System Level Simulation of Microgrid Power Electronic Systems

In this paper, we describe a procedure for designing an accurate simulation model using a price-wised linear approach referred to as the power semiconductor converters of a DC microgrid concept. Initially, the selection of topologies of individual power stage blocs are identified. Due to the requirements for verifying the accuracy of the simulation model, physical samples of power converters are realized with a power ratio of 1:10. The focus was on optimization of operational parameters such as real-time behavior (variable waveforms within a time domain), efficiency, and the voltage/current ripples. The approach was compared to real-time operation and efficiency performance was evaluated showing the accuracy and suitability of the presented approach. The results show the potential for developing complex smart grid simulation models, with a high level of accuracy, and thus the possibility to investigate various operational scenarios and the impact of power converter characteristics on the performance of a smart gird. Two possible operational scenarios of the proposed smart grid concept are evaluated and demonstrate that an accurate hardware-in-the-loop (HIL) system can be designed.

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IoT-Based Patient Movement Monitoring: The Post-Operative Hip Fracture Rehabilitation Model

Future Internet ◽

10.3390/fi13080195 ◽

2021 ◽

Vol 13 (8) ◽

pp. 195

Author(s):

Akash Gupta ◽

Adnan Al-Anbuky

Keyword(s):

Hip Fracture ◽

Real Time ◽

System Performance ◽

Digital Health ◽

Time Behavior ◽

Functional Requirements ◽

Rehabilitation Process ◽

Rehabilitation Model ◽

The Impact ◽

Movement Monitoring

Hip fracture incidence is life-threatening and has an impact on the person’s physical functionality and their ability to live independently. Proper rehabilitation with a set program can play a significant role in recovering the person’s physical mobility, boosting their quality of life, reducing adverse clinical outcomes, and shortening hospital stays. The Internet of Things (IoT), with advancements in digital health, could be leveraged to enhance the backup intelligence used in the rehabilitation process and provide transparent coordination and information about movement during activities among relevant parties. This paper presents a post-operative hip fracture rehabilitation model that clarifies the involved rehabilitation process, its associated events, and the main physical movements of interest across all stages of care. To support this model, the paper proposes an IoT-enabled movement monitoring system architecture. The architecture reflects the key operational functionalities required to monitor patients in real time and throughout the rehabilitation process. The approach was tested incrementally on ten healthy subjects, particularly for factors relevant to the recognition and tracking of movements of interest. The analysis reflects the significance of personalization and the significance of a one-minute history of data in monitoring the real-time behavior. This paper also looks at the impact of edge computing at the gateway and a wearable sensor edge on system performance. The approach provides a solution for an architecture that balances system performance with remote monitoring functional requirements.

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Smart Sensors for Smart Grid Reliability

Sensors ◽

10.3390/s20082187 ◽

2020 ◽

Vol 20 (8) ◽

pp. 2187 ◽

Cited By ~ 1

Author(s):

Monica Alonso ◽

Hortensia Amaris ◽

Daniel Alcala ◽

Diana M. Florez R.

Keyword(s):

Smart Grid ◽

Real Time ◽

Smart Grids ◽

Short Circuit ◽

Test System ◽

Smart Sensors ◽

Smart Sensor ◽

Protection Scheme ◽

Time Operation ◽

Real Time Operation

Sensors for monitoring electrical parameters over an entire electricity network infrastructure play a fundamental role in protecting smart grids and improving the network’s energy efficiency. When a short circuit takes place in a smart grid it has to be sensed as soon as possible to reduce its fault duration along the network and to reduce damage to the electricity infrastructure as well as personal injuries. Existing protection devices, which are used to sense the fault, range from classic analog electro-mechanics relays to modern intelligent electronic devices (IEDs). However, both types of devices have fixed adjustment settings (offline stage) and do not provide any coordination among them under real-time operation. In this paper, a new smart sensor is developed that offers the capability to update its adjustment settings during real-time operation, in coordination with the rest of the smart sensors spread over the network. The proposed sensor and the coordinated protection scheme were tested in a standard smart grid (IEEE 34-bus test system) under different short circuit scenarios and renewable energy penetration. Results suggest that the short-circuit fault sensed by the smart sensor is improved up to 80% and up to 64% compared with analog electromechanics relays and IEDs, respectively.

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

Volume 3: Coal, Biomass and Alternative Fuels; Cycle Innovations; Electric Power; Industrial and Cogeneration ◽

10.1115/gt2015-43604 ◽

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.

