Modern dc power supplies provide power factor correction but the classical two-stage approach,
using hard-switched preregulators, has detrimental effects on efficiency and reliability,
particularly for high power applications. With some circuit modifications and the
addition of a few magnetic components, diodes and capacitors, we have turned a classical
boost power factor corrector into a high efficiency soft-switched version. The proposed
converter turns on its single switch with zero current and turns it off with zero voltage. In
this paper we explain the proposed changes, we study the waveforms and equations and we
verify them with an experimental prototype. We also show how the converter can be used
for modular single- and three-phase high power applications.
Modeling and Analysis of Transformerless High Gain Buck-boost DC-DC ConvertersIAES-IJPEDS
This paper proposes a transfomerless switched capacitor buck boost converter model, which provides higher voltage gain and higher efficiency when compared to the conventional buck boost converter. The averaged model based on state- space description is analyzed in the paper. The simulation results are presented to confirm the capability of the converter to generate high voltage ratios. The comparison between the proposed model and the traditional model is also provided to reveal the improvement. The proposed converter is suitable for for a wide application which requires high step-up DC-DC converters such as DC micro-grids and solar electrical energy.
An Efficient High Gain DC-DC Converter for Automotive ApplicationsIJPEDS-IAES
This paper presents a high gain DC-DC converter which uses a clamp circuit
to achieve soft switching. The proposed converter is designed to supply a
high intensity discharge (HID) lamp used in automobile head lamps. The
converter operates from a 12V input supply and provides an output voltage
of 120V at 35W output power. A clamp circuit consisting of a clamp
capacitor, clamp switch and resonant inductor will help to achieve zero
voltage switching (ZVS) of the both main and clamp switches. The practical
performance of the converter was validated through experimental results.
Results obtained from the prototype hardware prove that the converter meets
the requirements of HID lamp application and can be a very good alternative
to existing converters.
An Approach to Voltage Quality Enhancement by Introduction of CWVM for Distri...IAES-IJPEDS
This paper presented with problems related with voltage flicker in power
system networks. Several international standard issued to control the voltage
flicker are briefly described and some important methods to analyse
electrical circuits with sinusoidal and non-sinusoidal waveforms are
introduced and evaluated. One of these methods-Cockcroft Walton Voltage
Multiplier (CWVM) has been used to increase the voltage of a filter, which is
also described in this paper as a practical application. The filter can
compensate for harmonic currents, power factor, and unbalance voltage.The
simulation results using Multisimare presented, showing that good dynamic
and steady-state response can be achieved with this approach.
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.
Modeling and Analysis of Transformerless High Gain Buck-boost DC-DC ConvertersIAES-IJPEDS
This paper proposes a transfomerless switched capacitor buck boost converter model, which provides higher voltage gain and higher efficiency when compared to the conventional buck boost converter. The averaged model based on state- space description is analyzed in the paper. The simulation results are presented to confirm the capability of the converter to generate high voltage ratios. The comparison between the proposed model and the traditional model is also provided to reveal the improvement. The proposed converter is suitable for for a wide application which requires high step-up DC-DC converters such as DC micro-grids and solar electrical energy.
An Efficient High Gain DC-DC Converter for Automotive ApplicationsIJPEDS-IAES
This paper presents a high gain DC-DC converter which uses a clamp circuit
to achieve soft switching. The proposed converter is designed to supply a
high intensity discharge (HID) lamp used in automobile head lamps. The
converter operates from a 12V input supply and provides an output voltage
of 120V at 35W output power. A clamp circuit consisting of a clamp
capacitor, clamp switch and resonant inductor will help to achieve zero
voltage switching (ZVS) of the both main and clamp switches. The practical
performance of the converter was validated through experimental results.
Results obtained from the prototype hardware prove that the converter meets
the requirements of HID lamp application and can be a very good alternative
to existing converters.
An Approach to Voltage Quality Enhancement by Introduction of CWVM for Distri...IAES-IJPEDS
This paper presented with problems related with voltage flicker in power
system networks. Several international standard issued to control the voltage
flicker are briefly described and some important methods to analyse
electrical circuits with sinusoidal and non-sinusoidal waveforms are
introduced and evaluated. One of these methods-Cockcroft Walton Voltage
Multiplier (CWVM) has been used to increase the voltage of a filter, which is
also described in this paper as a practical application. The filter can
compensate for harmonic currents, power factor, and unbalance voltage.The
simulation results using Multisimare presented, showing that good dynamic
and steady-state response can be achieved with this approach.
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.
The International Journal of Engineering and Science (The IJES)theijes
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.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This paper proposes a non-isolated soft-switching bidirectional dc/dc converter for interfacing energy storage in DC microgrid. The proposed converter employs a half-bridge boost converter at input port followed by a LCC resonant tank to assist in soft-switching of switches and diodes, and finally a voltage doubler circuit at the output port to enhance the voltage gain by two times. The LCC resonant circuit also adds a suitable voltage gain to the converter. Therefore, overall high voltage gain of the converter is obtained without a transformer or large number of multiplier circuit. For operation in buck mode, the high side voltage is divided by half with capacitive divider to gain higher step-down ratio. The converter is operated at high frequency to obtain low output voltage ripple, reduced magnetics and filters. Zero voltage turn-on is achieved for all switches and zero current turn-on and turn-off is achieved for all diodes in both modes i.e., buck/boost operation. Voltage stress across switches and diode is clamped naturally without external snubber circuit. An experimental prototype has been designed, built and tested in the laboratory to verify the performance of the proposed converter.
An Active Input Current Waveshaping with Zero Switching Losses for Three-Phas...IDES Editor
In this paper a zero voltage switched active network
(Fig. 1) which can be used in conjunction with single-phase or
three-phase ac to dc diode rectifiers is presented. It is shown
that application of the proposed switching network in threephase
ac to dc boost converter yields zero switching losses
while maintaining a unity input power factor. Active network
capacitor, Cs, diodes D7, and D8, maintain a zero voltage during
turn-off of Q1, and Q2, Capacitor, Cs, discharges through
the boost inductors of the circuit thus limiting the rate of rise
of current during turn-on. Moreover, the advantage of the
proposed active network is that it can maintain a zero voltage
switching over the entire range of the duty cycle of the operation.
Consequently, boost stage can be used directly to control
the dc bus voltage by varying the duty cycle at Constant switching
frequency. The resulting advantages include higher
switching frequencies, and better efficiency. Finally the operation
of the active switching network is verified experimentally
on a prototype three-phase ac to dc converter.
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.
This paper presents a new single switched inductor-capacitor coupled transformer-less high gain DC-DC converter which can be used in renewable energy sources like PV, fuelcell in which the low DC output voltage is to be converted into high dc output voltage. With the varying low input voltages, the output of DC-DC converter remains same and does not change. A state space model of the converter is also presented in the paper. This constant output voltage is obtained by close loop control of converter using PID controller. High voltage gain of 10 is obtained without use of transformer. All the simulations are done in MATLAB-SIMULINK environment.
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.
To overcome the problem of mismatched voltage levels between parallel-connected low voltage photovoltaic (PV)
arrays and the higher grid voltage, a hybrid boost three level dc-dc converter is developed based on three level inverter with
the traditional single phase diode clamping. Only one inductor, two capacitors in series, and those power switches and diodes,
which are easy to be integrated, are used for establish the topology with transformerless high voltage gain. The operation
principle of the topology is analyzed, and then the pulse width modulation (PWM) control method is obtained according to
the switching functions about the output pulse voltages of both half-bridges. Therefore, the converter can not only operate
with high voltage gain, but also make the duty cycles of power switches closer to 0.5. A feedforward closed loop control
operation is proposed such that even in varying input the converter is capable of giving a constant output. Finally an
experimental is set up in the laboratory for open loop control operation. All experimental results verify the feasibility of the
circuit and validity of the PWM control method.
Analysis and characterization of different high density on chip switched capa...Aalay Kapadia
Power converter is a key component in micro-scale energy harvesting systems. Micro-scale energy harvesting has become an increasingly viable and promising area for powering ultra-low power systems. Switched-capacitor (SC) power converters that use capacitors as energy storage elements offer much better power density than switched-inductor counterparts and are thus attractive in low-power area-constrained applications. Switched-capacitor (SC) converters have shown tremendous promise in this regard due to favorable device utilization and scaling trends, and the emergence of high-density silicon-compatible capacitor technologies. With the rising integration levels used to increase digital processing performance, there is a clear need for multiple independent on-chip supplies in order to support per-IP or block power management. The growing demand for both performance and battery life in portable consumer electronics requires SoCs and power management circuits to be small, efficient, and dynamically powerful. This project first reviews various design techniques for implementing high density On-chip Switched-capacitor (SC) power converters and secondly suggests the best technique to solve aspects of power converter design: Area Density, Power Consumption & Efficiency.
ER Publication,
IJETR, IJMCTR,
Journals,
International Journals,
High Impact Journals,
Monthly Journal,
Good quality Journals,
Research,
Research Papers,
Research Article,
Free Journals, Open access Journals,
erpublication.org,
Engineering Journal,
Science Journals,
Design of a Single Phase Isolated Bidirectional AC to DC Converter for Batter...Tom Gibson
This paper analyses the design of a 3 kW isolated bidirectional ac to dc converter for Battery Energy Storage Systems (BESS). This is an increasingly popular solution to overcome the differences seen in electricity supply and demand introduced by renewable energy sources. In order to connect these systems to the grid an ac to dc converter is required. In this paper a converter is considered to interface a 300 V battery bank to the grid at 110 V, 60 Hz ac. A dual active bridge is implemented with a 100 kHz transformer. Control systems for the converter are also considered allowing autonomous regulation of the power flow to and from the storage.
This paper was written as part of the ELEC 497 Research Project while I was studying at Queen's University, Ontario.
This paper proposes the use of Embedded EZ-source
inverter system (EZSI) as a single stage power conversion
concept for adjustable speed drives (ASD) in photovoltaic
applications. Open loop and closed loop control strategy of
EZSI system are proposed. EZSI produces the same voltage
gain as Z-source inverter (ZSI) but due to the DC sources
embedded within the X- shaped impedance network, it has
the added advantage of inherent source filtering capability
and also reduced capacitor sizing. This is attained without
any extra passive filters. By controlling the shoot-through
duty ratio and modulation index, EZSI system can produce
any desired AC output voltage even greater than DC rail
voltage and it also provides ride-through capability under
voltage sag. These advantages are more significant for
adjustable speed drive (ASD) applications in order to regulate
the speed. The operational analysis, control strategy and
simulation results exemplify that an EZSI is the most
promising technique for renewable energy applications in
order to reduce the overall system complexity and thereby
improving the inverter efficiency.
