scholarly journals A rare-event study of frequency regulation and contingency services from grid-scale batteries

2021 ◽  
Vol 379 (2202) ◽  
pp. 20190433 ◽  
Author(s):  
Maldon Patrice Goodridge ◽  
John Moriarty ◽  
Andrea Pizzoferrato
Keyword(s):  
Event Study ◽  
Frequency Control ◽  
Rare Event ◽  
Energy Systems ◽  
Load Shedding ◽  
Monte Carlo Algorithm ◽  
Frequency Regulation ◽  
Conditional Distributions ◽  
Theme Issue ◽  
Power Disturbances

We perform a rare-event study on a simulated power system in which grid-scale batteries provide both regulation and emergency frequency control ancillary services. Using a model of random power disturbances at each bus, we employ the skipping sampler, a Markov Chain Monte Carlo algorithm for rare-event sampling, to build conditional distributions of the power disturbances leading to two kinds of instability: frequency excursions outside the normal operating band, and load shedding. Potential saturation in the benefits, and competition between the two services, are explored as the battery maximum power output increases. This article is part of the theme issue ‘The mathematics of energy systems’.

Frequency and inertia response effects, capabilities, and possibilities in renewable energy sources

2021 ◽  
Vol 14 ◽  
Author(s):  
Jishu Mary Gomez ◽  
Prabhakar Karthikeyan Shanmugam
Keyword(s):  
Renewable Energy ◽  
Power System ◽  
Frequency Control ◽  
Renewable Energy Sources ◽  
Energy Systems ◽  
Load Shedding ◽  
System Stability ◽  
Frequency Regulation ◽  
Control Schemes ◽  
Inertia Response

Background & Objectives: The global power system is in a state of continuous evolution, incorporating more and more renewable energy systems. The converter-based systems are void of inherent inertia control behavior and are unable to curb minor frequency deviations. The traditional power system, on the other hand, is made up majorly of synchronous generators that have their inertia and governor response for frequency control. For improved inertial and primary frequency response, the existing frequency control methods need to be modified and an additional power reserve is to be maintained mandatorily for this purpose. Energy self-sufficient renewable distributed generator systems can be made possible through optimum active power control techniques. Also, when major global blackouts were analyzed for causes, solutions, and precautions, load shedding techniques were found to be a useful tool to prevent frequency collapse due to power imbalances. The pre-existing load shedding techniques were designed for traditional power systems and were tuned to eliminate low inertia generators as the first step to system stability restoration. To incorporate emerging energy possibilities, the changes in the mixed power system must be addressed and new frequency control capabilities of these systems must be researched. Discussion: In this paper, the power reserve control schemes that enable frequency regulation in the widely incorporated solar photovoltaic and wind turbine generating systems are discussed. Techniques for Under Frequency Load Shedding (UFLS) that can be effectively implemented in renewable energy enabled micro-grid environment for frequency regulation are also briefly discussed. The paper intends to study frequency control schemes and technologies that promote the development of self- sustaining micro-grids. Conclusion: The area of renewable energy research is fast emerging with immense scope for future developments. The comprehensive literature study confirms the possibilities of frequency and inertia response enhancement through optimum energy conservation and control of distributed energy systems.

The Control Strategy Study of Doubly-Fed Wind Turbine Participated in Frequency Regulation

2012 ◽  
Vol 512-515 ◽  
pp. 788-793
Author(s):  
Xiao Hua Zhou ◽  
Ming Qiang Wang ◽  
Wei Wei Zou
Keyword(s):  
Wind Turbine ◽  
Control Strategy ◽  
Large Scale ◽  
Control Strategies ◽  
Frequency Control ◽  
Frequency Regulation ◽  
Strategy Study ◽  
Fuzzy Control Strategy ◽  
Doubly Fed ◽  
System Frequency

Traditional decoupling control strategy of doubly-fed induction generator (DFIG) wind turbine makes little contribution to system inertia and do not participate in the system frequency control, the synchronization of large-scale wind power requires wind turbine have the ability to participate in the regulation of power system frequency. This paper adds a frequency control segment to traditional DFIG wind turbine and considers the doubly-fed wind turbine operating on the state of the super-synchronous speed, by analysis the effect of inertia and proportional control strategies, a fuzzy control strategy which combines the advantages of the former two control strategies is proposed, simulation results show that this control strategy can more effectively improve the system frequency response.

