Showing papers on "Flyback transformer published in 2023"

A Novel Transformerless Single-Stage Grid-Connected Solar Inverter

Abstract: A novel tranformerless single-stage grid-connected solar inverter with a combination of a bidirectional dc/dc boost converter followed by a flyback inductor inverter is proposed. The inverter shares a common ground with the photovoltaic (PV) panel and the grid, which realizes a zero leakage current and it is the most desired feature in transformerless inverters. Further, the proposed inverter provides the boost voltage operation, hence it does not require a second stage which decreases the system cost and increases the system reliability. The other advantage of the proposed inverter is that it provides both the symmetrical positive voltage gain and negative voltage gain, which allows to use simple sinusoidal pulsewidth modulation technique for realizing the ac sinusoidal output voltage. The proposed inverter steady-state operation and the design equations are presented in detail. The converter dynamic model is developed using state-space averaging approach, and a proportional resonant current controller is designed for inverter closed-loop operation with the grid. The presented analysis and the design are verified with both the simulation and experimental results.

Efficient Soft Switching Single-Stage PFC for Low-Power Applications

Abstract: Single-stage (SS) power factor correction (PFC) converters are applied as the power supply for low-power devices. Usually, the flyback converter is merged with the PFC stage to eliminate the reset winding required for the transformer. This article merges a new resonant forward converter with the buck-boost PFC stage. Thus, reset winding of the forward converter is eliminated while soft switching is achieved. Due to the low flux of the forward transformer core, transformer volume is reduced. Also, for the same volume of the transformer, transformer losses can be reduced in comparison to the flyback converter. The proposed converter is analyzed, and design considerations are discussed. A prototype converter is implemented. According to the experimental results, high efficiency and low total harmonic distortion (THD) are achieved.

A High-Efficiency QR Flyback DC–DC Converter with Reduced Switch Voltage Stress Realized by Applying a Self-Driven Active Snubber (SDAS)

Abstract: In this paper, a QR flyback converter using a self-driven active snubber (SDAS) was proposed to solve the problem of voltage surge in the switch of QR flyback converters. In the proposed converter, the SDAS consisting of a clamping capacitor and an active switch can be configured in parallel with the main switch or transformer to reduce the voltage surge in the switch. To confirm the steady-state characteristics of the QR flyback converter to which the proposed SDAS is applied, equivalent circuits for each state were constructed, and the equations and characteristics for each state were determined. A 60 W class small AC–DC adapter was constructed to confirm the effectiveness of the proposed converter and the control circuit method, and the experimental results were analyzed. The size of the experimental AC–DC adapter was 74×29×23 mm, and it had a high power density of 20 W/in3 or more. The experimental circuit was limited to the high power conversion efficiency of up to 91.56%, and the maximum voltage surge in the switch was approximately 450 V. One of the reasons for such high efficiency is the SDAS circuit, which sufficiently reduces the voltage surge of the QR flyback switch, compared with the RCD clamp circuit, and does not consume power in principle.

An Adaptive Constant Voltage Control Scheme for Primary-Side Controlled Flyback Converter

Abstract: An adaptive multimode constant voltage (CV) control scheme for primary-side regulation flyback converters operating in discontinuous conduction mode and continuous conduction mode operation is presented, which significantly enhances the light-load efficiency and thereby the overall average efficiency. Compared to conventional control scheme, the proposed control scheme performs analog control approach to integrate multiple operating modes adaptively based on load conditions. Besides, line voltage compensation and freewheeling diode compensation are proposed to improve the CV precision operating in multiple modes. The proposed adaptive multimode control scheme is implemented in 0.18 μ m 5 V/40 V BCD process and occupies a die size (with pads) of 1.05×0.8 mm ² . The experimental results show that the average efficiency is 88.52% under 265 Vac, whereas peak efficiency can reach 89.65% under 265 Vac. The deviation of the output voltage is within ± 2.33%.

