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Search results for: MEDIUM FREQUENCY TRANSFORMER, POWER CONVERTER, DCDC, DUAL ACTIVE BRIDGE, SOLID STATE TRANSFORMER

3phase medium frequency transformer for a 100kW 1.2kV 20kHz Dual Active Bridge converter
PublicationThe article presents a threephase Medium Frequency Transformer being a part of a 100kW 1.2kV 20kHz Dual Active Bridge DCDC converter. The transformer design is detailed focusing on winding and core power loss calculation. The high power threephase MFT prototype is presented. The experimental results include the transformer impedance characteristics, no load test and threephase DAB full load test waveforms

Lagrangian model of an isolated dcdc converter with a 3phase medium frequency transformer accounting magnetic cross saturation
PublicationThis article presents a nonlinear equivalent circuit model of an isolated dcdc converter with a 3phase medium frequency transformer. The model takes into account the magnetic cross saturation of the 3phase coretype magnetic circuit. The model is suitable in detailed electromagnetic transient simulations of power systems involving isolated dcdc converters. The model is developed using the Lagrange energy method. It involves...

Dual Active Bridge (DAB) DCDC converter for multilevel propulsion converters for electrical multiple units (EMU)
PublicationSemiconductor power devices made from silicon carbide (SiC) reached a level of technology enabling their widespread use in power converters. Two different approaches to implementation of modern traction converters in electric multiple units (EMU) have been presented in recent years: (i) 3.3kV SiC MOSFETbased threelevel PWM inverter with regenerative braking and (ii) 6.5kV IGBTbased fourquadrant power electronic traction transformer...

Effective Permeability of Multi Air Gap Ferrite Core 3Phase Medium Frequency Transformer in Isolated DCDC Converters
PublicationThe magnetizing inductance of the medium frequency transformer (MFT) impacts the performance of the isolated dcdc power converters. The ferrite material is considered for high power transformers but it requires an assembly of type “I” cores resulting in a multi air gap structure of the magnetic core. The authors claim that the multiple air gaps are randomly distributed and that the average air gap length is unpredictable at the...

SiCbased phaseshift dual half bridge DCDC converter as a key component of multilevel cascaded MV converters
PublicationThe paper describes SiCbased dual half bridge (DHB) DCDC converter considered as a key component of high frequency isolated multilevel cascaded medium voltage converters. Two topologies of bidirectional DCDC converters: the resonant halfbridge DCDC converter and the phaseshift DHB converter are compared in the paper. Experimental results of SiCbased 50 kHz DHB DCDC converter are presented in the paper.

Power electronic transformer based on cascaded Hbridge converter
PublicationIn this paper the control strategy of power electronic transformer (PET) is proposed. The analyzed structure of PET uses two sevenlevel cascaded Hbridge (CHB) rectifiers. The electrical power of PET is transferred between DClinks of CHB converters using dualactivebridges (DABs) and low voltage high frequency transformers. The roposed solution allows for controlling the active and reactive power with a low level of harmonic...

Design of a SiC based triple active bridge ceil for a multimegawatt DCDC converter
PublicationThe paper describes the design methodology of a novel Triple Active Bridge cell used as the building block for modular DCDC converters. The intended application is for Medium Voltage Direct Current grids, such as the DC collector for offshore wind farms. The latest generation of SiC MOSFET semiconductors is utilized to operate in the medium frequency range while optimizing the efficiency. The dimensioning of the main cell components,...

Hysteresis modelling of a medium frequency singlephase transformer
PublicationThe article describes a feedback Preisach hysteresis model equivalent circuit implementation of a medium frequency singlephase transformer being a part of a high power and high efficiency DCDC converter. The macroscopic models of magnetic hysteresis are introduced and the feedback Preisach model is selected for further analysis. The hysteresis model is developed for a prototype transformer and the hysteresis loops are compared...

Power Electronic Transformer For Smart Grid Application
PublicationIn this paper the control system of Power Electronic Transformer (PET) for the Smart Grid application is proposed. The structure of PET is based on two Cascaded Hbridge (CHB) converters. The electrical energy is transferred between converters using DualActiveBridges (DAB) and highfrequency transformers. This type of coupling has been used to connect the DClinks of all Hbridges. The proposed control system for PET makes it...

