International Journal of Automation and Power Engineering
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Open Access journal
ISSN (Print) 2161-6442 - ISSN (Online) 2161-5055
Published by Science and Engineering Publishing Company [49 journals]
- A New Virtual Isolation Technique for Power Supplies
Abstract: A New Virtual Isolation Technique for Power Supplies
Author Spiros Cofina
This paper describes a new technique of isolation without a transformer. The basic principle of virtual isolation relies on two pairs of switching semiconductors such as IGBT transistors and two capacitors. Each IGBT transistor is connected in parallel to the other: one in the positive rail of the supply and one in the negative. Each pair of the paralleled IGBTs is conducting at different times. Assuming as infinite the impedance of an off state IGBT, there is flow of energy from the input energy source to the output load without an actual ohmic connection, thus achieving isolation between input and output. For a 230V/50Hz neutrally earthed, rectified mains as an input energy source, laboratory and theoretical results converged with good accuracy, even though the addition of a 100KΩ/0.25Watts resistance between an output terminal and the earth was found necessary to alleviate the slightly uncomfortable feeling of an earthed human who touches this terminal. The convergence between practical and theoretical results also validates the theoretical approach of the relevant, previous publications , . These results show that future work which includes the addition of a Buck converter in the output can create a highly efficient isolated and regulated power supply. Here, it must be stressed that any commercial production based on the publications of virtual isolation must be made strictly only with the written consent of the present author, as patents have been applied for.
- Enhancing Micro Energy Grid (MEG) Performance by Novel D-FACTS based on
Abstract: Enhancing Micro Energy Grid (MEG) Performance by Novel D-FACTS based on GA-ANFIS Integration
Author Hossam A.GabbarAhmed OthmanAboelsood ZidanJason RungeOwais MuneerManir IshamMayn Toma
This paper concerns with enhancing Micro Energy Grid (MEG) performance by Novel Developed Flexible AC Transmission System (D-FACTS) based on the integration of Genetics algorithm (GA) and Adaptive Neuro-Fuzzy Inference System (ANFIS). The design and development of MEG, with hardware demonstration, is developed at the Energy Safety and Control Laboratory (ESCL), University of Ontario Institute of Technology. The hardware/software based system includes implementation of control strategies for Distributed Energy Resources (DER) and programmable loads in a laboratory scale; and the appropriate software was developed to monitor all MEG parameters and to control the various components. The interconnection of renewable energy sources, such as wind power, solar PV and others, are implemented, studied and integrated into this MEG. Furthermore, gas based DERs operate as Combined Heat and Power (CHP) to supply both thermal and electrical loads. The design, development, and hardware setup of this MEG has been presented in a planning stage and an operational stage. Firstly, the planning stage optimizes the size and type of DERs for minimum cost and emissions. Then, in the operational stage, there will be the evaluation of the dynamic response to fine tuning the dynamic response. So a novel D-FACTS device, Green Plug-Energy Economizer (GP-EE) with two DC/AC schemes, is proposed and integrated into this MEG. The integrated GA with ANFIS has been applied to control the settings of GP-EE to fine-tune the system dynamic response. The proposed controller ensures the adaptation of the global control error of dynamic tri-loop regulation for GP-EE. The proposed control strategy leads to get full MEG utilization by increasing the energy efficiency and reliability. Power factor improvement, bus voltage stabilizing, feeder loss minimization and power quality enhancement are realized and achieved. Hardware demonstration with digital simulations have been used to validate the results to show the effectiveness and the improved performance.
- A Linear Model for Characterizing Transient Behaviour in Wide Bandgap
Semiconductor-based Switching Circuits
Abstract: A Linear Model for Characterizing Transient Behaviour in Wide Bandgap Semiconductor-based Switching Circuits
Author Raghav KhannaAnsel BarchowksyAndrew AmrheinWilliam StanchinaGregory ReedZhi-Hong Ma
This paper presents a linear model for characterizing transient behavior in power conversion circuits that use wide bandgap semiconductors. It details analytical and experimental characterization of the circuit-level transient phenomena affecting the performance of wide bandgap (WBG) semiconductors. Specifically observed behaviors including voltage overshoot, ringing, and false turn-on are analyzed using equivalent linear circuit models supplemented with experimental characterization. The effect that the parasitic device capacitances have on each of these transient events is also investigated. In order for WBG semiconductor devices to deliver their full performance potential of significantly enhancing next generation power electronic systems, the aforementioned transient characteristics must be eliminated. Due to the agreement between the models’ predicted results and experimental waveforms, the work presented here lays the foundation for optimizing the transient performance of power conversion circuits using WBG semiconductor devices.