Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
Comparative Steady State Analysis of Boost and Cascaded Boost Converter with ...IAES-IJPEDS
In this paper, an overall comparison between the Boost Converter (BC) &
Cascaded Converter/ Cascaded Boost Converter (CBC) has been depicted in
terms of ideal condition, as well as with the consideration of Equivalent
Series Resistance (ESR) of inductor(s). The loss comparison in the two
converters due to the ESR is also included in this paper. It can be seen that in
CBC, voltage gain is more but the power loss due to ESR is also more
compared to BC. The parameters of the converters are derived with a
consideration of per unit ripple quantity of inductor current and capacitor
voltage. A boundary condition between the continuous conduction mode
(CCM) & discontinuous conduction mode (DCM) of the inductor current is
also shown. The behaviour of the capacitor current for the converters is
discussed during ON and OFF condition of the switch(es) during DCM. At
the end, the simulation results of both the converters are given for a
20V/100V, 100 W output. The analysis and simulation results are presented
in this paper for the verification of the feasibility.
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
Prof. Cuk invited talk at APEC 2011 plenary session to celebrate
35 years of his creation of this modeling and analysis method.
This talk was also recorded on video by IEEE.tv and can be viewed together. Here is a link to that video.
https://youtu.be/BLx57J2fF5w
Note: first few minutes of the video is Prof. Cuk's interview made after his presentation. This is thern followed by full 25 minutes presentation, which can be followed by the enclosed 67 slides.
IMPLEMENTATION OF DISCONTINUOUS INDUCTOR CURRENT MODE IN CUK CONVERTERS FED B...Journal For Research
This paper presents a bridgeless Cuk converter-fed brushless DC (BLDC) motor drive. A Bridgeless Cuk converter is constructed to operate at discontinuous inductor current mode to improve the quality of power and power factor at the AC mains for better speed control. The bridgeless converter is designed for obtaining the low conduction losses and requirement of low size of heat sink for the switches. TI-TMS320-F2812-based Digital Signal Processor (DSP) is used for the development of the hardware prototype of proposed BLDC motor drive.
A Low Cost Single-Switch Bridgeless Boost PFC ConverterIJPEDS-IAES
This paper proposes the single-switch bridgeless boost power factor correction (PFC) converter to achieve high efficiency in low cost. The proposed converter utilizes only one active switching device forPFC operation as well as expecting higher efficiency than typical boost PFC converters. On the other hand, the implementation cost is less than traditional bridgeless boost PFC converters, in where two active switching deivces are necessary. The operational principle, the modeling, and the control scheme of the proposed converter arediscussed in detail. In order to verify the operation of the proposed converter, a 500W switching model is built in PSIM software package. The simulation results show that the proposed converter perfectly achieves PFC operation with only a single active switch.
Comparative Steady State Analysis of Boost and Cascaded Boost Converter with ...IAES-IJPEDS
In this paper, an overall comparison between the Boost Converter (BC) &
Cascaded Converter/ Cascaded Boost Converter (CBC) has been depicted in
terms of ideal condition, as well as with the consideration of Equivalent
Series Resistance (ESR) of inductor(s). The loss comparison in the two
converters due to the ESR is also included in this paper. It can be seen that in
CBC, voltage gain is more but the power loss due to ESR is also more
compared to BC. The parameters of the converters are derived with a
consideration of per unit ripple quantity of inductor current and capacitor
voltage. A boundary condition between the continuous conduction mode
(CCM) & discontinuous conduction mode (DCM) of the inductor current is
also shown. The behaviour of the capacitor current for the converters is
discussed during ON and OFF condition of the switch(es) during DCM. At
the end, the simulation results of both the converters are given for a
20V/100V, 100 W output. The analysis and simulation results are presented
in this paper for the verification of the feasibility.
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
Prof. Cuk invited talk at APEC 2011 plenary session to celebrate
35 years of his creation of this modeling and analysis method.
This talk was also recorded on video by IEEE.tv and can be viewed together. Here is a link to that video.
https://youtu.be/BLx57J2fF5w
Note: first few minutes of the video is Prof. Cuk's interview made after his presentation. This is thern followed by full 25 minutes presentation, which can be followed by the enclosed 67 slides.
IMPLEMENTATION OF DISCONTINUOUS INDUCTOR CURRENT MODE IN CUK CONVERTERS FED B...Journal For Research
This paper presents a bridgeless Cuk converter-fed brushless DC (BLDC) motor drive. A Bridgeless Cuk converter is constructed to operate at discontinuous inductor current mode to improve the quality of power and power factor at the AC mains for better speed control. The bridgeless converter is designed for obtaining the low conduction losses and requirement of low size of heat sink for the switches. TI-TMS320-F2812-based Digital Signal Processor (DSP) is used for the development of the hardware prototype of proposed BLDC motor drive.
A Low Cost Single-Switch Bridgeless Boost PFC ConverterIJPEDS-IAES
This paper proposes the single-switch bridgeless boost power factor correction (PFC) converter to achieve high efficiency in low cost. The proposed converter utilizes only one active switching device forPFC operation as well as expecting higher efficiency than typical boost PFC converters. On the other hand, the implementation cost is less than traditional bridgeless boost PFC converters, in where two active switching deivces are necessary. The operational principle, the modeling, and the control scheme of the proposed converter arediscussed in detail. In order to verify the operation of the proposed converter, a 500W switching model is built in PSIM software package. The simulation results show that the proposed converter perfectly achieves PFC operation with only a single active switch.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
Soft Switched Multi-Output Flyback Converter with Voltage DoublerIJPEDS-IAES
A novel multi-output voltage doubler circuit with resonant switching
technique is proposed in this paper. The resonant topology in the primary
side of the flyback transformer switches the device either at zero voltage or
current thus optimizing the switching devices by mitigating the losses. The
voltage doubler circuit introduced in the load side increases the voltage by
twice the value thereby increasing the load power and density. The proposed
Multi-output Isolated Converter removes the need for mutiple SMPS units
for a particular application. This reduces the size and weight of the
converters considerably leading to a greater payload. This paper aims at
optimizing the proposed converter with some design changes. The results
obtained from the hardware prototype are given in a comprehensive manner
for a 3.5W converter operating at output voltages of 5V and 3.3V at 50 kHz
switching frequency. The converter output is regulated with the PI controller
designed with SG3523 IC. The effects of load and line regulation for ±20%
variations are analyzed in detail.
A three level quasi-two-stage single-phase pfc converter with flexible output...LeMeniz Infotech
A three level quasi-two-stage single-phase pfc converter with flexible output voltage and improved conversion efficiency
To Get this projects Call : 9566355386 / 99625 88976
Visit : www.lemenizinfotech.com / www.ieeemaster.com
Mail : projects@lemenizinfotech.com
A hybrid converter topologies which can supply simultaneously AC as well as DC from a single DC source. The new Hybrid Converter is derived from the single switch controlled Boost converter by replacing the controlled switch with voltage source inverter (VSI). This new hybrid converter has the advantages like reduced number of switches as compared with conventional design having separate converter for supplying AC and DC loads, provide DC and AC outputs with an increased reliability, resulting from the inherent shoot through protection in the inverter stage. For controlling switches PWM control, based upon unipolar Sine-PWM is described.
ADCMT Products Selection Guide
Digital Electrometers
System
Digital Multimeters
Optical Measuring Instruments
DC Voltage Current Source/Monitors
Modular & Multifunction Instrument
https://www.n-denkei.com/singapore/inquiry/
Now day’s the power factor has become a major problem in power system to improve the power quality of the grid, as power factor is affected on the grid due to the nonlinear loads connected to it. Single phase bridgeless AC/DC power factor correction (PFC) topology to improve the power factor as well as the total harmonic distortion (THD) of the utility grid is proposed. By removing the input bridge in conventional PFC converters, the control circuit is simplified; the total harmonics distortion (THD) and power factor (PF) are improved. The PI controller operates in two loops one is the outer control loop which calculates the reference current through LC filter and signal processing. Inner current loop generates PWM switching signals through the PI controller. The output of the proposed PFC topology is verified for prototype using MATLAB circuit simulations. The experimental system is developed, and the simulation results are obtained.
Novel Single Phase Full Bridge Inverter Formed by Floating CapacitorsIAES-IJPEDS
In this paper, a new single-phase bridge inverter is described which can
generate a more steps of voltage levels with reduced number of switches,
gate driver circuits and diodes as compare to normal multilevel inverter.
Another feature of this inverter is its ability to prodeuce the voltages from a
single dc-link power supply which enables back-to-back operation of
converter. The proposed method with more number of levels can improve
power quality, lower switching losses and produce high quality voltage
waveforms. Moreover at all load power factors the proposed method can be
operated.The research of the model is done by means of computer simulation
with the software MATLAB/SIMULINK. This topology has very low
common mode voltage variation and dv/dt stress. Also this inverter is help
full for reactive power compensation.