Compact MV-Insulated MHz Transformer-Coupled Gate Driver With Staged Turn-Off Scheme for Series-Connected Power Devices in DC Circuit Breaker Applications

Abstract: The short-circuit protection equipment of dc circuit breaker (DCCB) is important for the dc grid. Also, the series-connected power devices are usually employed in the solid-state circuit breaker (SSCB) or hybrid circuit breaker (HCB) to meet the clamping voltage requirement. A simple passive gate driver and power supply solution is a critical component to drive the circuit breakers more cost-effective and reliable. This article proposed a novel compact MV-insulated transformer-coupled gate driver method, which combines the auxiliary power and gate signal together. The proposed high-frequency-modulated multilevel transformer voltage enables both the simultaneous and the staged turn-off schemes. Besides, the cascade high- and low-voltage transformer structures simplify the insulation design and demonstrate better scalability. The common-mode current could be suppressed as well using this structure. The design example of a compact 2-MHz high-voltage planar transformer with >13-kV partial-discharge-free insulation capability is illustrated. Finally, the simulation and experimental results are also given to demonstrate the feasibility of the proposed gate driver method.

Design of a LED driver with a flyback topology for intelligent lighting systems with high power and efficiency

Abstract: Considered in this paper are the parameters and characteristics of the developed highly efficient electronic control systems for powerful LED modules (drivers), built on the basis of a single-stage flyback converter with a nominal power close to 200 W. The results of experimental tests show that, at the nominal load, the minimum efficiency of the developed driver reaches 88.2% with the power factor above 0.97 and the coefficient of total harmonic current distortion close to 23.4%. With the maximum value of the efficiency factor of the developed system 90.3% and the supply voltage 240 V, the power factor is higher than 0.99, and the total harmonic current distortion is 3.6%. The values of current harmonics of the driver do not exceed the maximum allowable values defined by the current standards. Used driver construction topology enabled to reduce the cost of the final product due to the unification of the component base, which increases the availability and manufacturability of the design. The use of a modern element base made it possible to ensure the deviation of the output current from the set one by no more than 1% over the whole range of the operating voltage of the supply (180…250 V), which allows using the developed driver in intelligent lighting systems and lighting systems with a combined power supply.

Discrete time domain modeling and design of current mode controlled flyback LED driver.

Abstract: In this paper, modeling for a current mode controlled (CMC) flyback LED driver with a stabilizing ramp is performed in a step-by-step procedure. Discrete time state equations for the system are derived and linearized with respect to a steady-state operating point. At this operating point, the switching control law, the condition that determines the duty ratio, is also linearized. In the next step, a closed-loop system model is derived by combining the two models of the flyback driver and the switching control law. The root locus analysis in the z-plane is used to investigate the characteristics of the combined linearized system and obtain design guidelines for feedback loops. The feasibility of the proposed design is confirmed through the experimental results for the CMC flyback LED driver.

A novel energy router based on multi‐winding line frequency transformer

Abstract: Energy routers based on the electronic power transformer are suitable for the AC–DC hybrid grid with multiple voltage levels, but their structures are complex. This paper proposes a novel energy router based on the multi-winding line frequency transformer. By a combination of a multi-winding line frequency transformer and power electronic devices, the proposed energy router can take advantage of the high reliability of the multi-winding line frequency transformer and the high controllability of power electronic devices. The proposed energy router is suitable for the AC–DC hybrid grid with multiple voltage levels and has the characteristic of a simple structure. The simulations and experimental results demonstrate the effectiveness of the proposed energy router.

An Improved Constant Current Control Scheme for Multimode PSR Flyback Converter

Abstract: For low cost and wide power range, the constant current (CC) control scheme for multimode primary-side regulation (PSR) flyback converter is prevalent in low and medium power applications. Although some multimode CC control schemes have been presented to raise CC accuracy, the current deviation caused by the mode conversion and inherent propagation delay remains unsolved. An improved CC control scheme is adopted to mitigate the influence of propagation delay or mode conversion on CC accuracy, which can be added into an IC controller with no extra pin penalty. The proposed scheme is implemented in 0.18lm 5V/40V BCD process. The experimental results reveal that the deviation of the output current is within 1 0.8% under different input and load conditions.