Conjugated control of triple active bridge converter with common HFT
PublicationPaper presents synthetic analyses of single input, dual output DC/AC/DC converter with common high frequency transformer. Rise the problem of crosscoupling power flows between secondary terminals, under asymmetrical control operating condition. It also proposes a new approach to converter control, based on conjugated phase shift modulation and defines its limitations. Finally, the developed control technique was verified by simulation...

Structure and the space vector modulation for a mediumvoltage powerelectronictransformer based on two sevenlevel cascade Hbridge inverters
PublicationThis study presents the structure and the space vector pulsewidth modulation (SVPWM) for power electronic transformer (PET) based on two sevenlevel cascade Hbridge (CHB) inverters. The DC links of CHB inverters are coupled with nine dualactive bridge (DAB) converters with mediumfrequency transformers. The DClink voltages are equalised with two methods – through the control of DAB voltages...

Hybrid stepless distribution transformer with fourquadrant AC/DC/AC converter at low voltage side  simulation tests
PublicationThe article presents the work of the stepless hybrid distribution transformer (HT), as an alternative to the so far applied Automatic Voltage Regulator (AVR) solutions, used to control the voltage in the power system in terms of the fundamental harmonic. The HT is a combination of a conventional distribution transformer and an AC/DC/AC converter connected in series with the transformers secondary winding. In the work the basic...

MultiTransformer Flyback Converter for Supplying Isolated IGBT and MOSFET Drivers
PublicationA multi transformer flyback converter topology for supplying transistor drivers is presented. The topology presents some advantages over typical multi output single transformer, as reduction of effective leakage inductance, equal magnetic coupling between primary and secondary circuits and better isolation between outputs. Simulation study carried out in the LTSpice IV program and preliminary experimental results indicate high...

Power Electronics Building Blocks for implementing Smart MV/LV Distribution Transformers for Smart Grid
PublicationWith an observed increase in the involvement of active consumers in activities aimed at improving energy efficiency and increasing interest in producing energy from renewable sources, there is a need for the development of new technologies enabling the distribution network operators to offer new services and functionalities. Smart MV/LV distribution transformers are characterized by a compact threestage design, including an...

Multitransformer primaryside regulated flyback converter for supplying isolated IGBT and MOSFET drivers
PublicationThis paper presents primaryside voltage regulated multitransformer quasiresonant flyback converter (MTFC) for supplying isolated power switch drivers. The proposed topology offers distinct advantages over frequently used flyback converter possessing one high frequency transformer with isolated multiple outputs. Particularly, when a large number of separate dc supply units is required, then MTFC enables improved regular distribution...

Przegląd systemów ładowania elektrycznych osobowych pojazdów i koncepcja dwukierunkowej ładowarki pokładowej
PublicationAktualnie trwa intensywny rozwój pojazdów elektrycznych (EV) i hybrydowych typu plugin (PHEV) z pokładowymi bateriami akumulatorów. Badania w tej dziedzinie skupiają się na maksymalizowaniu sprawności oraz minimalizowaniu masy i objętości systemów ładowania baterii. W artykule przedstawiono podział systemów ładowania osobowych pojazdów typu EV/PHEV. Opisano systemy ładowania przewodowego z podziałem na ładowarki pokładowe i zewnętrzne, systemy...

Low Current Transformer Utilizing CoBased Amorphous Alloys
PublicationMetal oxide surge arresters have been widely used for protection of power system networks against overvoltages due to atmospheric discharges or malfunction of devices connected to the network. During its operation a surge arrester structure is degradated, what can be observed as an increase of a surge arrester leakage current. Paper presents an implementation of a new, highpermeability, Co64Fe4Ni1Si15B14 amorphous alloy as a current...

Low current transformer utilizing Cobased amorphous alloys
PublicationMetal oxide surge arresters have been widely used for protection of power system networks against overvoltages due to atmospheric discharges or malfunction of devices connected to the network. During its operation a surge arrester structure is degradated, what can be observed as an increase of a surge arrester leakage current. Paper presents an implementation of a new, highpermeability, Co64Fe4Ni1Si15B14 amorphous alloy as a current...

