Design Of High Frequency Transformer Research Articles

4.5 kW High Frequency Transformer Design for Dual Active Bridge (DAB)

4.5 kW High Frequency Transformer Design for Dual Active Bridge (DAB)

Litz-Wire Winding Loss Calculation Method for Optimal Design of High-Frequency Transformers

Litz-Wire Winding Loss Calculation Method for Optimal Design of High-Frequency Transformers

Optimization Design of Medium-Voltage High-Frequency Transformers Based on Parallel Sampling Kriging Surrogate Model

In the design process of medium-voltage high-frequency transformers, numerical simulation methods often result in long design cycles and significant computational resource consumption. To achieve rapid and high-precision design for medium-voltage high-frequency transformers, a parallel kriging surrogate model is proposed based on the maximum expected improvement criterion. Initially, Latin hypercube sampling is employed to establish the initial sampling points, and corresponding three-dimensional models of medium-voltage high-frequency transformers are constructed for each sampling point configuration. Finite element simulation software is then used to compute the transformer loss and volume for each model. Subsequently, a kriging surrogate model is developed based on the initial sampling point configuration, and an enhanced parallel sampling strategy is implemented to enhance the fitting accuracy of the kriging surrogate model. Finally, the high-precision kriging surrogate model is utilized as the fitness function for a particle swarm optimization algorithm, with the objectives of minimizing transformer loss and volume. The Pareto optimal solution is sought under multi-objective optimization. The effectiveness of the proposed optimization method is verified through experimental measurements of the loss in a prototype of a medium-voltage high-frequency transformer.

High-Frequency Transformer Design With Medium-Voltage Insulation for Resonant Converter in Solid-State Transformer

A Solid-state transformer (SST) can directly convert medium voltage to low voltage (e.g. 400 V) with minimized power-conversion stages. The transformer in the DC-DC module not only provides medium voltage insulation but also significantly affects the power density of the module. In this paper, an innovative compact transformer structure is proposed to handle medium voltage insulation using an insulation coordination with epoxy, bobbin, shielding layer and stress-control layer. A brand-new bobbin design and related fabrication process ensures a partial-discharge-free insulation. Besides traditional core loss and winding loss, high-frequency related core loss and shielding loss is modeled in detail for an accurate loss evaluation. A simple and comprehensive multi-parameter, multi-objective optimization process is proposed to achieve the size and loss trade-off. The transformer prototype passes the related insulation tests, following the standard IEEE Std. C57.12.01. Finally, the design is demonstrated on a 15 kW, 200 kHz CLLC converter with 98.9% peak efficiency and 3.8 kW/L power density.

High power - high frequency transformer design constrains

High power - high frequency transformer design constrains

Pulse Frequency Modulated Interleaved Boost-Integrated LC Series Resonant Converter With Frequency-Free Designed Transformer

In this article, we propose a novel interleaved boost-integrated <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LC</i> series resonant converter, in which the series resonant tank is located on the secondary side. Moreover, the input and output of the interleaved boost unit are in series directly, which is helpful to reduce the voltage stress of the output filter capacitor of boost unit. With the proposed pulse frequency modulation, except for that the output voltage can be controlled as constant under different input voltages, another feature is that the high-frequency transformer design is related to the series resonant frequency instead of the switching frequency. Hence, the proposed converter can operate under a very wide switching frequency range with a constant maximum magnetic flux density. The zero voltage switching and zero current switching can be achieved for all switches diodes. Finally, a 500-W prototype with a switching frequency range from 60 to 200 kHz is built to verify the operation principles of the proposed converter and modulation.

Optimal Design of High Frequency Transformer for High Power Density Flyback Converter

This brief presents an optimal design of high power frequency transformer for flyback converter based on E-mode GaN device, which could be used in personal portable chargers. The new generation of wide band gap semiconductor GaN switch is used to improve the switching frequency of the circuit. The high-frequency magnetic core and the winding method of magnetic components are optimized. The leakage inductance of the transformer of magnetic components is greatly reduced. Consequently, the overall power density of the circuit is improved. The feasibility of the design scheme is verified by hardware implementation and experimental results. The test results show that compared with the traditional flyback magnetic element design, the volume of magnetic element is reduced by 30%. Meanwhile, the loss is reduced by 30%, and the peak efficiency of the converter can reach 94.2%. The ratio of leakage inductance of magnetic transformer to excitation inductance decreased from 2.2% to 1%. In addition, power density of the converter reached 20.26W/in3, which is much higher than the existing commercial ones.