The International Journal of Engineering and Science (The IJES)theijes
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.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This paper proposes a non-isolated soft-switching bidirectional dc/dc converter for interfacing energy storage in DC microgrid. The proposed converter employs a half-bridge boost converter at input port followed by a LCC resonant tank to assist in soft-switching of switches and diodes, and finally a voltage doubler circuit at the output port to enhance the voltage gain by two times. The LCC resonant circuit also adds a suitable voltage gain to the converter. Therefore, overall high voltage gain of the converter is obtained without a transformer or large number of multiplier circuit. For operation in buck mode, the high side voltage is divided by half with capacitive divider to gain higher step-down ratio. The converter is operated at high frequency to obtain low output voltage ripple, reduced magnetics and filters. Zero voltage turn-on is achieved for all switches and zero current turn-on and turn-off is achieved for all diodes in both modes i.e., buck/boost operation. Voltage stress across switches and diode is clamped naturally without external snubber circuit. An experimental prototype has been designed, built and tested in the laboratory to verify the performance of the proposed converter.
An Active Input Current Waveshaping with Zero Switching Losses for Three-Phas...IDES Editor
In this paper a zero voltage switched active network
(Fig. 1) which can be used in conjunction with single-phase or
three-phase ac to dc diode rectifiers is presented. It is shown
that application of the proposed switching network in threephase
ac to dc boost converter yields zero switching losses
while maintaining a unity input power factor. Active network
capacitor, Cs, diodes D7, and D8, maintain a zero voltage during
turn-off of Q1, and Q2, Capacitor, Cs, discharges through
the boost inductors of the circuit thus limiting the rate of rise
of current during turn-on. Moreover, the advantage of the
proposed active network is that it can maintain a zero voltage
switching over the entire range of the duty cycle of the operation.
Consequently, boost stage can be used directly to control
the dc bus voltage by varying the duty cycle at Constant switching
frequency. The resulting advantages include higher
switching frequencies, and better efficiency. Finally the operation
of the active switching network is verified experimentally
on a prototype three-phase ac to dc converter.
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.
This paper presents a new single switched inductor-capacitor coupled transformer-less high gain DC-DC converter which can be used in renewable energy sources like PV, fuelcell in which the low DC output voltage is to be converted into high dc output voltage. With the varying low input voltages, the output of DC-DC converter remains same and does not change. A state space model of the converter is also presented in the paper. This constant output voltage is obtained by close loop control of converter using PID controller. High voltage gain of 10 is obtained without use of transformer. All the simulations are done in MATLAB-SIMULINK environment.
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.
To overcome the problem of mismatched voltage levels between parallel-connected low voltage photovoltaic (PV)
arrays and the higher grid voltage, a hybrid boost three level dc-dc converter is developed based on three level inverter with
the traditional single phase diode clamping. Only one inductor, two capacitors in series, and those power switches and diodes,
which are easy to be integrated, are used for establish the topology with transformerless high voltage gain. The operation
principle of the topology is analyzed, and then the pulse width modulation (PWM) control method is obtained according to
the switching functions about the output pulse voltages of both half-bridges. Therefore, the converter can not only operate
with high voltage gain, but also make the duty cycles of power switches closer to 0.5. A feedforward closed loop control
operation is proposed such that even in varying input the converter is capable of giving a constant output. Finally an
experimental is set up in the laboratory for open loop control operation. All experimental results verify the feasibility of the
circuit and validity of the PWM control method.
Analysis and characterization of different high density on chip switched capa...Aalay Kapadia
Power converter is a key component in micro-scale energy harvesting systems. Micro-scale energy harvesting has become an increasingly viable and promising area for powering ultra-low power systems. Switched-capacitor (SC) power converters that use capacitors as energy storage elements offer much better power density than switched-inductor counterparts and are thus attractive in low-power area-constrained applications. Switched-capacitor (SC) converters have shown tremendous promise in this regard due to favorable device utilization and scaling trends, and the emergence of high-density silicon-compatible capacitor technologies. With the rising integration levels used to increase digital processing performance, there is a clear need for multiple independent on-chip supplies in order to support per-IP or block power management. The growing demand for both performance and battery life in portable consumer electronics requires SoCs and power management circuits to be small, efficient, and dynamically powerful. This project first reviews various design techniques for implementing high density On-chip Switched-capacitor (SC) power converters and secondly suggests the best technique to solve aspects of power converter design: Area Density, Power Consumption & Efficiency.
ER Publication,
IJETR, IJMCTR,
Journals,
International Journals,
High Impact Journals,
Monthly Journal,
Good quality Journals,
Research,
Research Papers,
Research Article,
Free Journals, Open access Journals,
erpublication.org,
Engineering Journal,
Science Journals,
Design of a Single Phase Isolated Bidirectional AC to DC Converter for Batter...Tom Gibson
This paper analyses the design of a 3 kW isolated bidirectional ac to dc converter for Battery Energy Storage Systems (BESS). This is an increasingly popular solution to overcome the differences seen in electricity supply and demand introduced by renewable energy sources. In order to connect these systems to the grid an ac to dc converter is required. In this paper a converter is considered to interface a 300 V battery bank to the grid at 110 V, 60 Hz ac. A dual active bridge is implemented with a 100 kHz transformer. Control systems for the converter are also considered allowing autonomous regulation of the power flow to and from the storage.
This paper was written as part of the ELEC 497 Research Project while I was studying at Queen's University, Ontario.
This paper proposes the use of Embedded EZ-source
inverter system (EZSI) as a single stage power conversion
concept for adjustable speed drives (ASD) in photovoltaic
applications. Open loop and closed loop control strategy of
EZSI system are proposed. EZSI produces the same voltage
gain as Z-source inverter (ZSI) but due to the DC sources
embedded within the X- shaped impedance network, it has
the added advantage of inherent source filtering capability
and also reduced capacitor sizing. This is attained without
any extra passive filters. By controlling the shoot-through
duty ratio and modulation index, EZSI system can produce
any desired AC output voltage even greater than DC rail
voltage and it also provides ride-through capability under
voltage sag. These advantages are more significant for
adjustable speed drive (ASD) applications in order to regulate
the speed. The operational analysis, control strategy and
simulation results exemplify that an EZSI is the most
promising technique for renewable energy applications in
order to reduce the overall system complexity and thereby
improving the inverter efficiency.
A Review to AC Modeling and Transfer Function of DCDC ConvertersRadita Apriana
In this paper, AC modeling and small signal transfer function for DC-DC converters are
represented. The fundamentals governing the formulas are also reviewed. In DC-DC converters, the
output voltage must be kept constant, regardless of changes in the input voltage or in the effective load
resistance. Transfer function is the necessary knowledge to design a proper feedback control such as PID
control to regulate the output voltage as linear PID and PI controllers are usually designed for DC-DC
converters using standard frequency response techniques based on the small signal model of the
converter.
Modern trend in power generation is the use of two-stage configuration i.e., allocating a single PV cell
to a converter to produce grid voltage of adequate requirement and then to convert DC to AC voltage for grid
cnnection. Usually, the first stage is a DC-DC boost type converter which is responsible for extracting maximum
power from panel and boosting PV voltage to a value higher than peak of grid voltage. A converter is proposed,
which is derived from an active network based converter, is chosen as the first stage and a five level inverter is
used as the second stage of the configuration. Thus, in overall, the converter used is having high gain and reduced
switching stress. The Inverter used is having the advantage of low filter requirement, reduced stress, EMI and
reduced THD level. A closed loop control of the converter is done to maintain constant output voltage under
varying input voltage. MATLAB R2014a version software is used to simulate the model. The prototype of the
two stage configuration was developed and tested in the laboratory and results were verified using PIC 16F877A.
A ZVS Interleaved Boost AC/DC Converter Using Super Capacitor Power for Hybri...IJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
Improvement In Pre-Regulation For Power Factor Using CUK ConverterIJRES Journal
Cuk converters, operating in Discontinuous Capacitor Voltage Mode can achieve unity power factor when used as rectifiers with no need of duty-cycle modulation. This operating mode causes high voltage stresses across the semiconductors, calling for high-voltage switches like IGBT's. However, zero-voltage turn-off is achieved, resulting in limited power loss even at high frequency. Both current- and voltage-fed approaches as well as constant- and variable-frequency control are analyzed in the paper. Simulation and experimental results are Explained, which demonstrate actual converter performance. Most of the power factor regulator topologies in continuous conduction mode result in bulky magnetic, and in discontinuous conduction mode result in high harmonic content. To solve these problems a Cuk topology is presented in discontinuous conduction mode with coupled inductors for power factor regulation, the unique feature exhibited by the converter that makes the converter better than the other converter in operation for power factor regulation. Inductive coupling is used to transfer the ripple from the input to the output side thereby reducing the switching harmonics in the line current. Experimental results obtained on a some Watt prototype are also presented.
Reduction of common mode voltage for cascaded multilevel inverters using phas...nooriasukmaningtyas
Demand of cascaded multilevel inverters in industries of electric drives and
renewable energy is increasing due to their large-scale capacity and high
voltage. The modulation technique of inverters significantly affects the
power quality of the inverter output voltage. This paper proposes a new
method of carrier wave modulation using the phase shift keying technique for
cascaded multilevel inverters. The phase of a constant frequency carrier wave
is changed at an accurate time by an input sinusoidal control signal. This
modulation technique is simply implemented and only needs a small
memory. It also helps reduce the common mode voltage of inverters in order
to suppress the output voltage harmonics. Moreover, the ability to reduce
switching count also helps the inverters decrease switching loss. The
simulated and experienced results on a cascaded 9-level 3-phase inverter and
an F28379D DSP kit have validated the performance of the proposed
technique compared with that of the APOD and POD methods.