Hierarchical Battery Equalizer based on Flyback Transformer Multiplexing

Abstract: An effective battery equalizer is important to eliminate the inconsistency of the battery pack and improve its performance of the battery pack. As the battery equalizers generally have the problems of low equalization efficiency, slow equalization speed, and poor control of equalization energy. In this paper, a hierarchical battery equalizer based on flyback transformer multiplexing is proposed and analyzed. Flyback transformers can be used as energy storage elements for both the first and second equalization stage. The equalizer uses the multiplexing of flyback transformers to effectively reduce the size and cost of the equalizer, and the hierarchical equalization improves equalization speed and equalization efficiency. In addition, the working principle of the equalizer and the equalization control strategy are introduced in detail. Finally, the equalization of the simulation model with six single cells connected in series is verified by using MATLAB/Simulink, which proves that the equalizer has good performance.

Design of Quasi-Resonant Flyback Converter Integrated by Fuzzy Controller

Abstract: AbstractOne of the disadvantages of on-off switching of the Flyback Converter (FBC) at a fixed frequency is the power switching losses that negatively affect the efficiency of the switching process. This problem can be met in switching modes: Discontinuous Conduction Mode (DCM) and Continuous Conduction Mode (CCM). Development of the Quasi Resonant Flyback Converter (QRFBC) operating with variable frequency decreases the loss of switching and improves its efficiency. This study considers the development of QRFBC converter using MATLAB Simulink controlled by fuzzy logic controllers (FLC). The performance analysis of the FLC is compared with traditional PI-controller using the different values of the input, reference voltages and loads. The results show that FLC provides efficiency control to the output voltage of QRFBC, the efficient switching of zero voltage, reducing switching losses, and increasing switching speed and precision.KeywordsFlyback converterFuzzy logic controllerPI controllerQuasi-resonant

Design and Implementation of Closed loop control for Flyback Converter

Abstract: One of the high frequency switching power supply circuits is the flyback converter. Due to its inexpensive cost and electrical isolation properties, it is mostly employed in low power applications. It is well known that high frequency switching results in losses and lowers inverter efficiency, particularly at low powers. Consequently, a flyback DC-DC converter that is run in a closed control loop is explained in this study. Closed-loop control is the proposed topology for the flyback converter. For the same input/output conditions, the findings from the closed-loop converter are compared to those from the open-loop feedback topology. A closed-loop flyback has been found to be more effective than an open-loop flyback. MATLAB simulates the outcomes. One of the high frequency devices is the flyback converter.

A Scalable Electronic-Embedded Transformer (EET), a New Concept toward Ultra-high-frequency High-power Transformer in DC-DC Converters

Abstract: The demand for high-power and high-density isolated dc-dc converter is driven by the rapid development of energy storage system, data center power supplies and transportation electrification. However, designing a high-power and high-frequency transformer presents significant challenges due to the trade-off between thermal management, leakage inductance minimization, and insulation requirements. In order to overcome this trade-off between power rating and operation frequency, a scalable electronic-embedded transformer (EET) is proposed with a low voltage bridge integrated into the transformer windings. The EET addresses the challenge through its simple open-loop control and natural current sharing, enabling easy parallel connection and scaling to different power ratings. Based on this concept, a bi-directional EET-based dc transformer (EET-DCX) is proposed to solve the transformer-level paralleling and resonant point shift issues in traditional LLC-DCX designs. By employing the embedded full bridge, the EET-DCX effectively cancels out the impedance of the leakage inductance, ensuring optimal operation at any frequency. Additionally, the EET-DCX retains the inherent advantages of the LLC-DCX, such as load-independent voltage gain, simple open-loop control, full load range zero voltage switching (ZVS), and low circulating current. Leveraging these advantages, the proposed EET-DCX solution has the potential to push the boundaries of transformer performance to the MHz operation frequency range with hundreds of kilowatts power capability. To validate these merits, a 12 kW 500 kHz EET-DCX with four planar EET units was built. This article is accompanied by two videos demonstrating the dynamic load changing and frequency changing test.

