Operating Experiences on Commercial Fuel Cell Units for Back Up Power Generation

2010 ◽  
Vol 7 (3) ◽  
Author(s):  
Mauro Scagliotti ◽  
Carmen Valli
Keyword(s):  
Steady State ◽  
Fuel Cell ◽  
Power Systems ◽  
Power System ◽  
Polymer Electrolyte Fuel Cell ◽  
System Response ◽  
Safety Issues ◽  
Endurance Testing ◽  
Endurance Tests ◽  
Power System Performance

Extensive residential demonstration programs and the needs for innovative and reliable back up power systems are driving the development and diffusion of small (<10 kWe) stationary fuel cell power systems. Low temperature polymer electrolyte fuel cell (PEFC) power systems are particularly suitable for back up and UPS applications due to short start up times, whereas for small cogenerative residential applications both PEFC and solid oxide fuel cells (SOFCs) are emerging as promising technologies. The technical and economical viabilities of fuel cell based systems have been already demonstrated for a few niche applications such as back up system with high autonomy. Nevertheless fuel cell technologies are not yet mature. Durability and reliability are of great concern and have to be specifically addressed. Real world experiences and extensive laboratory testing are paramount for the development of reliable products, as well as to harmonize and refine codes and standards required for the market entry. This paper presents and discusses the results of a 3 year experience on commercial PEFC 1 kWe units. Basic characterization, cycling, and steady state endurance testing data are analyzed herein with a focus on power system performance, reliability, and degradation issues. End user and system integrator testing approaches were applied. Power system response to load demand and electrical efficiency were measured following as much as possible the prescriptions of codes and standards. The influences of operating and environmental conditions on system efficiency were investigated as well. Positive results were achieved and, in particular, system availability resulted extremely high. Steady state long term endurance tests evidenced, however, critical durability and safety issues to be improved.

scholarly journals Series Compensation of Transmission Systems: A Literature Survey

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1717
Author(s):  
Camilo Andrés Ordóñez ◽  
Antonio Gómez-Expósito ◽  
José María Maza-Ortega
Keyword(s):  
Steady State ◽  
Power Systems ◽  
Power System ◽  
Case Studies ◽  
Electronic Devices ◽  
Literature Survey ◽  
Power Electronic ◽  
Transmission Systems ◽  
Series Compensation ◽  
Near Future

This paper reviews the basics of series compensation in transmission systems through a literature survey. The benefits that this technology brings to enhance the steady state and dynamic operation of power systems are analyzed. The review outlines the evolution of the series compensation technologies, from mechanically operated switches to line- and self-commutated power electronic devices, covering control issues, different applications, practical realizations, and case studies. Finally, the paper closes with the major challenges that this technology will face in the near future to achieve a fully decarbonized power system.

scholarly journals Multiple-Point Voltage Control to Minimize Interaction Effects in Power Systems

Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 274 ◽  
Author(s):  
Yun-Hyuk Choi ◽  
Yoon-Sung Cho
Keyword(s):  
Power Systems ◽  
Power System ◽  
Control Method ◽  
Voltage Control ◽  
Control Area ◽  
Multiple Point ◽  
Control Scheme ◽  
Control Schemes ◽  
Power System Performance ◽  
Neighboring Area

This paper proposes an advanced continuous voltage control method that implements multiple-point control to ensure peak power system performance. Most control schemes utilize generators to regulate the pilot point voltage of a control area. However, exact control of a single pilot point is difficult because of the influence of adjacent areas in a meshed power system. To address this challenge, the proposed method accesses multiple pilot points to mitigate the effects of the neighboring area. In simulations of the Korean power system, the proposed control scheme offered a considerable improvement in performance when compared with the conventional, currently implemented voltage control system.

scholarly journals Controlled Impedance-Admittance-Torque Nonlinear Modeling and Analysis of Modern Power Systems

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2461
Author(s):  
Panos C. Papageorgiou ◽  
Antonio T. Alexandridis
Keyword(s):  
Power Systems ◽  
Power System ◽  
System Analysis ◽  
Power Converter ◽  
Lyapunov Methods ◽  
Duty Ratio ◽  
System Response ◽  
Power Electronic ◽  
Dynamic Representation ◽  
Dynamic Description