This paper presents a new simplified cascade multiphase DC-DC buck power converter suitable for low voltage and large current applications. Cascade connection enables very low voltage ratio without using very small duty cycles nor transformers. Large current with very low ripple content is achieved by using the multiphase technique. The proposed converter needs smaller number of components compared to conventional cascade multiphase DC-DC buck power converters. This paper also presents useful analysis of the proposed DC-DC buck power converter with a method to optimize the phase and cascade number. Simulation and experimental results are included to verify the basic performance of the proposed DC-DC buck power converter.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Hybrid Two Quasi Z-Source Converter for Photovoltaic ApplicationPremier Publishers
This paper presents a Hybrid Two Quasi Z-source (HTQZS) DC-DC converter for photovoltaic applications. These are mainly employed to full fill the demand of the voltage boost in photovoltaic applications from the lower value voltage. The traditional z source networks have some limitations in voltage boosting, so the modified z source means the different combination of the LC components is combined to form the hybrid quasi z source networks. This hybrid two quasi z source dc-dc converters can be applied for the dc-ac, ac-ac, and ac-dc conversions. The structure of the proposed converter is simpler. This converter adds the benefits to the traditional z source converter. This converter draws the continuous input current. The converter simulated is the combination of two different quasi z source networks. This converter uses the duty cycle less than the traditional z source network and gives the more gain than that. PV panel used as source to converter and then the output is inverted and step up.
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.
High Efficiency Dc-Dc Converter for Renewable Energy Applications and High Vo...IOSRJEEE
Renewable sources like solar PV cell is prefer to be operated at low voltages. This paper proposes a novel high voltage gain, high efficiency dc-dc converter based on coupled inductor, intermediate capacitor. The input energy acquired from the source is first stored in the coupled inductor and intermediate capacitor in a lossless manner. Improve the voltage gain and efficiency of the system. Exorbitant duty cycle values are not required for high voltage gain, when prevent the problems such as diode reverse recovery. Presence of a passive clamp network causes reduced voltage stress on the switch. Overall performance of the renewable energy with a step-up DC/DC converter using closed loop control action is used in the proposed system, improving the overall efficiency of the system.
Similar to Single-Switch Soft-Switched Boost Power Factor Corrector for Modular Applications (20)
42 30 nA Comparative Study of Power Semiconductor Devices for Industrial PWM ...IAES-IJPEDS
The growing demand of energy translates into efficiency requirements of
energy conversion systems and electric drives. Both these systems are based
on Pulse Width Modulation (PWM) Inverter. In this paper we firstly present
the state of art of the main types of semiconductors devices for Industrial
PWM Inverter. In particular we examine the last generations of Silicon
Carbide (SiC) MOSFETs and Insulated Gate Bipolar Transistors (IGBTs)
and we present a comparison between these devices, obtained by SPICE
simulations, both for static characteristics at different temperatures and for
dynamic ones at different gate resistance, in order to identify the one which
makes the PWM inverter more efficient.
Modeling and State Feedback Controller Design of Tubular Linear Permanent Mag...IAES-IJPEDS
In this paper a state feedback controller for tubular linear permanent magnet
synchronous motor (TLPMSM) containing two gas springs, is presented.
The proposed TLPMSM controller is used to control reciprocating motions
of TLPMSM. The analytical plant model of TLPMSM is a multi-input
multi-output (MIMO) system which is decoupled to some sub single-input
single-output (SISO) systems, then, the sub SISO systems are converted to
sub-state space models. Indeed, the TLPMSM state space model is decoupled
to some sub-state spaces, and then, the gains of state feedback are calculated
by linear quadratic regulation (LQR) method for each sub-state space
separately. The controller decreases the distortions of the waveforms.
The simulation results indicate the validity of the controller.
Analysis of Harmonics and Ripple Current in Multi-Module Converters with Incr...IAES-IJPEDS
Controlled rectifiers are considered as the most important hardware part in
the field of HVDC systems in transmission lines and can be used for a
number of power electronics based system operation, control and utility
applications. In this paper, a brief design of a 12-pulse, 24-pulse, 36-pulse
and a 48-pulse converter connected to the grid is presented along with the
harmonic and ripple current analysis with its comparison statistics and thus
providing a justification for the suitable ones. The performance of the
12, 24, 36 and 48-pulse converters are compared for their effectiveness in
both quantitatively as well as qualitatively. Further, comparison of the
48-pulse converter on its THD and current ripple which is connected towards
the grid with simple pulse width modulation technique is also proposed. It
combines all features of the low switching concepts and DC current reinjection
techniques. Some basic topological explanation of the controlled
rectifiers and simulation results using MATLAB are also presented in this
paper in order to justify the harmonic analysis. The simulation results along
with the quantitative results shows the effectiveness of the proposed scheme
for the cancelation or the elimination of the harmonics result in maximum
harmonic mitigation, for high power utility applications, the 48-pulse
converter is most fitting to improve the conversion efficiency, low di/dt
and dv/dt and active and reactive power controllability.
Comparative Study of Various Adjustable Speed Drives during Voltage SagIAES-IJPEDS
This Paper compares the sensitivity of various adjustable speed drives to
voltage sag for the process control applications. Three phase voltage sag of
type B caused due to SLG fault is considered and four topologies of ASD’s
are compared in this paper. The comparison is done especially in speed,
voltage, current and torque of the ASDs. Diode rectifier without z source
inverter, diode rectifier with z source inverter, single phase two leg Vienna
rectifier and single phase neutral linked Vienna with z source inverter are
compared and the best one is highlighted. The circuits of various ASD’s are
simulated using Matlab /Simulink.
Modified Distribution Transformer for Enhancing Power Quality in Distribution...IAES-IJPEDS
The percentage of non-linear loads in the power distribution sector is increasing
day by day. Harmonics injected by these non-linear loads circulate in the delta
windings of the conventional distribution transformer thereby increasing the
temperature and losses. This reduces the efficiency and life of the transformers.
In a modified distribution transformer configuration proposed recently, called
star-star-delta_utilized configuration (YYD_utilized), the harmonics circulating
in the delta winding was utilized and the drainage power thus recovered was
used to power auxiliary loads. This paper presents the experimental studies
conducted on YYD_utilized distribution transformer. When compared to
conventional star-star, delta-star and star-star-delta transformers, the new
configuration of YYD_utilized transformer has shown considerable
improvement in transformer efficiency. The results obtained show that when
the power from the circulating harmonics is recovered and utilized, it not only
improves transformer efficiency but also improves the power factor
and reduces the harmonic distortions at the primary side of the transformer.
The results obtained also suggest the existence of maximum power point or an
optimum loading for the recovered harmonic power.
Modelling of Virtual Synchronous Converter for Grid-Inverter Synchronization ...IAES-IJPEDS
In this paper, virtual synchronous converter (VSCon) is been developed
which mimic the behavior of synchronous generator as in order to have fast
synchronization between the inverter with the grid. This synchronization is
important before can sent the power among inverter-grid connection. This
technique can also been applied at the distributed generated sources when are
connected to the local microgrids. Here, the frequency and voltage
synchronization also can be controlled at the same time some improvement
on synchronous generator mathematical model that is suitable to be
implemented into the inverter control. The whole unit of VSCon is operated
and simulated in Matlab/Simulink in order to observe all consequences
during synchronizing the voltage, frequency and phase-angle. It has been
verified by the simulation circuit where, the power converter can be
synchronized with the microrids without using a PLL unit for self
synchronization. This VSCon technique has proven that, by applying the
concept of the synchronous generator model in inverter control, it can cause
the inverter to behave as generator system, which does not required any
phase information from the grid in order to be synchronized.
Enhanced Crowbar Protection for Fault Ride through Capability of Wind Generat...IAES-IJPEDS
Due to increasing demand in power, the integration of renewable sources like
wind generation into power system is gaining much importance nowadays.
The heavy penetration of wind power into the power system leads to many
integration issues mainly due to the intermittent nature of the wind and the
desirability for variable speed operation of the generators. As the wind power
generation depends on the wind speed, its integration into the grid has
noticeable influence on the system stability and becomes an important issue
especially when a fault occurs on the grid. The protective disconnection of a
large amount of wind power during a fault will be an unacceptable
consequence and threatens the power system stability. With the increasing
use of wind turbines employing Doubly Fed Induction Generator (DFIG)
technology, it becomes a necessity to investigate their behavior during grid
faults and support them with fault ride through capability. This paper
presents the modeling and simulation of a doubly fed induction generator
according to grid code compatibility driven by a wind turbine connected to
the grid. This paper analyses the voltage sag due to a three-phase fault in the
wind connected grid. A control strategy including a crowbar circuit has been
developed in MATLAB/SIMULINK to bypass the rotor over currents during
grid fault to enhance the fault ride through capability and to maintain system
stability. Simulation results show the effectiveness of the proposed control
strategies in DFIG based grid connected wind turbine system.
An Improved of Multiple Harmonic Sources Identification in Distribution Syste...IAES-IJPEDS
This paper introduces an improved of multiple harmonic sources
identification that been produced by inverter loads in power system using
time-frequency distribution (TFD) analysis which is spectrogram.
The spectrogram is a very applicable method to represent signals in
time-frequency representation (TFR) and the main advantages
of spectrogram are the accuracy, speed of the algorithm and use low memory
size such that it can be computed rapidly. The identification of multiple
harmonic sources is based on the significant relationship of spectral
impedances which are the fundamental impedance (Z1) and harmonic
impedance (Zh) that extracted from TFR. To verify the accuracy of the
proposed method, MATLAB simulations carried out several unique cases
with different harmonic producing loads on IEEE 4-bus test feeder cases. It is
proven that the proposed method is superior with 100% correct identification
of multiple harmonic sources. It is envisioned that the method is very
accurate, fast and cost efficient to localize harmonic sources in distribution
system.
Performance and Energy Saving Analysis of Grid Connected Photovoltaic in West...IAES-IJPEDS
The paper presents performance and energy saving analysis of 1.25 kWp grid
connected photovoltaic system under difference weather condition in West
Sumatera. The measured data were performed during weather data that often
occur in West Sumatra i.e. sunny, overcast, raining and cloudy.