Comparison of ImpedanceSource Networks for Two and Multilevel Buck–Boost Inverter Applications
Publicationmpedancesource networks are an increasingly popular solution in power converter applications, especially in singlestage buckboost power conversion to avoid additional frontend dcdc power converters. In the survey papers published, no analytical comparisons of different topologies have been described, which makes it difficult to choose the best option. Thus, the aim of this paper is to present a comprehensive analytical comparison...

Laboratory Load Model Based on 150 kVA Power Frequency Converter and Simulink RealTime – Concept, mplementation, Experiments
PublicationFirst section of the paper provides technical specification of laboratory load model basing on 150 kVA power frequency converter and Simulink RealTime platform. Assumptions, as well as control algorithm structure is presented. Theoretical considerations based on criteria which load types may be simulated using discussed laboratory setup, are described. As described model contains transformer with thyristorcontrolled tap changer,...

Jednofazowy falownik napięcia z aktywnym obwodem odsprzęgającym
PublicationZnanym zagadnieniem w jednofazowych falownikach napięcia jest pobieranie ze źródła napięcia stałego składowej przemiennej o częstotliwości dwukrotnie większej od częstotliwości generowanej przez falownik. Jednym z rozwiązań problemu jest stosowanie dużej baterii kondensatorów elektrolitycznych, lecz lepszym sposobem z punktu widzenia niezawodności i gęstości mocy przekształtnika jest stosowanie aktywnych układów odsprzęgania mocy....

Adaptive estimation of the transformer stray capacitances for DC–DC converter modelling
PublicationNew low cost and accurate estimation method of transformer stray capacitances for wide band DC–DC converter modelling and design is proposed. The Wiener filter (WF) method is applied to estimate the transformer impedance – referred to the selected transformer winding configurations. Laboratory tests are used to adapt the filter, that is to find optimal impedance which minimises mean square error between measured, noise perturbed...

Determination of Mathematical Model Parameters of a Medium Frequency Transformer
PublicationThe paper presents the results of experimental studies of the medium frequency transformer. The object of the research was a prototype of a singlephase transformer with a core made of ferrite Icore elements and windings made of Litz conductors. The research was carried out to determine the parameters of the transformer's mathematical model. The scope of the tests included determining the magnetic hysteresis loop and measuring...

Prediction of ringing frequencies in DCDC boost converter
PublicationIn the paper ringing phenomena in a DCDC boost converter is presented. The ringing frequency is calculated using an analytical formula. The necessary wide band models of MOSFET transistor, passive and parasitics are described. The calculation results are verified in simulation and laboratory tests.

LightPowered Starter for MicroPower Boost DC–DC Converter for CMOS Image Sensors
PublicationThe design of a starter for a lowvoltage, micropower boost DC–DC converter intended for powering CMOS image sensors is presented. A unique feature of the starter is extremely low current, below 1 nA, supplying its control circuit. Therefore, a highvoltage (1.3 V) configuration of seriesconnected photovoltaic diodes available in a standard CMOS process or a small external LED working in photovoltaic mode can be used as an auxiliary...

LightPowered Starter for MicroPower Boost DC–DC Converter for CMOS Image Sensors
PublicationThe design of a starter for a lowvoltage, micropower boost DC–DC converter intended for powering CMOS image sensors is presented. A unique feature of the starter is extremely low current, below 1 nA, supplying its control circuit. Therefore, a highvoltage (1.3 V) configuration of seriesconnected photovoltaic diodes available in a standard CMOS process or a small external LED working in photovoltaic mode can be used as an auxiliary...

EMI attenuation in a DCDC buck converter using GaN HEMT
PublicationA dcdc buck converter using gallium nitride (GaN) high electron mobility transistors (HEMT) is experimentally investigated at the discontinuous current mode (DCM) and at the triangular current mode (TCM) operation. The paper objective is to specify the power conversion efficiency and attenuation of common mode (CM) and differential mode (DM) noise voltage, measured at the line impedance stabilization network (LISN) for compared...