AC - AC power conversions were traditionally done by using thyristor power controllers, phase angle control or by
integral cycle control, but had low PF and other disadvantages. Variable voltage, variable frequency high power conversions
are nowadays use DC link and Matrix converters, with higher efficiency and better regulation. But in situations where only
voltage regulation is required and the circuit need to be simple and less complicated, directed PWM AC-AC converters are
more preferred, due to reduced size and components. This project presents the design and simulation of a new type of AC-AC
converter which can operate as traditional non-inverting buck and boost converters, and inverting buck-boost converter as
well. This converter uses six unidirectional current flowing and bidirectional voltage blocking switches, implemented by six
reverse blocking IGBTs or series MOSFET-diode pairs, two input and output filter capacitors, and one inductor. It has no
shoot-through problem of voltage source (or capacitor) even when all switches are turned-on and therefore; PWM dead times
are not needed resulting in high quality waveforms, and solves the commutation problem without using bulky and lossy RC
snubbers or dedicated soft-commutation strategies. It has smaller switching losses because; only two switches out of six are
switched at high frequency during each half cycle of input voltage, and it can use power MOSFETs as body diode never
conducts, making it immune from MOSFET failure risk..
A Single-Stage High-Frequency Isolated Secondary- Side Controlled AC-DC Conve...IDES Editor
This paper presents a new single-stage highfrequency
isolated ac-dc converter that uses a simple control
circuit. It is well suitable for wide input variation power
sources. The circuit configuration combines a diode rectifier,
boost converter and half-bridge dc-dc resonant converter. A
high power factor is achieved by discontinuous current mode
(DCM) operation of the front-end integrated power factor
correction circuit. The output voltage is regulated by fixedfrequency,
secondary-side phase-shift active rectifier. Softswitching
operation is achieved for all the switches. This
converter operates in three modes, which is classified
according to conduction of different switches and diodes. The
intervals of operation and steady-state analysis are presented
in detail. Design example of a 100 W proposed converter is
given together with its simulation and experiment results for
wide variation in input voltage.
Review of Step down Converter with Efficient ZVS OperationIJRST Journal
This paper presents the review of step down converter with efficient ZVS operation. The designed buck converter uses ZCS technique and the function is realized so that the power form is converted from 12V DC 5V DC (1A). A detailed analysis of zero current switching buck converters is performed and a mathematical analysis of the mode of operation is also presented. In order to reduce the switching losses in associated with conventional converters; resonant inductor and resonant capacitor (LC resonant circuit) is applied which helps to turn on-off the switch at zero current. The dc-dc buck converter receives the energy from the input source, when the switch is turned-on. The buck–buck converters have characteristics that warrant a more detailed study. The buck converters under discontinuous conduction mode /continuous conduction mode boundary.
Closed Loop Analysis of Bridgeless SEPIC Converter for Drive ApplicationIJPEDS-IAES
In this paper closed loop analysis of Single phase AC-DC Bridgeless Single
Ended Primary Inductance Converter (SEPIC) for Power Factor Correction
(PFC) rectifier is analyzed. In this topology the absence of an input diode
bridge and the due to presence of two semiconductor switches in the current
flowing path during each switching cycle which will results in lesser
conduction losses and improved thermal management compared to the
conventional converters. In this paper the operational principles, Frequency
analysis, and design equations of the proposed converter are described in
detail. Performance of the proposed SEPIC PFC rectifier is carried out using
Matlab Simulink software and results are presented.
Effects of Language of the Catchment Area in Learning Kiswahiliinventy
Kiswahili one of the compulsory subjects that is nationally examined but there has been complaints about poor performance in schools. This paper is a report of a study carried out in 2012 in Kapseret Division of Uasin Gishu County. The study assessed the effects of the language of the catchment area in learning Kiswahili. The study was guided by sociocultural theory (SCT) and was descriptive in nature. Simple random sampling was used to select 15 out of 50 schools in Kapseret Division, it was also used to select 20 %(750) of standard six pupils from each of the selected schools. Purposive sampling was used to select 30 upper primary Kiswahili teachers; one class six Kiswahili teacher and a Kiswahili panel head from the selected schools. Data was collected using questionnaires, observation checklists. It was analyzed using descriptive statistical techniques such as percentages and frequencies. The investigation found out Nandi was the language of the catchment area but Kiswahili was used in communication because of different ethnic communities. Kiswahili be used in schools, parents be sensitized to have a positive attitude towards Kiswahili hence changing the learners attitude.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
Soft Switched Multi-Output Flyback Converter with Voltage DoublerIJPEDS-IAES
A novel multi-output voltage doubler circuit with resonant switching
technique is proposed in this paper. The resonant topology in the primary
side of the flyback transformer switches the device either at zero voltage or
current thus optimizing the switching devices by mitigating the losses. The
voltage doubler circuit introduced in the load side increases the voltage by
twice the value thereby increasing the load power and density. The proposed
Multi-output Isolated Converter removes the need for mutiple SMPS units
for a particular application. This reduces the size and weight of the
converters considerably leading to a greater payload. This paper aims at
optimizing the proposed converter with some design changes. The results
obtained from the hardware prototype are given in a comprehensive manner
for a 3.5W converter operating at output voltages of 5V and 3.3V at 50 kHz
switching frequency. The converter output is regulated with the PI controller
designed with SG3523 IC. The effects of load and line regulation for ±20%
variations are analyzed in detail.
A three level quasi-two-stage single-phase pfc converter with flexible output...LeMeniz Infotech
A three level quasi-two-stage single-phase pfc converter with flexible output voltage and improved conversion efficiency
To Get this projects Call : 9566355386 / 99625 88976
Visit : www.lemenizinfotech.com / www.ieeemaster.com
Mail : projects@lemenizinfotech.com
A hybrid converter topologies which can supply simultaneously AC as well as DC from a single DC source. The new Hybrid Converter is derived from the single switch controlled Boost converter by replacing the controlled switch with voltage source inverter (VSI). This new hybrid converter has the advantages like reduced number of switches as compared with conventional design having separate converter for supplying AC and DC loads, provide DC and AC outputs with an increased reliability, resulting from the inherent shoot through protection in the inverter stage. For controlling switches PWM control, based upon unipolar Sine-PWM is described.
ADCMT Products Selection Guide
Digital Electrometers
System
Digital Multimeters
Optical Measuring Instruments
DC Voltage Current Source/Monitors
Modular & Multifunction Instrument
https://www.n-denkei.com/singapore/inquiry/
Now day’s the power factor has become a major problem in power system to improve the power quality of the grid, as power factor is affected on the grid due to the nonlinear loads connected to it. Single phase bridgeless AC/DC power factor correction (PFC) topology to improve the power factor as well as the total harmonic distortion (THD) of the utility grid is proposed. By removing the input bridge in conventional PFC converters, the control circuit is simplified; the total harmonics distortion (THD) and power factor (PF) are improved. The PI controller operates in two loops one is the outer control loop which calculates the reference current through LC filter and signal processing. Inner current loop generates PWM switching signals through the PI controller. The output of the proposed PFC topology is verified for prototype using MATLAB circuit simulations. The experimental system is developed, and the simulation results are obtained.
Novel Single Phase Full Bridge Inverter Formed by Floating CapacitorsIAES-IJPEDS
In this paper, a new single-phase bridge inverter is described which can
generate a more steps of voltage levels with reduced number of switches,
gate driver circuits and diodes as compare to normal multilevel inverter.
Another feature of this inverter is its ability to prodeuce the voltages from a
single dc-link power supply which enables back-to-back operation of
converter. The proposed method with more number of levels can improve
power quality, lower switching losses and produce high quality voltage
waveforms. Moreover at all load power factors the proposed method can be
operated.The research of the model is done by means of computer simulation
with the software MATLAB/SIMULINK. This topology has very low
common mode voltage variation and dv/dt stress. Also this inverter is help
full for reactive power compensation.
AC - AC power conversions were traditionally done by using thyristor power controllers, phase angle control or by
integral cycle control, but had low PF and other disadvantages. Variable voltage, variable frequency high power conversions
are nowadays use DC link and Matrix converters, with higher efficiency and better regulation. But in situations where only
voltage regulation is required and the circuit need to be simple and less complicated, directed PWM AC-AC converters are
more preferred, due to reduced size and components. This project presents the design and simulation of a new type of AC-AC
converter which can operate as traditional non-inverting buck and boost converters, and inverting buck-boost converter as
well. This converter uses six unidirectional current flowing and bidirectional voltage blocking switches, implemented by six
reverse blocking IGBTs or series MOSFET-diode pairs, two input and output filter capacitors, and one inductor. It has no
shoot-through problem of voltage source (or capacitor) even when all switches are turned-on and therefore; PWM dead times
are not needed resulting in high quality waveforms, and solves the commutation problem without using bulky and lossy RC
snubbers or dedicated soft-commutation strategies. It has smaller switching losses because; only two switches out of six are
switched at high frequency during each half cycle of input voltage, and it can use power MOSFETs as body diode never
conducts, making it immune from MOSFET failure risk..
