Study on Characteristics of Modes Instability in Power System with Close Modes

2012 ◽  
Vol 614-615 ◽  
pp. 761-765
Author(s):  
Shu Qiang Zhao ◽  
Hui Xin Lu
Keyword(s):  
Power Systems ◽  
Power System ◽  
New England ◽  
Perturbation Method ◽  
Modal Interaction ◽  
Modal Assurance Criterion ◽  
System Parameters ◽  
Machine System ◽  
Oscillation Modes

When there exist close oscillation modes in power systems, modes instability may occur due to small changes of system parameters. The mechanism of modes instability in power system with close modes is analyzed using perturbation method and Modal Assurance Criterion is presented to measure the modes instability. New England 10-machine system is applied to analyze characteristics of modes instability by perturbing system parameters. The results show that modal interaction is a crucial factor in the modes instability, and the characteristics of modes instability may be different because of the different interaction happened between close modes.

An Underfrequency Load Shedding Scheme with Minimal Knowledge of System Parameters

2015 ◽  
Vol 16 (1) ◽  
pp. 33-46 ◽  
Author(s):  
Athbel Joe ◽  
S. Krishna
Keyword(s):  
Power Systems ◽  
Power System ◽  
New England ◽  
Load Shedding ◽  
Spinning Reserve ◽  
Generator System ◽  
Pass Filter ◽  
Low Pass Filter ◽  
System Parameters ◽  
Frequency Measurements

Abstract Underfrequency load shedding (UFLS) is a common practice to protect a power system during large generation deficit. The adaptive UFLS schemes proposed in the literature have the drawbacks such as requirement of transmission of local frequency measurements to a central location and knowledge of system parameters, such as inertia constant H and load damping constant D. In this paper, a UFLS scheme that uses only the local frequency measurements is proposed. The proposed method does not require prior knowledge of H and D. The scheme is developed for power systems with and without spinning reserve. The proposed scheme requires frequency measurements free from the oscillations at the swing mode frequencies. Use of an elliptic low pass filter to remove these oscillations is proposed. The scheme is tested on a 2 generator system and the 10 generator New England system. Performance of the scheme with power system stabilizer is also studied.

scholarly journals A novel method for locating the source of sustained oscillation in power system using synchrophasors data

2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Mohd Zuhaib ◽  
Mohd Rihan ◽  
Mohd Tayyab Saeed
Keyword(s):  
Signal Processing ◽  
Power Systems ◽  
Power System ◽  
New England ◽  
Natural Oscillation ◽  
Sustained Oscillation ◽  
Correlation Technique ◽  
Intrinsic Mode Functions ◽  
Data Set ◽  
Machine System

AbstractLarge interconnected power systems are usually subjected to natural oscillation (NO) and forced oscillation (FO). NO occurs due to system transient response and is characterized by several oscillation modes, while FO occurs due to external perturbations driving generation sources. Compared to NO, FO is considered a more severe threat to the safe and reliable operation of power systems. Therefore, it is important to locate the source of FO so corrective actions can be taken to ensure stable power system operation. In this paper, a novel approach based on two-step signal processing is proposed to characterize FO in terms of its frequency components, duration, nature, and the location of the source. Data recorded by the Phasor Measurement Units (PMUs) in a Wide Area Monitoring System (WAMS) is utilized for analysis. As PMU data usually contains white noise and appears as multi-frequency oscillatory signal, the first step is to de-noise the raw PMU data by decomposing it into a series of intrinsic mode functions (IMF) using Improved Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (ICEEMDAN) technique. The most appropriate IMF containing the vital information is selected using the correlation technique. The second step involves various signal processing and statistical analysis tools such as segmented Power Spectrum Density (PSD), excess kurtosis, cross PSD etc. to achieve the desired objectives. The analysis performed on the simulated two-area four-machine system, reduced WECC-179 bus 29 machine system, and the real-time power system PMU data set from ISO New England, demonstrates the accuracy of the proposed method. The proposed approach is independent of complex network topologies and their characteristics, and is also robust against measurement noise usually contained in PMU data.

scholarly journals Converter-driven Stability Analysis of Power Systems Integrated with Hybrid Renewable Energy Sources

2021 ◽  
Author(s):  
Jianqiang Luo ◽  
Yiqing Zou ◽  
Siqi Bu
Keyword(s):  
Renewable Energy ◽  
Stability Analysis ◽  
Power Systems ◽  
Power System ◽  
Dynamic Models ◽  
Renewable Energy Sources ◽  
Energy Sources ◽  
Power Electronic ◽  
Modal Interaction ◽  
Hybrid Renewable Energy