Modern power systems are continuously transformed into decentralized ones where distributed generation (DG) plays a key role. Almost all the different distributed energy resources (DERs) are connected in geographically dispersed places through controlled power electronic interfaces in a manner that essentially affects the dynamic performance and control of the whole power system. Simultaneously, rotating machines in power production or absorption, dominate the system response and stability. In this new frame, this paper proposes a novel generalized dynamic representation and full scale modeling of a modern power system based on the well-known impedance-admittance (IA) network model for the electricity grid, substantially extended to include in detail both the power converter devices by considering the controlled power electronic dynamics and the electrical machines by inserting their full electromechanical dynamics. This formulation results in a holistic nonlinear dynamic description, defined here as controlled impedance-admittance-torque (CIAT) model of the whole system which features common structural characteristics. The model is deployed in state space, involves all the controlled inputs in DG, namely the duty-ratio signals of each power converter interface, all the other external inputs affecting the system, namely all the known or unknown voltage, current, and torque inputs. As shown in the paper, the proposed CIAT model retains its fundamental properties for any DG and network topology, standard or varying. This enables the compression of the accurate analytic power system dynamic description into a matrix-based generic nonlinear model that can be easily used for analysis studies of such large-scale systems. Taking into account the nonlinear nature of the CIAT matrix-based model and the persistent action of the external inputs, Lyapunov methods deployed on recently established input to state stability (ISS) notions are systematically applied for the system analysis. Hence, the traditionally used small-signal model-based analysis that suffers from the intermittent and continuously changing operation of DERs is completely substituted by the proposed formulation. A modern power system example with different DERs involved is analyzed by this way and is extensively simulated to verify the validity of the proposed method.

scholarly journals The Geometry of Power Systems Steady-State Equations– Part I: Power Surface

2020 ◽  
pp. 37-46
Author(s):  
B. Ayuev ◽  
V. Davydov ◽  
P. Erokhin ◽  
V. Neuymin ◽  
A. Pazderin
Keyword(s):  
Steady State ◽  
Power Systems ◽  
Power System ◽  
Power Flow ◽  
Analytical Study ◽  
State Theory ◽  
Steady States ◽  
State Equations ◽  
Feasibility Region ◽  
Steady State Solutions

Steady-state equations play a fundamental role in the theory of power systems and computation practice. These equations are directly or mediately used almost in all areas of the power system state theory, constituting its basis. This two-part study deals with a geometrical interpretation of steady-state solutions in a power space. Part I considers steady states of the power system as a surface in the power space. A power flow feasibility region is shown to be widely used in power system theories. This region is a projection of this surface along the axis of a slack bus active power onto a subspace of other buses power. The findings have revealed that the obtained power flow feasibility regions, as well as marginal states of the power system, depend on a slack bus location. Part II is devoted to an analytical study of the power surface of power system steady states.

scholarly journals Development of a Simulation Framework for Analyzing Security of Supply in Integrated Gas and Electric Power Systems

2016 ◽  
Author(s):  
Kwabena Addo Pambour ◽  
Burcin Cakir Erdener ◽  
Ricardo Bolado-Lavin ◽  
Gerard P. J. Dijkema
Keyword(s):  
Steady State ◽  
Power Systems ◽  
Power System ◽  
Data Exchange ◽  
Power Plants ◽  
Optimal Power Flow ◽  
Power Network ◽  
Simulation Framework ◽  
Security Of Supply ◽  
State Models

Gas and power networks are tightly coupled and interact with each other due to physically interconnected facilities. In an integrated gas and power network, a contingency observed in one system may cause iterative cascading failures, resulting in network wide disruptions. Therefore, understanding the impacts of the interactions in both systems is crucial for governments, system operators, regulators and operational planners, particularly, to ensure security of supply for the overall energy system. Although simulation has been widely used in the assessment of gas systems as well as power systems, there is a significant gap in simulation models that are able to address the coupling of both systems. In this paper, a simulation framework that models and simulates the gas and power network in an integrated manner is proposed. The framework consist of a transient model for the gas system and a steady state model for the power system based on AC-Optimal Power Flow. The gas and power system model are coupled through an interface which uses the coupling equations to establish the data exchange and coordination between the individual models. The bidirectional interlink between both systems considered in this studies are the fuel gas offtake of gas fired power plants for power generation and the power supply to LNG terminals and electric drivers installed in gas compressor stations and underground gas storage facilities. The simulation framework is implemented into an innovative simulation tool named SAInt (Scenario Analysis Interface for Energy Systems) and the capabilities of the tool are demonstrated by performing a contingency analysis for a real world example. Results indicate how a disruption triggered in one system propagates to the other system and affects the operation of critical facilities. In addition, the studies show the importance of using transient gas models for security of supply studies instead of successions of steady state models, where the time evolution of the line pack is not captured correctly.

scholarly journals Steady state stability in electrical power systems considering operation limits in generators, transformers and transmission lines

