This document discusses the implementation of a PI controller for a fourth order resonant power converter with a capacitive output filter. It begins by introducing the LCLC resonant converter topology, which employs more resonant elements and has desirable features for high voltage conversion. It then presents the mathematical model of the LCLC converter using state space equations. Finally, it discusses using a PI controller in a closed loop control scheme for the resonant converter to provide better voltage regulation under dynamic load conditions.
Comparators are basic building elements for designing modern analog and mixed signal systems. Speed and resolution are two important factors which are required for high speed applications. This paper presents a design for an on chip high-speed dynamic latched comparator for high frequency signal digitization. The dynamic latched comparator consists of two cross coupled inverters comprising a total of 9 MOS transistors. The measured and simulation results show that the dynamic latched comparator design has higher speed, low power dissipation and occupying less active area compared to double tail latched and preamplifier based clocked comparators. A new fully dynamic latched comparator which shows lower offset voltage and higher load drivability than the conventional dynamic latched comparators has been designed. With two additional inverters inserted between the input-stage and output-stage of the conventional double-tail dynamic comparator, the gain preceding the regenerative latch stage was improved and the complementary version of the output-latch stage, which has bigger output drive current capability at the same area, was implemented.
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.
Comparators are basic building elements for designing modern analog and mixed signal systems. Speed and resolution are two important factors which are required for high speed applications. This paper presents a design for an on chip high-speed dynamic latched comparator for high frequency signal digitization. The dynamic latched comparator consists of two cross coupled inverters comprising a total of 9 MOS transistors. The measured and simulation results show that the dynamic latched comparator design has higher speed, low power dissipation and occupying less active area compared to double tail latched and preamplifier based clocked comparators. A new fully dynamic latched comparator which shows lower offset voltage and higher load drivability than the conventional dynamic latched comparators has been designed. With two additional inverters inserted between the input-stage and output-stage of the conventional double-tail dynamic comparator, the gain preceding the regenerative latch stage was improved and the complementary version of the output-latch stage, which has bigger output drive current capability at the same area, was implemented.
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.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
International Journal of Engineering Research and Development is an international premier peer reviewed open access engineering and technology journal promoting the discovery, innovation, advancement and dissemination of basic and transitional knowledge in engineering, technology and related disciplines.
Speed Control Of Separately Excited Dc Motor Using A High Efficiency Flyback ...IJERA Editor
This paper deals with Speed control of separately excited DC motor using flyback converter with a new non complementary active clamp control method to achieve soft switching and high efficiency for heavy motor load and light load conditions. This is quite attractive for low power application with universal ac inputs, such as external adaptors. With the proposed control technique, the energy in the leakage inductance can be fully recycled. The soft switching can be achieved for the main switch and the absorbed leakage energy is transferred to the output and input side. In the Proposed model the resistive and DC motor is connected to flyback converter and it is simulated with different nominal voltages and rated speed is controlled at different levels for the N-type active clamp flyback converter and P-type active clamp flyback converter respectively. N-type active clamp flyback converter is suitable for high speed variation applications and P-type active clamp flyback converter is suitable for low speed variation applications.
Design Topology of Low Profile Transformer forSlim AdaptorIJRES Journal
This paper presents the implementation of a topologyfor low profile transformer using an LLC
resonant converter. A new structure of the slim-type transformer is proposed, which is composed of copper wire
as the primary winding and printed circuit-board winding on the outer layer as the secondary winding.The
proposed circuit operates at high switching frequency to increase power density. The proposed structure is
suitable for a slim and high-efficiency converter because it has advantages of easy utilization and wide
conductive cross-sectional area. In addition, the voltage-doubler rectifier is applied to the secondary side due to
its simple structure of secondary winding, and a CLC filter is adopted to reduce the output filter size.The
specification are to design input voltage 400v,power 120w with 17ms hold time.
Implementation of Full-Bridge Single-Stage Converter with Reduced Auxiliary C...IJERA Editor
The inclusion of a few additional diodes and passive elements in the high-frequency full-bridge ac–dc converter with galvanic isolation permits one to achieve sinusoidal input-current wave shaping and output-voltage regulation simultaneously without adding any auxiliary transistors. Recently, this procedure, together with an appropriate control process, has been used to obtain low-cost high-efficiency single-stage converters. In an attempt to improve the performance of such converters, this paper introduces three new single-stage full-bridge ac–dc topologies with some optimized characteristics and compares them with the ones of the existing full-bridge single-stage topologies. The approach used consists in the definition of the operating principles identifying the boost function for each topology, their operating limits, and the dependence between the two involved conversion processes. Experimental results for each topology were obtained in 500-W modular voltage disturbances that result from the input-current wave-shaping process.
This paper presents a study on a new full bridge series resonant converter (SRC) with wide zero voltage switching (ZVS) range, and higher output voltage. The high frequency transformer is connected in series with the LC series resonant tank. The tank inductance is therefore increased; all switches having the ability to turn on at ZVS, with lower switching frequency than the LC tank resonant frequency. Moreover, the step-up high frequency (HF) transformer design steps are introduced in order to increase the output voltage to overcome the gain limitation of the conventional SRC. Compared to the conventional SRC, the proposed converter has higher energy conversion, able to increase the ZVS range by 36%, and provide much higher output power. Finally, the a laboratory prototypes of the both converters with the same resonant tank parameters and input voltage are examined based on 1 and 2.2 kW power respectively, for veryfing the reliability of the performance and the operation principles of both converters.
