Summary of the Stability Chanllenges and Safe Operation of Power Systems in View of Dispatching

2014 ◽  
Vol 960-961 ◽  
pp. 1588-1591
Author(s):  
Xiang Dong Zhao ◽  
Xin Zhao ◽  
Ming Jun Lv ◽  
Jian Guo Liu ◽  
Feng Zhen Liu ◽  
...  
Keyword(s):  
Power Systems ◽  
Power System ◽  
Rapid Development ◽  
Power Grids ◽  
System Stability ◽  
Stable Operation ◽  
Safe Operation ◽  
The Stability ◽  
Continuous Power ◽  
Grid Market

The Internet and the gradual implementation of the continuous power grid market in recent years make the power system more complex under different operating environment. Safe and stable operation of power grids have become increasingly important . With the rapidf development of the grid and constant innovation, safe and stable operation also has a new requirement , because the rapid development of the power system brings more This paper analyzes the causes of blackouts and reviews security of the power system stability problems related to measures on the security and stability of the power system operation .

scholarly journals Contribution of Wind Farms to the Stability of Power Systems with High Penetration of Renewables

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2207
Author(s):  
Jesus Castro Martinez ◽  
Santiago Arnaltes ◽  
Jaime Alonso-Martinez ◽  
Jose Luis Rodriguez Amenedo
Keyword(s):  
Power Systems ◽  
Power System ◽  
Wind Farms ◽  
Rate Of Change ◽  
System Stability ◽  
Droop Control ◽  
High Penetration ◽  
Controller Performance ◽  
The Stability ◽  
System Inertia

Power system inertia is being reduced because of the increasing penetration of renewable energies, most of which use power electronic interfaces with the grid. This paper analyses the contribution of inertia emulation and droop control to the power system stability. Although inertia emulation may appear the best option to mitigate frequency disturbances, a thorough analysis of the shortcomings that face real-time implementations shows the opposite. Measurement noise and response delay for inertia emulation hinder controller performance, while the inherently fast droop response of electronic converters provides better frequency support. System stability, expressed in terms of rate of change of frequency (ROCOF) and frequency nadir, is therefore improved with droop control, compared to inertia emulation.

scholarly journals Obtaining Probability Distribution Laws of Power System Steady-State Mode Parameters

2020 ◽  
Vol 20 (3) ◽  
pp. 41-51
Keyword(s):  
Renewable Energy ◽  
Probability Distribution ◽  
Power Systems ◽  
Power System ◽  
Renewable Energy Sources ◽  
Current Trend ◽  
System Stability ◽  
Energy Sources ◽  
Stable Operation ◽  
Distribution Laws

Stable operation of electrical power systems is one of the crucial issues in the power industry. Current vo­lumes of electricity consumption cause the need to constantly increase the generated capacity, repeatedly modifying and complicating the original circuit. In addition to this, given the current trend towards the use of digital power systems and renewable energy sources, more and more uncertainties difficult to predict by standard mathematical methods appear. Events in the power system are deterministic, i.e. random. Thus, it is difficult to fully assess the system stability, voltage levels, currents, or possible power losses. Finding the probability distribution laws can give us an understanding of all the possible states in which an object can exist. Obtaining them is complicated by the difficulty of accounting for all the correlations between the random arguments of the source data. These laws are necessary to determine the optimal operating modes, the possibility of solving the problem of determining the optimal renewable energy sources installation locations and the required amount of generated energy in a non-deterministic way. The purpose of this article is to test the developed SIBD method for obtaining the full probabilistic characteristics. This method, unlike the Monte Carlo methods, does not use a random sample of initial data, but completely covers the studied functional dependence. The problem was solved using the provisions of probability theory and mathematical statistics, numerical optimization methods in particular. The MATLAB Matpower application package was also used to solve technical computing problems.

scholarly journals Enhancement of Power System Transient Stability by the Coordinated Control between an Adjustable Speed Pumping Generator and Battery