A Single-Stage High-Frequency Isolated Secondary- Side Controlled AC-DC Conve...IDES Editor
This paper presents a new single-stage highfrequency
isolated ac-dc converter that uses a simple control
circuit. It is well suitable for wide input variation power
sources. The circuit configuration combines a diode rectifier,
boost converter and half-bridge dc-dc resonant converter. A
high power factor is achieved by discontinuous current mode
(DCM) operation of the front-end integrated power factor
correction circuit. The output voltage is regulated by fixedfrequency,
secondary-side phase-shift active rectifier. Softswitching
operation is achieved for all the switches. This
converter operates in three modes, which is classified
according to conduction of different switches and diodes. The
intervals of operation and steady-state analysis are presented
in detail. Design example of a 100 W proposed converter is
given together with its simulation and experiment results for
wide variation in input voltage.
Review of Step down Converter with Efficient ZVS OperationIJRST Journal
This paper presents the review of step down converter with efficient ZVS operation. The designed buck converter uses ZCS technique and the function is realized so that the power form is converted from 12V DC 5V DC (1A). A detailed analysis of zero current switching buck converters is performed and a mathematical analysis of the mode of operation is also presented. In order to reduce the switching losses in associated with conventional converters; resonant inductor and resonant capacitor (LC resonant circuit) is applied which helps to turn on-off the switch at zero current. The dc-dc buck converter receives the energy from the input source, when the switch is turned-on. The buck–buck converters have characteristics that warrant a more detailed study. The buck converters under discontinuous conduction mode /continuous conduction mode boundary.
Closed Loop Analysis of Bridgeless SEPIC Converter for Drive ApplicationIJPEDS-IAES
In this paper closed loop analysis of Single phase AC-DC Bridgeless Single
Ended Primary Inductance Converter (SEPIC) for Power Factor Correction
(PFC) rectifier is analyzed. In this topology the absence of an input diode
bridge and the due to presence of two semiconductor switches in the current
flowing path during each switching cycle which will results in lesser
conduction losses and improved thermal management compared to the
conventional converters. In this paper the operational principles, Frequency
analysis, and design equations of the proposed converter are described in
detail. Performance of the proposed SEPIC PFC rectifier is carried out using
Matlab Simulink software and results are presented.
Effects of Language of the Catchment Area in Learning Kiswahiliinventy
Kiswahili one of the compulsory subjects that is nationally examined but there has been complaints about poor performance in schools. This paper is a report of a study carried out in 2012 in Kapseret Division of Uasin Gishu County. The study assessed the effects of the language of the catchment area in learning Kiswahili. The study was guided by sociocultural theory (SCT) and was descriptive in nature. Simple random sampling was used to select 15 out of 50 schools in Kapseret Division, it was also used to select 20 %(750) of standard six pupils from each of the selected schools. Purposive sampling was used to select 30 upper primary Kiswahili teachers; one class six Kiswahili teacher and a Kiswahili panel head from the selected schools. Data was collected using questionnaires, observation checklists. It was analyzed using descriptive statistical techniques such as percentages and frequencies. The investigation found out Nandi was the language of the catchment area but Kiswahili was used in communication because of different ethnic communities. Kiswahili be used in schools, parents be sensitized to have a positive attitude towards Kiswahili hence changing the learners attitude.
Open Access Publishing - The Journal of Medical Internet ResearchGunther Eysenbach
A presentation about the Journal of Medical Internet Research, a founding member of the Open Access Scholarly Publishers Association (OASPA) - A contribution to Open Access Week 2010!
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
Interleaved High Step-Down Synchronous Convertertheijes
For low output voltage, high output current systems applications, Synchronous switching power converters give better performance than non synchronous converters. This paper presents an interleaved synchronous buck converter which has low switch voltage stress with high conversion ratio. The input current can be shared among the inductors so that high reliability and efficiency can be obtained and ripples also reduced, the converter performance can be improved. Thus converter features automatic uniform current sharing characteristic of the interleaved phases without adding extra circuitry or complex control methods. Capacitors switching circuits are combined with interleaved four-phase buck converter for getting a high step-down conversion ratio without adopting an extreme short duty ratio. Synchronous rectifier technology is adopted to increase the converter efficiency. A 30V input voltage, 1.8V output voltage, circuit is simulated to verify the performance. The simulation is done in MATLAB/SIMULINK R2012a.
NON-ISOLATED SOFT SWITCHING DC-DC CONVERTER AND LOAD AT FULL RANGE OF ZVS IAEME Publication
A non isolated soft switching DC–DC converter and load at full range of zero-voltage
switching (ZVS) characteristic is proposed. The proposed converter consists of an auxiliary circuit,
an inductor, two switches, and 2 diodes to achieving high efficiency at full range of load. At low
and heavy loads, ZVS of switching device is achieved by energy storing component. The inductor
energy stored varies with load and hence results in minimizes conduction loss. This leads to
switching of device for full range of load. The proposed DC - DC converter achieves high
efficiency as switching loss is reduced due to soft switching and ZVS operation which severe to
reduce conduction loss. The efficiency is improved about 4% in boost mode (2.5% in buck mode) at
full range of load. To verify the performance of the proposed converter, experimental results
prototype are presented.
International Journal of Engineering Research and Applications (IJERA) aims to cover the latest outstanding developments in the field of all Engineering Technologies & science.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
Extremely high duty cycle of boost converter may result in higher conduction losses. To achieve a high
conversion ratio without operating at extremely high duty ratio, some converters based on transformers or coupled
inductors or tapped inductors have been provided. However, the leakage inductance in the transformer, coupled
inductor or tapped inductor will cause high voltage spikes in the switches and reduce system efficiency. A novel
single switch cascaded dc-dc converter of boost and buck boost converters have extended voltage conversion ratio
to d/(1-d)2. The features of the converter are high voltage gain; only one switch for realizing the converter, the
number of magnetic components is small etc. So comparing with other topologies cascaded converter is more
effective. Simulation of the converter for a dc input voltage and fixed duty cycle was done, and the same was
verified experimentally for a low input voltage. The software used for simulation was MatlabR2014a
High Gain Interleaved Cuk Converter with Phase Shifted PWMtheijes
DC-DC converters with ripple on input source current inject harmonics to the power system which in turn cause harmful to other connected devices. These converters with high efficiency and low input current ripple are essential in most common applications. Cuk converter provide reduction in the ripple of input and output current compared to other traditional converters which can be used for either step up or step down applications. Generally, a conventional cuk converter in continuous conduction mode brings in large current ripple on input side which in turn injects harmonics to the source. This undesirable input current ripple is mitigated by employing the interleaved cuk converter (ICC). Simulation results of ICC shows that the input ripple current has been reduced significantly from 7.5A to 1A compared to conventional cuk converter. The energy-transfer-capacitor in basic cuk converters is splitted into two capacitors. The rectifier diode is replaced by two diodes that form with the two capacitors a switched-capacitor circuit, which appears connected between the input and output inductances of the original converter. A hybrid circuit, presenting a higher DC voltage ratio than the classical Cuk circuit can be obtained. A high gain interleaved cuk converter is designed and simulated in MATLAB/SIMULINK for 40V with an input of 20V.
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
A High Step Up Hybrid Switch Converter Connected With PV Array For High Volt...ijitjournal
T
his paper
presents
a
ste
p up DC
-
to
-
DC converter with
hybrid switch capacitor technique having
high
voltage conversion ratio with small
switch voltage stress
. The converter is suitable for the applications
where high voltage conversion is required. The proposed
DC
-
DC converter
has low voltage ratted
MOSFET switch and is connected to PV array to get high output voltage at small duty ratios.
Hence it has
high efficiency.
The principles of operations and the theoretical analysis are presented in this paper.
All the
simulations are
done in MATLAB
-
SIMULINK Environment and
results were obtained with voltage
conversion ratio of 4.
A DC-DC converter topology is presented
combining the soft switching effects of the Snubber Assisted Zero
Voltage and Zero Current Transition (SAZZ) topology and the
increased inductor frequency of the dual interleaved boost
converter with interphase transformer. The snubber capacitors
and output capacitances of the main devices are discharged prior
to turn on using a single auxiliary inductor, eliminating turn on
losses. Furthermore, the turn off losses are significantly reduced
since the energy stored in the device output capacitance at turn
off is recovered at turn on. The effectiveness of the topology is
demonstrated on a SiC prototype operating at 12.5 kW, 112 kHz,
reducing the switching losses by 50%.
This paper presents a step up DC-to-DC converter with hybrid switch capacitor technique having high voltage conversion ratio with small switch voltage stress . The converter is suitable for the applications where high voltage conversion is required. The proposed DC-DC converter has low voltage ratted MOSFET switch and is connected to PV array to get high output voltage at small duty ratios. Hence it has high efficiency. The principles of operations and the theoretical analysis are presented in this paper. All the simulations are done in MATLAB- SIMULINK Environment and results were obtained with voltage conversion ratio of 4.9.