Various renewable energy sources such as wind power and photovoltaic (PV) have been increasingly integrated into the power system through power electronic converters in recent years. However, power electronic converter-driven stability issues under specific circumstances, for instance, modal resonances might deteriorate the dynamic performance of the power systems or even threaten the overall stability. In this paper, the integration impact of a hybrid renewable energy source (HRES) system on modal interaction and converter-driven stability is investigated in an IEEE 16-machine 68-bus power system. Firstly, an HRES system is introduced, which consists of full converter-based wind power generation (FCWG) and full converter-based photovoltaic generation (FCPV). The equivalent dynamic models of FCWG and FCPV are then established, followed by the linearized state-space modeling. On this basis, converter-driven stability analyses are performed to reveal the modal resonance mechanisms of the interconnected power systems and the modal interaction phenomenon. Additionally, time-domain simulations are conducted to verify effectiveness of dynamic models and support the converter-driven stability analysis results. To avoid detrimental modal resonances, an optimization strategy is further proposed by retuning the controller parameters of the HRES system. The overall results demonstrate the modal interaction effect between external AC power system and the HRES system and its various impacts on converter-driven stability.

Effect of Large-Scale Wind Power Integration on Inter-Area Oscillation of Power System

2014 ◽  
Vol 672-674 ◽  
pp. 227-232
Author(s):  
Xu Zhi Luo ◽  
Hai Feng Li ◽  
Hua Dong Sun ◽  
An Si Wang ◽  
De Zhi Chen
Keyword(s):  
Power Systems ◽  
Power System ◽  
Wind Power ◽  
Large Scale ◽  
Oscillation Mode ◽  
Equivalent Model ◽  
Synchronous Generators ◽  
Actual System ◽  
Oscillation Modes ◽  
The Impact

With the fast development of the wind power, security constraints of power systems have become the bottleneck of the acceptable capacity for wind power. The underdamping oscillation modes of the inter-area is an important aspect of the constraints. In this paper, an equivalent model of a power system with wind plants has been established, and the impact of the integration of the large-scale wind power on the inter-area oscillation modes has been studied based on the frequency-domain and time-domain simulations. The results indicate that the damping of inter-area oscillation mode can be enhanced by the replacement of synchronous generators (SGs) with the wind generators. The enhancing degree is up to the participation value of the SGs replaced. The conclusion has been verified by the actual system example of Xinjiang-Northwest grid. It can provide a reference for system programming and operation.

Chaotic dynamics for a class of single-machine-infinite bus power system

2016 ◽  
Vol 24 (3) ◽  
pp. 582-587 ◽  
Author(s):  
Liangqiang Zhou ◽  
Fangqi Chen
Keyword(s):  
Power Systems ◽  
Power System ◽  
Single Machine ◽  
Chaotic Dynamics ◽  
Numerical Results ◽  
Chaotic Motions ◽  
System Parameters ◽  
Critical Curves ◽  
Single Machine Infinite Bus

The chaotic motions are investigated both analytically and numerically for a class of single-machine-infinite bus power systems. The mechanism and parametric conditions for chaotic motions of this system are obtained rigorously. The critical curves separating the chaotic and non-chaotic regions are presented. The chaotic feature of the system parameters is discussed in detail. It is shown that there exist chaotic bands for this system, and the bands vary with the system parameters. Some new dynamical phenomena are presented. Numerical results are given, which verify the analytical ones.

scholarly journals An approach for a multi-stage under-frequency based load shedding scheme for a power system network

2020 ◽  
Vol 10 (6) ◽  
pp. 6071
Author(s):  
Mkhululi Elvis Siyanda Mnguni ◽  
Yohan Darcy Mfoumboulou
Keyword(s):  
Decision Making ◽  
Power Systems ◽  
Power System ◽  
New England ◽  
Operating Conditions ◽  
Load Shedding ◽  
Power Network ◽  
Load Demand ◽  
Multi Stage ◽  
System Frequency

The integration of load shedding schemes with mainstream protection in power system networks is vital. The traditional power system network incorporates different protection schemes to protect its components. Once the power network reaches its maximum limits, and the load demand continue to increase the whole system will experience power system instability. The system frequency usually drops due to the loss of substantial generation creating imbalance. The best method to recover the system from instability is by introducing an under-frequency load shedding (UFLS) scheme in parallel with the protection schemes. This paper proposed a new UFLS scheme used in power systems and industry to maintain stability. Three case studies were implemented in this paper. Multi-stage decision-making algorithms load shedding in the environment of the DIgSILENT power factory platform is developed. The proposed algorithm speeds-up the operation of the UFLS scheme. The load shedding algorithm of the proposed scheme is implemented as a systematic process to achieve stability of the power network which is exposed to different operating conditions. The flexibility of the proposed scheme is validated with the modified IEEE 39-bus New England model. The application of the proposed novel UFLS schemes will contribute further to the development of new types of engineers.

