEE 9 bus system is chosen as a test system, which standard parameters. MATLAB Simpower System toolbox is used for load flow and transient stability analysis.

scholarly journals Power System Transient Stability Assessment Based on Snapshot Ensemble LSTM Network

2021 ◽  
Vol 13 (12) ◽  
pp. 6953
Author(s):  
Yixing Du ◽  
Zhijian Hu
Keyword(s):  
Power Systems ◽  
Power System ◽  
Transient Stability ◽  
Short Term Memory ◽  
Risk Function ◽  
Stability Margin ◽  
Risk Level ◽  
Stability Assessment ◽  
Lstm Network ◽  
Hierarchical Assessment

Data-driven methods using synchrophasor measurements have a broad application prospect in Transient Stability Assessment (TSA). Most previous studies only focused on predicting whether the power system is stable or not after disturbance, which lacked a quantitative analysis of the risk of transient stability. Therefore, this paper proposes a two-stage power system TSA method based on snapshot ensemble long short-term memory (LSTM) network. This method can efficiently build an ensemble model through a single training process, and employ the disturbed trajectory measurements as the inputs, which can realize rapid end-to-end TSA. In the first stage, dynamic hierarchical assessment is carried out through the classifier, so as to screen out credible samples step by step. In the second stage, the regressor is used to predict the transient stability margin of the credible stable samples and the undetermined samples, and combined with the built risk function to realize the risk quantification of transient angle stability. Furthermore, by modifying the loss function of the model, it effectively overcomes sample imbalance and overlapping. The simulation results show that the proposed method can not only accurately predict binary information representing transient stability status of samples, but also reasonably reflect the transient safety risk level of power systems, providing reliable reference for the subsequent control.

scholarly journals A Novel Methodology for Adaptive Coordination of Multiple Controllers in Electrical Grids

Mathematics ◽  
2021 ◽  
Vol 9 (13) ◽  
pp. 1474
Author(s):  
Ruben Tapia-Olvera ◽  
Francisco Beltran-Carbajal ◽  
Antonio Valderrabano-Gonzalez ◽  
Omar Aguilar-Mejia
Keyword(s):  
Power Systems ◽  
Power System ◽  
Electric Power ◽  
Large Scale ◽  
Short Circuit ◽  
Dynamic Performance ◽  
Low Frequency ◽  
Electric Power System ◽  
Design Stage ◽  
Positive Interaction

This proposal is aimed to overcome the problem that arises when diverse regulation devices and controlling strategies are involved in electric power systems regulation design. When new devices are included in electric power system after the topology and regulation goals were defined, a new design stage is generally needed to obtain the desired outputs. Moreover, if the initial design is based on a linearized model around an equilibrium point, the new conditions might degrade the whole performance of the system. Our proposal demonstrates that the power system performance can be guaranteed with one design stage when an adequate adaptive scheme is updating some critic controllers’ gains. For large-scale power systems, this feature is illustrated with the use of time domain simulations, showing the dynamic behavior of the significant variables. The transient response is enhanced in terms of maximum overshoot and settling time. This is demonstrated using the deviation between the behavior of some important variables with StatCom, but without or with PSS. A B-Spline neural networks algorithm is used to define the best controllers’ gains to efficiently attenuate low frequency oscillations when a short circuit event is presented. This strategy avoids the parameters and power system model dependency; only a dataset of typical variable measurements is required to achieve the expected behavior. The inclusion of PSS and StatCom with positive interaction, enhances the dynamic performance of the system while illustrating the ability of the strategy in adding different controllers in only one design stage.

A Simple Design Approach for Excitation Controller and Power System Stabilizer

2010 ◽  
Author(s):  
G. Fusco ◽  
M. Russo
Keyword(s):  
Power System ◽  
Transient Stability ◽  
Short Circuit ◽  
Design Procedure ◽  
Voltage Regulation ◽  
Operating Conditions ◽  
Power System Stabilizer ◽  
Simple Design ◽  
Wide Range ◽  
System Stabilizer

This paper proposes a simple design procedure to solve the problem of controlling generator transient stability following large disturbances in power systems. A state-feedback excitation controller and power system stabilizer are designed to guarantee robustness against uncertainty in the system parameters. These controllers ensure satisfactory swing damping and quick decay of the voltage regulation error over a wide range of operating conditions. The controller performance is evaluated in a case study in which a three-phase short-circuit fault near the generator terminals in a four-bus power system is simulated.

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