Decentralized H ∞ control for damping power system oscillations

2012 ◽  
Vol 2 (1) ◽  
Author(s):  
Guo-Jie Li ◽  
Tek Lie
Keyword(s):  
Power Systems ◽  
Power System ◽  
Large Scale ◽  
Digital Simulation ◽  
Design Procedure ◽  
Disturbance Attenuation ◽  
System Stability ◽  
Frequency Noise ◽  
Stability Robustness ◽  
Norm Bound

AbstractInter-area oscillations are serious problems to large-scale power systems. A decentralized H ∞ generator excitation controller of a power system is proposed to damp the inter-area oscillations and to enhance power system stability. The design procedure for a linear composite system is presented in terms of positive semi-definite solutions to modified algebraic inequalities. The resulting controller guarantees closed-loop stability, robustness and an H ∞-norm bound on disturbance attenuation even under uncertainties such as high frequency noise. The control is decentralized in the sense that the control of each generator depends on local information only. The effectiveness of the H ∞ controller is demonstrated through digital simulation studies on a two-machine power system.

scholarly journals A Feasibility Solution of a Synchronous Generator for Optimisation of the System Power Stability using an Integrated Development Environment of Visual Basic-Excel

2020 ◽  
Vol 9 (3) ◽  
pp. 1261-1268
Keyword(s):  
Power Systems ◽  
Power System ◽  
Digital Simulation ◽  
Synchronous Generator ◽  
Power System Stability ◽  
System Stability ◽  
Development Environment ◽  
Runge Kutta ◽  
Mathematical Techniques ◽  
Computational Resources

Power systems are considered highly non-linear because the environment in which they operate keep changing and hence require iterative mathematical techniques to analyse them. Such changes have a resultant effect on the system`s stability. Fluctuations in parameters are experienced in loads across the networks of the system, generator`s outputs, network topology and other operating parameters. Practically, there is no analytical solution exists for solving the problem of stability. On the other hand, there are techniques available to obtain an acceptable approximate solution of such a problem, known as digital simulation. Runge-kutta method is one of these techniques which has been used broadly as it calculates every step in a sequence of sub-steps. The method relies on a complex mathematical modelling of the synchronous generator with the help of Park-Gorev`s transformation, for the sake of simplicity and intuitiveness the method is used to analyse and study the complex equations of the three-phase synchronous generator. Generally, the system is said to be stable if the opposing forces within it are balanced and at a perfect equilibrium. The aims of this research are to establish the effects of synchronous generator`s design and transient conditions upon power system stability with the help of Embedded Microsoft Excel Sheet based on Power System Stability Analysis (EMES-PSS), using the Runge-Kutta integration method. The study has proved that EMES-PSS can find the limits of Salient and Non-Salient machines stability when changing their essential parameters. The optimisation solutions of the power system stability problem can be achieved by using basic computational resources. The software can also be used on a number of modern tablets e.g., Apple`s tablets.

scholarly journals Assessing Power System Stability Following Load Changes and Considering Uncertainty

2018 ◽  
Vol 8 (2) ◽  
pp. 2758-2763 ◽  
Author(s):  
D. V. Ngo ◽  
K. V. Pham ◽  
D. D. Le ◽  
K. H. Le ◽  
K. V. Huynh
Keyword(s):  
Power Systems ◽  
Power System ◽  
Large Scale ◽  
Voltage Drop ◽  
Load Capacity ◽  
Power System Stability ◽  
System Stability ◽  
Stability Assessment ◽  
Uncertainty Factors ◽  
Node Capacity

An increase in load capacity during the operation of a power system usually causes voltage drop and leads to system instability, so it is necessary to monitor the effect of load changes. This article presents a method of assessing the power system stability according to the load node capacity considering uncertainty factors in the system. The proposed approach can be applied to large-scale power systems for voltage stability assessment in real-time.