This paper presents a phase shifted series resonant converter with step up high frequency transformer to achieve the functions of high output voltage, high power density and wide range of Zero Voltage Switching (ZVS). In this approach, the output voltage is controlled by varying the switching frequency. The controller has been designed to achieve a good stability under different load conditions. The converter will react to the load variation by varying its switching frequency to satisfy the output voltage requirements. Therefore in order to maintain constant output voltage, for light load (50% of the load), the switching frequency will be decreased to meet the desired output, while for the full load (100%) conditions, the switching frequency will be increased. Since the controlled switching frequency is limited by the range between the higher and lower resonant frequencies , the switches can be turned on under ZVS. In this study, a laboratory experiment has been conducted to verify the effectiveness of the system performance.
SIMULATION ANALYSIS OF CLOSED LOOP DUAL INDUCTOR CURRENT-FED PUSH-PULL CONVER...Journal For Research
The current electronic devices require DC power source, which is taken from a battery or DC power supply. DC-DC converter is utilized to get regulated dc voltage from unregulated one. Switched mode power supply (SMPS) are commonly used in industrial applications, because of more advantages compared to linear power supply. In SMPS we have isolated and non-isolated converters, where isolated converters are frequently used, in order to get more voltage with multiple outputs. So among different isolated converters, push-pull converter is chosen for micro converter applications to obtain high voltage conversion ratio by using HF transformer, due to their better utilization of transformer. New methodology of control is implemented for making ZVS and ZCS at same time and to reduce the number of switches in the secondary side of dual inductor CFPP converter, which is a voltage doubler circuit. This becomes the solution for problem identification. Thus this converter with soft-switching reduces the switching losses.The current-fed push-pull converters are used in many applications like photo-voltaic (PV) power converters for boosting the output voltage. Push-pull converter is chosen for micro converter applications, to obtain high voltage conversion ratio by using high frequency (HF) transformer, due to their better utilization of transformer. This deals with the design of dual inductor CFPP converter, where zero voltage switching (ZVS) and zero current switching (ZCS) is achieved for the primary side of the converter by using secondary switches. Primary side switches are controlled by closed loop control topology. The secondary side is made with voltage doubler to obtain high voltage. Open loop and closed loop control of dual inductor current fed push pull converter simulation is finished by MATLAB/SIMULINK and their outcomes are analyzed.
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.
Fuzzy Logic Controller Based High Frequency Link AC-AC Converter For Voltage ...IJTET Journal
Abstract—In this paper, an advanced high frequency link AC-AC Push-pull cycloconverter for the voltage compensation is proposed in order to maintain the power quality in electric grid. The proposed methodology can be achieve arbitrary output voltage without using large energy storage elements. So that the system is more steadfast and less costly compared with the conventional inverter topology. Additionally, the proposed converter does not contain any line frequency transformer, which reduces the cost further. The control scheme for the push pull cycloconverter employs the fuzzy logic controller based sinusoidal pulse width modulation (SPWM) to accomplish better performance on voltage compensation, like unbalanced voltage harmonics elimination. The simulation results are given to show the effectiveness of the proposed high frequency link AC-AC converter and fuzzy logic controller based SPWM technology
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.
A Five – Level Integrated AC – DC ConverterIJTET Journal
This paper presents the implementation of a new five – level integrated AC – DC converter with high input power factor and reduced input current harmonics complied with IEC1000-3-2 harmonic standards for electrical equipments. The proposed topology is a combination of boost input power factor pre – regulator and five – level DC – DC converter. The single – stage PFC (SSPFC) approach used in this topology is an alternative solution to low – power and cost – effective applications.
This paper proposed a new sparce matrix converter with Z-source network to provide unity voltage transfer ratio. It is an ac-to-ac converter with diode-IGBT bidirectional switches. The limitations of existing matrix converter like higher current THD and less voltage transfer ratio issues are overcome by this proposed matrix converter by inserting a Z-source. Due to this Z-source current harmonics are totally removed. The simulation is performed for different frequencies. The simulation results are presented to verify the THD and voltage transfer ratio and compared with the existing virtual AC/DC/AC matrix converter. The experimental output voltage amplitude can be varied with the variable frequencies.
Small Signal Modelling of a Buck Converter using State Space Averaging for Ma...paperpublications3
Abstract: Nowadays, step-down power converters such as buck scheme are widely employed in a variety of applications such as power supplies, spacecraft power systems, hybrid vehicles and power supplies in particle accelerators. This paper presents a comprehensive small-signal model for the DC-DC buck converter operated under Continuous Conduction Mode (CCM) for a magnetic load. Initially, the buck converter is modeled using state-space average model and dynamic equations, depicting the converter, are derived. The proposed model can be used to design powerful, precise and robust closed loop controller that can satisfy stability and performance conditions of the DC-DC buck regulator. This model can be used in any DC-DC converter (Buck, Boost, and Buck-Boost) by modifying the converter mathematical equations.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
International Journal of Engineering Research and Development is an international premier peer reviewed open access engineering and technology journal promoting the discovery, innovation, advancement and dissemination of basic and transitional knowledge in engineering, technology and related disciplines.
