scholarly journals Clamping system for series connected IGBTs to avoid transient breakdown voltages

2017 ◽  
Author(s):  
Masoomeh Boloorian ◽  
Tonny W. Rasmussen ◽  
Walid Z. El-Khatib
Keyword(s):  
Experimental Tests ◽  
Buck Converter ◽  
Theory And Practice ◽  
Output Current ◽  
Insulated Gate Bipolar Transistor ◽  
Blocking Voltage ◽  
Wave Forms ◽  
Clamping System ◽  
Converter Design ◽  
Synchronized Switching

<p>IGBTs (Insulated Gate Bipolar Transistor) can be used for power DC-DC converters at higher voltages. A series connection is needed due to the blocking<br />capability limit of 6500V. The voltage must be shared among the IGBTs both dynamic when switching and blocking mode. A non-synchronized switching creates transient voltage that might damage the IGBT. The non-synchronized switching comes from different delays in the gate drivers and deviation in the IGBT parameters. This paper investigates in theory and practice a solution<br />contains of clamp circuit, dynamic and static circuit. Turning on process of the stack of three IGBTs are in focus in a buck converter design. An operating<br />voltage closer to the IGBT limit is used in order to press the system. For the simulations (Pspice) and experimental tests, fast IGBTs (1200V /30A IXYH40N120C3) are used to show the good dynamic of the chosen solution. The Lab tests also show that because of the deviation in parameters preadjustment of the gate signals is needed. The experimental tests have been carried out in different clamp voltage to finally have clamp voltage close to<br />the blocking voltage of the IGBTs and maximum 2A as output current. Examples of wave forms for voltages are given and discussed.</p>

scholarly journals Stacked Buck Converter: Current Ripple Elimination Effect and Transient Response

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 64
Author(s):  
Chien-Chun Huang ◽  
Yu-Chen Liu ◽  
Chia-Ching Lin ◽  
Chih-Yu Ni ◽  
Huang-Jen Chiu
Keyword(s):  
Transient Response ◽  
Dead Time ◽  
Control Method ◽  
Buck Converter ◽  
Modulation Method ◽  
Output Current ◽  
Time Modulation ◽  
Advantages And Disadvantages ◽  
Improvement Method ◽  
Current Ripple

To balance the cost and volume when applying a low output current ripple, the power supply design should be able to eliminate the current ripple under any duty cycle in medium and high switching frequencies, and considerably reduce filter volume to improve power density. A stacked buck converter was eventually selected after reviewing the existing solutions and discussing their advantages and disadvantages. A stacked buck converter is used as a basis to propose the transient response and output current ripple elimination effect, boundary limit control method, and low output ripple dead time modulation method to make individual improvements. The principle, mathematical derivation, small-signal model, and compensator design method of the improvement method are presented in detail. Moreover, simulation results are used to mutually verify the correctness and effectiveness of the improvement method. A stacked buck converter with 330-V input, 50-V output, and 1-kW output power was implemented to verify the effect of the low output current ripple dead time modulation. Experimental results showed that the peak-to-peak value of the output current ripple was reduced from 2.09 A to 559 mA, and the RMS value was reduced from 551 mA to 91 mA, thereby effectively improving the output current ripple.

Controller for a reduced output current ripple DC-DC buck converter

2015 ◽  
Author(s):  
Jose M. Sosa ◽  
P.R. Martinez-Rodriguez ◽  
G. Escobar ◽  
J.C. Nava-Cruz ◽  
C.A. Limones-Pozos
Keyword(s):  
Buck Converter ◽  
Output Current ◽  
Current Ripple

New Zealand translocations: theory and practice

1995 ◽  
Vol 2 (1) ◽  
pp. 39 ◽  
Author(s):  
Doug P. Armstong ◽  
Ian G. McLean
Keyword(s):  
Population Dynamics ◽  
New Zealand ◽  
Experimental Tests ◽  
Theory And Practice ◽  
Habitat Requirements ◽  
Metapopulation Dynamics ◽  
Behavioural Adaptation ◽  
New Locations ◽  
History Of ◽  
Tests Of Hypotheses

One of the most common tools in New Zealand conservation is to translocate species to new locations. There have now been over 400 translocations done for conservation reasons, mainly involving terrestrial birds. Most translocations have been done strictly as management exercises, with little or no reference to theory. Nevertheless, translocations always involve some underlying theory, given that people must inevitably choose among a range of potential translocation strategies. We review theory relevant to translocations in the following areas: habitat requirements, susceptibility to predation, behavioural adaptation, population dynamics, genetics, metapopulation dynamics, and community ecology. For each area we review and evaluate the models that seem to underpin translocation strategies used in New Zealand. We report experiments testing some of these models, but note that theory underlying translocation strategies is largely untested despite a long history of translocations. We conclude by suggesting key areas for research, both theoretical and empirical. We particularly recommend that translocations be designed as experimental tests of hypotheses whenever possible.