Nonisolated resonant quasiZsource network DC–DC converter
PublicationA novel nonisolated resonant quasiimpedance (quasiZ)source network DC–DC converter is proposed. The resonant impedance source network is derived from the quasiZsource network by including the autotransformerbased resonant cell instead of the second inductor of the quasiZnetwork. The leakage inductance of the autotransformer and two resonant capacitors connected in series with the autotransformer windings constitute a highfrequency...

Accurate modeling of layout parasitic to forecast EMI emitted from a DCDC converter.
PublicationThis paper illustrates how to account for all parasitic due to the layout of a power converter (inductive and capacitive), in order to forecast electromagnetic interferences (EMI). The method is generic, and is validated here in the simple example of a DCDC converter, realized on different technologies: insulated metal substrate (IMS), printed circuit board (PCB). In addition, several layouts aspects will be investigated. Conclusions...

DClink voltage balancing in cascaded HBridge converters
PublicationIn the paper a DClink voltage balancing strategy for multilevel Cascaded HBridge (CHB) converter is proposed. Presented solution bases on optimal choice of active vector durations in SpaceVector Pulse Width Modulation (SVPWM). It makes it possible to DClink voltages control and to properly generate the output voltage vector in the case of DClink voltage unbalance. Results of simulation and experimental researches...

Size and mass minimization of capacitor bank in a power converter DC line of DC drive with closed loop control system with PWM and current limitation
PublicationPaper deals with evaluation equations for power filter of ACDC power converter which allows to provide size and mass minimization of capacitor bank in DC drive closed loop systems with PWM and current limitation. Reliability of provided equations is proved by simulation in MATLAB/Simulink

Unidirectional DC/DC Converter with Voltage Inverter for Fast Charging of Electric Vehicle Batteries
PublicationThe paper proposes the adaptation of the industrial plant’s power network to supply electric vehicle (EV) fastcharging converters (above 300 kW) using renewable energy sources (RESs). A 600 V DC microgrid was used to supply energy from RESs for the needs of variable speed motor drives and charging of EV batteries. It has been shown that it is possible to support the supply of drive voltage frequency converters (VFCs) and charging...

High Frequency Harmonics Emission of Modern Power Electronic ACDC Converters
PublicationModern AC/DC converters with bidirectional power flow employing PWM boost topology generate harmonic distortions of input current in relatively high frequency range tightly related to modulation carrier frequency. These frequencies and its multiples in typical applications are usually located in frequency range from single up to several of kHz. Increased harmonic emission in this frequency range can easily and harmfully influence...

Modeling of conducted emission of dcdc switchmode converter
PublicationW publikacji zaprezentowano sposób modelowania i wyznaczania emisji przewodzonej zaburzeń elektromagnetycznych w przekształtnikach energoelektronicznych. Na przykładzie przekształtnika DCDC, zostały dobrane odpowiednie narzędzia CAD do szerokopasmowego modelowania i symulacji przekształtnika energoelektronicznego. Otrzymane rezultaty zostały eksperymentalnie potwierdzone i porównane zarówno w dziedzinie czasu jak i częstotliwości...

Optimisation of ZVZCS DC/DC converter with tapped inductor.
PublicationW artykule zaprezentowano możliwości wykorzystania dławika z odczepem oraz obwodu LC w celu uzyskania warunków miękkiej komutacji kluczy energoelektronicznych w przetwornicy DCDC.Na podstawie modelu matematycznego zbadany został wpływ wartości elementów na zachowanie miękkiej komutacji.Przedstawiono wyniki badań symulacyjnych i eksperymentalnych.

Four Level DiodeClamped BackToBack Converter with Active DC Link Voltage Control
PublicationThis article presents the design and control of 4LDC backtoback converter. To solve the DC link voltage balancing problem in fourlevel converter a new threelevel double chopper topology based on POPWM modulation was designed and successfully tested. Also, the paper describes two phase space vector pulse width modulation 2PSVPWM based on the shape function of finite elements. The control structure with modified DeadBeat...