Relative Gain Array Based Decoupled Controller design for GaN-Based Multiple Output Flyback Converter

Abstract: The recently proposed independently controlled multiple output flyback converter (ICMOFC) utilizes gallium nitride (GaN) switches with negative gate turn OFF voltage to improve cross-regulation between multiple output voltages. A cross-coupling between the control and output variables exists in such a multiple-input multiple-output control system. This cross-coupling leads to severe interactions between control loops if the conventional decentralized feedback compensators are designed for high closed-loop bandwidths. These interactions may affect the converter's dynamic performance. As a result, the attainable closed-loop bandwidth for non-decoupled decentralized control is limited. To address this issue, this paper delineates a methodology for decoupled controller design for the ICMOFC to attain a fast transient response. The effect of the right half-plane zero of the plant transfer function is also addressed in the suggested decoupled controller. Simulation and experimental results for a 40 W two-output flyback converter are provided to validate the suggested control scheme.

An Efficient and Compact Equalizer Based on Forward-Flyback Conversion for Large-Scale Energy Storage Systems

Abstract: An effective battery equalizer is of great significance to eliminate inconsistencies and improve the performance of large-scale battery packs. Nevertheless, the existing balancing circuits have various problems such as slow balancing speed, high cost, bulky size, complex control, etc. Therefore, this paper designs an efficient and compact transformer-based equalizer, which works at forward-flyback conversion. Distinguished from the conventional transformer-based equalizers, the proposed equalizer requires only one MOSFET and one transformer winding equipped with each cell. Two complementary PWM signals can control all MOSFETs used in the proposed equalizer. The equalizer can automatically equalize all cells without the need for additional voltage sensing and demagnetization circuits, reducing the cost and volume. It can directly transfer energy between any two adjacent modules, improving the equalization efficiency and speed. An experimental prototype of eight series-connected cells was set up. The experimental results and systematic comparison with the existing balancing topologies show that the proposed equalizer is appropriate for balancing large-scale energy storage systems. The energy delivery efficiency among cells can be as high as 93.15% over various loading conditions.

Simulation Study of An Interleaved Flyback Converter for Micro Grid Systems Operating in the CCM Mode

Abstract: <p> This paper presents a design and an implementation of an isolated grid connected micro inverter system that is based on an interleaved flyback topology. The developed system gets input from a 250 W PV panel, converts the dc energy into ac and connects it to the grid. This work covers the simulation aspect of developing the above mentioned system where extensive simulations are performed in order to find and optimize values of desired parameters and simulate the overall system. The CCM (Continues Conduction Mode) of operation for the flyback converter is preferred as it generates considerably less amount of the current ripple at converter output when compared to DCM operation and less amount of power loss. A feedback loop with a PI controller is incorporated into the design in order to properly stabilize the system. Simulation results demonstrated that the developed system generates sinusoidal voltage and current signals of 50 Hz in frequency with desired amplitudes at the output of the system. Connection of generated ac waveforms to the grid is accomplished by means of a PLL block. THD of the grid current is found as 11.57% due to spikes at zero crossings. </p>

Design and implementation of flyback converter design and control of driving power supply for unmanned robot

Abstract: In accordance with the requirements of unmanned robot driving power supply for power supply reliability, strong power output, and portability, this paper introduces a design scheme for unmanned robot driving power supply on the basis of a flyback converter, establishes the mathematical model of driving power supply (flyback converter), designs the transformer part of a flyback converter, and recommends a straightforward and efficient clamping circuit to enhance it. The controller of the flyback converter is designed in detail. Ultimately, the feasibility and effectiveness of the design method in the driving power supply of unmanned robots are demonstrated by simulation and experiments.

