Event-based hierarchical control for power flow in vehicle systems

2016 ◽  
Author(s):  
Justin P. Koeln ◽  
Andrew G. Alleyne
Keyword(s):  
Power Flow ◽  
Hierarchical Control ◽  
Vehicle Systems ◽  
Event Based

scholarly journals A Hierarchical Control Methodology for Renewable DC Microgrids Supporting a Variable Communication Network Health

Electronics ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 418 ◽  
Author(s):  
Muhammad Shahid ◽  
Muhammad Khan ◽  
Jianming Xu ◽  
Khurram Hashmi ◽  
Salman Habib ◽  
...  
Keyword(s):  
Power Flow ◽  
Renewable Energy Sources ◽  
Hierarchical Control ◽  
Network Connectivity ◽  
Voltage Regulation ◽  
Monitoring And Control ◽  
Dc Microgrids ◽  
Communication Links ◽  
Microgrid Control ◽  
And Control

The monitoring and control of renewable energy sources (RESs) based on DC (Direct Current) microgrids (DC MG) are gaining much consideration at this time. In comparison with the isolated individual control of converters in a microgrid, DC microgrids provide better voltage regulation and harmonized energy generation/consumption. To address the inherent vulnerability of communication links, robust methods have been proposed that improve the resilience of communication-based control. However, the failure of the communication links in microgrid control layers remains a considerable issue that may lead to one or more nodes being disconnected and operating as a communication island. Such types of communication islanding may cause the unpredictable behavior of the system and further destabilization may lead to a cascaded failure. This paper proposes a fast algorithm to detect and evaluate network connectivity based on the information stored at every node in the form of a look-up table. The control structure has been modified under communication islanding, and a communication connectivity observer is used at every node to detect and address power flow issues under communication islanding. The proposed method has been verified through mathematical analysis, simulation, and experimental results.

scholarly journals From Hierarchical Control to Flexible Interactive Electricity Services: A Path to Decarbonization

2021 ◽  
Vol 15 ◽  
pp. 1558-1570
Author(s):  
Marija D. Ilic ◽  
Pedro M. S. Carvalho
Keyword(s):  
Power Flow ◽  
Distribution Systems ◽  
Reactive Power ◽  
Hierarchical Control ◽  
Electric Energy ◽  
Specific Model ◽  
Net Energy ◽  
Primary Control ◽  
Interaction Variables ◽  
And Control

We propose to conceptualise electric energy systems as complex dynamical systems using physically intuitive multilayered energy modelling as the basis for systematic diverse technology integration, and control in on-line operations. It is shown that such modelling exhibits unique structure which comes from the conservation of instantaneous power (P) and of instantaneous reactive power ( _Q), (interaction variables (intVar)) at the interfaces of subsystems. The intVars are used as a means to model and control the interactive zoomed-out inter-modular (inter-area, inter-component) system dynamics. Control co-design can then be pursued using these models so that the primary control shapes intVars of its own module by using its own lowlevel detailed technology-specific model and intVar info exchange with the neighbours. As a result, we describe how the proposed approach can be used to support orderly evolution from today’s hierarchical control to a platform enabling flexible interactive protocols for electricity services. The potential for practical use of the proposed concepts is far-reaching and transparent. All that needs to be conceived is that intVar characterising any intelligent Balancing Authority (iBA) is a generalisation of today’s Area Control Error (ACE) characterising net energy balance of a Balancing Authority (BA). An iBA can be any subsystem with its own sub-objectives, such as distributed energy resources (DERs) comprising customers and grid forming microgrids; distribution systems; transmission systems; Independent System Operators (ISOs); and, ultimately, electric energy markets within large interconnection. Several industry problems are described as particular sub-problems of general interactive electricity services. These formulations help one compare models and assumptions used as part of current solutions, and propose enhanced solutions. Most generally, feasibility and stability conditions can be introduced for ensuring feasible power flow solutions, regulated frequency and voltage and orderly power exchange across the iBAs.

scholarly journals Secondary Control for Storage Power Converters in Isolated Nanogrids to Allow Peer-to-Peer Power Sharing