2020 ◽  
Vol 10 (24) ◽  
pp. 9034
Author(s):  
Junji Tamura ◽  
Atsushi Umemura ◽  
Rion Takahashi ◽  
Atsushi Sakahara ◽  
Fumihito Tosaka ◽  
...  
Keyword(s):  
Power Systems ◽  
Power System ◽  
Wind Farm ◽  
Transient Stability ◽  
Wind Farms ◽  
System Stability ◽  
Synchronous Generators ◽  
Adjustable Speed ◽  
The Stability ◽  
Network Fault

The penetration level of large-scale wind farms into power systems has been increasing significantly, and the frequency stability and transient stability of the power systems during and after a network fault can be negatively affected. This paper proposes a new control method to improve the stability of power systems that are composed of large wind farms, as well as usual synchronous generators. The new method is a coordinated controlling method between an adjustable-speed pumping generator (ASG) and a battery. The coordinated system is designed to improve power system stability during a disconnection in a fixed-rotor-speed wind turbine with a squirrel cage-type induction generator (FSWT-SCIG)-based wind farm due to a network fault, in which a battery first responds quickly to the system frequency deviation due to a grid fault and improves the frequency nadir, and then the ASG starts to supply compensatory power to recover the grid frequency to the rated frequency. The performance of the proposed system was confirmed through simulation studies on a power system model consisting of usual synchronous generators (SGs), an ASG, a battery, and an SCIG-based wind farm. Simulation results demonstrated that the proposed control system can enhance the stability of the power system effectively.

scholarly journals Transient Stability Improvement of the Power Systems

2018 ◽  
Vol 12 (3) ◽  
pp. 916
Author(s):  
Zaid H. Al-Tameemi ◽  
Hayder H. Enawi ◽  
Karrar M. Al-Anbary ◽  
Hussam M. Almukhtar
Keyword(s):  
Power Systems ◽  
Power System ◽  
Transmission Lines ◽  
Transient Stability ◽  
Electrical Power ◽  
Limiting Factor ◽  
Stable Operation ◽  
Electric Power Networks ◽  
Matlab Package ◽  
The Stability

<p>During the last few decades, electrical power demand enlarged significantly whereas power production and transmission expansions has been brutally restricted as a result of restricted resources as well as ecological constrains. Consequently, many transmission lines have been profoundly loading so the stability of power system became as Limiting factor for transferring electrical power. So, maintaining a secure and stable operation of the electric power networks is deemed an imporatant and challenge issue.transient stability of a power system has been gained a considerable attention from researchers dute to it importance . Therefore,this paper sheds light on A substantial number of the adopted techniques, including an inclease in  inertia constant of generator, shunt capacitor, reduction reactance of the transmission line to acheive this purpose. A 7-Machine CIGRE system has been considered a case study. Matlab package has been employed to implement this study. The simulation results show that the transient stability of the repective system enhanced considerably with these techniques.</p>

Research of the Adaptation of Turbine Model Related to the Grid

2014 ◽  
Vol 960-961 ◽  
pp. 1437-1441
Author(s):  
Ge Jin ◽  
Shu Chang Liu ◽  
Yu Jia Ma
Keyword(s):  
Power System ◽  
Rapid Development ◽  
System Stability ◽  
System A ◽  
The Stability ◽  
Turbine Speed ◽  
The Impact ◽  
Safety And Stability ◽  
Important Basis ◽  
Turbine Model

With the rapid development of China's interconnected power grid, power system operation environment has become increasingly complex. The safety and stability of the power system requirements are also increasing. Turbine is an important basis for the analysis of power system stability. This paper studied the influence of turbine parameters related to network on the stability of the grid from the perspective of the frequency domain, and obtained the impact properties of turbine speed control system parameters related to different oscillation frequency of the power system. The conclusions are validated from time domain. So that when analyzing the stability of the power system, a more targeted turbine model according to different research purposes can be chosen because the parameters’ importance can show the necessity of the modules.