The Research of Power System Stability Problems Caused by Integration of Large-Scale Wind Power

2013 ◽  
Vol 391 ◽  
pp. 291-294
Author(s):  
Xiao Ning Xu ◽  
Xue Song Zhou
Keyword(s):  
Power Systems ◽  
Power System ◽  
Wind Power ◽  
Large Scale ◽  
Voltage Stability ◽  
Wind Farms ◽  
Power System Stability ◽  
System Stability ◽  
Dynamic Voltage ◽  
Dynamic Voltage Stability

In recent years, wind power in China developed rappidly. More and more problems occurred with the integration of large-scale wind power. Arounding the issues of power system stability which are resulted from the integration of wind power and ite relevant technology, this paper mainly introduced the voltage stability from the angle of the definition and the classification, and analyzed power systems which contains wind farms from the angle of the research contents and methods of static and dynamic voltage stability, especially emphasizing the necessity of the bifurcation theory used in power system contains wind power.

scholarly journals Role of Big Data Analytics in Power System Application

2020 ◽  
Vol 184 ◽  
pp. 01017 ◽  
Author(s):  
Ravi V Angadi ◽  
P. S Venkataramu ◽  
Suresh Babu Daram
Keyword(s):  
Big Data ◽  
Power Systems ◽  
Power System ◽  
Smart Grids ◽  
Large Scale ◽  
Database Systems ◽  
System Stability ◽  
Stressed Condition ◽  
Effective Manner

Power system sector is the back bone for any country economic growth. In current years, electric power systems have experienced various challenges and technological innovations and have become digitalized with the introduction concept of smart grids. Power systems are being operated in a stressed condition mainly due to the ever increasing load demand, depleting energy resources and environmental constraints on Transmission line expansion. This article focus mainly role of Big Data in various industrialization in brief and specifically applied in the power system studies along with other sectors. Also focuses on using very large data collections, which are difficult to access in standard database systems and also refers to as big data, to manage and monitor the power system. System stability is an significant goal for power engineers to use this huge amount of data to run the system in their rated capacity, power sector can beneficial of various potential solicitation of power system by the use of large-scale data analysis that can help improve the optimization process and helps for the power system to operate in the effective manner.

A Descriptive Approach for Power System Stability and Security Assessment

2011 ◽  
pp. 293-314 ◽  
Author(s):  
A. G. Tikdari ◽  
H. Bevrani ◽  
G. Ledwich
Keyword(s):  
Power Systems ◽  
Power System ◽  
Large Scale ◽  
Control Measures ◽  
System Stability ◽  
Security Assessment ◽  
Electrical Measurements ◽  
Emergency Control ◽  
Control Framework ◽  
Scale Test

Finally, a new power system emergency control framework based on descriptive study of electrical measurements and electromechanical wave propagation in large electric power systems is introduced. Since, fast and accurate detection of instability is essential in initiating certain emergency control measures, the proposed methodology could be also useful to detect the contingency condition and performing the well-known islanding and load shedding techniques. The chapter is supplemented by some illustrative nonlinear simulations on large scale test systems.

scholarly journals Small-Signal Stability of Multi-Converter Infeed Power Grids with Symmetry

Symmetry ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 157
Author(s):  
Jiawei Yu ◽  
Ziqian Yang ◽  
Jurgen Kurths ◽  
Meng Zhan
Keyword(s):  
Power Systems ◽  
Power System ◽  
Large Scale ◽  
System Stability ◽  
Characteristic Matrix ◽  
Small Signal ◽  
Power Electronic ◽  
Energy Integration ◽  
Small Signal Stability ◽  
Signal Stability

Traditional power systems have been gradually shifting to power-electronic-based ones, with more power electronic devices (including converters) incorporated recently. Faced with much more complicated dynamics, it is a great challenge to uncover its physical mechanisms for system stability and/or instability (oscillation). In this paper, we first establish a nonlinear model of a multi-converter power system within the DC-link voltage timescale, from the first principle. Then, we obtain a linearized model with the associated characteristic matrix, whose eigenvalues determine the system stability, and finally get independent subsystems by using symmetry approximation conditions under the assumptions that all converters’ parameters and their susceptance to the infinite bus (Bg) are identical. Based on these mathematical analyses, we find that the whole system can be decomposed into several equivalent single-converter systems and its small-signal stability is solely determined by a simple converter system connected to an infinite bus under the same susceptance Bg. These results of large-scale multi-converter analysis help to understand the power-electronic-based power system dynamics, such as renewable energy integration. As well, they are expected to stimulate broad interests among researchers in the fields of network dynamics theory and applications.