2021 ◽  
Vol 18 (2) ◽  
Author(s):  
Fredy Estuardo Tamayo Guzmán ◽  
Carlos Andrés Barrera-Singaña
Keyword(s):  
Steady State ◽  
Power Systems ◽  
Power System ◽  
Transmission Lines ◽  
Electrical Power ◽  
Operating Conditions ◽  
Electrical Power Systems ◽  
Capacity Curves ◽  
Remedial Actions ◽  
Steady State Stability

Electrical power systems are exposed to several events that can cause unstable operation scenarios. This is due to improper operation of certain components. If an event occurs, the system must be designed to overcome that contingency, thus remaining in a permanent condition that must be evaluated in order to monitor and prevent a possible collapse of the system. An evaluation of steady state stability is proposed at this work based on the capacity curves of generators, transformers and transmission lines. These remarked curves provide information on the operation point of these elements, thus allowing the application of remedial actions. PowerFactory and Matlab are used to carry out the tool for monitoring the operation points after a contingency. The effectiveness of the developed tool is validated at the IEEE 39-bus power system model, where results shows that the functionalaty for different contingencies based on the operating conditions when the components of the power system are varied, cosnquently, the tool identifies cases that require actions at the operational level.

Demonstration of Efficient Water Recovery for Fuel Cell Power Systems

2009 ◽  
Author(s):  
Michael G. Izenson ◽  
Jay C. Rozzi
Keyword(s):  
Fuel Cell ◽  
Power Systems ◽  
Power System ◽  
High Water ◽  
Water Recovery ◽  
Recovery Efficiency ◽  
Input Stream ◽  
Higher Power ◽  
Exhaust Stream ◽  
Very High

Water recovery and recycling are key technologies for fuel cell power systems. This paper describes technology to recover and recycle water using a compact, efficient condenser to separate water from a fuel cell exhaust stream. The condenser uses an innovative, micromachined condensing surface to achieve very high condensation mass flux and enable very high water recovery efficiency from a compact system. The condenser is sized for a 5 kWe, solid oxide fuel cell (SOFC) power system, but can easily be scaled up for higher power systems. We demonstrated operation of the condenser using an input stream that simulated the exhaust from an SOFC power system. Our device condensed and recovered 97–99% of the water in the input stream while consuming very little power (about 50 W).

scholarly journals Multicriteria Assessment of Combined Heat and Power Systems

2018 ◽  
Vol 10 (9) ◽  
pp. 3240 ◽  
Author(s):  
Santoso Wibowo ◽  
Srimannarayana Grandhi
Keyword(s):  
Power Systems ◽  
Power System ◽  
Combined Heat And Power ◽  
Assessment Model ◽  
Intuitionistic Fuzzy Numbers ◽  
Ideal Solutions ◽  
Multicriteria Assessment ◽  
Overall Performance ◽  
Power System Performance ◽  
Interval Valued

This paper presented a multicriteria assessment model for evaluating the performance of combined heat and power systems. Interval-valued intuitionistic fuzzy numbers were used for representing the subjective and imprecise assessments of the decision maker in evaluating the relative importance of the criteria, and the performance of individual combined heat and power systems. An effective algorithm was developed based on the concept of ideal solutions for calculating the overall performance index, for each combined heat and power system across all criteria. An example was presented to demonstrate the applicability of the multicriteria assessment model, for dealing with real world combined heat and power system performance evaluation problems.

scholarly journals Review of Steady-State Electric Power Distribution System Datasets

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4826
Author(s):  
Steffen Meinecke ◽  
Leon Thurner ◽  
Martin Braun
Keyword(s):  
Steady State ◽  
Power Systems ◽  
Power System ◽  
Power Distribution ◽  
Distribution System ◽  
New Technologies ◽  
Electrical Power ◽  
Background Information ◽  
Electrical Power Systems ◽  
Power Distribution System

Publicly available grid datasets with electric steady-state equivalent circuit models are crucial for the development and comparison of a variety of power system simulation tools and algorithms. Such algorithms are essential to analyze and improve the integration of distributed energy resources (DERs) in electrical power systems. Increased penetration of DERs, new technologies, and changing regulatory frameworks require the continuous development of the grid infrastructure. As a result, the number and versatility of grid datasets, which are required in power system research, increases. Furthermore, the used grids are created by different methods and intentions. This paper gives orientation within these developments: First, a concise overview of well-known, publicly available grid datasets is provided. Second, background information on the compilation of the grid datasets, including different methods, intentions and data origins, is reviewed and characterized. Third, common terms to describe electric steady-state distribution grids, such as representative grid or benchmark grid, are assembled and reviewed. Recommendations for the use of these grid terms are made.

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