Solid State Phenomena
Journals 
Analysis of transformer state by fuzzy TOPSIS and AHP method
PublicationThe paper presents mathematical models TOPSIS and AHP methods, which was utilized on insulating state of distribution transformer to analyze and sensibility of individual measurements methods mutual comparison. We can uniquely determine the importance of these measurements methods with this mathematical apparatus in these measurements methods in insulating state of transformers.

Implementation of power transformer controlled switching algorithm
PublicationThe article presents two new algorithms of controlled switching the power transformer. The main aim of the paper is to obtain formulas that determine the moments of closing of the circuit breaker poles. The study contains projects of control systems for both algorithms. Mathematical formulas for the time instants of the breaker poles closing were developed on the basis of electric circuit theory and magnetic circuit theory. The...

Four level inverter's DC bus voltage balancing with 3terminal DAB converter
Publication—Multilevel inverters become more and more popular, especially in the medium or high voltage and high power applications. Unfortunately, some of inverter topologies require additional DC bus voltage balancing systems. This paper presents a novel approach to such systems, which is based on a multiple terminal DAB converter. Along with the voltage balancing function the proposed solution enables the connection of energy storage devices...

New highgain stepup DC/DC converter with highfrequency isolation
Publication 
Transient modeling in common DC link of power converters
PublicationПредмет исследования. Представлена математическая модель силовых преобразователей электропривода, питающихся от общего звена постоянного тока, на примере тяговых электроприводов карьерного самосвала БЕЛАЗ90 мощностью 280 кВт. Модель выполнена в пакете MATLAB/Simulink. Новизна предложенной модели заключается в применении новой топологии силовой схемы для исследования работы двух инверторов, под ключенных к одному звену постоянного...

A simple modular active power electronic transformer
Publication 
Mathematical analysis of transformer insulation state by means of composite indicator
PublicationThe paper is presenting mathematical model – composite indicator (CI), which was utilized on insulating state of distribution transformer to analyze and sensibility of individual measurements methods mutual comparison. We can uniquely determine importance of these measurements methods with this mathematical apparatus in these measurements methods in insulating state of transformers.

A Canonical Switched Capacitor DCDC Converter. A look at how the historical SC synthesis problem is getting solved
PublicationWe reconsider a solution to the historical problem in switched capacitor (SC) DCDC converter synthesis. Specifically, we retackle the problem of constructing an SC twophase network realizing arbitrary voltage conversion ratio within rational bounds defined. Theoretical foundations are available in our earlier research [3] where a nonconstructive proof of existence was given. We briefly review and comment on known circuit solutions...

Activity coordination of capacitor banks and power transformer controllers in order to reduce power losses in the MV grid
PublicationOne of the main issues related to the optimization of the MV (middle voltage) network is to reduce losses of active and reactive power. Lower losses of active and reactive power give not only economic advantage, but also improvement of energy quality. The object of regulation that can be used for these purposes are transformer with OnLoad Tap Changer and capacitor's banks. This paper presents results of analysis of the possibility...

Simplified saturation modelling in threeleg power transformer for the system stability analisys
PublicationThe paper presents a simplified method for modelling nonlinearity of the magnetic circuit of the power transformer. The saturation effect is implemented by describing the self and mutual inductances as a function of the magnetic flux. The most important element of this function is the saturation coefficient which is calculated based on transient state during the unloaded transformer switch on. The transformer model is described...

Control strategy for the multilevel cascaded Hbridge converter
PublicationThe paper presents the control strategy for Cascaded Hbridge (CHB) converter . The converter output voltage using SpaceVector Pulse Width Modulation (SVPWM) strategy is controlled. The DClink voltages are controlled by appropriate choice of HBridges and appropriate choice of active and passive vectors.

A method of nonlinearities of transformer noload characteristic modelling
PublicationA way in which changes of the noload characteristic are taken into account in the mathematical model of the transformer is presented. Changes of saturation within core of transformer are presented as a combined nonlinear flux curve. Analysis of magnetization of the transformer core and simulation of noload state for distribution transformer of 30 kVA power rating and 15.75/0.4 kV/kV (especially supplying VLV) transformation...

Design of a simple modular active power electronic transformer
Publication