Speed Control Of Separately Excited Dc Motor Using A High Efficiency Flyback ...IJERA Editor
This paper deals with Speed control of separately excited DC motor using flyback converter with a new non complementary active clamp control method to achieve soft switching and high efficiency for heavy motor load and light load conditions. This is quite attractive for low power application with universal ac inputs, such as external adaptors. With the proposed control technique, the energy in the leakage inductance can be fully recycled. The soft switching can be achieved for the main switch and the absorbed leakage energy is transferred to the output and input side. In the Proposed model the resistive and DC motor is connected to flyback converter and it is simulated with different nominal voltages and rated speed is controlled at different levels for the N-type active clamp flyback converter and P-type active clamp flyback converter respectively. N-type active clamp flyback converter is suitable for high speed variation applications and P-type active clamp flyback converter is suitable for low speed variation applications.
Design Topology of Low Profile Transformer forSlim AdaptorIJRES Journal
This paper presents the implementation of a topologyfor low profile transformer using an LLC
resonant converter. A new structure of the slim-type transformer is proposed, which is composed of copper wire
as the primary winding and printed circuit-board winding on the outer layer as the secondary winding.The
proposed circuit operates at high switching frequency to increase power density. The proposed structure is
suitable for a slim and high-efficiency converter because it has advantages of easy utilization and wide
conductive cross-sectional area. In addition, the voltage-doubler rectifier is applied to the secondary side due to
its simple structure of secondary winding, and a CLC filter is adopted to reduce the output filter size.The
specification are to design input voltage 400v,power 120w with 17ms hold time.
Implementation of Full-Bridge Single-Stage Converter with Reduced Auxiliary C...IJERA Editor
The inclusion of a few additional diodes and passive elements in the high-frequency full-bridge ac–dc converter with galvanic isolation permits one to achieve sinusoidal input-current wave shaping and output-voltage regulation simultaneously without adding any auxiliary transistors. Recently, this procedure, together with an appropriate control process, has been used to obtain low-cost high-efficiency single-stage converters. In an attempt to improve the performance of such converters, this paper introduces three new single-stage full-bridge ac–dc topologies with some optimized characteristics and compares them with the ones of the existing full-bridge single-stage topologies. The approach used consists in the definition of the operating principles identifying the boost function for each topology, their operating limits, and the dependence between the two involved conversion processes. Experimental results for each topology were obtained in 500-W modular voltage disturbances that result from the input-current wave-shaping process.
This paper presents a study on a new full bridge series resonant converter (SRC) with wide zero voltage switching (ZVS) range, and higher output voltage. The high frequency transformer is connected in series with the LC series resonant tank. The tank inductance is therefore increased; all switches having the ability to turn on at ZVS, with lower switching frequency than the LC tank resonant frequency. Moreover, the step-up high frequency (HF) transformer design steps are introduced in order to increase the output voltage to overcome the gain limitation of the conventional SRC. Compared to the conventional SRC, the proposed converter has higher energy conversion, able to increase the ZVS range by 36%, and provide much higher output power. Finally, the a laboratory prototypes of the both converters with the same resonant tank parameters and input voltage are examined based on 1 and 2.2 kW power respectively, for veryfing the reliability of the performance and the operation principles of both converters.
This paper presents a phase shifted series resonant converter with step up high frequency transformer to achieve the functions of high output voltage, high power density and wide range of Zero Voltage Switching (ZVS). In this approach, the output voltage is controlled by varying the switching frequency. The controller has been designed to achieve a good stability under different load conditions. The converter will react to the load variation by varying its switching frequency to satisfy the output voltage requirements. Therefore in order to maintain constant output voltage, for light load (50% of the load), the switching frequency will be decreased to meet the desired output, while for the full load (100%) conditions, the switching frequency will be increased. Since the controlled switching frequency is limited by the range between the higher and lower resonant frequencies , the switches can be turned on under ZVS. In this study, a laboratory experiment has been conducted to verify the effectiveness of the system performance.
SIMULATION ANALYSIS OF CLOSED LOOP DUAL INDUCTOR CURRENT-FED PUSH-PULL CONVER...Journal For Research
The current electronic devices require DC power source, which is taken from a battery or DC power supply. DC-DC converter is utilized to get regulated dc voltage from unregulated one. Switched mode power supply (SMPS) are commonly used in industrial applications, because of more advantages compared to linear power supply. In SMPS we have isolated and non-isolated converters, where isolated converters are frequently used, in order to get more voltage with multiple outputs. So among different isolated converters, push-pull converter is chosen for micro converter applications to obtain high voltage conversion ratio by using HF transformer, due to their better utilization of transformer. New methodology of control is implemented for making ZVS and ZCS at same time and to reduce the number of switches in the secondary side of dual inductor CFPP converter, which is a voltage doubler circuit. This becomes the solution for problem identification. Thus this converter with soft-switching reduces the switching losses.The current-fed push-pull converters are used in many applications like photo-voltaic (PV) power converters for boosting the output voltage. Push-pull converter is chosen for micro converter applications, to obtain high voltage conversion ratio by using high frequency (HF) transformer, due to their better utilization of transformer. This deals with the design of dual inductor CFPP converter, where zero voltage switching (ZVS) and zero current switching (ZCS) is achieved for the primary side of the converter by using secondary switches. Primary side switches are controlled by closed loop control topology. The secondary side is made with voltage doubler to obtain high voltage. Open loop and closed loop control of dual inductor current fed push pull converter simulation is finished by MATLAB/SIMULINK and their outcomes are analyzed.
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.