Desain Dan Implementasi Transformator Satu-Fasa Dry-Type Dengan Pendekatan Core Geometry

Abstract: Energy is one of the most important needs for humans to support daily life, especially for developing countries such as Indonesia. One of the energies needed in human life is electrical energy. For this reason, innovation was developed, namely a dry-type Single-Phase Transformer with a core geometry approach developed in the AL 1.01 building of the State Polytechnic of Malang. Calculations performed on the tool are to calculate the value of windings per volt (GPV) and the number of primary and secondary windings. Its manufacture uses a toroid-shaped transformer core. The core specification of the transformer is an outer diameter of 15cm, then an inner diameter of 5.8 cm, and a height of 7cm. The toroid transformer core that will be used is previously isolated from the transformer first to avoid leakage current which can cause heat in the transformer core. The density of the email wire from the transformer winding both from the primary and secondary windings will affect the performance of the transformer, the more tightly the email Wire is wrapped in the transformer core, the vibration generated from the transformer will be smaller, this will affect the voltage losses later in the transformer testing phase carried out using different beaban, each load changes the efficiency of the transformer that has been made will also change, this is because each load tested has different factors.

A Modular Push–Pull–Flyback High-Voltage Pulse Generator for Electric Field Emulation During a Lightning Strike

Abstract: To meet the requirements of simulating the electric field during a lightning strike, there is an urgent need for a voltage pulse generator that generates voltage pulses that are equivalent to the electric field during the lightning strike. A new pulse generator structure based on a push–pull dc–dc converter and a flyback converter is proposed. The pulses produced by the proposed generator have a variable voltage rise rate, and a modular design is used for the generator. Each module works independently and is powered by an exclusive lithium battery, which avoids the problems of the need for a high-voltage dc source, current sharing, and a complex control strategy in existing generators. The electrical behavior of the proposed generator during the switching transient is analyzed considering the effects of both the semiconductor switching device (insulated-gate bipolar transistor) and transformer. The method of selecting the specifications of each component and the method of designing the core component are presented in this study. The accuracy of the transient model and the feasibility of the proposed generator are verified in experiments, and a 60-stage prototype that produces pulses with amplitudes in excess of 1 MV, widths of 1–3 ms, and a variable voltage rise rate is developed.

A High Power Factor LED Driver with Intrinsic Current Balancing Capability

Abstract: The research proposed a novel LED driver with the functions of power-factor correction (PFC) and current balancing. A flyback converter and a Class-D series resonant converter were integrated by sharing an active switch to form a single-stage circuit topology. The flyback converter played the role of a PFC circuit. The component parameters were designed to make the flyback converter to operate at discontinuous-conduction mode (DCM). In this way, the input line current can be sinusoidal, resulting in near unity power factor and low total harmonic distortion in current (THDi). The resonant converter was connected in series with a differential-mode transformer with a turns ratio of 1 to drive four LED strings. The current of the four LED strings will be automatically and evenly balanced by using the 1:1 transformer. This article analyzed the different modes of operation in detail, derived the mathematical equations and designed the parameters of the circuit components. Finally, a 72-W prototype LED driver was implemented and tested. A satisfactory performance has verified the feasibility of the proposed LED driver.

Multiport Converter based Solar PV System using Flyback Converter

Abstract: The advent of converters and recent trends in power electronics are intended for use in green energy. This paper presented a multiport converter-based solar PV using a Flyback converter. Generally, the multiport system is capable of the bidirectional flow of energy and increases the available energy utilization because; it has multi-input sources and multi-output loads. Due to adaptability, multiport converters has numerous uses such as Uninterrupted Power Supply (UPS), Electric vehicles (EV), Renewable Energy sources (RES), and Hybrid Energy Storage Systems (HESS). Now, mainly utilizing AC supply for the consumers and the DC sources like solar PV might be producing less efficiency during the atmospheric condition. The proposed flyback converter operates in both conversions such as, AC/DC and DC/DC which seems to be adaptable in any cause. The proposed converter consists of three modes of operations and has the ability to provide different output voltages. As a result, it is possible to regulate the multiple output voltages with a single control and run a variety of input voltages. In contrast to other converters already on the market, the proposed zeta-flyback hybrid converter has the capability of serving both the function of voltage control and that of energy storage for PV applications. The MATLAB/Simulink tool has been used to demonstrate the proposed scheme’s steady-state response and behaviours.