Electronics ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 140 ◽  
Author(s):  
Eva González-Romera ◽  
Enrique Romero-Cadaval ◽  
Carlos Roncero-Clemente ◽  
Mercedes Ruiz-Cortés ◽  
Fermín Barrero-González ◽  
...  
Keyword(s):  
Power Flow ◽  
Control Method ◽  
Low Voltage ◽  
Hierarchical Control ◽  
Power Converter ◽  
Power Sharing ◽  
Primary Control ◽  
Secondary Control ◽  
Control Loops ◽  
Energy Interchange

It is usual in literature that power sharing among grid-forming sources of an isolated microgrid obeys their energy rating, instead of economic agreements between stakeholders, and circulating energy among them is usually avoided. However, these energy interchanges make strong sense and classical power sharing methods must be reformulated in the context of prosumer-based microgrids. This paper proposes a secondary control method for a prosumer-based low-voltage nanogrid that allows for energy interchange between prosumers, where storage systems, together with PV generators, are the controllable grid-forming sources. A power flow technique adapted to islanded microgrids is used for secondary control algorithm and the whole hierarchical control strategy for the prosumer converter is simulated and validated. This hierarchical control consists of three stages: tertiary control plans the energy interchange among prosumers, secondary obtains different voltage and power setpoints for each of the grid-forming sources, and, finally, primary control guarantees stable voltage and frequency values within the nanogrid with droop rules. Inner control loops for the power converter are also defined to track setpoints and assure stable performance. Simulation tests are carried out, which prove the stability of the proposed methods and the accuracy of the setpoint tracking.

Hierarchical Control of Multi-Domain Power Flow in Mobile Systems: Part II — Aircraft Application

2015 ◽  
Author(s):  
Matthew A. Williams ◽  
Justin P. Koeln ◽  
Andrew G. Alleyne
Keyword(s):  
Power Systems ◽  
Power Flow ◽  
Large Scale ◽  
Control Method ◽  
Hierarchical Control ◽  
Mobile Systems ◽  
Centralized Control ◽  
Modeling Framework ◽  
Control Framework ◽  
Aircraft Application

This two-part paper presents the development of a hierarchical control framework for the control of power flow throughout large-scale systems. Part II presents the application of the graph-based modeling framework and three-level hierarchical control framework to the power systems of an aircraft. The simplified aircraft system includes an engine, electrical, and thermal systems. A graph based approach is used to model the system dynamics, where vertices represent capacitive elements such as fuel tanks, heat exchangers, and batteries with states corresponding to the temperature and state of charge. Edges represent power flows in the form of electricity and heat, which can be actuated using control inputs. The aircraft graph is then partitioned spatially into systems and subsystems, and temporally into fast, medium, and slow dynamics. These partitioned graphs are used to develop models for each of the three levels of the hierarchy. Simulation results show the benefits of hierarchical control compared to a centralized control method.

scholarly journals Energy Storage Power and Energy Sizing and Specification Using HSSPFC

Electronics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 638
Author(s):  
Mehrzad M. Bijaieh ◽  
Wayne W. Weaver ◽  
Rush D. Robinett
Keyword(s):  
Energy Storage ◽  
Power Flow ◽  
Storage Systems ◽  
Hierarchical Control ◽  
Power Sharing ◽  
Power Flow Control ◽  
Three Phase ◽  
Surface Shaping ◽  
Power And Energy ◽  
Simulated Hybrid

The intermittent nature of renewable sources requires the integration of Energy Storage Systems (ESSs) with appropriate power and energy densities. One of the applications of Hamiltonian Surface Shaping and Power Flow Control (HSSPFC) is to size ESSs for power and energy densities by employing them as sole actuators of Microgrid (MG) systems. This Article provides a comprehensive yet simplified example of utilization of HSSPFC to size ESSs of inverter-based three-phase MG systems under hierarchical control. Here, the distributed Hamiltonian controller is expanded for control of parallel ESSs and power sharing metrics are defined to distribute power between hybrid storage systems according to their power and energy density capabilities. Simulated hybrid ESSs comprising battery and flywheel systems are used as examples to demonstrate the behaviour of the expanded control, verify the power sharing criteria and illustrate ESS design and specification by utilizing HSSPFC.

