scholarly journals Integrating runtime validation and hardware-in-the-loop (HiL) testing with V & V in complex hybrid systems

2019 ◽  
Vol 47 (4) ◽  
pp. 393
Author(s):  
S.D. Dewasurendra ◽  
A.C. Vidanapathirana ◽  
S.G. Abeyratne
Keyword(s):  
Hybrid Systems ◽  
Hardware In The Loop ◽  
Runtime Validation ◽  
Complex Hybrid

Development and Verification of Complex Hybrid Systems Using Synthesizable Monitors

2013 ◽  
pp. 182-198 ◽  
Author(s):  
Andreas Abel ◽  
Allon Adir ◽  
Torsten Blochwitz ◽  
Lev Greenberg ◽  
Tamer Salman
Keyword(s):  
Hybrid Systems ◽  
Complex Hybrid

scholarly journals A Real-Time Degradation Model for Hardware in the Loop Simulation of Fuel Cell Gas Turbine Hybrid Systems

2015 ◽  
Author(s):  
Valentina Zaccaria ◽  
Alberto Traverso ◽  
David Tucker
Keyword(s):  
Fuel Cell ◽  
Real Time ◽  
Gas Turbine ◽  
Hybrid Systems ◽  
Current Density ◽  
Gas Turbines ◽  
Hardware In The Loop ◽  
Fuel Utilization ◽  
Time Operation ◽  
The Impact

The theoretical efficiencies of gas turbine fuel cell hybrid systems make them an ideal technology for the future. Hybrid systems focus on maximizing the utilization of existing energy technologies by combining them. However, one pervasive limitation that prevents the commercialization of such systems is the relatively short lifetime of fuel cells, which is due in part to several degradation mechanisms. In order to improve the lifetime of hybrid systems and to examine long-term stability, a study was conducted to analyze the effects of electrochemical degradation in a solid oxide fuel cell (SOFC) model. The SOFC model was developed for hardware-in-the-loop simulation with the constraint of real-time operation for coupling with turbomachinery and other system components. To minimize the computational burden, algebraic functions were fit to empirical relationships between degradation and key process variables: current density, fuel utilization, and temperature. Previous simulations showed that the coupling of gas turbines and SOFCs could reduce the impact of degradation as a result of lower fuel utilization and more flexible current demands. To improve the analytical capability of the model, degradation was incorporated on a distributed basis to identify localized effects and more accurately assess potential failure mechanisms. For syngas fueled systems, the results showed that current density shifted to underutilized sections of the fuel cell as degradation progressed. Over-all, the time to failure was increased, but the temperature difference along cell was increased to unacceptable levels, which could not be determined from the previous approach.

scholarly journals Hardware-in-the-Loop Operations With an Emulator Rig for SOFC Hybrid Systems

2017 ◽  
Author(s):  
Mario L. Ferrari ◽  
Alessandro Sorce ◽  
Aristide F. Massardo
Keyword(s):  
Fuel Cell ◽  
Real Time ◽  
Hybrid Systems ◽  
Control Strategies ◽  
Experimental Tests ◽  
Outlet Temperature ◽  
Hardware In The Loop ◽  
Set Point ◽  
The Real ◽  
System Components

This paper shows the Hardware-In-the-Loop (HIL) technique developed for the complete emulation of Solid Oxide Fuel Cell (SOFC) based hybrid systems. This approach is based on the coupling of an emulator test rig with a real-time software for components which are not included in the plant. The experimental facility is composed of a T100 microturbine (100 kW electrical power size) modified for the connection to an SOFC emulator device. This component is composed of both anodic and cathodic vessels including also the anodic recirculation system which is carried out with a single stage ejector, driven by an air flow in the primary duct. However, no real stack material was installed in the plant. For this reason, a real-time dynamic software was developed in the Matlab-Simulink environment including all the SOFC system components (the fuel cell stack with the calculation of the electrochemical aspects considering also the real losses, the reformer, and a cathodic recirculation based on a blower, etc.). This tool was coupled with the real system utilizing a User Datagram Protocol (UDP) data exchange approach (the model receives flow data from the plant at the inlet duct of the cathodic vessel, while it is able to operate on the turbine changing its set-point of electrical load or turbine outlet temperature). So, the software is operated to control plant properties to generate the effect of a real SOFC in the rig. In stand-alone mode the turbine load is changed with the objective of matching the measured Turbine Outlet Temperature (TOT) value with the calculated one by the model. In grid-connected mode the software/hardware matching is obtained through a direct manipulation of the TOT set-point. This approach was essential to analyze the matching issues between the SOFC and the micro gas turbine devoting several tests on critical operations, such as start-up, shutdown and load changes. Special attention was focused on tests carried out to solve the control system issues for the entire real hybrid plant emulated with this HIL approach. Hence, the innovative control strategies were developed and successfully tested considering both the Proportional Integral Derivative and advanced approaches. Thanks to the experimental tests carried out with this HIL system, a comparison between different control strategies was performed including a statistic analysis on the results The positive performance obtainable with a Model Predictive Control based technique was shown and discussed. So, the HIL system presented in this paper was essential to perform the experimental tests successfully (for real hybrid system development) without the risks of destroying the stack in case of failures. Mainly surge (especially during transient operations, such as load changes) and other critical conditions (e.g. carbon deposition, high pressure difference between the fuel cell sides, high thermal gradients in the stack, excessive thermal stress in the SOFC system components, etc.) have to be carefully avoided in complete plants.