The synchronizing process successfully done even bad weather conditions
when sunlight was low automatically. Photovoltaic in average start
producing power from 7:00 AM to 6:00 PM for normal or clear sky, however
under overcast, raining and cloudy weather, the PV power decreased and
disconnected earlier before sunset. During intermittent raining, overcast and
cloud covered the PV power output show an irregular profile. The PV energy
saving performed for three residential connection cases: 1300 VA, 900 VA
with subsidized and 900 VA without subsidized. The solar PV installation
have more benefits and energy saving for 1300 VA, 900 VA without
subsidized with payback period around 8.5 years. However, the 900 VA with
subsidized take longer 20.8 years, but still in PV lifespan 25 years. In the
future, household subsidies may be reduced or eliminated, the solar energy
will be viable alternative of energy resources when it can produce electricity
at a cost equivalent to utility grid PLN rate.
An Improved Constant Voltage Based MPPT Technique for PMDC MotorIAES-IJPEDS
Stand-alone photovoltaic (SAPV) systems are being used in remote areas
and are being seen as one of the promising solution in this regard. The SAPV
system as presented in the paper consists of solar PV panel, a DC-DC
converter, a controller and a PMDC motor. The current-voltage and powervoltage
characteristics being nonlinear, the SAPV system require maximum
power point techniques (MPPT) control techniques to extract maximum
power available from the PV cell. A voltage based MPPT technique which is
capable of tracking MPP has been selected because of numerous advantages
it offers such as: simple and low cost of implementation. The limitation of
constant voltage method is that its efficiency is low as the PV panel has to be
disconnected from the load for measurement of the open circuit voltage
(Voc). In the presented paper, the authors have removed this limitation by
using a pilot PV panel for measurement of Voc. A proportional-integrator (PI)
based controller is used in implementation of constant voltage MPP
technique and the modeling is done in MATLAB®/SIMULINK simulation
environment. The simulation results are presented and discussed in the paper,
the results shows that the efficiency of the system has increased.
A Discrete PLL Based Load Frequency Control of FLC-Based PV-Wind Hybrid Power...IAES-IJPEDS
The sun and wind-based generation are considered to besource of green
power generation which can mitigate the power demand issues. As solar and
wind power advancements are entrenched and the infiltration of these
Renewable Energy Sources (RES) into to network is expanding dynamically.
So, as to outline a legitimate control and to harness power from RES the
learning of natural conditions for a specific area is fundamental. Fuzzy Logic
Controller (FLC) based Maximum Power Point Tracking (MPPT) controlled
boost converter are utilized for viable operation and to keep DC voltage
steady at desired level. The control scheme of the inverter is intended to keep
the load voltage and frequency of the AC supply at aconstant level regardless
of progress in natural conditions and burden. A Simulink model of the
proposed Hybrid system with the MPPT controlled Boost converters
and Voltage regulated Inverter for stand-alone application is developed in
MATLAB R2015a, Version 8.5.0. The ongoing information of Wind Speed
and Solar Irradiation levels are recorded at BITS-Pilani, Hyderabad Campus
the performance of the voltage regulated inverter under constant and varying
linearAC load is analyzed. The investigation shows that the magnitude of
load voltage and frequency of the load voltage is maintained at desired level
by the proposed inverter control logic.
An Adaptive Virtual Impedance Based Droop Control Scheme for Parallel Inverte...IAES-IJPEDS
This paper presents an adaptive virtual impedance based droop control
scheme for parallel inverter operation in low voltage microgrid. Because it is
essential to achieve power sharing between inverters in microgrid, various
droop control schemes have been proposed. In practice, the line impedance
between inverters and the point of common coupling (PCC) in microgrid are
not always equal. This imbalance in line impedance often results in a reactive
power mismatch among inverters. This problem has been solved by
introducing a virtual impedance loop in the conventional droop control
scheme. However, the reactive power sharing performance of this method is
still deteriorated when the line impedances change during operation. To
overcome such a problem, a new control scheme that is based on a virtual
impedance loop and an impedance estimation scheme is proposed.
To monitor the changes in line impedances, the impedance estimator is
implemented by using the output voltages and currents of inverters as well as
the voltages at the PCC. To compensate for the reactive power mismatch due
to the line impedance changes, the estimated line impedance is fed to the
virtual impedance loop in which it adjusts the virtual impedance value.
Comparative simulation results with the conventional ones verify the
effectiveness of the proposed adaptive virtual impedance based droop control
scheme.
Open-Switch Fault-Tolerant Control of Power Converters in a Grid-Connected Ph...IAES-IJPEDS
This paper presents the study of an open switch fault tolerant control of a
grid-connected photovoltaic system. The studied system is based on the
classical DC-DC boost converter and a bidirectional 6-pulse DC-AC
converter. The objective is to provide an open-switch fault detection method
and fault-tolerant control for both of boost converter and grid-side converter
(GSC) in a grid-connected photovoltaic system. A fast fault detection method
and a reliable fault-tolerant topology are required to ensure continuity of
service, and achieve a faster corrective maintenance. In this work, the mean
value of the error voltages is used as fault indicator for the GSC, while, for
the boost converter the inductor current form is used as fault indicator. The
fault-tolerant topology was achieved by adding one redundant switch to the
boost converter, and by adding one redundant leg to the GSC. The results of
the fault tolerant control are presented and discussed to validate the proposed
approach under different scenarios and different solar irradiances.
Photovoltaic System with SEPIC Converter Controlled by the Fuzzy LogicIAES-IJPEDS
In this work, a fuzzy logic controller is used to control the output voltage of a
photovoltaic system with a DC-DC converter; type Single Ended Primary
Inductor Converter (SEPIC). The system is designed for 210 W solar
photovoltaic (SCHOTT 210) panel and to feed an average demand of 78 W.
This system includes solar panels, SEPIC converter and fuzzy logic
controller. The SEPIC converter provides a constant DC bus voltage and its
duty cycle controlled by the fuzzy logic controller which is needed to
improve PV panel’s utilization efficiency. A fuzzy logic controller (FLC) is
also used to generate the PWM signal for the SEPIC converter.
Electric Power Converter with a Wide Input Voltage RangeIAES-IJPEDS
The electric power converter for downhole telemetry systems of oil-well
pumps include a downhole block connected to the pump that contains
electronic circuits required for the operation of the motor pump sensors
and transmission of data about their condition to the surface are described.
A few methods of electric power conversion for this purpose are considered.
The circuit contained two steps of voltage converting are proposed.
The electrical scheme of this method is considered in the article. Proposed
decisions are simulated and verified experimentally. The input high supply
voltage range (200-4200 V) without loss of efficiency (even temporary) was
obtained. The results of simulation and experimental studies have shown
very close results.
Design and Implementation of Real Time Charging Optimization for Hybrid Elect...IAES-IJPEDS
Electric vehicle (EV) has gained incredible interest from the past two decade
as one of the hopeful greenhouse gasses solution. The number of Electric
Vehicle (EV) is increasing around the world; hence that making EVs user
friendly becomes more important. The main challenge in usage of EV is the
charging time required for the batteries used in EV. As a consequence, this
subject matter has been researched in many credentials where a wide range
of solutions have been proposed. However those solutions are in nature due
to the complex hardware structure. To provide an unswerving journey
an Android application based charging optimization is proposed.
This application is aimed at giving relevant information about the EV’s
battery state of charge (SOC), accurate location of the EV, booking of the
charging slots using token system and route planner. At emergency
situations, an alternative service is provided by mobile charging stations.
Route planner indicates the temperature by which prediction of reaching the
destination can be done. In addition to that nearest places such as parks,
motels are indicated. The estimated time and distance between the electric
vehicle and the charging station is calculated by the charging station server
according to which the parking lot is allocated. Vehicle to charging station
communication is established for the time estimation of charging. This will
help the EV users to know about charge status and charging station, which
support fast charging method and availability of the station on the go
and also when to charge their EV. The Arduino UNO board has been used
for the hardware part. The hardware results are confirming the conceptual of
the proposed work.
Performance Analysis of Photovoltaic Induction Motor Drive for Agriculture Pu...IAES-IJPEDS
This paper presents water pumping system using renewable source (solar)
without the use of chemical storage batteries. In this converter-inverter
circuit is used to drive Induction motor. The Converter used here is Two
Inductor boost converter (TIBC), which consists of a resonant tank, voltage
doubler rectifier and a snubber circuit. TIBC is designed to drive the three
phase induction motor from PV energy. TIBC converter is also known as
current fed multi resonant converter having high voltage gain and low input
current ripple. Converter switches are controlled through hysteresis controller
and ZCS resonant topologies. Solar PV power fluctuates according to
irradiation level of sunlight and hence tracking of maximum power at all
time is mandatory. SPWM control with third harmonic injection is used to
trigger the IGBT’s in the inverter. The development is oriented to achieve a
more efficient, reliable, maintenance free and cheaper solution than the
standard ones, that uses DC motors or low voltage synchronous motors.
The proposed method is verified with MATLAB/SIMULINK and the system
simulation confirms the performance of the proposed system.
Comparison of Sine and Space Vector Modulated Embedded Z-Source Inverter fed ...IAES-IJPEDS
This paper deals with performance of photovoltaic powered Embedded
Z-Source Inverter (EZSI) fed Induction motor drive. The DC output from the
PV-Panel is boosted and converted into AC using Embedded Z-Source
Inverter. EZSI system based on the concept of Z-Source Inverter (ZSI),
which provides single stage power conversion. The EZSI also produce same
voltage gain as that of the ZSI based system. In EZSI the DC source is
embedded within the X-shaped LC impedance network, due to this EZSI has
the added advantage of inherent source filtering capability, this can be
achieved without any extra passive filter. EZSI can produce the AC output
voltage which is greater than the DC link voltage. EZSI system also provides
ride-through capability under voltage sags. In this paper the performance of
space vector modulated EZSI fed Induction Motor Drive is compared with
sinusoidal PWM controlled EZSI fed Drive system. The PV powered EZSI
fed three phase Induction Motor System is designed, modeled and simulated
using MAT LAB-SIMULINK and the corresponding results are presented.
This drive system has advantages like voltage boosting ability and reduced
harmonic content.