Fuzzy Logic Controller Based High Frequency Link AC-AC Converter For Voltage ...IJTET Journal
Abstract—In this paper, an advanced high frequency link AC-AC Push-pull cycloconverter for the voltage compensation is proposed in order to maintain the power quality in electric grid. The proposed methodology can be achieve arbitrary output voltage without using large energy storage elements. So that the system is more steadfast and less costly compared with the conventional inverter topology. Additionally, the proposed converter does not contain any line frequency transformer, which reduces the cost further. The control scheme for the push pull cycloconverter employs the fuzzy logic controller based sinusoidal pulse width modulation (SPWM) to accomplish better performance on voltage compensation, like unbalanced voltage harmonics elimination. The simulation results are given to show the effectiveness of the proposed high frequency link AC-AC converter and fuzzy logic controller based SPWM technology
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.
A Five – Level Integrated AC – DC ConverterIJTET Journal
This paper presents the implementation of a new five – level integrated AC – DC converter with high input power factor and reduced input current harmonics complied with IEC1000-3-2 harmonic standards for electrical equipments. The proposed topology is a combination of boost input power factor pre – regulator and five – level DC – DC converter. The single – stage PFC (SSPFC) approach used in this topology is an alternative solution to low – power and cost – effective applications.
This paper proposed a new sparce matrix converter with Z-source network to provide unity voltage transfer ratio. It is an ac-to-ac converter with diode-IGBT bidirectional switches. The limitations of existing matrix converter like higher current THD and less voltage transfer ratio issues are overcome by this proposed matrix converter by inserting a Z-source. Due to this Z-source current harmonics are totally removed. The simulation is performed for different frequencies. The simulation results are presented to verify the THD and voltage transfer ratio and compared with the existing virtual AC/DC/AC matrix converter. The experimental output voltage amplitude can be varied with the variable frequencies.
Small Signal Modelling of a Buck Converter using State Space Averaging for Ma...paperpublications3
Abstract: Nowadays, step-down power converters such as buck scheme are widely employed in a variety of applications such as power supplies, spacecraft power systems, hybrid vehicles and power supplies in particle accelerators. This paper presents a comprehensive small-signal model for the DC-DC buck converter operated under Continuous Conduction Mode (CCM) for a magnetic load. Initially, the buck converter is modeled using state-space average model and dynamic equations, depicting the converter, are derived. The proposed model can be used to design powerful, precise and robust closed loop controller that can satisfy stability and performance conditions of the DC-DC buck regulator. This model can be used in any DC-DC converter (Buck, Boost, and Buck-Boost) by modifying the converter mathematical equations.
Soil-transmitted helminth infections in relation to the knowledge and practic...IOSR Journals
The relationship between soil-transmitted helminth infections and the knowledge and practice of preventive measures among school children in rural communities in Igbo-Eze South Local Government Area of Enugu State, South-Eastern Nigeria, was investigated. Stool samples were obtained from 1,296 school children (ages 4 – 15 years) from six schools randomly selected from the study area. Structured epidemiological questionnaires were administered to the children. Out of 1,296 school children examined, 106 (8.1 %) of the children were infected by soil-transmitted infections thus: 64 (4.9 %) with Ascarislumbricoides, 33 (2.5 %) with hookworm, and 9 (0.7 %) with Trichuristrichiura. There were significant differences in the prevalence of these infections (P < 0.05). Soil-transmitted helminth infections showed statistically significant (P < 0.05) relationships with knowledge and practice of preventive measures among school children in the study area. The study revealed that soil-transmitted helminth infections were abundant among school children of the study area, indicating the necessity of implementing control measures such as chemotherapy, provision of adequate sanitary facilities and safe drinking water.
Bryophyllum Pinnatum: A Potential Attenuator of Cadmium-Induced Oxidative Str...IOSR Journals
Cadmium has been famously implicated in the stimulation of free radical production in biosystems resulting in oxidative deterioration of lipids, proteins and DNA, and initiating various pathological conditions in humans and animals. This study therefore, examined the antidotal and ameliorative capacity of crude ethanolic extract of Bryophyllum pinnatum on cadmium-induced oxidative stress using rabbit models. A total of fifteen rabbits (1.30±0.05kg) were used for the study. After two weeks of acclimatization, the rabbits were randomly rifted into three experimental groups- (N, CD & CB) with five animals per group. The control group (N) was injected normal saline intraperitoneally (3mg/kg body weight) and the test groups (CD & CB) were administered cadmium once daily by subcutaneous injection (3mg/kg body weight). The ethanolic extract of the plant was orally administered once daily at a dose of 100mg/kg body weight. The oxidative and antioxidative stress parameters were assessed in tissues. The results showed significant difference (p˂ 0.05)in treated groups relative to the control group with the exception of glutathione peroxidase activity in leg muscles. Therefore, the results obtained in this study confirmed the potency of the plant to annihilate cadmium toxicity in animals
To study the factors effecting sales of leading tractor brands in Haryana (In...IOSR Journals
Every aspect of the economic life in India is influenced by the agriculture. Agriculture contributes nearly 32% of the national income of India and it offers live hood nearly 70% of the total population and the agriculture is influenced by the tractors industry. Tractor industry plays an important role on the development of agriculture. Indian tractor market is very complex so marketer must care in analysing consumer behaviour. Green Revolution in India had its origin in northern India where Haryana is situated. Thus Haryana’s Contribution to Green Revolution in India is the maximum, In 1966-67 production of food grains in Haryana was 2090 thousand tones. In 1970-71 it increased to 3939 thousand tones and in 1994-2000 it further rose to 131 lakh tones, all this due to the development of tractor manufacturing industries like FARMTRAC, HMT, EICHER, TAFE etc. Present work covers studying sales of different tractor brands in Haryana (India) and how various brands have become the choice of agriculturist on the basis of getting experienced by others. The best brand so for is found to be FARMTRAC by agriculturist by the recommendation of relatives who have experinecd the same. It was depicted from the studies that farmers purchasing tractors by recommendations of relatives are not much educated.