Pareto-Optimal Design of Litz-Wire Gapped-Core High-Frequency Transformer for LLC Converters

The optimization of Litz-wire gapped-core high-frequency transformer (LGHT) for <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LLC</i> converters is a challenging task owing to application requirements and complex relationship between multiple design-objectives and constraints. This necessitates the use of multiobjective optimization-techniques to obtain tradeoff design-solutions; however, these are cumbersome methods that require many iterations and resources. Therefore, this article proposes an improved and efficient Pareto-optimization method for LGHT-design. It combines multiobjective whale-optimization algorithm and analytical core-geometry factor model based core and winding selection method while keeping in consideration the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LLC</i> converter requirements. The proposed method utilizes benefits of both method-types; it obtains the best LGHT-design in shortest-time and minimum-iterations with optimized volume and losses, integrated magnetizing-inductance, and satisfied thermal-limit. The method is made resource-efficient by carefully selecting independent and necessary LGHT design-parameters as optimization variables keeping in view interdependency among the parameters and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LLC</i> converter performance; these include peak-flux-density, LGHT design-frequency, core-window utilization-factor, core-material, and core-shape. For best design-selection, supplementary decision functions (total-loss and loss-and -volume-product) are used together with the objective functions (core-loss, winding-loss, and total-volume) to enhance the optimal Pareto-solutions’ diversity and to assist designers in decision-making. The method is proven via comparison with existing benchmark-methods and validated through performance demonstration of LGHT-prototype in 400 Vdc-to-12 Vdc <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LLC</i> converter.

High-Frequency Transformer Design with Hollow Core for Solid State Transformer

Solid-state transformer (SST) is one of the new technologies that has kept pace with the development of renewable energy sources such as the solar energy and wind turbines. The SST consists of a high-frequency (HF) transformer and power electronic converter at both ends of the HF transformer. Despite the high efficiency of the traditional transformers, is they are quite large in size and also very heavy. In order to reduce the size and weight of the transformers, SST is used as an alternative for the conventional transformer which also brings along other advantages. The type of core material, the type of wire used, and the method of winding the coils on the HF transformer core affects the core losses, copper losses, the cost, efficiency, and power density of the HF transformer. In this paper a new method has been proposed to form the core of the HF transformer used in SST where a hollow core is used, thus reducing the size and weight of the HF transformer along with the reduction in the core loss. The proposed core is designed using ANSYS Maxwell 3D software in addition to calculating the inductance matrix and the coupling coefficient. Finally, the proposed model of a high-frequency transformer was simulated using MATLAB Simulink software.

Magnetic measurement and analysis of c-type amorphous by an improved adjustable air gap tester

A novel magnetic properties tester is designed to accurately and conveniently change the air gap of the core, which can fix cores of various types. The dynamic magnetic characteristics of the amorphous core under sinusoidal excitation within 20 kHz is measured with different air gap lengths and magnetic flux density. It is found that in the case of the small air gap, the total loss decreases as the air gap increases. When the frequency is 20 kHz and the flux density is 0.1 T, the loss can even be reduced by 7%. This paper analyzes the experimental data and summarizes the influence of the air gap and magnetic flux density about the core loss. Besides, the influence of air gap on magnetic flux density distribution is illustrated and analyzed by the means of FEM (Finite Element Method). It is valuable for the design of high frequency transformer and inductor.

Optimal design of minimal footprint high frequency transformer

Transformer design procedure may vary essentially in respect of the transformer type and its operating frequency (ranging between 50/60 Hz and a few megahertz). This paper presents a simple and straightforward method based on the optimal choice of core geometry of a high frequency transformer (HFT) used in Solid State Transformer (SST) applications. The core of SST is the HFT which largely influences its size and overall performance. The proposed design procedure for HFT focuses on optimizing the core geometry coefficient (in cm5) with a constraint inflicted on loss density. The core geometry coefficient has direct impact on the regulation and copper loss and the procedure results in a robust overall design with minimal footprint. Also, the procedure intends to bring all the operating parameters like regulation, losses and temperature rise within permissible limits while retaining desired efficiency. Thus an energy-efficient design is achieved with minimal footprint. The optimization procedure is implemented using recently developed Moth-flame Optimization (MFO) algorithm. The results of the MFO algorithm are compared with the wellestablished PSO technique. An experimental prototype is built to validate the findings.

Design of high frequency transformers in different shape of core using matlab program

&lt;p&gt;This paper deals with the design, simulation and implementation&lt;br /&gt;of the high-frequency transformer for a push-pull converter. It&lt;br /&gt;also includes transformer design and simulation for two switches,&lt;br /&gt;two outputs forward converter. Design these transformers by&lt;br /&gt;building a program, this program is designed in MATLAB&lt;br /&gt;software using a graphical user interface (GUI). The program is&lt;br /&gt;aimed to reduce the efforts and reduce the time compare with the&lt;br /&gt;manual design which takes time and effort. This paper provided&lt;br /&gt;the shape and geometry of the core that can influence the&lt;br /&gt;efficiency of the converter by designing these transformers in two&lt;br /&gt;types of core. The design results were validated by simulation in&lt;br /&gt;power simulation software (PSIM), and compare the results of&lt;br /&gt;simulation and design.&lt;/p&gt;

Increasing quality of SMPS through proper design of a high-frequency transformer

High frequency transformer significantly influences power losses, power density and efficiency of isolated switched mode power supply. With the use of optimal design of high frequency transformer, the higher efficiency and power density can be achieved. This is necessary for fulfilment of the upcoming regulations and standards of the dc-dc converters. This paper deals with verification of the design procedure of high frequency transformer, which id oriented for the achievement of high efficiency of switched mode power supply. For verification purposes simulation models of dc-dc converter together with precise model of high frequency transformer are developed. The proposed procedure serves for optimal selection of the best solution for high-frequency transformer in terms of ferrite material as well as shape of magnetic core.

