Interleaved Flyback Converter Research Articles

An Improved Interleaved Flyback Converter with Reduced Voltage Stress and Current Auto-sharing

An Improved Interleaved Flyback Converter with Reduced Voltage Stress and Current Auto-sharing

A novel isolated multi‐port interleaved flyback converter operated TPSL‐DVR for smallscale distribution system

SummaryThis study describes a three‐phase six‐level (TPSL) inverter‐based dynamic voltage restorer (DVR) that employs a newly designed isolated multi‐port interleaved flyback converter (IMPIFC). A conventional DVR needs a big and heavy series transformer even for a three‐phase low‐voltage system, which is rated up to 400 V. Power electronic engineers have developed high‐frequency isolated DC–DC converters as a result of the introduction of advanced semiconductor devices and magnetic cores. Control and performance of a low‐voltage DVR utilizing a high‐frequency isolated DC–DC converter are discussed. In the proposed IMPIFC, the high‐frequency (25 kHz) transformer, which is smaller in size than the line‐frequency transformer, is utilized to reduce the size and to integrate multiple energy sources together. In addition, the introduction of a TPSL inverter into the configuration of DVR considerably reduces the injection of harmonic components into the distribution network. The proposed structure of DVR is named as “TPSL‐DVR.” The experimental findings of a three‐phase, three‐wire, 400 V, 50 Hz, 2kW laboratory system validate the boosting ability, feasibility, and efficiency of the system layout.

Comparative Analysis and Evaluation of the Different Active Cell Balancing Topologies in Lithium Ions Batteries

Series connected batteries must have their cells balanced whenever charging and discharging to extend battery lifespans, assure safe operation, and increase battery pack useful capacity. It also causes charge imbalance issues, which will result in battery cell damage and battery life loss. Several charge/discharge equalization circuits have been suggested however, presently there has been no work regarding the comparison and evaluation of the speed and efficiencies in both modes. In this study, cell balancing on dc-to-dc buck-boost converter and interleaved flyback converter topologies operating in discontinuous current mode are analyzed, designed, and implemented. A simulation model of the converter-based topologies of an active cell balancing system is proposed and designed along with a power loss analysis, efficiencies, and control technique. With the purpose of establishing an energy storage application, the system’s cells are grouped into 8 series cells for SOC balancing and 2 series cells for voltage balancing circuit design. Power loss analysis is performed to analyze the efficiency of these two converter topologies to identify which system performs better. In SOC balancing in charging mode, the buck-boost and interleaved flyback converters’ power efficiencies are 85.596% and 65.1521% respectively and during voltage balancing 93.9078% and 73.1506% respectively.

An Enhanced Modified Multiport Interleaved Flyback Converter for Photovoltaic-Shunt Active Power Filter (PV-SHAPF) Applications

This paper presents a newly designed modified multiport interleaved flyback converter (MMPIFC) to transfer the photovoltaic (PV) power to the DC bus of the parallel-connected multilevel inverter-based shunt active power filter (SHAPF). The proposed modified multiport interleaved flyback converter (MMPIFC) is designed to interconnect N number of input power sources into the DC bus of the SHAPF to fix the problems with the partial shadow and improve the SHAPF’s ability to compensate. Compared to the commonly used interleaved flyback converter (IFC), the proposed MMPIFC has a larger boost factor toward the DC voltage input. The flow of power between the different power sources and SHAPF is controlled by varying the duty ratio of the main switches. The working principles of the proposed MMPIFC-operated PV-SHAPF are explored in this paper, and essential design concerns are highlighted. A prototype model with 1 kVA, 400 V, and 50 HZ is built and tested under various conditions to validate the theoretical analysis, design, and control method.

A new zero voltage transition interleaved flyback converter

The paper introduced a new zero voltage transition (ZVT) interleaved flyback converter which has two similar flyback converters. Two flyback converters are in parallel connection and auxiliary circuit in this converter provides ZVT condition for all of the main switches and also provides zero current switching and zero voltage zero current switching (ZVZCS) conditions for the auxiliary switch. Also, ZCS conditions are created for diodes turning off, so reverse recovery problem is solved. The auxiliary circuit in the suggested converter is modular, and by adding parallel branches to the flyback circuit, this circuit can provide soft switching conditions for all switches without significantly change. A complete analysis of the converter is provided and its operating intervals are explained. A 180 W laboratory prototype of the converter is made to approve the theoretical calculations. The experimental results show 7.7% increase in efficiency.