The electronic band parameters calculated by the Triangular potential model f...IOSR Journals
This work reports on theoretical investigation of superlattices based on Cd1-xZnxS quantum dots
embedded in an insulating material. This system, assumed to a series of flattened cylindrical quantum dots with
a finite barrier at the boundary, is studied using the triangular potential. The electronic states and the effective
mass of 1 Γ miniband have been computed as a function of inter-quantum dot separation for different zinc
compositions. Calculations have been made for electrons, heavy holes and light holes. Results are discussed and
compared with those of the Kronig-Penney and sinusoidal potentials
International Refereed Journal of Engineering and Science (IRJES)irjes
The core of the vision IRJES is to disseminate new knowledge and technology for the benefit of all, ranging from academic research and professional communities to industry professionals in a range of topics in computer science and engineering. It also provides a place for high-caliber researchers, practitioners and PhD students to present ongoing research and development in these areas.
MODELLING OF 200W LED DRIVER CIRCUIT DESIGN WITH LLC CONVERTERJournal For Research
LED is a recent technology, which has replaced all other conventional light sources in the past few years and since it is current controlled, accurate driver design is necessary. The LED driver should have the capability of providing constant current regardless of the LED forward voltage variations. The LLC converter is controlled to operate as a constant current mode LED driver. A 100 kHz, 200W LLC LED driver is designed and calculated to verify the proposed circuit and design method. This paper proposes mathematical model of 200W LED driver circuit design with LLC resonant converter. The proposed circuit uses a full bridge rectifier to convert AC to DC and increases the rectified output voltage using boost converter which is operated in continuous conduction mode and a quasi-half bridge resonant converter to drive the LED lamp load with coupling transformer. The LLC converter is designed such that solid state switches of quasi half bridge are working under zero switching scheme to reduce switching losses. The analysis, design and modelling of 200 W LED driver is carried out by mathematical model and stability analysis for universal AC mains.
International Journal of Engineering and Science Research. It is a international journal publishing high-quality articles dedicated to all aspects of engineering. IJESR is to publish peer reviewed research and review articles. fastly without delay in the developing field of engineering and science Research.
Various Resonant Converters for high voltage and high power applications have been designed. Different Topologies of LLC, LCC, and CLL Resonant Converters have been simulated and compared for the same input voltage. The simulation was done at a very high frequency. The Output Power and the Efficiency of all the three Resonant Converters were calculated.With the results, it has been proved that LCC Resonant Converters were very much suited to give an output voltage of around 62 Kilovolts with a output power of 20 kilowatts.
The FHA Analysis of Dual-Bridge LLC Type Resonant ConverterIAES-IJPEDS
The dual bridge resonant converter is designed in this paper. In this converter the LLC type resonance configuration is proposed. This types is compared with the other configurations and its benefits are narrated in this paper. The steady-state analysis of the LLC configuration is done using fundamental harmonics approximation method and the values for the components of resonance configuration is found and used for simulation. The simulation results shows that the converter is able to achieve the zero voltage switching for the wide load range and attains a good efficiency.
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.
The long established battery chargers are having many drawbacks such as prominent ripple charging current, less efficiency and bulky in size. To overcome these drawbacks of conventional battery charger, several charging circuits have been proposed and inevitability force to design a high-performance battery charger with small in size and improved efficiency. In this paper solar photovoltaic system based half-bridge series–parallel resonant converter (HBSPRC) charger is proposed for battery interface. The converter is designed to abolish low and high-frequency ripple currents and thus take full advantage of the life of secondary battery circuit. This is achieved by designing converter switches turn on at zero current and zero voltage with switching frequency greater than that of resonance frequency which leads to freewheeling diodes need not have very fast reverse-recovery characteristics. The performance of the power converters depends upon the control method adopted; in this work fuzzy logic controller is used for controlling the output voltage of HBSPRC. The fuzzy control scheme for the HBSPR converter has been designed and validated in hardware implementation of HBSPRC switching technique. From the results, it is found that the proposed battery charging system which reduces the switching loss and voltage stress across the power switches which increases the efficiency of the converter.
A Resonant Converter with LLC for DC-to-DC Converter Based ApplicationsIJMTST Journal
Conventional voltage mode control only offers limited performance for LLC series resonant DC-to-DC converters experiencing wide variations in operational conditions. When the existing voltage mode control is employed, the closed-loop performance of the converter is directly affected by unavoidable changes in power stage dynamics. Thus, a specific control design optimized at one particular operating point could become unacceptable when the operational condition is varied. This paper presents a new current mode control scheme which could consistently provide good closed-loop performance for LLC resonant converters for the entire operational range. The proposed control scheme employs an additional feedback from the current of the resonant tank network to overcome the limitation of the existing voltage mode control. The superiority of the proposed current mode control over the conventional voltage mode control is verified using an experimental 150 W LLC series resonant DC-to-DC converter.