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Efficiency Analysis of Gas Turbine Combined-Cycle Fed with Synthetic Natural Gas (SNG) and Mixture of Syngas and SNG

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.656-657.113 ◽

2015 ◽

Vol 656-657 ◽

pp. 113-118

Author(s):

Hsiu Mei Chiu ◽

Po Chuang Chen ◽

Yau Pin Chyou ◽

Ting Wang

Keyword(s):

Natural Gas ◽

Simulation Model ◽

Steam Turbine ◽

Gas Turbine ◽

Gas Turbines ◽

Combined Cycle ◽

System Level ◽

Minimum Requirement ◽

Synthetic Natural Gas ◽

System Level Simulation

The effect of synthetic natural gas (SNG) and mixture of syngas and SNG fed to Natural Gas Combined-Cycle (NGCC) plants is presented in this study via a system-level simulation model. The commercial chemical process simulator, Pro/II®V8.1.1, was used in the study to build the analysis model. The NGCC plant consists of gas turbine (GT), heat recovery steam generator (HRSG) and steam turbine (ST). The study envisages two analyses as the basic and feasibility cases. The former is the benchmark case which is verified by the reference data with the GE 7FB gas turbine. According to vendor’s specification, the typical net plant efficiency of GE 7FB NGCC with two gas turbines to one steam turbine is 57.5% (LHV), and the efficiency is the benchmark in the simulation model built in the study. The latter introduces a feasibility study with actual parameters in Taiwan. The SNG-fed GE 7FB based combined-cycle is evaluated, and the mixture of SNG and syngas is also evaluated to compare the difference of overall performance between the two cases. The maximum ratio of syngas to SNG is 0.14 due to the constraint for keeping the composition of methane at a value of 80 mol%, to meet the minimum requirement of NG in Taiwan. The results show that the efficiency in either case of SNG or mixture of SNG and syngas is slightly lower than the counterpart in the benchmark one. Because the price of natural gas is much higher than that of coal, it results in higher idle capacity of NGCC. The advantage of adopting SNG in Taiwan is that it could increase the capacity factor of combined-cycles in Taiwan. The study shows a possible way to use coal and reduce the CO2emission, since coal provides nearly half of the electricity generation in Taiwan in recent years.

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Estimation of Semiconductor Switching Losses under Hard Switching using Matlab/Simulink Subsystem

Electrical Control and Communication Engineering ◽

10.2478/ecce-2013-0003 ◽

2013 ◽

Vol 2 (1) ◽

pp. 20-26 ◽

Cited By ~ 15

Author(s):

Volodymyr Ivakhno ◽

Volodymyr V. Zamaruiev ◽

Olga Ilina

Keyword(s):

Semiconductor Devices ◽

Average Power ◽

Power Converter ◽

System Level ◽

Automatic Regulation ◽

Regulation System ◽

Matlab Simulink ◽

Turn On ◽

System Level Simulation ◽

Power Switch

AbstractThe conventional tools for the system level simulation of the switch-mode power converters (for example, MATLAB/SIMILINK) allow simulating the behavior of a power converter jointly operating with the control system in a closed automatic regulation system. This simulation tools either represent semiconductor devices as ideal switches or implement the simplest models based on volt-ampere characteristics of standard types of semiconductor devices for conducting loss estimation. This fact makes direct calculation of dynamic power losses in the semiconductor devices impossible. The MATLAB/SIMILINK subsystem that calculates the average power dissipated in the power switch during turn-on and turn-off transition is proposed in this paper. The represented approach used in the subsystem estimates by the means of MATLAB/SIMILINK the values of turn-on and turn-off energies at power switch commutation instances on the base of switching current and voltage measurements and the values of commutation energies given in datasheet on power switch. The simulation results of step-down converter with IGBT and proposed subsystem in MATLAB/SIMULINK were compared with the calculation results obtained in Semisel

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A study on the impact of packet loss and latency on real-time demand response in smart grid

2012 IEEE Globecom Workshops ◽

10.1109/glocomw.2012.6477805 ◽

2012 ◽

Cited By ~ 4

Author(s):

Marco Pruckner ◽

Abdalkarim Awad ◽

Reinhard German

Keyword(s):

Smart Grid ◽

Real Time ◽

Demand Response ◽

Packet Loss ◽

The Impact

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A Tool for Evaluating the Performance of SiC-Based Bidirectional Battery Chargers for Automotive Applications

Energies ◽

10.3390/en13246733 ◽

2020 ◽

Vol 13 (24) ◽

pp. 6733

Author(s):

Giuseppe Aiello ◽

Mario Cacciato ◽

Francesco Gennaro ◽

Santi Agatino Rizzo ◽

Giuseppe Scarcella ◽

...

Keyword(s):

Design Method ◽

Block Diagram ◽

Power Converter ◽

System Level ◽

Design And Optimization ◽

Dual Active Bridge ◽

System Level Simulation ◽

Dc Power ◽

Battery Chargers ◽

Diagram Design

In this paper, a procedure to simulate an electronic power converter for control design and optimization purposes is proposed. For the addressed application, the converter uses SiC-MOSFET technology in bidirectional battery chargers composed of two power stages. The first stage consists of a single-phase AC/DC power factor correction synchronous rectifier. The following stage is a DC/DC dual active bridge. The converter has been modulated using a phase-shift technique which is able to manage bidirectional power flows. The development of a model-based simulation approach is essential to simplify the different design phases. Moreover, it is also important for the final validation of the control algorithm. A suitable tool consisting of a system-level simulation environment has been adopted. The tool is based on a block diagram design method accomplished using the Simulink toolbox in MATLAB™.

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