Simulation Study of An Interleaved Flyback Converter for Micro Grid Systems Operating in the CCM Mode

Abstract: Abstract This paper presents a design and an implementation of an isolated grid connected micro inverter system that is based on an interleaved flyback topology. The developed system gets input from a 250 W PV panel, converts the dc energy into ac and connects it to the grid. This work covers the simulation aspect of developing the above mentioned system where extensive simulations are performed in order to find and optimize values of desired parameters and simulate the overall system. The CCM (Continues Conduction Mode) of operation for the flyback converter is preferred as it generates considerably less amount of the current ripple at converter output when compared to DCM operation and less amount of power loss. A feedback loop with a PI controller is incorporated into the design in order to properly stabilize the system. Simulation results demonstrated that the developed system generates sinusoidal voltage and current signals of 50 Hz in frequency with desired amplitudes at the output of the system. Connection of generated ac waveforms to the grid is accomplished by means of a PLL block. THD of the grid current is found as 11.57% due to spikes at zero crossings.

A Four-Capacitor Model for Interprimary-Winding Capacitances Analysis in the Input-Series Transformer-Integration Converters

Abstract: The input-series transformer-integration (ISTI) converters are suitable for the high-input voltage multiple-output applications. In these converters, interprimary-winding capacitances are the unique stray capacitances of the integrated transformer, and energy influences of these capacitances cannot be ignored in the high-voltage applications. In order to analyze energy influences of the interprimary-winding capacitances, in this article, a four-capacitor model is proposed to represent these capacitances within arbitrary two primary windings of the integrated transformer. Based on the proposed model, energy varying of the interprimary-winding capacitances is analyzed in detail during each switching period. Furthermore, estimation of the four lumped capacitors is discussed. Finally, three different integrated transformers are designed for a 1-kV/60-W laboratory-made flyback ISTI converter, and validity of the proposed model is verified through the simulating and the experimental comparisons of these integrated transformers.

The Mathematic Analytical Results of Self Excited Flyback Converter with Double Switches

Abstract: AbstractThe primary power voltage of spacecraft is increasing gradually in our country. The DC/DC converter in spacecraft, its circuit topology is changing in order to reduce the voltage of the main switch with its shutoff. The double switch forward converter, The double switch flyback converter, Half-bridge, Full-bridge, Phased-shifted Full-bridge converter. In these five circuit topologies, components and cost used in the double switch flyback converter circuit are the least and the lowest without PWM integrated circuit. The self excited flyback converter with double switches is discussed with the mathematic analytical method in this paper. By using the input voltage, the output voltage, the output power and the parameters of the transformer of the converter as independent variables, we construct the representation of the operating period, the representation of the maximum magnetic density and the representation of the ratio of duty time D. On the basis of this, we get an important conclusion: the relationship between energy transmission coefficient η, the ratio of duty time and \((\frac{{N}_{1}}{{V}_{1}}\))/(\(\frac{{N}_{0}}{{V}_{0}}\)), it shows that energy transmission coefficient η is higher when the value of \((\frac{{N}_{1}}{{V}_{1}}\))/(\(\frac{{N}_{0}}{{V}_{0}}\)) is 0.3–0.6.KeywordsFlyback converter with double switchesThe operating periodThe maximum magnetic densityThe ratio of duty time DEnergy transmission coefficient η

New PWM Soft Single Switched Step-Up Coupled Inductor Converter with Improved Efficiency

Abstract: Abstract This article presents a new high-step-up converter based on the combination of the diode-coupled inductor technique and a Zeta-Flyback converter. This technique helps to achieve high-step-up gain, also provides soft-switching condition. The switch turns on at zero-current switching (ZCS) and extremely near zero-voltage switching (ZVS) and turns off at ZVS. The diodes are turned off at ZCS, so the reverse recovery problem is alleviated. Experimental results were obtained as a 100 W to validate the converter’s performance, and the concepts are presented in the article. At the end of article, a family of nonisolated and isolated converters based on the studied converter is proposed. The proposed converters, which are based on the CUK family converters, benefiting from the intrinsic magnetizing isolation property.