SIMULATION ANALYSIS OF CLOSED LOOP DUAL INDUCTOR CURRENT-FED PUSH-PULL CONVER...Journal For Research
The current electronic devices require DC power source, which is taken from a battery or DC power supply. DC-DC converter is utilized to get regulated dc voltage from unregulated one. Switched mode power supply (SMPS) are commonly used in industrial applications, because of more advantages compared to linear power supply. In SMPS we have isolated and non-isolated converters, where isolated converters are frequently used, in order to get more voltage with multiple outputs. So among different isolated converters, push-pull converter is chosen for micro converter applications to obtain high voltage conversion ratio by using HF transformer, due to their better utilization of transformer. New methodology of control is implemented for making ZVS and ZCS at same time and to reduce the number of switches in the secondary side of dual inductor CFPP converter, which is a voltage doubler circuit. This becomes the solution for problem identification. Thus this converter with soft-switching reduces the switching losses.The current-fed push-pull converters are used in many applications like photo-voltaic (PV) power converters for boosting the output voltage. Push-pull converter is chosen for micro converter applications, to obtain high voltage conversion ratio by using high frequency (HF) transformer, due to their better utilization of transformer. This deals with the design of dual inductor CFPP converter, where zero voltage switching (ZVS) and zero current switching (ZCS) is achieved for the primary side of the converter by using secondary switches. Primary side switches are controlled by closed loop control topology. The secondary side is made with voltage doubler to obtain high voltage. Open loop and closed loop control of dual inductor current fed push pull converter simulation is finished by MATLAB/SIMULINK and their outcomes are analyzed.
International Journal of Engineering Research and DevelopmentIJERD Editor
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Aerospace Engineering.
Experimental Investigation of a Household Refrigerator Using Evaporative-Cool...inventy
The objective of this paper was to investigate experimentally the effect of Evaporative-cooled condenser in a household refrigerator. The experiment was done using HCF134a as the refrigerant. The performance of the household refrigerator with air-cooled and Evaporative-cooled condenser was compared for different load conditions. The results indicate that the refrigerator performance had improved when evaporative-cooled condenser was used instead of air-cooled condenser on all load conditions. Evaporativecooled condenser reduced the energy consumption when compared with the air-cooled condenser. There was also an enhancement in coefficient of performance (COP) when evaporative-cooled condenser was used instead of air-cooled condenser. The Evaporative cooled heat exchanger was designed and the system was modified by retrofitting it, instead of the conventional air-cooled condenser by making drop wise condensation using water and forced circulation over the condenser. From the experimental analysis it is observed that the COP of evaporative cooled system increased by 13.44% compared to that of air cooled system. So the overall efficiency and refrigerating effect is increased. In minimum constructional, maintenance and running cost, the system is much useful for domestic purpose. This study also revealed that combining a evaporative cooled system along with conventional water cooled system under the condition that the defrost water obtained from the freezer is used for drop wise condensation over condenser and water cooled condensation of the condenser at the bottom using remaining defrost water would reduce the power consumption, work done and hence further increase in refrigerating effect of the system. The study has shown that such a system is technically feasible and economically viable
Copper Strip Corrossion Test in Various Aviation Fuelsinventy
This research work takes in to account of corrosiveness test on various aviation fuels in the state of Telengana (India). The purpose of this experiment is to determine the corrosiveness test of fuels. This determination will be accomplished by using copper strip corrosion test by using the copper strip experiment we can determine the corrosive property of the fuel and hence the efficiency of fuel. The research covers the importance of knowing the corrosive property of different petroleum fuels including aviation turbine fuel.
Additional Conservation Laws for Two-Velocity Hydrodynamics Equations with th...inventy
A series of the differential identities connecting velocities, pressure and body force in the twovelocity hydrodynamics equations with equilibrium of pressure phases in reversible hydrodynamic approximation is obtaned.
Comparative Study of the Quality of Life, Quality of Work Life and Organisati...inventy
People’s lives are increasingly centred on work; they spend at least one-third of their time within the organisations that employ them. Investigating the factors that interfere with employees’ well-being and the organisational environment is becoming an increasing concern in organisations. This article identifies the criteria of the quality of life (QoL), quality of working life (QWL) and organisational climate instruments to point out their similarities. For bibliographic construction and data research, articles were sought in national and international journals, books and dissertations/articles in SciELO, Science Direct, Medline and Pub Med databases. The results show direct relationships amongst QoL, QWL and organisational climate instruments. The relationship between QoL and QWL instruments is based on fair compensation, social interaction, organisational communication, working conditions and functional capacity. QWL and organisational climate instruments are related through social interaction and interfaces. QoL and organisational climate instruments are related based on social interaction, organisational communication, and work conditions.
A Study of Automated Decision Making Systemsinventy
The decision making process of many operations are dependent on analysing very large data sets, previous decisions and their results. The information generated from the large data sets are used as an input for making decisions. Since the decisions to be taken in day to day operations are expanding, the time taken for manual decision making is also expanding. In order to reduce the time, cost and to increase the efficiency and accuracy, which are the most important things for customer satisfaction, many organisations are adopting the automated decision making systems. This paper is about the technologies used for automated decision making systems and the areas in which automated decisions systems works more efficiently and accurately.
Crystallization of L-Glutamic Acid: Mechanism of Heterogeneous β -Form Nuclea...inventy
The mechanism of heterogeneous nucleation of β-form L-glutamic acid was deeply investigated in cooling crystallization. The present study found that the β-form crystals were epitaxially grown on the α-form crystals and they were preferably crystallized on the (011) and (001) surfaces instead of the (111) surfaces of α- form crystals. This result was explained via the molecular simulation. The molecular simulation indicated that the different surfaces of α-form crystals provided different functional groups, resulting in different sites for the heterogeneous nucleation of β-form crystals. Here, the functional group were COO- , C=O and O-H on the (011) and (001) surfaces of α-form crystals, respectively, while it was the NH3 + on the (111) surfaces of α-form crystals. As such, the degree of lattice matching (E) between the β-form crystals and the various surfaces of α- form crystal was distinguished, where the degree of lattice matching (E) between the β-form crystals and the (011), (001) and (111) surfaces of α-form crystal were estimated as 5.30, 5.25 and 2.39, respectively, implying that the (011) and (001) surfaces of α-form crystal were more favorable to generate the heterogeneous nucleation of β-form crystals than the (111) surfaces of α-form crystal
Evaluation of Damage by the Reliability of the Traction Test on Polymer Test ...inventy
In recent decades, polymers have undergone a remarkable historical development and their use has been greatly imposed by gradually dethroning most of the secular materials. These polymer materials have always distinguished themselves by their simple shaping and inexpensive price, their versatility, lightness, and chemical stability but despite their massive use in everyday life as well as in advanced technologies. Generally, these materials still not understood which requires a thorough knowledge of their chemical, physical, rheological and mechanical properties. This paper, we study the mechanical behavior of an amorphous polymer: Acrylonitrile Butadiene Styrene “ABS” by means of uniaxial tensile testing on pierced test pieces with different notch lengths ranging between 1 to 14mm.The proposed approach consists in analyzing the evolution of the global geometry of the obtained strain curves by taking into account the zones and characteristic points of these curves as well as the effect of the damage on the mechanical behavior of the polymer ABS, in order to visualize the evolution of the damage by a static model
Application of Kennelly’model of Running Performances to Elite Endurance Runn...inventy
: The model of Kennelly between distance (Dlim) and exhaustion time (tlim) has been applied to the individual performances of 19 elite endurance runners (World-record holders and Olympic winners) from P. Nurmi (1920-1924) to M. Farah (2012) whose individual best performances on several different distances are known. Kennelly’s model (Dlim = k tlim ) can describe the individual performances of elite runners with a high accuracy (errors lower than 2 %). There is a linear relationship between parameters k and exponents of the elite runners and the extreme values correspond to S. Coe (k = 15.8; = 0.851) and E. Zatopek (k = 6.57; = 0.984). Exponent can be considered as a dimensionless index of aerobic endurance which is close to 1 in the best endurance runners. If it is assumed than maximal aerobic speed can be maintained 7 min in elite endurance runners, exponent is equal to the normalized critical speed (critical speed/maximal aerobic speed) computed from exhaustion times equal to 3 and 12.5 min in these runners.
Development and Application of a Failure Monitoring System by Using the Vibra...inventy
In this project, a failure monitoring system is developed by using the vibration and location information of balises in railway signaling. A lot of field equipment in railway are loosening and broken in time period so that they need maintenance due to the vibrations that occur due to high speed trains traffic and railway vehicles impact. Among the field equipment, balises have very important role of communication in terms of transmitting information to trains. In this scope, it is aimed to make maintenance works more efficient, have no delayed trains, detect previously failure location and intervene in failure timely, by detecting and controlling balise cases such as loosening, out of place and the data consistency error that happens because of balise physical state. In this project, the communication is provided with I2C, Modbus RTU (Remote Terminal Unit) and RS485 standards by using Arduino Uno cards and MPU6050 IMU (Inertial Measurement Unit) sensors in laboratory. Each used sensors are in slave mode and computer interface designed with C# is in master mode. Fault situations in the system are checked instant by the interface. (it is assumed to mount the IMU sensor and the Arduino circuit on the balise) it is seen that the interface responds to the sensor movements instant and the system works well in the end of test processes.