This paper presents the simulation design of dc/dc interleaved boost converter with zero-voltage switching (ZVS). By employin the interleaved structure, the input current stresses to switching devices were reduced and this signified to a switching conduction loss reduction. All the parameters had been calculated theoretically. The proposed converter circuit was simulated by using MATLAB/Simulink and PSpice software programmes. The converter circuit model, with specifications of output power of 200 W, input voltage range from 10~60 V, and operates at 100 kHz switching frequency was simulated to validate the designed parameters. The results showed that the main switches of the model converter circuit achieved ZVS conditions during the interleaving operation. Consequently, the switching losses in the main switching devices were reduced. Thus, the proposed converter circuit model offers advantages of input current stress and switching loss reductions. Hence, based on the designed parameters and results, the converter model can be extended for hardware implementation.
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C010311320
1. IOSR Journal of Electrical and Electronics Engineering (IOSR-JEEE)
e-ISSN: 2278-1676,p-ISSN: 2320-3331, Volume 10, Issue 3 Ver. I (May – Jun. 2015), PP 13-20
www.iosrjournals.org
DOI: 10.9790/1676-10311320 www.iosrjournals.org 13 | Page
Implementation of PI controller for fourth order Resonant Power
Converter with capacitive output filter
R. Geetha1
, Dr.T.S. Sivakumaran2
1
(Research Scholar, Bharath University, Chennai, India)
2
(Dean PG Studies, Arunai College of Engineering, Tiruvannamalai, India)
Abstract: A closed loop control of the fourth order (LCLC configuration) resonant converter has been
simulated and presented in this paper. The PI controller has been used for closed loop operation and the
performance of proposed converter has been estimated with the closed loop and the open loop condition. The
steady state-transient responses of nominal load, sudden line and load disturbances have been obtained to
validate the controller performance. The proposed approach is expected to provide better voltage regulation for
dynamic load conditions.
Keywords: Resonant Power Converter, LCLC configuration, PI Controller, State Space analysis
I. Introduction
The increasing efforts on pushing to high power density and high efficiency DC/DC converter have
lead us to develop converters capable of operating at higher switching frequency with high efficiency. For this
reason, resonant converters have made lots of attentions due to high efficiency, high switching frequency and
high power density. The invention and evolution of various DC–DC resonant converters (RC) have been
focused for telecommunication and aerospace applications in the recent past. It has been set up that these
converters experience high switching loss, reduced reliability, increased electro-magnetic interference (EMI)
and high acoustic noise at high frequencies [1-12]. The LCLC resonant inverter is a forth order resonant
topology which has been successfully used in different industrial applications such as space power distribution
systems, resonant inverters, Ion generator power supplies, multi lamp operation ballasts, renewable energy
power conditioning systems, constant-current power supplies and dual-output resonant converters [13-19]. This
topology employs more parasitic elements and has many desirable features. Thus, it appears to be a serious
prospect for high voltage conversion [20-25]. The converter of this topology uses an inductive output filter
similar to a Parallel Resonant Converter (PRC) [1, 2]. In [12], [26] LCLC resonant converters with an LC output
filter are analyzed using the First Harmonic Approximation technique (FHA). In high voltage applications, a
resonant converter with a capacitive output filter is used, because the inductor in an output filter is bulky and
very difficult to fabricate [20]–[25].
II. Resonant Converters
Resonant converters contain resonant L-C networks whose voltage and current waveforms vary
sinusoidally during one or more subintervals of each switching period. The resonant network has the effect of
filtering higher harmonic voltages such that a nearly sinusoidal current appears at the input of the resonant
network [4]. There are three main types of resonant networks, which are shown in Fig. 1.
Ls
R
Input
DC
Output
DC
Cp
Ls
R
Input
DC
Output
DC
Cp
Cs
(a) (b) (c)
Fig. 1. Resonant networks: (a) Series Resonant; (b) Parallel Resonant; (c) Series- Parallel Resonant.
Series resonant, parallel resonant and series-parallel resonant [26]. Depending on how the resonant
networks are combined with other circuit configurations, one can obtain several types of resonant converters.
The more common configurations are: DC-to-high-frequency-AC inverters, resonant DC-DC converters and
resonant link converters. In this work, the focus will be on the resonant DC-DC converters.
CsLs
R
Input
DC
Output
DC
2. Implementation of PI controller for fourth order Resonant Power Converter with capacitive ….
DOI: 10.9790/1676-10311320 www.iosrjournals.org 14 | Page
A main advantage of resonant converters is the reduced switching losses. Resonant converters can run
in either the zero-current-switching (ZCS) or zero-voltage-switching (ZVS) mode [27]. That means that turn-on
or turn-off transitions of semiconductor devices can occur at zero crossings of tank voltage or current
waveforms, thus reducing or eliminating some of the switching loss mechanisms. Since the losses are
proportional to switching frequency, converters can operate at higher switching frequencies than comparable
PWM converters [28].
1. Series Parallel Resonant Converters (SPRC)
The closed loop control of series-parallel resonant DC-DC converter (LCLC) with capacitive output
filter is shown in Fig. 2.
Cf
G1
G2
G3
G4
DS1
DS2
DS3
DS4
A
B
Ideal
1:n
RL
D1
D2
D3
D4
Iout
Vdc
Vout
L1 L2
iL
C1
C2
PIPWM
Vref
DC/AC converter
Resonant Converter
(LCLC)
Diode Bridge
Rectifier
Load
+
-
Fig. 2 closed loop control of resonant converter with LCLC configuration
This converter has also been often used with inductive output filter [29], [4]. However, in the current
work the focus will be on the converter with capacitive output filter because this configuration is better suited
for high-voltage applications. Eq. (1) gives the voltage conversion ratio of the series-parallel resonant converter.
v
21
in
o
k
k4
nV
V
(1)
2
ep
2
N,s
2
ep
2
N,s
21
RC
1
1f.