Single-Phase Multilevel Inverter with Simpler Basic Unit Cells for Photovolta...IAES-IJPEDS
This paper presents a single-phase multilevel inverter (MLI) with simpler
basic unit cells. The proposed MLI is able to operate in two modes, i.e.
charge mode to charge the batteries, and inverter mode to supply AC power
to load, and therefore, it is inherently suitable for photovoltaic (PV) power
generation applications. The proposed MLI requires lower number of power
MOSFETs and gate driver units, which will translate into higher cost saving
and better system reliability. The power MOSFETs in the basic unit cells
and H-bridge module are switched at near fundamental frequency, i.e. 100
Hz and 50 Hz, respectively, resulting in lower switching losses. For low total
harmonic distortion (THD) operation, a deep scanning method is employed
to calculate the switching angles of the MLI. The lowest THD obtained is
8.91% at modulation index of 0.82. The performance of the proposed MLI
(9-level) has been simulated and evaluated experimentally. The simulation
and experimental results are in good agreement and this confirms that the
proposed MLI is able to produce an AC output voltage with low THD.
A DC Inrush Current Minimisation Method using Modified Z-Source Inverter in A...IAES-IJPEDS
The adjustable speed drives employ PWM converter-inverter system in order
to obtain unity power factor. The DC inrush current in DC link capacitors of
the rectifier limits the operation of power devices. Hence, this paper proposes
a new approach to reduce the DC inrush current by employing modified
Z-source inverter in a Adjustable Speed Drive system. The operating
principles, design procedure and simulation results are shown and compared
with the conventional Z-Source inverter.
Harnessing WebAssembly for Real-time Stateless Streaming PipelinesChristina Lin
Traditionally, dealing with real-time data pipelines has involved significant overhead, even for straightforward tasks like data transformation or masking. However, in this talk, we’ll venture into the dynamic realm of WebAssembly (WASM) and discover how it can revolutionize the creation of stateless streaming pipelines within a Kafka (Redpanda) broker. These pipelines are adept at managing low-latency, high-data-volume scenarios.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
We have compiled the most important slides from each speaker's presentation. This year’s compilation, available for free, captures the key insights and contributions shared during the DfMAy 2024 conference.
Forklift Classes Overview by Intella PartsIntella Parts
Discover the different forklift classes and their specific applications. Learn how to choose the right forklift for your needs to ensure safety, efficiency, and compliance in your operations.
For more technical information, visit our website https://intellaparts.com
Water billing management system project report.pdfKamal Acharya
Our project entitled “Water Billing Management System” aims is to generate Water bill with all the charges and penalty. Manual system that is employed is extremely laborious and quite inadequate. It only makes the process more difficult and hard.
The aim of our project is to develop a system that is meant to partially computerize the work performed in the Water Board like generating monthly Water bill, record of consuming unit of water, store record of the customer and previous unpaid record.
We used HTML/PHP as front end and MYSQL as back end for developing our project. HTML is primarily a visual design environment. We can create a android application by designing the form and that make up the user interface. Adding android application code to the form and the objects such as buttons and text boxes on them and adding any required support code in additional modular.
MySQL is free open source database that facilitates the effective management of the databases by connecting them to the software. It is a stable ,reliable and the powerful solution with the advanced features and advantages which are as follows: Data Security.MySQL is free open source database that facilitates the effective management of the databases by connecting them to the software.
NUMERICAL SIMULATIONS OF HEAT AND MASS TRANSFER IN CONDENSING HEAT EXCHANGERS...ssuser7dcef0
Power plants release a large amount of water vapor into the
atmosphere through the stack. The flue gas can be a potential
source for obtaining much needed cooling water for a power
plant. If a power plant could recover and reuse a portion of this
moisture, it could reduce its total cooling water intake
requirement. One of the most practical way to recover water
from flue gas is to use a condensing heat exchanger. The power
plant could also recover latent heat due to condensation as well
as sensible heat due to lowering the flue gas exit temperature.
Additionally, harmful acids released from the stack can be
reduced in a condensing heat exchanger by acid condensation. reduced in a condensing heat exchanger by acid condensation.
Condensation of vapors in flue gas is a complicated
phenomenon since heat and mass transfer of water vapor and
various acids simultaneously occur in the presence of noncondensable
gases such as nitrogen and oxygen. Design of a
condenser depends on the knowledge and understanding of the
heat and mass transfer processes. A computer program for
numerical simulations of water (H2O) and sulfuric acid (H2SO4)
condensation in a flue gas condensing heat exchanger was
developed using MATLAB. Governing equations based on
mass and energy balances for the system were derived to
predict variables such as flue gas exit temperature, cooling
water outlet temperature, mole fraction and condensation rates
of water and sulfuric acid vapors. The equations were solved
using an iterative solution technique with calculations of heat
and mass transfer coefficients and physical properties.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
An Approach to Detecting Writing Styles Based on Clustering Techniquesambekarshweta25
An Approach to Detecting Writing Styles Based on Clustering Techniques
Authors:
-Devkinandan Jagtap
-Shweta Ambekar
-Harshit Singh
-Nakul Sharma (Assistant Professor)
Institution:
VIIT Pune, India
Abstract:
This paper proposes a system to differentiate between human-generated and AI-generated texts using stylometric analysis. The system analyzes text files and classifies writing styles by employing various clustering algorithms, such as k-means, k-means++, hierarchical, and DBSCAN. The effectiveness of these algorithms is measured using silhouette scores. The system successfully identifies distinct writing styles within documents, demonstrating its potential for plagiarism detection.
Introduction:
Stylometry, the study of linguistic and structural features in texts, is used for tasks like plagiarism detection, genre separation, and author verification. This paper leverages stylometric analysis to identify different writing styles and improve plagiarism detection methods.
Methodology:
The system includes data collection, preprocessing, feature extraction, dimensional reduction, machine learning models for clustering, and performance comparison using silhouette scores. Feature extraction focuses on lexical features, vocabulary richness, and readability scores. The study uses a small dataset of texts from various authors and employs algorithms like k-means, k-means++, hierarchical clustering, and DBSCAN for clustering.
Results:
Experiments show that the system effectively identifies writing styles, with silhouette scores indicating reasonable to strong clustering when k=2. As the number of clusters increases, the silhouette scores decrease, indicating a drop in accuracy. K-means and k-means++ perform similarly, while hierarchical clustering is less optimized.
Conclusion and Future Work:
The system works well for distinguishing writing styles with two clusters but becomes less accurate as the number of clusters increases. Future research could focus on adding more parameters and optimizing the methodology to improve accuracy with higher cluster values. This system can enhance existing plagiarism detection tools, especially in academic settings.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
Single-Switch Soft-Switched Boost Power Factor Corrector for Modular Applications
1. International Journal of Power Electronics and Drive Systems (IJPEDS)
Vol. 7, No. 2, June 2016, pp. 279 – 293
ISSN: 2088-8694 279
Single-Switch Soft-Switched Boost Power Factor Corrector for
Modular Applications
Toms A. Gonzlez*
, Daniel O. Mercuri*
, Hernn E. Tacca*
, and Mximo E. Pupareli**
*
Department of Electronics, Faculty of Engineering, University of Buenos Aires.
**
HT. S.A., Argentina.
Article Info
Article history:
Received Nov 14, 2015
Revised Feb 13, 2016
Accepted Feb 27, 2016
Keyword:
Power factor corrector
Boost converter
Soft-switching
Passive non-dissipative snubber
ABSTRACT
Modern dc power supplies provide power factor correction but the classical two-stage ap-
proach, using hard-switched preregulators, has detrimental effects on efficiency and reli-
ability, particularly for high power applications. With some circuit modifications and the
addition of a few magnetic components, diodes and capacitors, we have turned a classical
boost power factor corrector into a high efficiency soft-switched version. The proposed
converter turns on its single switch with zero current and turns it off with zero voltage. In
this paper we explain the proposed changes, we study the waveforms and equations and we
verify them with an experimental prototype. We also show how the converter can be used
for modular single- and three-phase high power applications.
Copyright c 2016 Institute of Advanced Engineering and Science.
All rights reserved.
Corresponding Author:
Toms A. Gonzlez.
Department of Electronics, Faculty of Engineering, UBA
Av. Paseo Coln 850, C1063ACV, Buenos Aires, Argentina.
Tel: +54 (11) 4343-0893 / 4343-0092
tgonzalez@fi.uba.ar
1. INTRODUCTION
Conventional power supplies exhibit low power factor and produce harmonic pollution of the mains. In
high power applications, passive filtering becomes nonviable due to the increasing size and weight of the required
components, such as low frequency line filters and capacitor banks. Nowadays, power electronic conversion techniques
facilitate the use of active power factor correction methods and circuits, known as PWM rectifiers [1].
The boost converter is one of the most used topologies in PWM rectifiers[2, 3, 4]. Single phase dc power
supplies are usually composed of the boost front-end or preregulator produces near unity power factor and an inter-
mediate high voltage bus and an isolated dc-dc converter to supply the desired output voltage regulation. At high
power, the efficiency of the front end is a key characteristic. Many high efficiency boost converters have been devel-
oped in the past using soft-switching techniques [5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16]; some of them use auxiliary
switches[5, 6, 7, 8, 9, 10, 11, 12], making them more complex and less reliable. Passive soft-switching techniques
combine higher reliability and simplicity of design [13, 14, 15]. The power supply manufacturer saves not only the
cost of auxiliary switches, but also the development of a specific integrated circuit to drive them [17].
Modularization is an attractive technique for power converter manufacturers and users since it provides re-
dundancy, flexibility, reduction of manufacturing cost and time [18];it also applies to power supplies with power factor
correction. Paralleling single phase converters in order to get a higher power supply was shown in [19] with boost
converters. Several fields exist where this is a useful practice: single phase railway systems [20] or L1/L2 battery
chargers for plug-in electric and hybrid vehicles [21]. Another example of modularization are three-phase power
supplies manufactured from single phase modules [22, 9, 13].
This paper introduces a boost-derived preregulator with novel passive soft-switching networks and shows its
application to modular high power converters. Zero Voltage Switching (ZVS) at turn-off and Zero Current Switching
(ZCS) at turn-on provide a reduction in losses compared to a classic boost converter [1].
In Section 2. we present the proposed circuit and we make qualitative and quantitative analyses to derive its
principle of operation, waveforms and characterizing equations. Next, we describe the experimental results of a single
Journal Homepage: http://iaesjournal.com/online/index.php/IJPEDS
2. 280 ISSN: 2088-8694
DA
DB
CO
LB
LC
DD
DC
LS
Q
Load
CS
vac
DE
CSND
D2
VX
N1
D1
N2
(a) Schematic circuit.