The Management of Protected Areas in Serengeti Ecosystem: A Case Study of Iko...inventy
The study assessed the management of protected areas in Serengeti ecosystem using the case of IGGRs. Specifically, the study aimed at identifying the strategies used for natural resources management; examining the impacts of those strategies; examining the hindrances of the identified strategies; and lastly, examining the methods for scaling up the performance of strategies used for natural resources in the study area. The study involved two villages among 31 villages bordering IGGRs where in each village; at least 5% of the households were sampled. Both Primary data and secondary data were collected and analyzed both manually and computer by using SPSS software. The study revealed that, study population ranked IGGRs performance on protection of natural resources, especially on conserving wildlife for future generation and in reducing poaching to be good(53.3%). In addition, the relationship with IGGRs was said to be considerable good (46.7%). In the aspect of reducing poaching, the findings show that poaching has been reduced by 96.2% from 2009 to 2012. Furthermore, 81.4% of respondents said they use different strategies to control loss of natural resources which in turn has considerably improved the relationship between protected areas and the surrounding communities in some of the aspects. Despite of above successes, the study findings has revealed a number of challenges that hinders the full attainment of conservation objectives. Among the challenges are loss of life and properties (86.4%), shortage of water for livestock (68.9%) since water sources such as Grumeti and Rubana rivers are within protected area while the adjacent local communities do not have a free access to those water sources. Other challenges especially on the IGGRs management include insufficient fund base, working facilities and inadequate staffs. Based on the above findings, the study concluded that the strategies used for natural resources management of protected areas in Serengeti ecosystem is fairly sustainable and need functional participatory approaches of local people and other stakeholders in order to bring about a collaborative natural resources management network in the ecosystem. Furthermore, based on the findings above, equity in benefit sharing accrued from natural resource management in protected areas, more financial support to IGGRs and local community, the use of non-lethal deterrents for crop protection, integration of croplivestock production systems, adoption of land use plans as a solution to land conflicts, strengthens of community based conservation (CBC), adoption of modern information technology such as geographical information system (GIS) and remote sensing are recommended.
Size distribution and biometric relationships of little tunny Euthynnus allet...inventy
This study is taken from data of commercial fishing of the little tunny, Euthynnus alletteratus (Rafinesque, 1810) caught in the Algerian coast, sampled between november 2011 and april 2016. Data were collected in order to determine size distributions of the population and biometric relationships of species including the size - weight relationships. A total of 601 fish ranged from 30.9 and 103 cm fork length (FL) were observed. The size distribution of Euthynnus alletteratus shows multiple modal values witch the most important cohort corresponds to the age class 2 (42-46 cm). The value of the allometric coefficient (b) of the FL/TW relationship is lower than 3, indicating a negative allometric growth.
Removal of Chromium (VI) From Aqueous Solutions Using Discarded Solanum Tuber...inventy
Industrial polluting effluents containing heavy metals are of serious environmental concern in India. Chromium is frequently used in industries like electroplating, metal finishing, cooling towers, dyes, paints, anodizing and leather tanning and is found as traces in effluents finding their way to natural water bodies causing hazardous toxicity to the health of humans, animals and aquatic lives directly or indirectly. Many methods for the removal of Chromium such as chemical reduction, precipitation, ion exchange, electrochemical reduction, evaporation, reverse osmosis and adsorption using activated carbon etc. have been reported but all being expensive and complicated to operate. Experimental practices reveal that adsorption by agricultural and horticultural wastes are quite simple, inexpensive and efficient method. Agra is famous for Potato farming, a lot of discarded potato waste from cold storages is thrown along road side drains causing solid waste generated which either creates solid waste disposal problem or otherwise it finds way to Yamuna river resulting high BOD and posing a serious threat to the aquatic environment. For developing countries like India adsorption studies using discarded potato (Solanum tuberosum) waste from cold storages (DPWC) a solid waste as low cost adsorbent for Chromium removal was dual beneficial i.e., an ideal solution to these solid wastes disposal problem of Agra and removal of Chromium from tannery effluents and thereby saving aquatic life from Chromium contamination in Yamuna river. Keeping this in view batch experiments were designed to study the feasibility of discarded potato waste from cold storages to remove chromium (VI) from the aqueous solutions. During the study various affecting parameters, such as pH, adsorbent does, initial concentration, temperature, contact time, adsorbent grain size and start up agitation speed were optimized as 5.0, 10-20 g/l, 50 mg/l, 250C, 135 minutes, average size and 80 rpm respectively on chromium removal efficiency. Various Isotherms such as Langmuir, Freundlich, Tempkin also fitted suitably and various corresponding constants determined from these Isotherms favor and support the adsorption. Thermodynamic constants ∆G, ∆H and ∆S were found to be 0.267 KJ/mole, 0.288 KJ/mole and 0.0013 KJ/mole respectively.
Effect of Various External and Internal Factors on the Carrier Mobility in n-...inventy
The effect of various external (temperature, electric field, light) and intracrystalline (doping, initial resistivity) factors on the mobility of carriers in layered n-InSe semiconductor experimentally have been investigated. Scientific explanations of the results are proposed
Transient flow analysis for horizontal axial upper-wind turbineinventy
This study is to carry out a transient flow field analysis on the condition that the wind turbine is working to generate turbine, the wind turbine operating conditions change over time, Purpose of this study is try to find out the rule from the wind turbine changing over time . In transient analysis, the wind velocity on inlet boundary and rotation speed in the rotor field will change over time, and an analytical process is provided that can be used for future reference. At present, the wind turbine model is designed on the concept of upwind horizontal axis type. The computer engineering software GH Bladed is used to obtain the relationship between the rotor velocity and the wind turbine. Then the ANSYS engineering software is used to calculate the stress and strain distribution in the blades over time. From the analytical result, the relationship between the stress distribution in the blades and the rotor velocity is got to be used as a reference for future wind turbine structural optimization.
Choice of Numerical Integration Method for Wind Time History Analysis of Tall...inventy
Wind tunnel tests are being performed routinely around the world for designing tall buildings but the advent of powerful computational tools will make time-history analysis for wind more common in near future. As the duration of wind storms ranges from tens of minutes to hours while earthquake durations are typically less than a three to four minutes, the choice of a time step size (Δt) for wind studies needs to be much larger both to reduce the computational time and to save disk space. As the error in any numerical solution of the equation of motion is dependent on step size (Δt), careful investigations on the choice of numerical integration methods for wind analyses are necessary. From a wide variety of integration methods available, it was decided to investigate three methods that seem appropriate for 3D-time history analysis of tall buildings for wind. These are modal time history analysis, the Hilber-Hughes-Taylor (HHT) method or α-method with α=- 0.1, and the Newmark method with β=0.25 and γ=0.5 ( i.e., trapezoidal rule). SAP2000, a common structural analysis software tool, and a 64-story structure are used to conduct all the analyses in this paper. A boundary layer wind tunnel (BLWT) pressure time history measured at 120 locations around the building envelope of a similar structure is used for the analyses. Analyses performed with both the HHT and Newmark-method considering P-delta effects show that second order effects have a considerable impact on both displacement and acceleration response. This result shows that it is necessary to account P-delta effect for wind analysis of tall buildings. As the direct integration time history analysis required very large computation times and very large computer physical memory for a wind duration of hours, a modal analysis with reduced stiffness is considered as a good alternative. For that purpose, a non-linear static analysis of the structure with a load combination of 1.0D + 1.0L is performed in SAP2000 and the reduced stiffness of the structure after the analysis is used to conduct an eigenvalue analysis to extract the mode shapes and frequencies of this structure. Then the first 20- modes are used to perform a modal time history analysis for wind load. The result shows that the responses from modal analysis with “20-mode (reduced stiffness)” are comparable with that from the P-Δ analyses of Newmark-method
Impacts of Demand Side Management on System Reliability Evaluationinventy
Electricity demand in Saudi Arabia is steadily increasing as electrical loads grows at a rate of about 7% per year, this represents a high rate by all standards, and largely due to population growth, as well as due to government subsidies which may lead to prices much lower than actual production cost. This growth represents a challenge that requires Saudi Electricity Company (SEC) to invest huge amounts of money every year, for the construction of additional generation capacity along with the reinforcement of transmission network to meet the consumption growth.Also the demand varies frequently throughout the day, causing a waste of a large part of the energy. SEC believes the optimum solution lies in altering the load shape in order to have a better balance between customer’s consumption and SEC’s generation, This paper describes the method for improving the power system reliability by shifting the portion of peak load to off-peak periods This load management scheme can be achieved by lifting the generation during off peak periods and utilizing the stored energy during peak periods. A hybrid set up involving solar and wind energy along with batteries can also be used to store energy and utilize it during peak periods.
