Modelling and Design of HF 200 kHz Transformers for Hard- and Soft-Switching Application

1970 ◽  
Vol 110 (4) ◽  
pp. 7-12 ◽  
Author(s):  
R. Radvan ◽  
B. Dobrucky ◽  
M. Frivaldsky ◽  
P. Rafajdus
Keyword(s):  
Low Power ◽  
Numerical Simulations ◽  
Soft Switching ◽  
Power Transformers ◽  
Leakage Inductance

The paper deals with modelling and design of HF 200 kHz (and more) low-power transformers with determinated leakage induct-ances for both hard- and soft-switching applications. The first group features by small value of the leakage inductance contrary to sec-ond one demanding that value substantially higher. The further aims of the design are minimized weights and dimensions of the trans-formers. Results of numerical simulations and experimental verifications of designed transformers operated in converter circuits are given at the end of the paper. Ill. 13, bibl. 5, tabl. 2 (in English; abstracts in English and Lithuanian).http://dx.doi.org/10.5755/j01.eee.110.4.276

Simulation of Modified Flyback Snubber Circuit for Isolated Bidirectional DC-DC Converter

2018 ◽  
Vol 19 (5) ◽  
Author(s):  
Kunalkumar Prakashbhai Bhatt ◽  
Ram Avtar Gupta ◽  
Nitin Gupta
Keyword(s):  
High Efficiency ◽  
Semiconductor Devices ◽  
Soft Switching ◽  
Leakage Inductance ◽  
Snubber Circuit ◽  
Mode Of Operation ◽  
Active Clamp ◽  
Semiconductor Switch ◽  
Effective Performance ◽  
Current Difference

Abstract Abstract: In this paper, a modified flyback snubber circuit for isolated bidirectional DC-DC converter has been introduced. The soft switching isolated snubber circuit provides an alternative path for the current difference created due to source inductance and leakage inductance. The auxiliary snubber circuit operates during the step-up conversion, and it only persists of the two semiconductor switch, two inductors one diode and two capacitors. Both semiconductor devices (G1, G2) of flyback snubber circuit achieve soft switching during turn ON and turn OFF condition. The PWM technique has been used to control the semiconductor devices. The different mode of operation has been discussed in detail. The effective performance of proposed converter system has been validated with the PSIM simulation tool. The proposed converter is compared with the active clamp converter based on efficiency. The loss comparison proves that flyback snubber circuit has high efficiency compared to active clamp converter.

Gradient-based algorithm for the distinction of fault and inrush currents in low power transformers

2021 ◽  
Author(s):  
Robson Fabricio Pinto Moreira ◽  
Vinicius Marins Cleff ◽  
Everton Granemann Souza ◽  
Chiara D. Do Nascimento
Keyword(s):  
Low Power ◽  
Power Transformers ◽  
Gradient Based ◽  
Inrush Currents

scholarly journals On Simplified Calculations of Leakage Inductances of Power Transformers

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4952 ◽  
Author(s):  
Tadeusz Sobczyk ◽  
Marcin Jaraczewski
Keyword(s):  
Power Transformer ◽  
Short Circuit ◽  
Power Transformers ◽  
Stray Field ◽  
Good Representation ◽  
The Finite Element Method ◽  
Leakage Inductance ◽  
Leakage Flux ◽  
Calculation Results ◽  
Discrete Differential Operator

This paper deals with the problem of the leakage inductance calculations in power transformers. Commonly, the leakage flux in the air zone is represented by short-circuit inductance, which determines the short-circuit voltage, which is a very important factor for power transformers. That inductance is a good representation of the typical power transformer windings, but it is insufficient for multi-winding ones. This paper presents simple formulae for self- and mutual leakage inductance calculations for an arbitrary pair of windings. It follows from a simple 1D approach to analyzing the stray field using a discrete differential operator, and it was verified by the finite element method (FEM) calculation results.

scholarly journals Novel Remanence Determination for Power Transformers Based on Magnetizing Inductance Measurements

Energies ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4616
Author(s):  
Chen Wei ◽  
Xianqiang Li ◽  
Ming Yang ◽  
Zhiyuan Ma ◽  
Hui Hou
Keyword(s):  
Numerical Simulations ◽  
Laboratory Experiments ◽  
Power Transformer ◽  
Power Transformers ◽  
Inrush Current ◽  
The Core ◽  
Novel Method ◽  
Simulation Results ◽  
Electro Magnetic ◽  
The Relationship

The remanence (residual flux) in the core of power transformers needs to be determined in advance to eliminate the inrush current during the process of re-energization. In this paper, a novel method is proposed to determine the residual flux based on the relationship between residual flux and the measured magnetizing inductance. The paper shows physical, numerical, and analytical explanations on the phenomenon that the magnetizing inductance decreases with the increase of residual flux under low excitation. Numerical simulations are performed by EMTP (Electro-Magnetic Transient Program) on a 1 kVA power transformer under different amounts of residual flux. The inductance–remanence curves are nearly the same when testing current changes. Laboratory experiments conducted on the same transformer are in line with the numerical simulations. Furthermore, numerical simulation results on a 240 MVA are reported to demonstrate the effectiveness of the proposed method.

scholarly journals Leakage Inductances of Transformers at Arbitrarily Located Windings