DA
DB
LB
LC
DD
DC
LS Q
CS
DE
VX
vI
VO
vCS
vCE
iC
iLS
iLC
vLB
LM
iLM
(b) Simplified model with voltage and current reference direc-
tions.
Figure 1. Boost power factor corrector basic module.
module in Section 3.. Finally, in Section 4., we explain the considerations that should be accounted for in order to use
the converter in a modular approach.
2. BOOST PFC SOFT-SWITCHED MODULE AND ITS PRINCIPLE OF OPERATION.
Figure 1a shows the considered module. The circuit composed of D1, D2, and CSND acts as a lossless
snubber for diode DA; it allows the discharge of the stored energy remaining in the secondary leakage inductance of
inductor LB. DB, DC, DD, CS, LS and LC comprises the basic soft-switching networks. A voltage source, VX,
connected through diode DE enables the transistor to switch softly throughout the entire input voltage cycle. We will
discuss the need of this source, its implementation and value in the following sections.
The circuit is based on the tapped boost converter, with a transfer function given by:
VO
vI
=
1 + d(t)N2
N1
1 − d(t)
, (1)
which approximates the classical boost transfer function when N1 > N2 and still produces a step up characteristic.
Thus, it is possible to use boost PFC commercial controllers [23] with average current mode control [1] in order to
regulate the output voltage and make the input current follow the input voltage waveform.
The simplified circuital model of Figure 1b allows us to perform the following qualitative and quantitative
analyses of the switching process.
2.1. Qualitative analysis
If vI < VX, the circuit is in mode I. When the IGBT turn-off occurs, at t = t0, the circuit transitions from
the conduction state shown in Figure 2a to the first state of the turn-off process shown in Figure 2b. The inductance of
both LB and LC force diode DC to carry the magnetizing current. Starting from vI − vCS
(t0), vCE rises linearly due
to the constant current discharging of CS. In order to ensure zero voltage switching vCS
(t0) must be equal to vI.
At t = t1, vLB
reaches VO − vI and turns diode DA on. CS keeps discharging through LC and vCE further
rises (Figure2c) until vCE = VO and vCS
= vI − VO, at t = t2; DB turns on and LC discharges the stored energy to
the load (Figure2f). When iLC
= 0 A at t = t3, the turn-off ends and the state of Figure 2g starts.
After the switch turns on at t = t4, its current starts rising gradually due to LC; zero current switching occurs.
Simultaneously, the LC resonance of CS and LS inverts the polarity of vCS
(Figure2h). If VO − vI > vI, the diode
DC turns on before the complete discharge of LS, vCS
clamps at vI, and the state pictured in Figure 2j starts. The
previous condition is equivalent to vI < VO/2 and it is of paramount importance because it guarantees the starting
value of vCS
in the next switching cycle to produce the ZVS turn-off of the converter.
The purpose of the voltage source VX is to provide ZVS turn-off for vI > VO/2. The idea is to clamp the
voltage of CS to a value lower than vI, since diode DC will not be able to turn on. In order to clarify this, we will
explore mode II that occurs for vI > VX.
At t = t0, the transistor turns off and the converter enters the state shown in Figure 2d. In this mode, the
magnetizing current flows through DE and transfers energy to VX. As in mode I, vCE and vCS
start rising linearly but
vCS
(t0) should be equal to VX so as to ensure ZVS turn-off. At t = t1, the state pictured in Figure 2e starts: vLB
turns
IJPEDS Vol. 7, No. 2, June 2016: 279 – 293
3. IJPEDS ISSN: 2088-8694 281
2*
DA
DB
LB
LC
vI
DD
DC
LS
Q
CSDE
VX
VO
(a) ON state
DA
DB
LB
LC
vI
DD
DC
LS
Q
CSDE
VX
VO
(b) State A mode I
DA
DB
LB
LC
vI
DD
DC
LS
Q
CSDE
VX
VO
(c) State B mode I
DA
DB
LB
LC
vI
DD
DC
LS
Q
CSDE
VX
VO
(d) State A mode II
DA
DB
LB
LC
vI
DD
DC
LS
Q
CSDE
VX
VO
(e) State B mode II
DA
DB
LB
LC
vI
DD
DC
LS
Q
CSDE
VX
VO
(f) State C
DA
DB
LB
LC
vI
DD
DC
LS
Q
CSDE
VX
VO
(g) OFF state
DA
DB
LB
LC
vI
DD
DC
LS
Q
CSDE
VX
VO
(h) State D
DA
DB
LB
LC
vI
DD
DC
LS
Q
CSDE
VX
VO
(i) State E
DA
DB
LB
LC
vI
DD
DC
LS
Q
CSDE
VX
VO
(j) State F mode I
Figure 2. Operating states in mode I (vI < VX) and mode II (vI > VX).
DA on, taking the magnetizing current, and CS continues its charge through LC. The final state of turn-off, shown in
Figure 2f, starts at t2 when vCE = VO. DB turns on and LC discharges to the output as in mode I.
The ZCS turn-on process is similar as before and presented in Figures 2h and 2i. The difference is that the
last state is missing, because the resonant oscillation of vCS
lasts until DC turns off. vCS
reverts its polarity to VX,
the required value for ZVS turn-off to occur.
In order to guarantee ZVS for all values of input voltage, VX should take a value that introduces the circuit
to mode II if vI > VO/2:
VX ≤
VO
2
. (2)
If VX = VO/2, mode I occurs for vI < VO/2 and mode II for vI > VO/2. Selecting a smaller value for VX
produces an additional transfer of energy to this source when vI > VO/2. As this energy should be dissipated or sent
back to the source, it is important to minimize it by adopting VX = VO/2. This condition will be better explained in
the quantitative analysis of the following section.
The tapped boost configuration allows in both modes the discharge of the energy stored in LC at the end of
the switching cycle, thus providing ZCS turn-on.
Single-Switch Soft-Switched Boost Power Factor Corrector for Modular Applications (T.A. Gonzlez)
4. 282 ISSN: 2088-8694
2.2. Quantitative analysis: equations and waveforms
By considering that the switching frequency is much higher than the line frequency, we employ an approxi-
mately constant value of vI for each switching period. Also, we neglect output voltage ripple:vO VO constant.
The controller modulates the transistor duty-cycle d(t) to produce iLM
(t) IImax
|sin(ωt)|. As a result, we
regard iLM
as constant during the switching cycle, also neglecting the current ripple. We also neglect transistor and
diode voltage drops and parasitic capacitances.
2.2.1. Mode I
• t0 < t ≤ t1 (Figure2b): The solution for vCS
is
vCS
(t) = vCS
(t0) +
1
CS
t
t0
iCS
dτ = vCS
(t0) −
iLM
CS
(t − t0). (3)
The transistor voltage rises following
vCE(t) = vI − vCS
(t) = vI − vCS
(t0) +
iLM
CS
(t − t0), (4)
where the ZVS condition arises
vCE(t0) = 0 ⇐⇒ vCS
(t0) = vI, (5)
and it follows that
vCE(t) =
iLM
CS
(t − t0). (6)
During this time interval iC(t) = 0 and iLC
= iLM
, and because we consider iLM
almost constant consequently
vLC = 0. vLB
rises following the changes in vCS until diode DA turns on, reaching
vLB
(t1) = VO − vI =
N1 + N2
N1
vCS
(t1). (7)
Using this result and Equation (4) gives
vCS
(t1) = (VO − vI)
N1
N1 + N2
(8)
and
vCE
(t1) = vI −
N1
N1 + N2
(VO − vI), (9)
which we can solve for t1
iLM
CS
(t1 − t0) = vI −
N1
N1 + N2
(VO − vI). (10)
• t1 < t ≤ t2 (Figure2c): When diode DA turns on, the boost inductor imposes a voltage to the series connection
of LC and CS. CS charges resonantly according to
d2
vCS
dt2
+
1
LCCS
vCS
=
(vI − VO)
LCCS
N1
N1 + N2
(11)
with initial conditions
vCS
(t1) = (vI − VO)
N1
N1 + N2
, (12)
dvCS
dt
(t1) = −
iLM
CS
. (13)
We solve Equation (11) in order to find
vCS
(t) =
(vI − VO) N1
N1 + N2
− iLM
LC
CS
sin
t − t1
√
LCCS
(14)
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5. IJPEDS ISSN: 2088-8694 283
and
vCE
(t) =vI − (vI − VO)
N1
N1 + N2
+ iLM
LC
CS
sin
t − t1
√
LCCS
. (15)
The state evolves as calculated until DB turns on at time t2, when
vCE(t2) = VO, (16)
and
vCS
(t2) = vI − VO. (17)
We can solve Equation (16) for t2
iLM
LC
CS
sin
t2 − t1
√
LCCS
=
(VO − vI) N2
N1 + N2
. (18)
During this state iC = 0 and iLC
oscillates according to
iLC
(t) = −CS
dvCS
dt
= iLM
cos
t − t1
√
LCCS
. (19)
• t2 < t ≤ t3 (Figure2f): Through the clamping action of DB, the energy stored in LC transfers to the output at
constant voltage
iLC
(t) = iLC
(t2) +
1
LC
t
t2
(vI − VO)
N2
N1 + N2
dτ = iLM
cos
t2 − t1
√
LCCS
−
(VO − vI)N2
N1 + N2
(t − t2)
LC
(20)
Meanwhile, iC(t) = 0, vCE(t) = VO, and vCS
(t) = vI − VO. This state ends at t3, when DB turns off;
iLC
(t3) = 0. We find t3 using
iLM
cos
t2 − t1
√
LCCS
−
(VO − vI)N2
N1 + N2
(t3 − t2)
LC
= 0. (21)
• t3 < t ≤ t4 (Figure2g). This interval corresponds to the conventional off state of a tapped boost.