Reliability Evaluation of Riyadh System Incorporating Renewable Generationinventy
In this paper, the experience of Saudi Electricity Company (SEC) in analyzing the generation adequacy for Year 2013 is presented. This analysis is conducted by calculating several reliability indices for Riyadh system hourly load during all four seasonal periods. The reliability indices are gauged against the international utility practice. SEC also plans to introduce renewable energy into the network in order to secure the environmental standards and reduce fuel costs of conventional generation. Thus, the reliability improvement due to different integration levels of Solar and Wind generating sources has also been investigated. The capacity value provided by these variable renewable energy sources (VERs) to reliably meet the system load has been calculated using effective load carrying capability (ELCC) technique with a loss of load expectancy metric.
The effect of reduced pressure acetylene plasma treatment on physical charact...inventy
The capacitors are increasingly being used as energy storage devicesin various power systems. The scientists of the world are tryingto maximize the electrical capacity of the supercapacitors. To achieve this purpose, numerous method sare used: the surface activation of electrodes, the surface etching using the electronbeam, the electrode etching with variousgasplasma, etc. The purpose of this work is toresearch how the properties of carbon electrodes depend on the plasma parameters at whichtheywere formed. The largest surface area ofcarbonelectrodeof47.25m2 /gis obtainedat 15 ofAr/C2H2gasratio. Meanwhile, theSEMimages show that the disruption of structures with low bond energies and the formation of new onesare taking place when the carbon electrodes are etched at acetylene plasma and placed on carbon electrode. The measurements of capacitance showthat capacitors with affectedelectrodes have about10-15% highercapacity than those not treated with acetyleneplasma.
Experimental Investigation of Mini Cooler cum Freezerinventy
In general cases the refrigerator could be converted into an air conditioner by attaching a fan. Thus a cooler as well as freezer is obtained in a single set up. The freezer can be converted to an air conditioner when the outside air is allowed to flow beside the cooling coil and is forced outside by an exhaust fan. In this case a mini scale cooler cum freezer using R134a as refrigerant was fabricated and tested In our mini project work we had designed, fabricated and experimentally analysed a mini cooler cum freezer. From the observations and calculations, the results of mini cooler cum freezer are obtained and are compared.
Growth and Magnetic properties of MnGeP2 thin filmsinventy
We have successfully grown MnGeP2 thin films on GaAs (100) substrate. A ferromagnetic transition near 320 K has been observed by temperature dependent magnetization and resistance measurements. Field dependent magnetization experiments have shown that the coercive fields at 5, 250, and 300 K are 3870, 1380 and 155 Oe, respectively. Magnetoresistance and Hall measurements have displayed that hole conduction is dominant in MnGeP2. PACS: 75.50.Pp, 75.70.-i, 85.70.-w, 73.50.-h
Software Delivery At the Speed of AI: Inflectra Invests In AI-Powered QualityInflectra
In this insightful webinar, Inflectra explores how artificial intelligence (AI) is transforming software development and testing. Discover how AI-powered tools are revolutionizing every stage of the software development lifecycle (SDLC), from design and prototyping to testing, deployment, and monitoring.
Learn about:
• The Future of Testing: How AI is shifting testing towards verification, analysis, and higher-level skills, while reducing repetitive tasks.
• Test Automation: How AI-powered test case generation, optimization, and self-healing tests are making testing more efficient and effective.
• Visual Testing: Explore the emerging capabilities of AI in visual testing and how it's set to revolutionize UI verification.
• Inflectra's AI Solutions: See demonstrations of Inflectra's cutting-edge AI tools like the ChatGPT plugin and Azure Open AI platform, designed to streamline your testing process.
Whether you're a developer, tester, or QA professional, this webinar will give you valuable insights into how AI is shaping the future of software delivery.
Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
91mobiles recently conducted a Smart TV Buyer Insights Survey in which we asked over 3,000 respondents about the TV they own, aspects they look at on a new TV, and their TV buying preferences.
UiPath Test Automation using UiPath Test Suite series, part 4DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 4. In this session, we will cover Test Manager overview along with SAP heatmap.
The UiPath Test Manager overview with SAP heatmap webinar offers a concise yet comprehensive exploration of the role of a Test Manager within SAP environments, coupled with the utilization of heatmaps for effective testing strategies.
Participants will gain insights into the responsibilities, challenges, and best practices associated with test management in SAP projects. Additionally, the webinar delves into the significance of heatmaps as a visual aid for identifying testing priorities, areas of risk, and resource allocation within SAP landscapes. Through this session, attendees can expect to enhance their understanding of test management principles while learning practical approaches to optimize testing processes in SAP environments using heatmap visualization techniques
What will you get from this session?
1. Insights into SAP testing best practices
2. Heatmap utilization for testing
3. Optimization of testing processes
4. Demo
Topics covered:
Execution from the test manager
Orchestrator execution result
Defect reporting
SAP heatmap example with demo
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Kubernetes & AI - Beauty and the Beast !?! @KCD Istanbul 2024Tobias Schneck
As AI technology is pushing into IT I was wondering myself, as an “infrastructure container kubernetes guy”, how get this fancy AI technology get managed from an infrastructure operational view? Is it possible to apply our lovely cloud native principals as well? What benefit’s both technologies could bring to each other?
Let me take this questions and provide you a short journey through existing deployment models and use cases for AI software. On practical examples, we discuss what cloud/on-premise strategy we may need for applying it to our own infrastructure to get it to work from an enterprise perspective. I want to give an overview about infrastructure requirements and technologies, what could be beneficial or limiting your AI use cases in an enterprise environment. An interactive Demo will give you some insides, what approaches I got already working for real.
Epistemic Interaction - tuning interfaces to provide information for AI supportAlan Dix
Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
The Art of the Pitch: WordPress Relationships and SalesLaura Byrne
Clients don’t know what they don’t know. What web solutions are right for them? How does WordPress come into the picture? How do you make sure you understand scope and timeline? What do you do if sometime changes?
All these questions and more will be explored as we talk about matching clients’ needs with what your agency offers without pulling teeth or pulling your hair out. Practical tips, and strategies for successful relationship building that leads to closing the deal.
Key Trends Shaping the Future of Infrastructure.pdfCheryl Hung
Keynote at DIGIT West Expo, Glasgow on 29 May 2024.
Cheryl Hung, ochery.com
Sr Director, Infrastructure Ecosystem, Arm.
The key trends across hardware, cloud and open-source; exploring how these areas are likely to mature and develop over the short and long-term, and then considering how organisations can position themselves to adapt and thrive.
Transcript: Selling digital books in 2024: Insights from industry leaders - T...BookNet Canada
The publishing industry has been selling digital audiobooks and ebooks for over a decade and has found its groove. What’s changed? What has stayed the same? Where do we go from here? Join a group of leading sales peers from across the industry for a conversation about the lessons learned since the popularization of digital books, best practices, digital book supply chain management, and more.
Link to video recording: https://bnctechforum.ca/sessions/selling-digital-books-in-2024-insights-from-industry-leaders/
Presented by BookNet Canada on May 28, 2024, with support from the Department of Canadian Heritage.
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
Builder.ai Founder Sachin Dev Duggal's Strategic Approach to Create an Innova...Ramesh Iyer
In today's fast-changing business world, Companies that adapt and embrace new ideas often need help to keep up with the competition. However, fostering a culture of innovation takes much work. It takes vision, leadership and willingness to take risks in the right proportion. Sachin Dev Duggal, co-founder of Builder.ai, has perfected the art of this balance, creating a company culture where creativity and growth are nurtured at each stage.
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...James Anderson
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
GraphRAG is All You need? LLM & Knowledge GraphGuy Korland
Guy Korland, CEO and Co-founder of FalkorDB, will review two articles on the integration of language models with knowledge graphs.
1. Unifying Large Language Models and Knowledge Graphs: A Roadmap.
https://arxiv.org/abs/2306.08302
2. Microsoft Research's GraphRAG paper and a review paper on various uses of knowledge graphs:
https://www.microsoft.com/en-us/research/blog/graphrag-unlocking-llm-discovery-on-narrative-private-data/
From Siloed Products to Connected Ecosystem: Building a Sustainable and Scala...
C043015024
1. Research Inventy: International Journal Of Engineering And Science
Vol.4, Issue 3(March 2014), PP 15-24
Issn (e): 2278-4721, Issn (p):2319-6483, www.researchinventy.com
15
Improved Step down Conversion in Interleaved Buck Converter
and Low Switching Losses
D.Lakshmi (M.Tech) , S.Zabiullah M.Tech, Dr. Venu gopal. N M.E PhD.,
ABSTRACT— This project is presented by a soft-switching techniques interleaved buck converter. And it’s
having order to guarantee small switching losses and, consequently, a high efficiency, a non-dissipative soft-
switching cell with auxiliary commutation circuit is used. But in this topology we expected a large step up
voltage, low switching stress, small switching losses, and high efficiency.