scholarly journals Asymmetry underlies stability in power grids

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ferenc Molnar ◽  
Takashi Nishikawa ◽  
Adilson E. Motter
Keyword(s):  
Symmetry Breaking ◽  
Real World ◽  
Power Grids ◽  
Stable Operation ◽  
World Systems ◽  
Symmetric State ◽  
Network Systems ◽  
Additional Improvement ◽  
The Stability ◽  
General Method

AbstractBehavioral homogeneity is often critical for the functioning of network systems of interacting entities. In power grids, whose stable operation requires generator frequencies to be synchronized—and thus homogeneous—across the network, previous work suggests that the stability of synchronous states can be improved by making the generators homogeneous. Here, we show that a substantial additional improvement is possible by instead making the generators suitably heterogeneous. We develop a general method for attributing this counterintuitive effect to converse symmetry breaking, a recently established phenomenon in which the system must be asymmetric to maintain a stable symmetric state. These findings constitute the first demonstration of converse symmetry breaking in real-world systems, and our method promises to enable identification of this phenomenon in other networks whose functions rely on behavioral homogeneity.

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 Sizing Hybrid Energy Storage Systems for Distributed Power Systems under Multi-Time Scales

2018 ◽  
Vol 8 (9) ◽  
pp. 1453 ◽  
Author(s):  
Huanan Liu ◽  
Dezhi Li ◽  
Yuting Liu ◽  
Mingyu Dong ◽  
Xiangnan Liu ◽  
...  
Keyword(s):  
Renewable Energy ◽  
Energy Storage ◽  
Power Systems ◽  
Power System ◽  
Time Scales ◽  
Carbon Emissions ◽  
Storage Capacity ◽  
Rapid Development ◽  
Super Capacitor ◽  
Energy Storage Capacity

With the rapid development of industry, more fossil energy is consumed to generate electricity, which increases carbon emissions and aggravates the burden of environmental protection. To reduce carbon emissions, traditional centralized power generation networks are transforming into distributed renewable generation systems. However, the deployment of distributed generation systems can affect power system economy and stability. In this paper, under different time scales, system economy, stability, carbon emissions, and renewable energy fluctuation are comprehensively considered to optimize battery and super-capacitor installation capacity for an off-grid power system. After that, based on the genetic algorithm, this paper shows the optimal system operation strategy under the condition of the theoretical best energy storage capacity. Finally, the theoretical best capacity is tested under different renewable energy volatility rates. The simulation results show that by properly sizing the storage system’s capacity, although the average daily costs of the system can increase by 10%, the system’s carbon emissions also reduce by 42%. Additionally, the system peak valley gap reduces by 23.3%, and the renewable energy output’s fluctuation range and system loss of load probability are successfully limited in an allowable range. Lastly, it has less influence on the theoretical best energy storage capacity if the renewable energy volatility rate can be limited to within 10%.

scholarly journals An Accurate Method for Delay Margin Computation for Power System Stability

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3466 ◽  
Author(s):  
Ashraf Khalil ◽  
Ang Swee Peng
Keyword(s):  
Time Delay ◽  
Power Systems ◽  
Power System ◽  
System Stability ◽  
Area Measurement ◽  
Power System Stabilizer ◽  
Iteration Algorithm ◽  
Measurement Units ◽  
System Stabilizer ◽  
Delay Margin

The application of the phasor measurement units and the wide expansion of the wide area measurement units make the time delay inevitable in power systems. The time delay could result in poor system performance or at worst lead to system instability. Therefore, it is important to determine the maximum time delay margin required for the system stability. In this paper, we present a new method for determining the delay margin in the power system. The method is based on the analysis in the s-domain. The transcendental time delay characteristics equation is transformed to a frequency dependent equation. The spectral radius is used to find the frequencies at which the roots cross the imaginary axis. The crossing frequencies are determined through the sweeping test and the binary iteration algorithm. A single machine infinite bus system equipped with automatic voltage regulator and power system stabilizer is chosen as a case study. The delay margin is calculated for different values of the power system stabilizer (PSS) gain, and it is found that increasing the PSS gain decreases the delay margin. The effectiveness of the proposed method has been proved through comparing it with the most recent published methods. The method shows its merit with less conservativeness and fewer computations.

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