RC
tan
11f1
1
k
2
sin27.01kv
Where
sp CC. - Ratio of the parallel to the series capacitor
θ - Output rectifier conduction angle
β - Phase displacement of the fundamentals of the voltage across the parallel
capacitor and the input current of the output rectifier
epRC - Dimensionless parameter
n - Transformer turns ratio
osN,s fff - Normalized switching frequency
fs - Switching frequency
1
Sso CL2f
- Series resonant frequency
This converter operates for low power close to the parallel resonant frequency (2π√LpCs)-1
) and for full
load, close to the series resonant frequency (2π√LsCs)-1
). The real resonant frequency of the circuit changes with
the load as shown in Fig.3. This happens because the load defines the influence of Cp on the resonant frequency.
For high load the resonant current flows for only a small part of the switching period through Cp. Thus, the
converter behaves as a series resonant converter and the resonant frequency is almost equal the series resonant
3. Implementation of PI controller for fourth order Resonant Power Converter with capacitive ….
DOI: 10.9790/1676-10311320 www.iosrjournals.org 15 | Page
frequency fo. On the other hand, for low load the resonant current flows almost the whole switching period
through Cp. Therefore, the converter behaves as a parallel resonant converter. When operating above resonance,
the converter behaves as a series resonant converter at lower frequencies (high load operation) and as a parallel
resonant converter at higher frequencies (low load operation) [30]. At higher switching frequencies the series
capacitance becomes so small that it behaves just as a DC blocking capacitance.
The resonant inductor then resonates with the parallel capacitor and the converter operates in the
parallel resonant mode [31]. By proper selection of the resonant elements, the series-parallel resonant converter
has better control characteristics than the resonant converters with only two resonant elements [32] being less
sensitive to component tolerances. This configuration aims to take advantage of the desirable characteristics of
the series and the parallel converter while reducing or eliminating their drawbacks. Unlike the series resonant
converter, the series-parallel resonant converter is capable of both step-up and step-down operation [33]. This
capability can be observed in the voltage conversion ratio curves of the series-parallel resonant converter as
shown in Fig. 3.
Fig. 3 Voltage conversion ratio of a series-parallel resonant converter independency on the load and on the
normalized switching frequency
The voltage conversion ratio curves also show that the output voltage can be regulated at no load. Thus,
the main disadvantage of the series resonant converter is successfully eliminated with this configuration. It is
important to note that the lower the value of the parallel resonant capacitor Cp the more the circuit will have the
characteristic of a series resonant converter. Therefore, the value of the parallel resonant capacitor Cp may not
be too low in order to permit that the converter takes the characteristic of the parallel resonant converter at light
load. When the resonant current flows for a long interval of the switching period through Cp (and this is the case
at light load operation), it is increased above the level expected in the series resonant converter, producing a
higher output voltage. Therefore the presence of Cp in combination with Ls results in boosting of the converter
output voltage at light load [33].
The main disadvantage of the parallel resonant converter, i.e. the high device current independent on
the load is supposed to be eliminated in the series-parallel resonant converter. Unfortunately this drawback
cannot be totally removed but, with the proper choice of the resonant elements, it can be considerably reduced
for certain load levels [29], [26]. The limiting factor in reducing Cp, to reduce circulating current is the upper
switching frequency limit. As the value of Cp gets lower relative to Cs, the ratio α = Cp/Cs also gets lower and
consequently the converter operating frequency range gets wider. As very high switching frequencies are not
desirable due to practical implementation limitations, one has to find a compromise between reducing the
circulating current for low loads and having a reasonable limit for the upper switching frequency. Normally one
designs the converter such that it operates essentially as a series resonant converter so that the circulating current
will decrease as the load decreases to a certain level. Below this level, the converter behaves like a parallel
resonant converter, and the circulating current no longer decreases with load [4]. Unfortunately, in the case of
high-voltage generation, where high voltage conversion ratio is required, the value of Cp cannot be significantly
reduced. Thus, the circulating current does not decrease considerably with the load and losses remain almost
unchanged.
4. Implementation of PI controller for fourth order Resonant Power Converter with capacitive ….
DOI: 10.9790/1676-10311320 www.iosrjournals.org 16 | Page
III. Modelling of LCLC Resonant Converter
The equivalent circuit of LCLC resonant converter is shown on in Fig.2. The mathematical model
using obtained assuming all the components to be ideal.
The state space equation for the proposed converter is given by
BUAXX (2)
Where,
2
2
1
1
vC
iL
vC
iL
dt
d
X ,
2
2
1
1
vC
iL
vC
iL
X ,
o
i
V
V
U
The state space equation for LCLC resonant converter is get from Fig.2.