Design of Fast and Zero Voltage Switching Of Interleaved Flyback Converter with H6 Type Inverter for Photovoltaic Applications

In this paper, a design of interleaved flyback converter with H6 inverter topology is proposed. Flyback converter is one among the DC-DC converter with high frequency which is used or low power applications. Because of high frequency operation switching losses and stresses are more. To reduce stresses and losses across the switch of interleaved flyback converter is proposed. In the grid tied inverter system leakage current is one of the disadvantages and to avoid this H6 type inverter is used.With this advantage of H6 inverter andflyback converter this paper is mainly focused on stresses across switches and eliminating leakage current, harmonic reduction. Further the fast switching is proposed within converter in order to deliver maximum power transfer delivered to load through grid. To validate the overall performance the proposed converter modeled in MATLAN-SIMULINK and prototype developed using DSP DSP TMS320F28377S and connected to grid connected load.

Interleaved high power improved two-stage flyback inverter for photovoltaic applications

The interleaved flyback converter is used to increase the power level and decrease the current ripple, Harmonics, passive component size, and total cost. The topology of flyback is used for lower output power in micro inverters. The flyback converter in this paper is designed for high output power. The grid is developed based on the interleaved topology of flyback converter, which is connected to central type photovoltaic inverter. The principles of the converter operation are discussed in detail. In MATLAB software the designed converter is simulated. Dual-stage flyback converter interleaving is being investigated for flyback inverter design rated at 01KW. The conversion system is run in DCM, providing a quick, easy to monitor dynamic response and no losses due to switchover action. As 90.16 percent, 3.9 percent and 0.998, the proposed efficiency of flyback inverter, total harmonic distortion, and the power factor were calculated.

Design and stability analysis of interleaved flyback converter control using Lyapunov direct method with FPGA implementation

Design and stability analysis of interleaved flyback converter control using Lyapunov direct method with FPGA implementation

Design and Implement Regulated DC-DC Interleaved Flyback Converter by Using Intelligent Controller in Airborne Application

This paper is designed, simulated and implemented DC-DC interleaved Flyback converter controlled by Arduino Uno which converts input voltage from battery 12 V to 180 V DC at 20 kHz for 120 W. Digital control design is done with the use of Arduino Uno microcontroller. Simulation carried out using MATLAB/Simulation. The objective of this paper is to design a DC converter that operates at low cost with high efficiency via improving Flyback converter topology. This occurs using interleaved Flyback converter. To obtain a regulated output voltage of the interleaved Flyback converter, closed-loop feedback with PI controller is employed (Proportional – Integral). The duty cycle is varied to control the output voltage and produced constant voltage under variation input voltage and load disturbance. The designed technique uses voltage mode control (VMC) to obtain a constant voltage under continuous conduction mode (CCM). To implement the interleaved Flyback converter with the PI controller, the microcontroller Arduino Uno is used. The Simulation and the practical results give a little output ripple voltage, current, and high efficiency 6% compared with conventional Flyback converter.

High voltage gain soft switching full bridge interleaved Flyback DC-DC converter for PV applications

This paper introduces a soft switching full bridge interleaved Flyback DC-DC converter with high gain. Half bridge Flyback converter will cause many problems in comparison with full bridge structure such as high-volume split capacitors and complex control for charging and discharging them for proper operation. By applying full bridge interleaved structure, the output current ripple can be reduced, and more power can be supplied to the load. Besides, the greatest way for reducing the weight, size and volume of the converter is applying soft switching methods. As well, the switching frequency is increased to boost the power density. To reduce switching losses, clamp circuit with a passive lossless snubber is applied in the suggested full bridge interleaved Flyback converter. In the proposed topology, soft switching conditions for all semiconductor elements are achieved by the passive snubber. It absorbs the stored energy in parasitic elements at the turn-off instant. The main superiority of the proposed topology in comparison with many other similar converters is that its passive snubber is load independent. A 110 W prototype of the topology is implemented. The experimental results confirm the aforementioned advantages of the converter such as high efficiency (92% at full load) and high gain (23.2).