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6464
Author(s):  
Marcin Jaraczewski ◽  
Tadeusz Sobczyk
Keyword(s):  
Differential Operators ◽  
Short Circuit ◽  
The Self ◽  
Power Transformers ◽  
Stray Field ◽  
The Finite Element Method ◽  
Leakage Inductance ◽  
Leakage Flux ◽  
Partial Differential Operators ◽  
Internal Asymmetry

The article presents the calculation of the leakage inductance in power transformers. As a rule, the leakage flux in the transformer window is represented by the short-circuit inductance, which affects the short-circuit voltage, and this is a very important factor for power transformers. This inductance reflects the typical windings of power transformers well, but is insufficient for special transformers or in any case of the internal asymmetry of windings. This paper presents a methodology for calculations of the self- and mutual-leakage inductances for windings arbitrarily located in the air window. It is based on the 2D approach for analyzing the stray field in the air zone only, using discrete partial differential operators. That methodology is verified with the finite element method tested on real transformer data.

scholarly journals Development of model of transient modes taking into account mutual inductance of scattering fields for implementation of digital twin of transformer

Vestnik IGEU ◽  
2021 ◽  
pp. 47-56
Author(s):  
I.S. Snit’ko ◽  
A.I. Tikhonov ◽  
A.V. Stulov ◽  
V.E. Mizonov
Keyword(s):  
Mathematical Models ◽  
Simulation Models ◽  
Mutual Inductance ◽  
Power Transformers ◽  
Electrical Networks ◽  
Production Environment ◽  
Modes Of Operation ◽  
Matlab Simulink ◽  
Leakage Inductance ◽  
Comparison Of The Results

Development of the refined mathematical models of power transformers (digital twins), which make it possible to calculate arbitrary modes of operation of these devices with high accuracy and increased speed is an urgent task. Currently, such problems are solved using simulation packages such as MatLab Simulink. One of the disadvantages of the existing simulation models of the transformer is the assumption that own leakage inductance of the windings is used. This assumption is not always acceptable. Thus, the purpose of this article is to develop models of transformers using matrices of mutual inductance of the scattering field. The finite element method is used to calculate the magnetic field in a 2D formulation, implemented by means of the EMLib library, as well as simulation methods with the MatLab Simulink package are applied. The authors have estimated the features and basic assumptions while developing refined mathematical models of power transformers of various designs (two- and three-winding). It makes possible to ensure the required accuracy when simulating transient and emergency modes of transformer operation. Field models have been developed to determine the own and mutual scattering inductance matrices. Simulation models of transformers of various designs with the use of winding leakage inductance matrices have been developed. The results of simulation of dynamic processes in a transformer in various modes are presented. Comparison of the results of the operation of models with matrices of mutual inductances and without them is carried out. The results of the research can be used during the design of power transformers in design companies and in production environment. It is also possible to use the developed models during operation of power transformers for the analysis of static and dynamic modes of operation of sections of electrical networks.

scholarly journals Three-Phase Three-Level Isolated DC-DC Soft Switching Converter For Solar Applications

2021 ◽  
Vol 9 (2) ◽  
pp. 443-451
Author(s):  
K.Girinath Babu, Et. al.
Keyword(s):  
Input Voltage ◽  
Soft Switching ◽  
Leakage Inductance ◽  
Switching Converter ◽  
Three Phase ◽  
Voltage Stress ◽  
Converter Topologies ◽  
Total Leakage ◽  
Converter Topology ◽  
Output Filter

Three-level isolated DC-DC converter is an attractive topology in high input voltage applications, which can provide the voltage stress of the power devices to only a half of the dc voltage and also reduce the size of dc filter requirement. But major limitations in the existing three level ZVS converter topologies are brought out with an increased inductance in the primary side and it required to provide complete ZVS of all primary devices down to light loads. By employing an external inductance in the primary of the transformer, total leakage inductance of the transformer increases which is required for realization of soft switching of the converter switches but there are some disadvantages of connecting external inductance in the primary of the transformer. To overcome all these drawbacks, the     three-phase three-level isolated DC-DC soft switching converter has been proposed in order to reduce voltage and current stresses. This converter topology requires less number of control switches and operates with an asymmetrical duty cycle control. The proposed three level DC-DC converters provide two- level voltage waveform before dc output filter, which significantly reduce the size of dc output filter. The proposed work has been implemented using MATLAB/SIMULINK and the performance of the proposed converter is verified through simulation results.  

Series-Loaded Resonant Converter DC-DC Buck Operating for Low Power

2017 ◽  
Vol 8 (1) ◽  
pp. 159
Author(s):  
M. F. Omar ◽  
H. C. M. Haris
Keyword(s):  
Low Power ◽  
High Frequency ◽  
Buck Converter ◽  
Soft Switching ◽  
Switching Topology ◽  
Resonant Converter ◽  
Zero Voltage Switching ◽  
Bridge Rectifier ◽  
Zero Voltage ◽  
Voltage Switching

This paper presents the functions of Series-Loaded Resonant Converter (SLRC). Series Loaded Resonant DC-DC converter is a type of soft-switching topology widely known for providing improved efficiency. Zero voltage switching (ZVS) buck converter is more preferable over hard switched buck converter for low power, high frequency DC-DC conversion applications. Zero Voltage switching techniques will be used to improve the efficiency of current and voltage at the series loaded half-bridge rectifier. The results will be described from PSIM simulation, Programming of MATLAB calculation and hardware testing.

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