scholarly journals On the Contribution of Wind Farms in Automatic Generation Control: Review and New Control Approach

2018 ◽  
Vol 8 (10) ◽  
pp. 1848 ◽  
Author(s):  
Arman Oshnoei ◽  
Rahmat Khezri ◽  
SM Muyeen ◽  
Frede Blaabjerg
Keyword(s):  
Power System ◽  
Wind Turbine ◽  
Frequency Control ◽  
Wind Farms ◽  
Automatic Generation ◽  
Load Frequency Control ◽  
Automatic Generation Control ◽  
Frequency Regulation ◽  
Proportional Integral ◽  
Generation Control

Wind farms can contribute to ancillary services to the power system, by advancing and adopting new control techniques in existing, and also in new, wind turbine generator systems. One of the most important aspects of ancillary service related to wind farms is frequency regulation, which is partitioned into inertial response, primary control, and supplementary control or automatic generation control (AGC). The contribution of wind farms for the first two is well addressed in literature; however, the AGC and its associated controls require more attention. In this paper, in the first step, the contribution of wind farms in supplementary/load frequency control of AGC is overviewed. As second step, a fractional order proportional-integral-differential (FOPID) controller is proposed to control the governor speed of wind turbine to contribute to the AGC. The performance of FOPID controller is compared with classic proportional-integral-differential (PID) controller, to demonstrate the efficacy of the proposed control method in the frequency regulation of a two-area power system. Furthermore, the effect of penetration level of wind farms on the load frequency control is analyzed.

scholarly journals Coordinated Frequency Control Strategy with the Virtual Battery Model of Inverter Air Conditionings

2019 ◽  
Vol 9 (15) ◽  
pp. 3052
Author(s):  
Jiafu Yin ◽  
Dongmei Zhao
Keyword(s):  
Control Strategy ◽  
Frequency Control ◽  
Hierarchical Control ◽  
Frequency Regulation ◽  
Consensus Protocol ◽  
Consensus Control ◽  
Response Characteristics ◽  
Battery Model ◽  
Control Framework ◽  
Control Scheme

Due to the potential of thermal storage being similar to that of the conventional battery, air conditioning (AC) has gained great popularity for its potential to provide ancillary services and emergency reserves. In order to integrate numerous inverter ACs into secondary frequency control, a hierarchical distributed control framework which incorporates a virtual battery model of inverter AC is developed. A comprehensive derivation of a second-order virtual battery model has been strictly posed to formulate the frequency response characteristics of inverter AC. In the hierarchical control scheme, a modified control performance index is utilized to evaluate the available capacity of traditional regulation generators. A coordinated frequency control strategy is derived to exploit the complementary and advantageous characteristics of regulation generators and aggregated AC. A distributed consensus control strategy is developed to guarantee the fair participation of heterogeneous AC in frequency regulation. The finite-time consensus protocol is introduced to ensure the fast convergence of power tracking and the state-of-charge (SOC) consistency of numerous ACs. The effectiveness of the proposed control strategy is validated by a variety of illustrative examples.

scholarly journals The experimental identification method of the dynamic efficiency for frequency regulation algorithms of AEDs

2021 ◽  
Vol 12 (1) ◽  
pp. 59 ◽  
Author(s):  
Vladimir L. Kodkin ◽  
Aleksandr S. Anikin
Keyword(s):  
Control Method ◽  
Frequency Control ◽  
Reference Signal ◽  
Frequency Regulation ◽  
Current Feedback ◽  
Electric Drives ◽  
Stator Current ◽  
Asynchronous Electric Drive ◽  
Input Side ◽  
Mechanical Moment

The article proposes and substantiates a method for studying the dynamics of an asynchronous electric drives with frequency control from the input side of the signal for setting the speed of rotation of the electric motor. In this method, a constant speed reference signal is added to a harmonic variable frequency signal. The set of amplitude changes and phase shifts of velocity oscillations are the initial data for identifying the dynamics of the studied control method. The logic of this method is determined by the previously obtained nonlinear transfer function of the link that forms the mechanical moment in the asynchronous electric drive with frequency control. Experiments have shown the dynamic benefits of the drive with positive stator current feedback.

scholarly journals Optimal Array Reconfiguration of a PV Power Plant for Frequency Regulation of Power Systems