Improvement of large power system with facts devices placement to maxim-IZE the system load ability

2018 ◽  
Vol 7 (2.28) ◽  
pp. 381
Author(s):  
O L. Bekri ◽  
F Mekri
Keyword(s):  
Power Systems ◽  
Power System ◽  
New England ◽  
Power Flow ◽  
Voltage Stability ◽  
Optimal Placement ◽  
Test Case ◽  
Static Synchronous Compensator ◽  
Large Power ◽  
Loading Parameter

Voltage instabilities and/or collapses have been recognized as one of the major causes of power system blackouts. The main objective of this paper is to provide some solutions to prevent large power systems from voltage collapse. The FACTS (Flexible AC Transmission Sys-tems) devices placement gives new opportunities for enhancing voltage stability. The calculation of the loadability point is based on the con-tinuation power flow technique (CPF) to choosing the optimal placement of STATCOM (Static Synchronous Compensator) in order to improve voltage stability by increasing the loading parameter, maintaining bus voltages at desired level and minimizing losses in a power system network.A 39-bus New England power system is chosen as test case in order to illustrate this approach. The obtained results show the efficiency of the proposed method for the planning of the Static Synchronous Compensator optimal placement and the voltage stability enhancement.  

PSS CONTROLLER FOR WIND POWER GENERATION SYSTEMS

2012 ◽  
Vol 26 (25) ◽  
pp. 1246012 ◽  
Author(s):  
J. L. DOMÍNGUEZ-GARCÍA ◽  
O. GOMIS-BELLMUNT ◽  
F. BIANCHI ◽  
A. SUMPER
Keyword(s):  
Power Systems ◽  
Power System ◽  
Wind Power ◽  
Wind Farm ◽  
Small Signal ◽  
Small Signal Stability ◽  
Signal Stability ◽  
System A ◽  
Oscillation Modes ◽  
Power Generation Systems

Small signal stability analysis for power systems with wind farm interaction is presented. Power systems oscillation modes can be excited by disturbance or fault in the grid. Variable speed wind turbines can be regulated to reduce these oscillations, stabilising the power system. A power system stabiliser (PSS) control loop for wind power is designed in order to increase the damping of the oscillation modes. The proposed power system stabiliser controller is evaluated by small signal analysis.

scholarly journals Performance of Power Systems under Sustained Random Perturbations

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Humberto Verdejo ◽  
Wolfgang Kliemann ◽  
Luis Vargas
Keyword(s):  
Power Systems ◽  
Power System ◽  
Electric Power ◽  
Linear Systems ◽  
Stationary Solution ◽  
Electric Power System ◽  
Random Perturbations ◽  
Performance Indices ◽  
System Parameters ◽  
Stable Operating

This paper studies linear systems under sustained additive random perturbations. The stable operating point of an electric power system is replaced by an attracting stationary solution if the system is subjected to (small) random additive perturbations. The invariant distribution of this stationary solution gives rise to several performance indices that measure how well the system copes with the randomness. These indices are introduced, showing how they can be used for the optimal tuning of system parameters in the presence of noise. Results on a four-generator two-area system are presented and discussed.

Sliding-mode perturbation observer-based sliding-mode control design for stability enhancement of multi-machine power systems

2018 ◽  
Vol 41 (5) ◽  
pp. 1418-1434 ◽  
Author(s):  
B Yang ◽  
T Yu ◽  
HC Shu ◽  
W Yao ◽  
L Jiang
Keyword(s):  
Sliding Mode Control ◽  
Power Systems ◽  
Power System ◽  
New England ◽  
Sliding Mode ◽  
Parameter Uncertainties ◽  
Control Effort ◽  
Mode Control ◽  
Perturbation Compensation ◽  
Stability Enhancement

This paper presents the design of a sliding-mode perturbation observer-based sliding-mode control for stability enhancement of multi-machine power systems. The combinatorial effect of nonlinearities, parameter uncertainties, unmodelled dynamics and time-varying external disturbances is aggregated into a perturbation, which is rapidly estimated by a sliding-mode state and perturbation observer and then fully compensated by a sliding-mode controller in real time. The attractiveness of the sliding surface is analysed theoretically in the context of the Lyapunov criterion. The proposed control does not require an accurate system model and only one state measurement is needed. In addition, an over-conservative control effort can be effectively avoided via perturbation compensation. Simulation results for a three-machine power system and the New England power system verify the effectiveness of the proposed approach.

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