• t4 < t ≤ t5 (Figure2h): Transistor Q turns on and its current has two components
iC(t) = iLS
(t) + iLC
(t). (22)
We find the first component solving the differential equation
d2
vCS
dt2
+
1
LSCS
vCS
= 0, (23)
vCS
(t4) = vI − VO, (24)
dvCS
dt
(t4) = 0, (25)
which results in
vCS
(t) = (vI − VO) cos
t − t4
√
LSCS
, (26)
and lets us compute
iLS
(t) = (vI − VO)
CS
LS
sin
t − t4
√
LSCS
. (27)
Simultaneously, LC starts taking the boost inductor current at constant voltage:
iLC
(t) = iLC
(t4) +
1
LC
t
t4
vI −
(vI − VO) N1
N1 + N2
dτ =
1
LC
vI − (vI − VO)
N1
N1 + N2
(t − t4). (28)
Single-Switch Soft-Switched Boost Power Factor Corrector for Modular Applications (T.A. Gonzlez)
6. 284 ISSN: 2088-8694
This state ends when LC takes the output current, the whole magnetizing current of the tapped boost inductor,
and DA turns off
iLC
(t5) = iLM
=
1
LC
vI −
(vI − VO) N1
N1 + N2
(t5 − t4). (29)
In practice, we have built LC as a swinging inductor in order to provide a greater inductance for low currents,
at the beginning of the turn-on process. At higher currents, the ungapped part of the core saturates, and the
inductance reduces. This structure lets us use a smaller core than a non-saturable inductor would require. It can
also prevent the destruction of the inductor due to excessive heat dissipation if a fully saturable core were to be
used: the non-saturable mass of the core acts as a heat sink if only the partial gap material is saturable. As a
result, the current does not rise linearly as stated in Equation (28).
• t5 < t ≤ t6 (Figure2i): The state evolves with current iLS
oscillating according to Equation (27) until diode
DC turns on, when vCS
= vI. To find t6 we solve
vI = (vI − VO) cos
t6 − t4
√
LSCS
, (30)
which has a solution only if VO − vI > vI, and leads to the condition
vI < VO/2. (31)
If VX and DE were not present, ZVS turn-off would not be possible for vI > VO/2: the voltage of CS would
not be clamped to vI at the end of this state, but to VO − vI > vI and the additional voltage would produce a
hard turn-off in the following switching cycle. If we somehow fix VX = VO/2, DE would turn on for values of
vI larger than VO/2, instead of DC, and vCS
would be clamped to VO/2. This situation corresponds to mode
II.
• t6 < t ≤ t7 (Figure2j): The remaining energy stored in LS discharges at constant voltage vI
iLS
(t) = iLS
(t6) −
1
LS
t
t6
vIdτ = (VO − vI)
CS
Ls
sin
t6 − t4
√
LSCS
−
vI
LS
(t − t6). (32)
It ends when diodes DC and DD turn-off, at t7, found from iLS
(t7) = 0
(VO − vI)
CS
Ls
sin
t6 − t4
√
LSCS
−
vI
LS
(t7 − t6) = 0. (33)
• t7 < t ≤ TS + t0 (Figure2a) ON-State.
The previously derived waveforms of vCE, iC, vCS
, iLC
, and iLS
are depicted in Figure 3.
2.2.2. Mode II
As previously derived, we choose VX = VO/2. This will be considered for the following theoretical analysis
and waveform derivations.
• t0 < t ≤ t1 (Figure2d): The solution for vCS
is
vCS
(t) = vCS
(t0) +
1
CS
t
t0
iCS
dτ = vCS
(t0) −
iLM
CS
(t − t0). (34)
The transistor voltage rises following
vCE(t) =
VO
2
− vCS
(t) =
VO
2
− vCS
(t0) +
iLM
CS
(t − t0), (35)
where the ZVS condition arises
vCE(t0) = 0 ⇐⇒ vCS
(t0) =
VO
2
, (36)
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7. IJPEDS ISSN: 2088-8694 285
t
vCE
t0 t1 t2 t3
VO
vI N2+VON1
N1+N2
iC
t
vCS
t
iLC
t
vI
N1(vI −VO)
N1+N2
vI − N1(vI −VO)
N1+N2
vI − VO
iLS
t
t4
t5
t6
t7
(VO − vI) CS
LS
iLM
+ (VO − vI) CS
LS
iLM
iLM
ONStates A B C OFF DE F
Figure 3. Main voltage and current waveforms for a mode I switching cycle. A dashed line shows a better approxima-
tion to the real waveforms, including the current ripple of iC.
and it follows that
vCE(t) =
iLM
CS
(t − t0). (37)
During this time interval iC(t) = 0 and iLC
= iLM
, and because we consider iLM
almost constant consequently
vLC = 0. vLB
rises following the changes in vCS until diode DA turns on, reaching
vLB
(t1) = VO − vI = −
N1 + N2
N1
VO
2
− vI − vCS
(t1) . (38)
Using this result and Equation (35) gives
vCS
(t1) =
VO
2
− vI − (VO − vI)
N1
N1 + N2
, (39)
and
vCE
(t1) = vI +
N1
N1 + N2
(VO − vI), (40)
which we can solve for t1
iLM
CS
(t1 − t0) = vI +
N1
N1 + N2
(VO − vI). (41)
• t1 < t ≤ t2 (Figure2e): When diode DA turns on, the boost inductor imposes a voltage to the series connection
of LC and CS. CS charges resonantly according to
d2
vCS
dt2
+
1
LCCS
vCS
=
1
LCCS
VO
2
− vI − (VO − vI)
N1
N1 + N2
(42)
with initial conditions
vCS
(t1) =
VO
2
− vI − (VO − vI)
N1
N1 + N2
, (43)
dvCS
dt
(t1) = −
iLM
CS
. (44)
Single-Switch Soft-Switched Boost Power Factor Corrector for Modular Applications (T.A. Gonzlez)
8. 286 ISSN: 2088-8694
We can solve Equation (42) in order to find
vCS
(t) =
VO
2
− vI − (VO − vI)
N1
N1 + N2
− iLM
LC
CS
sin
t − t1
√
LCCS
, (45)
and
vCE
(t) =vI + (VO − vI)
N1
N1 + N2
+ iLM
LC
CS
sin
t − t1
√
LCCS
. (46)
The state evolves as calculated until DB turns on at time t2, when
vCE(t2) = VO, (47)
and
vCS
(t2) =
VO
2
− VO = −
VO
2
. (48)
We can solve Equation (47) for t2
VO =vI + (VO − vI)
N1
N1 + N2
+ iLM
LC
CS
sin
t2 − t1
√
LCCS
. (49)
During this state iC = 0 and iLC
oscillates according to
iLC
(t) = −CS
dvCS
dt
= iLM
cos
t − t1
√
LCCS
. (50)
• t2 < t ≤ t3 (Figure2f): Through the clamping action of DB, the energy stored in LC transfers to the output at
constant voltage
iLC
(t) = iLC
(t2) +
1
LC
t
t2
(vI − VO)
N2
N1 + N2
dτ = iLM
cos
t2 − t1
√
LCCS
−
(VO − vI)N2
N1 + N2
(t − t2)
LC
. (51)
Meanwhile, iC(t) = 0, vCE(t) = VO, and vCS
(t) = −VO/2. This state ends at t3, when DB turns off;
iLC
(t3) = 0. We find t3 using
iLM
cos
t2 − t1
√
LCCS
− (VO − vI)
N2
N1 + N2
(t3 − t2)
LC
= 0. (52)
• t3 < t ≤ t4 (Figure2g) This interval corresponds to the conventional off state of a tapped boost.
• t4 < t ≤ t5 (Figure2h): Transistor Q turns on and its current has two components
iC(t) = iLS
(t) + iLC
(t). (53)
We find the first component solving the differential equation
d2
vCS
dt2
+
1
LSCS
vCS
= 0, (54)
vCS
(t4) = −
VO
2
, (55)
dvCS
dt
(t4) = 0, (56)
which results in
vCS
(t) = −
VO
2
cos
t − t4
√
LSCS
, (57)
and lets us compute
iLS
(t) =
VO
2
CS
LS
sin
t − t4
√
LSCS
. (58)
IJPEDS Vol. 7, No. 2, June 2016: 279 – 293
9. IJPEDS ISSN: 2088-8694 287
Table 1. Specifications and components of the experimental module.
Specification Value Device Value
PO 3 kW Q IRGP50B60PD1 (600 V/33 A)
vac 220 V/ 50 Hz DA HFA16TB120 (1200 V/16 A)
VO 500 V DB,C,D,1,2,3,5 MUR860 (600 V/8 A)
fS 70 kHz D4 1.5KE16
Simultaneously, LC starts taking current at constant voltage from the boost inductor
iLC
(t) = iLC
(t4) +
1
LC
t
t4
vI −
(vI − VO) N1
N1 + N2
dτ =
1
LC
vI − (vI − VO)
N1
N1 + N2
(t − t4). (59)
This state ends when LC takes the output current, the whole magnetizing current of the tapped boost inductor,
and DA turns off
iLC
(t5) = iLM
=
1
LC
vI −
(vI − VO) N1
N1 + N2
(t5 − t4). (60)
• t5 < t ≤ t6 (Figure2i): The state evolves with current iLS
oscillating according to Equation (58) until diode
DE turns off. We solve
0 =
VO
2
CS
LS
sin
t6 − t4
√
LSCS
, (61)
in order to find
t6 − t4 = π LSCS. (62)
Thus, capacitor CS ends charged with
vCS
(t6) =
VO
2
, (63)
which is the voltage needed in the next mode II turn-on switching to produce ZVS.
• t6 < t ≤ TS + t0 (Figure2a) ON-State.
The waveforms for this mode are similar to those pictured in Figure 3. The differences lie in the characteristic
values and in the iLS
(t) plot, which presents a complete resonant half cycle up to t6 instead of the linear discharge.
3. EXPERIMENTAL RESULTS
Figure 4 shows the complete schematic of the boost PFC module. In order to control the power factor
corrector, we used the UC3854 integrated circuit [24, 23], which implements average input current control [1]. The
controller provides both output voltage regulation and sinusoidal input current.
The input current is indirectly measured with current transformers CT1 and CT2 as proposed in [24]. Ex-
tra diodes D3 and transient voltage suppressor D4 were included to clamp overvoltages produced by CT2 leakage
inductance.
The voltage source VX is implemented as proposed in Figure 10b with a 47 µF capacitor, a 1 kΩ resistor and
diode D5, in order to return some of the energy to the input and improve the efficiency. The value of the clamp resistor
was experimentally adjusted to set the desired value of VX = VO/2, as we derived in Section 2..
Table 1 lists the complete specifications and significant components of the prototype. Figure 5 is a photograph
of the prototype and shows the relative sizing of the main inductive components.