Fabrication of a P-Channel SiC-IGBT with High Channel Mobility

2013 ◽  
Vol 740-742 ◽  
pp. 958-961 ◽  
Author(s):  
Shuji Katakami ◽  
Hiroyuki Fujisawa ◽  
Kensuke Takenaka ◽  
Hitoshi Ishimori ◽  
Shinji Takasu ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Leakage Current Density ◽  
Current Density ◽  
Field Effect ◽  
Oxidation Process ◽  
Doping Profile ◽  
Base Layer ◽  
Channel Mobility ◽  
Insulated Gate Bipolar Transistor ◽  
Blocking Voltage

We fabricated and characterized an ultrahigh voltage (>10kV) p-channel silicon carbide insulated gate bipolar transistor (SiC-IGBT) with high channel mobility. Higher field-effect channel mobility of 13.5 cm2/Vs was achieved by the combination of adopting an n-type base layer with a retrograde doping profile and additional wet re-oxidation annealing (wet-ROA) at 1100°C in the gate oxidation process. The on-state characteristics of the p-channel SiC-IGBT at 200°C showed the low differential specific on-resistance of 24 mΩcm2 at VG = -20 V. The forward blocking voltage of the p-channel SiC-IGBT at 25°C was 10.2 kV a the leakage current density of 1.0 μA/cm2.

scholarly journals An Optimal Method for Lubricating Oil Compounds Properties Estimation - the Computer - Based Approach

2019 ◽  
Vol 70 (11) ◽  
pp. 3942-3946
Author(s):  
Gabriel Radulescu ◽  
Diana Cursaru
Keyword(s):  
Process Improvement ◽  
Production Cost ◽  
Software Tool ◽  
Experimental Tests ◽  
Theory And Practice ◽  
Lubricating Oil ◽  
Optimal Method ◽  
Lubricating Oils ◽  
Computer Based ◽  
Optimal Mixing

Obtaining the commercial lubricating oils through an industrial method is a process which has an extensive complexity, requiring a very special attention paid to the final products quality. In this field, any new mixing compound, any new additive and any process improvement is more than welcome. Using the so called optimal mixing recipes � in order to get commercial lubricating oils by the base oils and corresponding additives � is a common way to lower the production cost and increase its quality. This paper proposes an original software tool, developed by the authors, which offers these recipes based on the final mixture properties (explicitly given). The application is built-up around the nonlinear programming and runs under MATLAB� environment. It is a remarkably robust application, with good functionality and accuracy. Its performance is proved both in theory and practice, after laboratory experimental tests.

scholarly journals Implementation of Buck-Boost Converter as Low Voltage Stabilizer at 15 V

2019 ◽  
Vol 9 (4) ◽  
pp. 2230
Author(s):  
Suwarno Suwarno ◽  
Tole Sutikno
Keyword(s):  
Power Electronics ◽  
Wind Power ◽  
Output Voltage ◽  
Low Voltage ◽  
Input Voltage ◽  
Boost Converter ◽  
Voltage Stabilizer ◽  
Voltage Regulator ◽  
Output Current ◽  
Converter Design

<p>This paper presents the implementation of the buck-boost converter design which is a power electronics applications that can stabilize voltage, even though the input voltage changes. Regulator to stabilize the voltage using PWM pulse that triger pin 2 on XL6009. In this design of buck-boost converter is implemented using the XL6009, LM7815 and TIP2955. LM7815 as output voltage regulator at 15V with 1A output current, while TIP2955 is able to overcome output current up to 5A. When the LM7815 and TIP2955 are connected in parallel, the converter can increase the output current to 6A.. Testing is done using varied voltage sources that can be set. The results obtained from this design can be applied to PV (Photovoltaic) and WP (Wind Power), with changes in input voltage between 3-21V dc can produce output voltage 15V.</p>

Augmented Buck Converter Design using Resonant Circuits for Fast Transient Recovery

2016 ◽  
Vol 31 (8) ◽  
pp. 5666-5679 ◽  
Author(s):  
Zhenyu Shan ◽  
Siew-Chong Tan ◽  
Chi K. Tse ◽  
Juri Jatskevich
Keyword(s):  
Buck Converter ◽  
Converter Design ◽  
Fast Transient
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