Evaluation of topologies for a solar powered bidirectional electric vehicle charger

Charging of electric vehicles (EVs) from solar energy provides a sustainable means to power EVs in the future. A comparison of topologies for a three-port converter to charge EVs directly from photovoltaic (PV) panels is presented in this study. The grid-connected EV charger has a nominal rating of 10 kW and is bidirectional, enabling vehicle-to-grid operation. The topologies are optimally designed considering different switching frequencies, silicon carbide devices, magnetic cores and number of interleaved stages. Nine topologies are compared using a comparison framework, and the best topology is chosen based on the number of components, converter efficiency, volume, controllability and current ripple. The analysis shows that the best topology is a three-port converter with a central direct current link with a 3-leg interleaved boost converter (IBC) for the PV, two-level inverter with sinusoidal modulation for the grid and a 4-phase interleaved flyback converter for the EV. The loss models built are experimentally verified using a 3-leg IBC.

High-efficiency design of a grid-connected PV inverter based on interleavedflyback converter topology

The importance of efficiency in photovoltaic (PV) inverter applications makes the topology selection as the critical first step. Due to the low efficiency concern, flyback converter is not the preferred topology in kilowatt range in spite of its galvanic isolation, low cost, and small size advantages. Therefore, the objective of this research is to change the perception in favor of flyback converter by designing a flyback-topology-based PV inverter at 2.5 kW with high efficiency. The enhancement in efficiency is achieved mainly by using silicon carbide switching devices, designing ultrahigh-efficiency flyback transformers with extremely low leakage inductance and by implementing a prototype with the lowest parasitic components. As a result, the efficiency of the experimental inverter is measured as 95.82 %. Moreover, the low cost and small size objectives are also maintained with very good grid side performance. Consequently, the experimental results demonstrated that the flyback-converter-topology-based inverters can be successfully implemented at high power with high efficiency and with high commercial value.

An Interleaved Flyback-Typed LED Driver With ZVS and Energy Recovery of Leakage Inductance

Flyback converter has advantages of simple circuit configuration and easy control. However, it suffers two problems. One is the active switch is hard switching. The other is a very high voltage spike when the active switch is turned off . In order to solve these problems, this paper presents a novel dc-to-dc converter that mainly consists of two interleaved flyback converters. Both active switches can achieve zero-voltage switching on without the use of any active clamp circuit or snubber circuit. In addition, the leakage flux energy can be delivered to the output by using two added diodes. It helps to reduce the voltage spikes on the active switches and improve circuit efficiency. The steady-state analyses at different operation modes and the mathematical equations for parameters design are provided. Finally, a 200-W prototype circuit for driving high-brightness light-emitting diodes (LEDs) is built and tested to verify the feasibility of the proposed circuit. The LEDs are dimmed from 100% to 10% full power. Satisfactory performances are obtained from the experimental results.

Design of interleaved flyback converter

This paper proposes a transformer design to achieve soft switching low power flyback converter. This proposed paper is having the soft switching which reduces the power loss in main switch while improving the over all EMI in the converter. It also proposes the design methodology for the transformer in a flyback converter which automatically accomplishes the complete soft switching of the main switch.

Design of interleaved flyback converter

This paper proposes a transformer design to achieve soft switching low power flyback converter. This proposed paper is having the soft switching which reduces the power loss in main switch while improving the over all EMI in the converter. It also proposes the design methodology for the transformer in a flyback converter which automatically accomplishes the complete soft switching of the main switch.

Interleaved Flyback Converter with Embedded Grid Interacting PV Cascaded MLI

The importance of extracting power from renewable energy sources are increasing in the modern world as the power demand is increasing day by day and the non renewable energy sources are getting dried up. Solar power is a domestic source of energy and its availability throughout the year makes it a primary target to solve this crisis. It will never produce any hazardous waste or pollution. But various issues like Power quality problems and Harmonic distortion seep in due to the intermittent nature of PV system. This paper proposes a cascaded H–bridge multilevel inverter for grid connected PV system with a flyback converter. This helps to achieve maximum power point tracking and also provides isolation which will further help to increase system efficiency. The DC–DC flyback converters are cascaded to generate multilevel output voltage. Then this multilevel dc output is given to H bridge inverter to generate multilevel output. A new control algorithm is used in this paper which combines voltage–hold Perturb and observe method and modified PWM algorithm which helps to achieve the best MPPT. The proposed topology is implemented in PSIM. The Simulation and Hardware results reveal that the suggested technique is highly.