2021 ◽  
Vol 9 ◽  
Author(s):  
Tingyi He ◽  
Shengnan Li ◽  
Yiping Chen ◽  
Shuijun Wu ◽  
Chuangzhi Li
Keyword(s):  
Power Plant ◽  
Power Systems ◽  
Pareto Front ◽  
Frequency Control ◽  
Storage System ◽  
Energy Storage System ◽  
Automatic Generation ◽  
Frequency Regulation ◽  
Nsga Ii ◽  
Partial Shading

This paper establishes a novel optimal array reconfiguration (OAR) of a PV power plant for secondary frequency control of automatic generation control (AGC). Compared with the existing studies, the proposed OAR can further take the AGC signal responding into account except the maximum power output, in which the battery energy storage system is used to balance the power deviation between the AGC signals and the PV power outputs. Based on these two conflicted objects, the OAR is formulated as a bi-objective optimization. To address this problem, the efficient non-dominated sorting genetic algorithm II (NSGA-II) is designed to rapidly obtain an optimal Pareto front due to its high optimization efficiency. The decision-making method called VIKOR is employed to determine the best compromise solution from the obtained Pareto front. To verify the effectiveness of the proposed bi-objective optimization of OAR, three case studies with fixed, step-increasing, and step-decreasing AGC signals are carried out on a 10 × 10 total-cross-tied PV arrays under partial shading conditions.

scholarly journals Advanced Load Shedding for Integrated Power and Energy Systems

2021 ◽  
Author(s):  
Bang L. H. Nguyen ◽  
Tuyen Vu ◽  
Colin Ogilvie ◽  
Harsha Ravindra ◽  
Mark Stanovich ◽  
...  
Keyword(s):  
Energy Systems ◽  
Load Shedding ◽  
Power And Energy Systems ◽  
Power And Energy

scholarly journals PI and LQR controllers for Frequency Regulation including Wind Generation

2018 ◽  
Vol 8 (5) ◽  
pp. 3711 ◽  
Author(s):  
Semaria Ruiz ◽  
Julian Patiño ◽  
Jairo Espinosa
Keyword(s):  
Power Systems ◽  
Wind Turbines ◽  
Frequency Control ◽  
Test System ◽  
Performance Comparison ◽  
Load Frequency Control ◽  
Superior Performance ◽  
Frequency Regulation ◽  
Control Effort ◽  
Load Frequency

<pre>The increasing use of renewable technologies such as wind turbines in power systems may require the contribution of these new sources into grid ancillary services, such as Load Frequency Control. Hence, this work dealt with the performance comparison of two traditional control structures, PI and <span>LQR</span>, for secondary regulation of Load Frequency Control with the participation of variable-speed wind turbines. For this purpose, the doubly-fed induction generator wind turbine was modeled with additional control loops for emulation of the inertial response of conventional machines for frequency regulation tasks. Performance of proposed strategies was verified through simulation in a benchmark adapted from the <span>WSCC</span> 3 machines 9-bus test system. Results showed overall superior performance for <span>LQR</span> controller, although requiring more strenuous control effort from conventional units than PI control.</pre>

scholarly journals A Novel Control Architecture for Hybrid Power Plants to Provide Coordinated Frequency Reserves

Energies ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 919 ◽  
Author(s):  
Daniel Vázquez Pombo ◽  
Florin Iov ◽  
Daniel-Ioan Stroe
Keyword(s):  
Power Plants ◽  
Wind Farm ◽  
Frequency Control ◽  
Storage System ◽  
Hybrid Plant ◽  
Power Grids ◽  
Control Architecture ◽  
Frequency Regulation ◽  
Hybrid Power ◽  
Two Stages

The inertia reduction suffered by worldwide power grids, along with the upcoming necessity of providing frequency regulation with renewable sources, motivates the present work. This paper focuses on developing a control architecture aimed to perform frequency regulation with renewable hybrid power plants comprised of a wind farm, solar photovoltaic, and a battery storage system. The proposed control architecture considers the latest regulations and recommendations published by ENTSO-E when implementing the first two stages of frequency control, namely the fast frequency response and the frequency containment reserve. Additionally, special attention is paid to the coordination among sub-plants inside the hybrid plant and also between different plants in the grid. The system’s performance is tested after the sudden disconnection of a large generation unit (N-1 contingency rules). Thus, the outcome of this study is a control strategy that enables a hybrid power plant to provide frequency support in a system with reduced inertia, a large share of renewable energy, and power electronics-interfaced generation. Finally, it is worth mentioning that the model has been developed in discrete time, using relevant sampling times according to industrial practice.

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