3.1. Switching Waveforms
We have captured switch voltage and current waveforms for output powers of 1.5 kW (Figure6) and 3 kW
(Figure7). Both were measured near the peak input voltage. Some features that we described in the theoretical
waveforms of Figure 3 are present: the slowly rising current during turn-on, the resonant oscillation of capacitor CS
with inductor LS, and the linearly increasing voltage during turn-off.
Single-Switch Soft-Switched Boost Power Factor Corrector for Modular Applications (T.A. Gonzlez)
10. 288 ISSN: 2088-8694
DA
DB
LB
LC
DD
DC
LS
Q
Load
CS
vac
DE
CSND
D2
N1
D1
N2
.1 µF
.147 µF
47 µF
1 kΩ
UC3854
Vss
1 14
Ct
12
Rset Vg
16
Vref 9
PKLMT
2
CAout
3
Isens
4
MulOut
5
VsensVAout
7 11
Vcc
15
ENA
10
SS
13
8 Vrms
6
IAC
D5
D4
2.7 kΩ
330 kΩ
330 kΩ
470 µF
470 µF
1 µF
270 kΩ
270 kΩ
10 kΩ
4.7 kΩ
10 Ω
10 Ω
2.7 kΩ
22 Ω
2.2 nF
8.2 kΩ
1 µF
10 kΩ
270 pF
1.5 kΩ
10 µF
22 kΩ
10 µF
.1 µF
150 kΩ
680 kΩ
820 kΩ
180 kΩ
22 kΩ
.1 µF .47 µF 10 µF
1.5 nF
20 pF
20 nF
22 kΩ
6.8 kΩ
2.2 Ω
1.2 kΩ
1 nF
5.6 kΩ
47 nF
180 kΩ
2.2 kΩ
1 µF
4.7 kΩ
vO
vO
VREF
vP
VCC = +18 V
VCC
vP
VREF
vI
vI
vI
vG
vG
TIP31
TIP32
1N5819
1N5819
1N4740
1N4007
KBPC5010
D3
1N5819
1N5819
CT2
CT1
vI
(36)
22 nF
80 µH
250 µH
20 µH
(7)
Figure 4. Complete circuit schematic of the boost PFC module.
Figure 5. Photograph of the 3 kW prototype. The main inductive components are labeled.
Additional non-ideal features appear: IGBT tail current and transistor turn-off overvoltage in Figure 6c —
limited by the non-dissipative snubber of Figure 1a—, inductor current ripple and overdamped oscillation of switch
voltage after LC discharges (Figure6a).
Unmodeled parasitic components produce some of the features present in Figure 7a, which are not justified
in the theoretical waveforms of Figure 3 or observable in Figure 6a. For example, we added diodes D3 and D4 in
order to reach the final nominal power of 3 kW. These diodes were removed to measure the waveforms of Figure 6a.
IJPEDS Vol. 7, No. 2, June 2016: 279 – 293
11. IJPEDS ISSN: 2088-8694 289
(a) Full switching cycle. (b) Turn-on detail. (c) Turn-off detail.
Figure 6. Switch voltage vCE (A) and current iC (B). PO 1.5 kW. Diodes D3 and D4 disconnected.
(a) Full switching cycle. (b) Turn-on detail. (c) Turn-off detail.
Figure 7. Switch voltage vCE (A) and current iC (B). PO 3 kW.
93
93.5
94
94.5
95
95.5
500 1000 1500 2000 2500 3000 3500
Efficiency(η)[%]
Output power (PO) [W]
(a) Efficiency .
0.97
0.975
0.98
0.985
0.99
0.995
1
500 1000 1500 2000 2500 3000 3500
PF
Output power (PO) [W]
(b) Power factor.
Figure 8. Efficiency and power factor of the converter presented in Figure4 for varying output power.
Figure 6a presents the switch voltage superimposed with the switch current to show the switching transitions.
Figure 6b presents the detailed ZCS turn-on transition and Figure 6c the near ZVS turn-off. Despite the presence
of non-zero voltage during the turn-off transition, a piecewise-linear approximation to the waveforms allowed us to
estimate a reduction of 93.3% in turn-off losses, compared to the hard switching case. Figure 7 displays the same
waveforms and detailed transitions as in the previous case. The near ZVS turn-off is more evident for this output
power level (Fig. 7c).
3.2. Power factor and efficiency
Figure 8 presents the efficiency and power factor measurements made for various load conditions. The power
factor is higher than 0.975 (Figure8b) and the prototype attains efficiencies higher than 93% (Figure8a).
The input voltage and current waveforms are presented in Figure 9. Despite the presence of zero crossing
distortion, the power factor is at a peak value as depicted by Figure 8b.
Single-Switch Soft-Switched Boost Power Factor Corrector for Modular Applications (T.A. Gonzlez)
12. 290 ISSN: 2088-8694
Figure 9. Input voltage (A) and current (B) waveforms for PO 2 kW.
4. MODULAR SYSTEM CONFIGURATIONS
In order to employ the converter in modular designs, the energy extracted by the soft-switching cell has to
be redirected or dissipated; Figure 10 shows different options to manage the power extracted. The simplest method
is to dissipate the energy with a resistor, as shown in Figure 10a. This solution is inexpensive but compromises
the efficiency, which is not advisable for high power applications: the amount of dissipated heat requires forced air
cooling, reducing the reliability of the system. The second method is a variation of the first in which part of the energy
returns to the source and part is dissipated in the resistor (see Figure10b).
The third alternative in Figure 10c exploits part of the energy to power the auxiliary circuitry. It needs a
careful design in order to provide enough energy for all loads and it could be complementary of the previous two
methods.
The last option, in Figure 10d, is the most efficient method but also the most expensive. The idea is to transfer
the energy to the output using a boost converter. It is also the ideal solution for high power modular applications, where
a boost soft-switched module may provide regulation of the clamping voltage VX with high efficiency conversion.
However, the control of this module should be modified in order to regulate the input voltage to VX = VO/2 instead
of the output voltage.
The first three alternatives should be applied in a per module approach: each module must provide its resistor,
to even the distribution of heat among modules, and/or to power its auxiliary circuits, so as to avoid compromising
the reliability and to take advantage of redundancy. The last one is more adequate for fully modular systems: all the
VX outputs connect to the input of the auxiliary converter, which can be a classical boost converter or one of the soft-
switched module; this is interesting in the case of higher power applications, such as in locomotive power supplies or
electric car fast battery chargers.
5. CONCLUSION
We studied, constructed and tested a modified boost PFC with additional soft-switching passive networks
using a commercial integrated controller. The proposed converter exhibits lower switching losses than a classical boost
and power factor correction. The 3 kW prototype can integrate higher power multimodular single phase and three-
phase power supplies. The experimental evidence shows that the module has an efficiency greater than 93 % with near
unity power factor for several load conditions. Using ancillary recovery converter modules higher efficiencies could
be expected.
We have shown the need of a voltage source to produce ZVS turn-off for the whole input voltage cycle and
we have introduced a variety of schemes in order to provide it. The experimental converter dissipates the power
transferred to the voltage source in a resistor; the efficiency could increase if, instead of the resistor, an additional
converter transferred the energy to the output. This alternative becomes very attractive in higher power multimodular
applications, where one of the modules can fulfill this task.
ACKNOWLEDGMENT
The authors wish to acknowledge the different funding sources that allowed the completion of this work.
The 2014/17 UBACYT grant (20020130100840BA) equipped us with some of the instruments and provided materials
used in this work. A Fundacin YPF grant was used to obtain the digital wattmeter. A technology transfer agreement
signed between HT S.A. and the University of Buenos Aires granted materials, components, and student internship
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13. IJPEDS ISSN: 2088-8694 291
LOAD
Pi Plossr Plossm
Po
Pss
SS-BOOST
(a) Resistor
LOAD
Pi Plossr
SS-BOOST
Plossm
Pss
Po
(b) Resistor and input
LOAD
SS-BOOST
PoPi
AUX
Pss
Plossm
Plossr
(c) Power the auxiliary circuitry
LOAD
SS-BOOST
PoPi
DC/DCPss
Plossm
PlossDC/DC
Plossr
PoDC/DC
(d) Transfer to the output
Figure 10. Different methods to manage the power extracted by the soft-switching cell.
salaries. The work of T. A. G. was sponsored by a scholarship from CONICET.
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BIOGRAPHIES OF AUTHORS
Toms A. Gonzlez was born in Buenos Aires, Argentina, in 1983. He received the B.E. degree in
electrical engineering from the University of Buenos Aires in 2010 and he is currently working
towards his Ph.D.. Since 2007, he has been instructor at the Department of Electrical Engineering
in the areas of Basic Electronics and Control Theory. His main research interests are power factor
correction, SMPS, and LED lighting.
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15. IJPEDS ISSN: 2088-8694 293
Daniel O. Mercuri was born in Buenos Aires, Argentina in 1980. He received the B.E. degree in
electrical engineering from the University of Buenos Aires in 2015. His research and development
interests are soft-switched conversion, high voltage power supplies and high efficiency power con-
verters. He currently works with the National Comission of Atomic Energy (CNEA) to develop
high-voltage switching power supplies.
Hernn E. Tacca was born in Argentina on December 15, 1954. He received the B.E. degree in
electrical engineering from the University of Buenos Aires (Argentina), in 1981 and the M.S. and
Ph.D. degrees from the University of Sciences and Technologies of Lille (France) in 1988 and 1993
, respectively. In 1998 he received the Doctorate degree from the University of Buenos Aires.
Since 1984 , he has been with the Faculty of Engineering of the University of Buenos Aires, where
he is currently Assistant Professor and engaged in teaching and research in the areas of industrial
electronics. His research interest are in the field of SMPS, UPS, battery chargers, soft-switching
techniques and microcontroller control of power converters.
Mximo E. Pupareli was born in Argentina on April 15, 1941. He received the B.E. in electrical
engineering from the University of Tucumn (Argentina) in 1867. He has worked as Professor in
the area of Electronic Materials Technology and as developer in the Institute of Space Physics and
Astronomy (CONICET). From 1975 to 1985 he was Vice Director at the Institute of Space Physics
and Astronomy. Since 1985, he has been involved exclusively in the business activities in the field
of development and manufacturing of electronic devices at H.T. S.A..
Single-Switch Soft-Switched Boost Power Factor Corrector for Modular Applications (T.A. Gonzlez)