scholarly journals A Comprehensive Diagnosis Methodology for Complex Hybrid Systems: A Case Study on Spacecraft Power Distribution Systems

2010 ◽  
Vol 40 (5) ◽  
pp. 917-931 ◽  
Author(s):  
Matthew J. Daigle ◽  
Indranil Roychoudhury ◽  
Gautam Biswas ◽  
Xenofon D. Koutsoukos ◽  
Ann Patterson-Hine ◽  
...  
Keyword(s):  
Hybrid Systems ◽  
Power Distribution ◽  
Distribution Systems ◽  
Power Distribution Systems ◽  
Comprehensive Diagnosis ◽  
Complex Hybrid

Fuel Composition Transients in Fuel Cell Turbine Hybrid for Polygeneration Applications

2014 ◽  
Vol 11 (6) ◽  
Author(s):  
Nor Farida Harun ◽  
David Tucker ◽  
Thomas A. Adams
Keyword(s):  
Fuel Cell ◽  
Hybrid Systems ◽  
Carbon Deposition ◽  
Dynamic Performance ◽  
Sudden Change ◽  
Department Of Energy ◽  
Test Facility ◽  
Fuel Composition ◽  
Hardware In The Loop ◽  
Fuel Flexibility

Transient impacts on the performance of solid oxide fuel cell/gas turbine (SOFC/GT) hybrid systems were investigated using hardware-in-the-loop simulations (HiLSs) at a test facility located at the U.S. Department of Energy, National Energy Technology Laboratory. The work focused on applications relevant to polygeneration systems, which require significant fuel flexibility. Specifically, the dynamic response of implementing a sudden change in fuel composition from syngas to methane was examined. The maximum range of possible fuel composition allowable within the constraints of carbon deposition in the SOFC and stalling/surging of the turbine compressor system was determined. It was demonstrated that the transient response was significantly impact the fuel cell dynamic performance, which mainly drives the entire transient in SOFC/GT hybrid systems. This resulted in severe limitations on the allowable methane concentrations that could be used in the final fuel composition when switching from syngas to methane. Several system performance parameters were analyzed to characterize the transient impact over the course of 2 h from the composition change.

Integrated approach to diagnosis of complex hybrid systems

2001 ◽  
Author(s):  
Sriram Narasimhan ◽  
Gautam Biswas ◽  
Gabor Karsai
Keyword(s):  
Hybrid Systems ◽  
Integrated Approach ◽  
Complex Hybrid

Complex Hybrid Systems: Stability Analysis for Omega Limit Sets

2006 ◽  
Author(s):  
Cai Chaohong ◽  
Goebel Rafal ◽  
G. Sanfelice Ricardo ◽  
R. Teel Andrew
Keyword(s):  
Stability Analysis ◽  
Hybrid Systems ◽  
Limit Sets ◽  
Complex Hybrid

Needs and Approaches for Novel Characterization of Direct Hybrid Fuel Cell/Gas Turbines

2015 ◽  
Author(s):  
David Tucker ◽  
Comas Haynes ◽  
Patrick Geoghegan
Keyword(s):  
Fuel Cell ◽  
Hybrid Systems ◽  
Gas Turbines ◽  
Low Cost ◽  
A Priori ◽  
The United States ◽  
Hardware In The Loop ◽  
Operational Flexibility ◽  
Developmental Needs ◽  
Heat Engines

Solid oxide fuel cell (SOFC)/ gas turbine (GT) hybrid systems possess the capacity for unprecedented performances, such as electric efficiencies nearly twice that of conventional heat engines at variable scale power ratings inclusive of distributed generation. Additionally, these hybrids can have excellent operational flexibility with turndowns possibly as great as 85%. There are, however, developmental needs such as turbomachinery characterization and re-design. A leading example is that of greater propensity to have occurrences of stall-surge given the significantly different operating environment in contrast to conventional heat engines. Additionally, dynamic variation in power generation has to be done with significant a priori insight to avoid thermomechanical threats to cell stack and turbomachinery. State-of-the-art approaches involving hardware-in-the-loop simulation and, ultimately, additive manufacturing are being pursued to enable such characterization and re-design considerations given variable and dynamic operability requirements. Compressor performance in hybrid systems has been characterized at the United States National Energy Technology Laboratory (NETL), inclusive of a capability of feed forward hardware-in-the-loop simulation of hybrid systems under dynamic conditions and a capability of replacing turbine and compressor components at a relatively low cost. This paper highlights some of the simulation results, and the net result is an approach that addresses hybrid system developmental needs for accommodating generation transients.

Hardware in the Loop Testing of Battery-less Hybrid Systems for Off-grid Power Supply

2019 ◽  
Author(s):  
Nikolaos Ntavarinos ◽  
Panos Kotsampopoulos ◽  
Dimitris T. Lagos ◽  
Nikos Hatziargyriou
Keyword(s):  
Hybrid Systems ◽  
Power Supply ◽  
Hardware In The Loop
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