High-Frequency Transformer Design for Modular Power Conversion From Medium-Voltage AC to 400 VDC

This paper presents a high-frequency modular medium-voltage AC (4160 VAC or 13.8 kVAC) to low-voltage DC (400 VDC) system that is scalable in order to be used for different scale microgrids. A 15 kW, 500 kHz DC/DC converter is demonstrated as the most important stage of the system overall, which can be scalable to a 225 kW 4160 VAC to 400 VDC system. Motivation of a CLLC resonant converter and its design parameters determination is carefully illustrated. The high-frequency transformer is the key element for the DC/DC converter. Then, the paper focuses on high-frequency transformer design to realize high-voltage insulation, high efficiency, and high density at the same time. Based on a split winding UU core transformer structure, transformer insulation materials and dimension parameters are determined referring to the IEEE insulation standard. The transformer magnetic loss model is reviewed based on which loss design tradeoff is carefully analyzed. Different working frequency impact on transformer design over three different core materials is also presented. Finally, a 500 kHz transformer prototype has been developed and demonstrated with the IEEE standard required insulation tests. A whole CLLC resonant converter is also present with experiments results. The converter holds outstanding 98% efficiency and 2.9 kW/L power density.

High Frequency Transformer Design and Optimization using Bio-inspired Algorithms

ABSTRACTHigh frequency (HF) transformer at the isolation stage of SST plays a vital role in deciding the power conversion efficiency of the SST system. This paper proposes a new design procedure for optimization of HF transformer used in SST applications such that it fulfils all the requirements pertaining to its operating conditions. The novel design procedure proposed is based on optimizing the core geometry (in 5th power of cm), which has direct influence on regulation and copper loss. An isolated half-bridge DC–DC converter topology is chosen for implementing the proposed design. Four bio-inspired algorithms, namely Particle swarm optimization (PSO), Whale Optimization algorithm (WOA), Dragonfly Algorithm (DA), and Ant Lion Optimizer (ALO) are used to solve the optimization problem and the results are compared with Genetic algorithm (GA). Finally, the optimization results are validated through PowerEsim, a web-based testing platform with huge database of real-time components from leading manufacturers across the globe.

ZVS Full Bridge Series Resonant Boost Converter with Series-Connected Transformer

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.

Loss Calculation and Optimization Design of High Frequency Transformer

In this paper, the magnetization and loss properties are analyzed and compared of topical magnetic materials. The calculation methods are studied for the losses of the core and windings of the High Frequency Transformer (HFT). Based on the evaluation of the temperature increment, an optimization method is presented for the design of HFT. Finally, the losses of a test model of HFT is calculated and the results are compared with those tested.

Optimal Design of High Frequency Transformer for 150W Class Module-Integrated Converter

Recently, the module-integrated converter has shown an interest in the photovoltaic generation system. In this system, the high frequency transformer should be compact and efficient. The proposed method is based on the correlation characteristic between the copper and core loss to minimize the loss of transformer. By sizing an effective cross-sectional area and window area of core, the amount of loss is minimized. This paper presents the design and analysis of high frequency transformer by using the 3D finite element model coupled with DC-DC converter circuit for more accurate analysis by considering the nonlinear voltage and current waveforms in converter circuit. The current waveform in each winding is realized by using the ideal DC voltage source and switching component. And, the thermal analysis is performed to satisfy the electrical and thermal design criteria.

Optimization Design of High Frequency Transformer for Multiple Outputs Switching Power Supply

With TOP243Y as control chip of multiplexed output flyback switch power supply, has the advantages of small volume, high integration and strong function, and the high-frequency transformer design and calculation large effect on the overall performance of multiple output the switch power supply. Based on the design computation to optimize the parameters of the transformer can be achieved to improve voltage accuracy, reducing the ripple effect. Seen from the experimental data and waveform of the switching power supply regulator, electromagnetic compatibility are good, meet the design requirements.

A Bidirectional UPS Inverter Utilising High Frequency Center–Tapped Transformer

A new variation of transformer-isolated inverter for UPS application is proposed. It is basically similar to the circuit proposed by Kourtroulis with the following modifications: 1) a modified modulation technique for the HF PWM interver stage and 2) replacing the full bridge active rectifier witha center-tapped active rectifier. With these modifications, the switches count is reduced, and expectedly, the efficiency is increased. Futhermore, the modified PWM technique will ensure that the transformer can be utilised near to its full potential. This is due to be absence of the low frequency component that can result in transformer saturation. The paper will detail the design considerations for the proposed topology. It will primarily focus on the power circuit, modulation method, and the high frequency transformer design. To prove the concept, a 1–kW prototype inverter was built and tested. Keywords: Inverter, bidirectional, high frequency transformer, pulse width modulation