1
1
1
i1
L
vC
L
V
m
dt
diL
(3)
21
1
1 iLiL
C
1
dt
dvC
21
2
2 vCvC
L
1
dt
diL
2
2
2
o2
C
iL
C
V
n
dt
dvC
From equations (2) and (3), we can get,
o
i
2
1
2
2
1
1
2
21
11
1
2
2
1
1
V
V
L
1
0
00
00
0
L
1
vC
iL
vC
iL
0
C
1
00
L
1
0
L
1
0
0
C
1
0
C
1
00
L
1
0
vC
iL
vC
iL
dt
d
(4)
From equation (4), we get,
,
0
C
1
00
L
1
0
L
1
0
0
C
1
0
C
1
00
L
1
0
A
2
21
11
1
2
1
L
1
0
00
00
0
L
1
B
IV. Control Strategy of LCLC Resonant Converter
Fig.2 shows a typical structure of LCLC-SPRC with capacitive output filter. In dc/dc conversion
application, the output filter can be either an LC network or a single capacitor. Considering the demand for
shrinking the volume and reducing the insulation cost in high voltage application, a unitary capacitor filter is
usually utilized. In the resonant tank, the Cp will be clamped by the parallel connected filter capacitor Cf when
the rectifier conducts. And the natural resonance is only constituted by Ls, Cs. After the rectifier turns OFF, the
Cp detaches from Cf and joins into the resonance. Such a complex behavior may take place in one switching
period, deepening the hardness to establish the model which could reflect the exact operation characteristics of
the converter.
The inverter consists of four MOSFETs S1–S4, and the fast recovery diodes D1–D4 are used to
organize the full-bridge rectifier. For simplification, the transformer turn ratio is set to 1:1, and some basic
assumptions are made as follows [34-35]. The conduction of S1 and S4 in the inverter or D1 and D4 in the
rectifier is defined as positive conduction and the conduction of S2, S3 in the inverter or D3, D2 in the rectifier
is defined as negative conduction.
5. Implementation of PI controller for fourth order Resonant Power Converter with capacitive ….
DOI: 10.9790/1676-10311320 www.iosrjournals.org 17 | Page
The PI controller used to tune the gate pulses of the inverter MOSFETs corresponding to the load
voltage with respect to the reference voltage. The pulse generation using PI controller as shown in Figs. 4 and 5.
Fig. 4 PWM generation with PI controller
Fig. 5 PWM pulse generator
V. Simulation Results and Discussion
The performance analysis of the proposed LCLC resonant power converter has been tested with
MATLAB/Simulink software platform. Zero voltage and Zero current switching time are obtained through
simulation for the proposed converter. When the switching frequency is higher than resonant frequency, the
voltage gain of LCLC converter is always less than one, and it operates as a resonant converter and zero voltage
switching (ZVS) can be achieved. When the switching frequency is lower than resonant frequency, for different
load conditions, both ZVS and zero current switching (ZCS) could be achieved. The Simulink diagram of the
closed loop LCLC resonant power converter with PI controller is shown in Fig.6. The servo and regulatory
responses of the proposed converter has been taken and the results are shown in Figs. 7-10.
Fig. 6 Matlab Simulink model of the proposed LCLC Resonant converter with closed loop operation
6. Implementation of PI controller for fourth order Resonant Power Converter with capacitive ….
DOI: 10.9790/1676-10311320 www.iosrjournals.org 18 | Page
0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1
-1
-0.5
0
0.5
1
1.5
2
S1
0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1
-1
-0.5
0
0.5
1
1.5
2
Time in sec
S2
Fig. 7 Switching pulses for S1 and S2
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
20
25
30
VoltageVin
(V)
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
0
0.2
0.4
CurrentI0
(A)
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
0
20
40
VoltageV0
(V)
Time (sec)
Fig. 8 Input and output responses of LCLC-SPRC with PI controller
0 0.2 0.4 0.6 0.8 1 1.2
0
0.1
0.2
0.3
0.4
Current(A)
0 0.2 0.4 0.6 0.8 1 1.2
0
10
20
30
40
Voltage(V)
Time (sec)
Fig. 9 Output voltage and current responses of LCLC –SPRC at initial condition
7. Implementation of PI controller for fourth order Resonant Power Converter with capacitive ….
DOI: 10.9790/1676-10311320 www.iosrjournals.org 19 | Page
1.3 1.4 1.5 1.6 1.7 1.8 1.9
0.35
0.4
0.45
Current(A)
1.3 1.4 1.5 1.6 1.7 1.8 1.9
34
36
38
40
42
Voltage(V)
Time (sec)
Fig.10 Output voltage and current responses of LCLC-SPRC with load changes
Fig.7 shows the zero voltage and zero current switching responses of switches S1 and S2 of the LCLC-
SPRC power converter. Fig.8 shows the input and output voltage and current responses of LCLC-SPRC with PI
controller. The servo response of the LCLC converter with PI controller has been observed from the figure 8. It
represents the input voltage suddenly incremented from 24V to 28V at t=1.4 sec and suddenly decremented to
20V at 1.6 sec and return back to the actual input voltage of 24V at 1.8 sec. During this time period of t=1. 4 -
1.8 Sec the output does not vary due to servo disturbance and the boosted output voltage is held as constant of
38V. Fig.9 shows the output voltage and current responses of LCLC –SPRC at initial condition. Fig.10 shows
the output voltage and current responses of LCLC-SPRC with load changes. During this regulatory response, the
converter output voltage has been quickly settled with its reference value without any fluctuation with load
increment at t=1.4 and load decrement at 1.8 sec.
VI. Conclusion
In this paper, a new LCLC configuration is proposed by using state space analysis. The output voltage
and current are obtained using zero voltage and zero current switching time using PI controller. The steady-state
solutions have been deduced and simplified by introducing the output voltage coefficient. The reaction time of
resonant current has been calculated using output voltage coefficient, indicating a frequency limit that takes in
the converter to operate in CCM. From the simulation results, it is apparent that the proposed LCLC resonant
power converter has reached its steady state response without any oscillations with implementation of PI
controller. In time to come it may continue the operation of LCLC-SPRC with fuzzy and neural controllers and
compare the performance about the same.
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