Because of that we proposed IBC that since the voltage stress across all the active switches is half of
the input voltage before turn-on or after turn-off when the operating duty is below 50%, the capacitive
discharging and switching losses can be reduced considerably. This allows the proposed IBC to have higher
efficiency and operate with higher switching frequency. In that additionally, the proposed IBC has a higher
step-down conversion ratio and a smaller output current ripple compared with a conventional IBC. The
features, operation principles, and relevant analysis results of the proposed IBC are presented in this project.
The validity of this study is confirmed by the experimental results of prototype converters with 150–200 V input,
24 V/10 A output.
Key words—Buck converter, interleaved, low switching loss.
I. INTRODUCTION
A basic buck converter converts a DC voltage to a step down DC voltage. Interleaving adds additional benefits
such as reduced ripple currents in both the input and output circuits. Higher efficiency is realized by splitting the output
current into two paths, substantially reducing losses and inductor AC losses In the field of power electronics, application of
interleaving technique can be traced back to very early days, especially in high power applications. In high power
applications, the voltage and current stress can easily go beyond the range that one power device can handle. Multiple power
devices connected in parallel and/or series could be one solution. However, voltage sharing and/or current sharing are still
the concerns. Instead of paralleling power devices, paralleling power converters is another solution which could be more
beneficial. Benefits like harmonic cancellation, better efficiency, better thermal performance, and high power density.
An interleaved buck converter usually combines more than two conventional topologies, and the current in the
element of the interleaved buck converter is half of the conventional topology in the same power condition. The single buck
converter can use the zero-voltage switching (ZVS) and/or zero-current switching (ZCS) to reduce the switching loss of the
high-frequency switching. However, they are considered for the single topology.
Fig (1) conventional IBC
In Applications where nonisolation, step-down conversion ratio, and high output current with low ripple are re-
quired, an interleaved buck converter (IBC) has received a lot of attention due to its simple structure and low control com-
plexity. However, in the conventional IBC shown in Fig. 1, all semiconductor devices suffer from the input voltage, and
hence, high-voltage devices rated above the input voltage should be used. High-voltage-rated devices have generally poor
characteristics such as high cost, high on-resistance, high for-ward voltage drop, severe reverse recovery, etc. In addition, the
converter operates under hard switching condition. Thus, the cost becomes high and the efficiency becomes poor. And, for
higher power density and better dynamics, it is required that the converter operates at higher switching frequencies .
However, higher switching frequencies increase the switching losses associated with turn-on, turn-off, and reverse recovery.
Consequently, the efficiency is further deteriorated. Also, it experiences an extremely short duty cycle in the case of high-
input and low-output voltage applications.
2. Improved Step down Conversion in Interleaved Buck Converter and Low Switching Losses
16
In previous applications, the PWM control is used in the converter circuits to get the desired shape of the
output voltage or current. By using this technique the following disadvantages are occurs:
1. The devices are turned on and off at the load current with a high di/dt value
2. The switches are subjected to a high-voltage stress.
3. The switching power loss also increases with the switching frequency.
4. The turn on and turn off loss could be a significant portion of the total power loss.
5. The electromagnetic interference is also produced due to high di/dt and du/dt in the converter waveforms.
The above disadvantages can be eliminated (or) minimized if the devices are turned „ON‟ and „OFF‟ by using
soft switching technique. These are Zero Voltage Switching and Zero Current Switching.
Fig (2) proposed IBC
The new IBC, which is suitable for the applications where the input voltage is high and the operating
duty is below 50%, is proposed. It is similar to the conventional IBC, but two active switches are connected in
series and a coupling capacitor is employed in the power path. The two active switches are driven with the phase
shift angle of 180◦
and the output voltage is regulated by adjusting the duty cycle at a fixed switching frequency.
The features of the proposed IBC are similar to those of the IBC in [14]. Since the proposed IBC also operates at
CCM, the current stress is low. During the steady state, the voltage stress across all active switches before turn-
on or after turn-off is half of the input voltage. Thus, the capacitive discharging and switching losses can be
reduced considerably. The voltage stress of the freewheeling diodes is also lower than that of the conventional
IBC so that the reverse-recovery and conduction losses on the freewheeling diodes can be improved by
employing schottky diodes that have generally low breakdown voltages, typically below 200 V. The conversion
ratio and output current ripple are lower than those of the conventional IBC.
II. CIRCUIT OPERATIONS
Fig. 2 shows the circuit configuration of the proposed IBC. The structure is similar to a conventional
IBC except two active switches in series and a coupling capacitor employed in the power path. Figs. 3 and 6
show the key operating waveforms of the proposed IBC in the steady state. Referring to the figures, it can be
seen that switches Q1 and Q2 are driven with the phase shift angle of 180◦
. This is the same as that for a
conventional IBC. Each switching period is divided into four modes, whose operating circuits are shown in Figs.
4 and 5. In order to illustrate the operation of the proposed IBC, some assumptions are made as follows:
1) the output capacitor CO is large enough to be considered as a voltage source;
2) the two inductors L1 and L2 have the same inductance L;
3) all power semiconductors are ideal;
4) the coupling capacitor CB is large enough to be considered as a voltage source.
Fig. 3. Key operating waveforms of the proposed IBC when D ≤ 0.5.
3. Improved Step down Conversion in Interleaved Buck Converter and Low Switching Losses
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Fig. 4. Operating circuits of the proposed IBC when D ≤ 0.5. (a) Mode 1. (b) Mode 2 or 4. (c) Mode 3.
A. Steady-State Operation when D ≤ 0.5
Mode 1 [t0 –t1 ]: Mode 1 begins when Q1 is turned ON at t0 . Then, the current of L1 , iL 1 (t), flows through Q1 , CB
, and L1 and the voltage of the coupling capacitor VC B is charged. The cur-rent of L2 , iL 2 (t), freewheels through D2 . During
this mode, the voltage across L1 , VL 1 (t), is the difference of the input voltage VS , the voltage of the coupling capacitor VC
B , and the output voltage VO , and its level is positive. Hence, iL 1 (t) increases lin-early from the initial value. The voltage
across L2 , VL 2 (t), is the negative output voltage, and hence, iL 2 (t) decreases linearly from the initial value. The voltage
across Q2 , VQ 2 (t), becomes the input voltage and the voltage across D1 , VD 1 (t), is equal to the difference of VS and VCB.
The voltages and currents can be expressed as follows:
VL1(t)=Vs-V CB-Vo (1)
VL2(t)= -Vo (2)
IL1(t)=Vs-VCB-Vo/L(t-t0)+iL1(t0)
=IQ1(t)=iCB(t) (3)
iL2(t)=-V0/L(t-t0)+iL2(t0)=iD2(t) (4)
VQ2=Vs (5)
VD1=Vs-VCB (6)
VCB-VCB(t0)+I0/2cb(t-t0) (7)
Mode 2 [t1 –t2 ]: Mode 2 begins when Q1 is turned OFF at t1 . Then, iL 1 (t) and iL 2 (t) freewheel through D1
and D2 , respectively. Both VL 1 (t) and VL 2 (t) become the negative VO , and hence, iL 1 (t) and iL 2 (t)
decrease linearly. During this mode, the voltage across Q1 , VQ1 (t), is equal to the difference of VS and VCB
and VQ2 (t) becomes VCB. The voltages and currents can be expressed as follows:
VL1 (t) = VL2 (t) = −VO (8)
iL1 (t) = iL1 (t1 ) – (VO/L)(t − t1) = iD1 (t) (9)
iL2 (t) = iL2 (t1 ) – (VO/L)(t − t1) = iD2 (t) (10)
VQ1 (t) = VS – VCB (11)
VQ2 (t) = VCB. (12)
Mode 3 [t2 –t3 ]: Mode 3 begins when Q2 is turned ON at t2 . At the same time, D2 is turned OFF. Then, iL 1
(t) freewheels through D1 and iL 2 (t) flows through D1 , CB , Q2 , and L2 . Thus, VCB is discharged. During
this mode, VL 2 (t) is equal to the difference of VCB and VO and its level is positive. Hence, iL 2 (t) increases
linearly. VL 1 (t) is the negative VO , and hence, iL 1 (t) decreases linearly. The voltages and currents can be
expressed
as follows:
VL1 (t) = −VO (13)
VL2 (t) = VCB –VO (14)
iL1 (t) =(−VO/L)(t − t2) + iL1 (t2 ) (15)
iL2 (t) =( (VCB – VO)/L)(t − t2) + iL2 (t2 )
= iQ2 (t) = −iCB(t) (16)
iD1 (t) = iL1 (t) + iL2 (t) (17)
VQ1 = VS – VCB (18)
VD2 = VCB (19)
VCB _ VCB(t2 ) –( IO/2CB)(t − t2 ). (20)
Mode 4 [t3 –t4 ]: Mode 4 begins when Q2 is turned OFF at t3 , and its operation is the same with that of mode 2.