Novel Control Scheme for an Interleaved Flyback Converter Based Solar PV Microinverter to Achieve High Efficiency

The paper proposes an optimal control strategy for the interleaved flyback based microinverter to improve its efficiency over the entire operating range. This control scheme is based on the choice of an appropriate operating mode [1-converter discontinuous conduction mode (DCM), 1-converter boundary conduction mode (BCM), 2-converter DCM, and 2-converter BCM] at various instantaneous power magnitudes. The proposed control method reduces the fixed losses associated with the gate driver and the transformer at the low power level. It also reduces the switching losses that may result due to the extremely high-frequency operation of the BCM at the low power level. Additionally, it also reduces the conduction losses through low current peak due to BCM and equal current sharing between the two converters at the high power level. Switching losses, due to the low-frequency operation of the BCM at a high power level, are also reduced. Operating mode selection of the interleaved inverter at a particular power level is based on the information of optimal efficiency. Detailed calculations of peak current references have been carried out for the various operating modes of the interleaved flyback based microinverter. Simulation and experimental results have validated that the proposed control method results in better efficiency compared with the conventional (DCM, hybrid DCM/BCM, hybrid 1-converter/2-converter) control methods with the output current total harmonic distortion remaining within the specified limits.

Smart fuzzy-based energy-saving photovoltaic burp charging system

ABSTRACTThis paper focuses on the optimal usage of photovoltaic energy by implementing ‘pulse charging’ technique to charge batteries and to keep the supply from the solar panel continuously without any interruption. The burp-pulse charging technique is used to supply multiple loads. Three different batteries Bp, Ba1 and Ba2 are smart charged concurrently and individually during three kinds of charge statuses controlled by a charge regulation system. The high-frequency input pulses are obtained from an interleaved flyback converter. The charge for prime battery (Bp) is from the positive pulse and that for auxiliary battery-1 (Ba1) is from the break period between the pulses. Finally the third battery, that is, auxiliary battery-2 (Ba2) is incorporated to utilise the negative pulse charge through an inductor when the step-up chopper is closed. This can otherwise be put as, utilising the discharge current of Bp to supply a load. The Ba2 voltage is stepped up to supply a motor load when supply from prime battery Bp is unavailable. The closed loop simulation introduces a fuzzy logic controller which controls the generation of pulses according to the variations in the input source voltage. By this way, a linear and smoother current is available to charge the batteries. Thus, the energy-saving concept is fulfilled by the proposed design. Faster and uninterrupted charging and better battery life are other facets of the proposed system. The closed loop simulation is performed and results are presented.

Grid Connected Solar Microinverter with interleaved Flyback Converter

Renewable power sources are the best way to reduce the effect of green house gases and thereby global warming. Among them solar power may be seen as the most reliable due to its availability. But the Solar PV system is expensive. So the main objective of this work is to develop a solar PV system which is cost effective without compromising on the efficiency of the system. The optimal operating point of each PV panel is different depending on the solar irradiation and temperature on the panel. In a string of panels the power of the entire string can be optimized and not on panel by panel basis. This paper focuses on power optimization tracking of individual PV panels using a single stage interleaved flyback converter. The proposed converter is having high voltage conversion ratio when compared to an ordinary buck boost converter. A detailed study conducted in this paper explains the practical and theoretical techniques for making the PV cells to work most efficiently all the time. A practical approach is made in this paper using the MATLAB atmosphere and to prove the quality of the theoretical concepts hardware results are also provided. The result proves that the efficiency of the entire system can be improved by optimizing each panel and the reduction of conversion stages helps to make the system more cost effective.

Fault diagnosis and fault-tolerant control of photovoltaic micro-inverter

An observer-based fault diagnosis method and a fault tolerant control for open-switch fault and current sensor fault are proposed for interleaved flyback converters of a micro-inverter system. First, based on the topology of a grid-connected micro-inverter, a mathematical model of the flyback converters is established. Second, a state observer is applied to estimate the currents online and generate corresponding residuals. The fault is diagnosed by comparing the residuals with the thresholds. Finally, a fault-tolerant control that consists of a fault-tolerant topology for the faulty switch and a simple software redundancy control for the faulty current sensor, is proposed to achieve a fault-tolerant operation. The feasibility and effectiveness of the proposed method has been verified by simulation and experimental results.