scholarly journals Optimized Hierarchical Control for an AC Microgrid Under Attack

Ingeniería ◽  
2019 ◽  
Vol 24 (1) ◽  
pp. 64-82
Author(s):  
Vladimir Toro ◽  
Eder David Baron ◽  
Eduardo Mojica-Nava
Keyword(s):  
Power Flow ◽  
Hierarchical Control ◽  
Active Power ◽  
Cyber Attacks ◽  
Cyber Attack ◽  
Secondary Control ◽  
Confidence Factor ◽  
Communication Links ◽  
Local Controller ◽  
The Stability

Context: An inverter-based microgrid working in islanded mode can suffer cyber- attacks, these can be done against either the local controller or the communication links among the inverters. Secondary control is able to reject those attacks, however, a tertiary control action is necessary in order to stabilize the power flow among the microgrid. Method: Confidence factor technique allows to reject attacks in a microgrid acting directly over the secondary control, however, this technique omits other factor related to the power available. In this case, secondary control was complemented with a tertiary control that includes optimization criteria. Results: An inverter-based microgrid is simulated in Matlab for different scenarios and under cyberattack, this allows checking the correct response of the controller under attacks and the effective powersharing among inverters. Conclusions: The tertiary control allows stabilizing the active power of the system after the rejection of a cyber-attack by the secondary control. Each inverter supplies active power according to its máximum power rating without affecting the stability of the whole system.

scholarly journals Power flow modeling of islanded AC microgrids with hierarchical control

2019 ◽  
Vol 105 ◽  
pp. 28-36 ◽  
Author(s):  
Gibran Agundis-Tinajero ◽  
Juan Segundo-Ramírez ◽  
Nancy Visairo-Cruz ◽  
Mehdi Savaghebi ◽  
Josep M. Guerrero ◽  
...  
Keyword(s):  
Power Flow ◽  
Hierarchical Control ◽  
Flow Modeling

Holomorphic Embedding Power Flow Algorithm for Isolated AC Microgrids with Hierarchical Control

2021 ◽  
pp. 1-1
Author(s):  
Ying Huang ◽  
Xiaomeng Ai ◽  
Jiakun Fang ◽  
Shichang Cui ◽  
Runfeng Zhong ◽  
...  
Keyword(s):  
Power Flow ◽  
Hierarchical Control ◽  
Holomorphic Embedding ◽  
Flow Algorithm

Adequacy and security analysis of interdependent electric and gas networks

2017 ◽  
Vol 232 (2) ◽  
pp. 121-139 ◽  
Author(s):  
Andrea Antenucci ◽  
Giovanni Sansavini
Keyword(s):  
Power Flow ◽  
Flow Model ◽  
Security Analysis ◽  
Operating Conditions ◽  
Coupled Systems ◽  
Gas Network ◽  
Gas Networks ◽  
Safety Strategies ◽  
Event Based ◽  
Modelling Approach

In this article, adequacy and security assessments on the coupled operations of the electric and gas networks are performed. Extreme operating conditions and fault of components are considered as events that can impact the interdependent systems. The electric and gas networks are represented by an event-based direct current power flow model and by a transient one-dimensional mass flow model, respectively. Furthermore, the automations and safety strategies enforced by transmission system operators are represented within an original modelling approach. A quantitative analysis is performed with reference to the simplified energy infrastructures of Great Britain. Results highlight the contingencies which can jeopardize security and identify the components that are prone to fail and induce large gas pressure instabilities and loss of supply, and the locations in the gas grid that are susceptible to pressure violation. Moreover, a simulated 30% increase of the peak gas demand in 2015 is a limit for safe operations of the gas network, but the coupled systems are robust enough to avoid the spread of a cascading failure across networks. These results allow preventing critical operating conditions induced by the interaction between networks and can guide safety-based decisions on system reinforcements and the development of mitigating actions.

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