4. Improved Step down Conversion in Interleaved Buck Converter and Low Switching Losses
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The steady-state operation of the proposed IBC operating with the duty cycle of D ≤ 0.5 has been
described. From the operation principles, it is known that the voltage stress of all semiconductor devices except
Q2 is not the input voltage, but is determined by the voltage of coupling capacitor VCB. The maximum voltage
of Q2 is the input voltage, but the voltage before turn-on or after turn-off is equal to VCB. As these results, the
capacitive discharging and switching losses on Q1 and Q2 can be reduced considerably. In addition, since
diodes with good characteristics such as schottky can be used for D1 and D2, the reverse-recovery and
conduction losses can be also improved. The loss analysis will be discussed in detail in the next section.
B. Steady-State Operation When D > 0.5
Mode 1 [t0 –t1 ]: Mode 1 begins when Q2 is in on-state and Q1 is turned ON at t0 . Then, iL 1 (t) flows through
Q1 , CB , and L1 and VCB(t) is charged. iL 2 (t) flows through Q1 , Q2 , and L2 . VL 1 (t) is equal to the difference of VS ,
VCB, and VO and its level is positive. Thus, iL 1 (t) increases linearly from the initial value. VL 2 (t) is equal to the
difference of VS and VO and iL 2 (t) also increases linearly from the initial value. The voltages and currents can be
expressed as follows:
VL1 (t) = VS − VCB – VO (21)
VL2 (t) = VS – VO (22)
VD1 = VS – VCB (23)
VD2 = VS (24)
iQ1 = iL1 (t) + iL2 (t) (25)
iQ2 = iL2 (t). (26)
Mode 2 [t1 –t2 ]: Mode 2 begins when Q2 is turned OFF at t1 . Then, iL 1 (t) flows through Q1 , CB , and L1 and iL 2 (t)
freewheels through D2 . The operation during this mode is the same with mode 1 in the case of D ≤ 0.5.
Mode 3 [t2 –t3 ]: Mode 3 begins when Q2 is turned ON at t2 , and the operation is the same with mode 1.
Mode 4 [t3 –t4 ]: Mode 4 begins when Q1 is turned OFF at t3 . Then, iL 1 (t) freewheels through D1 and iL 2 (t)
flows through D1 , CB , Q2 , and L2 . Thus, VCB is discharged. The operation during this mode is the same
with mode 3 in the case of D ≤0.5.
The steady-state operation of the proposed IBC operating with D > 0.5 has been described. Under this operating
condition, the voltage stress of Q1 and D1 is determined by VCB, but the voltage stress of Q2 and D2 is determined by the
input voltage. In addition, since VL 2 (t) is much larger than VL 1 (t) during mode 1 or mode 3, the unbalance between iL 1
(t) and iL 2 (t) occurs, as shown in Fig. 6. The current of Q1 , iQ1 (t), is the sum of iL 1 (t) and iL 2 (t) and the current of Q2
, iQ2 (t), is equal to iL 2 (t) in mode 1 or mode 3. Therefore, it can be said that switches Q1 and Q2 experience high current
stress in the case of D > 0.5. Until now, the steady-state operation of the proposed IBC has been described in detail.
Consequently, it can be known that the proposed IBC has advantages in terms of efficiency and component stress in the case
of onlyD≤0.5. Thus, the proposed IBC is recommended for the applications where the operating duty cycle is smaller than or
equal to 0.5.
III. RELEVANT ANALYSIS RESULTS
The proposed IBC will be only employed in the applications where the operating duty cycle is below
0.5, but the following relevant analyses are conducted over the entire duty cycle range for a detail design guide.
5. Improved Step down Conversion in Interleaved Buck Converter and Low Switching Losses
19
DC Conversion Ratio
The dc conversion ratio of the proposed IBC can be derived using the principle of inductor volt-second-
balance (VSB) .In the case ofD≤0.5, the following equations can be obtained from the VSB of L1 and L2 ,
respectively
(VS −VCB− VO )DTS = VO (1 − D)TS (27)
(VCB − VO )DTS = VO (1 − D)TS . (28)
The voltage of the coupling capacitor can be obtained by substituting (28) into (27) and is equal to half of the
input voltage as follows:
VCB = VS/2 . (29)
Then, the dc conversion ratio M can be obtained from (27) and (29) or (28) and (29) as follows:
M = VO/VS= D/2 . (30)
In the case of D > 0.5, the voltage of the coupling capacitor and the dc conversion ratio can be obtained by the
same procedure and are expressed as follows, respectively
VCB = VS (1 − D) (31)
The proposed IBC has a higher step-down conversion
As a result, the proposed IBC can overcome the extremely short duty cycle, which appears in the
conventionalIBC. ratio than the conventional IBC
Fig. 5. Operating circuits of the proposed IBC when D > 0.5 (a) Mode1 or 3.(b)Mode2.(c) Mode4.
6. Improved Step down Conversion in Interleaved Buck Converter and Low Switching Losses
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Fig. 6. Key operating waveforms of the proposed IBC when D >0.5.
EXPERIMENTAL RESULTS
The proposed and conventional IBCs are realized with the specifications shown next.
1) Input voltage: VS = 150–200 V.
2) Output voltage: VO = 24 V.
3) Output current: IO = 10 A.
4) Switching frequency: fS = 65 kHz or 300 kHz.
5) Inductor ripple current: below 3 A.
6) Ripple voltage of a coupling capacitor: below 4 V.
7) Output voltage ripple: below 250 mV.
The prototypes for the experiment, which are the conventional IBC and proposed IBCs, have been built and
tested to verify the operational principle, advantages, and performances of the proposed IBC, using the
components as shown in Table III. In order to alleviate the ringing caused by parasitic elements, two simple RC
snubbers are used across diodes D1 and D2 , respectively. Their values are as follows:
R =10 Ω/1 W, C = 10 nF/630 V.
For the experiment of the proposed IBC2, which is the proposed IBC with lower voltage rated freewheeling
diodes, the auxiliary circuit described in Section III is added.
7. Improved Step down Conversion in Interleaved Buck Converter and Low Switching Losses
21
III. Simulation circuits and outputs of the proposed IBC from D<50%
Fig: (7) Simulink Model of R Load Proposed diagram from D<50%
Fig(8). Triggering pulses for R-load
8. Improved Step down Conversion in Interleaved Buck Converter and Low Switching Losses
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Fig(9). Output voltage for proposed R-load
Fig(10). Cupling capacitor voltage wave & Diode 1 voltage& Diode 2 voltage output waveforms
For R-Load
Fig: (11) Simulink Model of RL Load Proposed diagram from D<50% For RL-Load
9. Improved Step down Conversion in Interleaved Buck Converter and Low Switching Losses
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Fig(12). Output voltage for proposed RL-load
Fig(13). Cupling capacitor voltage wave & Diode 1 voltage& Diode 2 voltage output waveforms
For RL-Load
IV. CONCLUSION
A new IBC is proposed in this project. While keeping the good characteristics of the IBC introduced in [14], it has
a more simple structure. The main advantage of the proposed IBC is that since the voltage stress across active switches is
half of the input voltage before turn-on or after turn-off when the operating duty is below 50%, the capacitive discharging
and switching losses can be reduced considerably. In addition, since the voltage stress of the freewheeling diodes is half of
the input voltage in the steady state and can be quickly reduced below the input voltage during the cold startup, the use of
lower voltage-rated diodes is allowed. Thus, the losses related to the diodes can be improved by employing schottky diodes
that have generally low breakdown voltages, typically below 200V. From these results, the efficiency of the proposed IBC is
higher than that of the conventional IBC and the improvement gets larger as the switching frequency increases. These are
verified with the experimental results. Moreover, it is confirmed that the proposed IBC has a higher step-down conversion
ratio and a smaller inductor current ripple than the conventional IBC. Therefore, the proposed IBC becomes attractive in
applications where non isolation, step-down conversion ratio with high input voltage, high output current with low ripple,
higher power density, and low cost are required.
10. Improved Step down Conversion in Interleaved Buck Converter and Low Switching Losses
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D. Lakshmi M.Tech Student from Kuppam Engineering College at Kuppam (JNTUA).I was awarded
B.Tech from Kuppam Engineering College at Kuppam (JNTU A) in 2011.
S. Zabiullah M.Tech. working as Assistant Professor, he was awarded M.Tech from Sri
Venkateshwara College of Engineering & Technologies in Chittoor (JNTU A) in 2011, he was awarded
B.Tech from (JNTU A) in 2009. He has 3 years of teaching experience. His area of interest is Power
Electronics & Electrical Drives.
Dr.Venugopal ME, Ph.D., working as Professor, he was awarded Ph.D(video processing) from Dr.
MGR University, Chennai, in 2011, he was awarded M.E (Power electronics) from University Visveshwaraya
College of Engineering, Bangalore, in 1998, he was awarded B.E (EEE) from R.V. College of Engineering,
Bangalore, in 1995. He has 16 years of teaching experience and he is currently working as Director (Research &
Development) in Kuppam engineering college, kuppam. His research area interested in power electronics, vedio
processing, power systems & renewable energy sources.