A Descriptive Approach for Power System Stability and Security Assessment

2013 ◽  
pp. 1527-1545
Author(s):  
A. G. Tikdari ◽  
H. Bevrani ◽  
G. Ledwich
Keyword(s):  
Power Systems ◽  
Power System ◽  
Large Scale ◽  
Renewable Energy Sources ◽  
Control Measures ◽  
System Stability ◽  
Security Assessment ◽  
Electrical Measurements ◽  
Emergency Control ◽  
Bus Voltage

Power system dynamic analysis and security assessment are becoming more significant today due to increases in size and complexity from restructuring, emerging new uncertainties, integration of renewable energy sources, distributed generation, and micro grids. Precise modeling of all contributed elements/devices, understanding interactions in detail, and observing hidden dynamics using existing analysis tools/theorems are difficult, and even impossible. In this chapter, the power system is considered as a continuum and the propagated electromechanical waves initiated by faults and other random events are studied to provide a new scheme for stability investigation of a large dimensional system. For this purpose, the measured electrical indices (such as rotor angle and bus voltage) following a fault in different points among the network are used, and the behavior of the propagated waves through the lines, nodes, and buses is analyzed. The impact of weak transmission links on a progressive electromechanical wave using energy function concept is addressed. It is also emphasized that determining severity of a disturbance/contingency accurately, without considering the related electromechanical waves, hidden dynamics, and their properties is not secure enough. Considering these phenomena takes heavy and time consuming calculation, which is not suitable for online stability assessment problems. However, using a continuum model for a power system reduces the burden of complex calculations. Finally, a new power system emergency control framework based on descriptive study of electrical measurements and electromechanical wave propagation in large electric power systems is introduced. Since, fast and accurate detection of instability is essential in initiating certain emergency control measures, the proposed methodology could be also useful to detect the contingency condition and performing the well-known islanding and load shedding techniques. The chapter is supplemented by some illustrative nonlinear simulations on large scale test systems.

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.

scholarly journals The Flexible Operation of Coal Power and Its Renewable Integration Potential in China

2019 ◽  
Vol 11 (16) ◽  
pp. 4424 ◽  
Author(s):  
Chunning Na ◽  
Huan Pan ◽  
Yuhong Zhu ◽  
Jiahai Yuan ◽  
Lixia Ding ◽  
...  
Keyword(s):  
Renewable Energy ◽  
Power Systems ◽  
Power System ◽  
Large Scale ◽  
Renewable Integration ◽  
Flexible Resources ◽  
Feasible Option ◽  
Coal Power ◽  
Simulation Results ◽  
Flexible Operation

At present time, China’s power systems face significant challenges in integrating large-scale renewable energy and reducing the curtailed renewable energy. In order to avoid the curtailment of renewable energy, the power systems need significant flexibility requirements in China. In regions where coal is still heavily relied upon for generating electricity, the flexible operations of coal power units will be the most feasible option to face these challenges. The study first focused on the reasons why the flexible operation of existing coal power units would potentially promote the integration of renewable energy in China and then reviewed the impacts on the performance levels of the units. A simple flexibility operation model was constructed to estimate the integration potential with the existing coal power units under several different scenarios. This study’s simulation results revealed that the existing retrofitted coal power units could provide flexibility in the promotion of the integration of renewable energy in a certain extent. However, the integration potential increment of 20% of the rated power for the coal power units was found to be lower than that of 30% of the rated power. Therefore, by considering the performance impacts of the coal power units with low performances in load operations, it was considered to not be economical for those units to operate at lower than 30% of the rated power. It was believed that once the capacity share of the renewable energy had achieved a continuously growing trend, the existing coal power units would fail to meet the flexibility requirements. Therefore, it was recommended in this study that other flexible resources should be deployed in the power systems for the purpose of reducing the curtailment of renewable energy. Furthermore, based on this study’s obtained evidence, in order to realize a power system with high proportions of renewable energy, China should strive to establish a power system with adequate flexible resources in the future.

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