scholarly journals Power Balance Method using Coupled Shunt Inductor and Multiple-Input Transformer for ISOP LLC Converter

Electronics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 352
Author(s):  
Soon-Sang Hwang ◽  
Seung-Woo Baek ◽  
Hag-Wone Kim
Keyword(s):  
High Capacity ◽  
Magnetic Coupling ◽  
Input Voltage ◽  
Power Balance ◽  
Switching Function ◽  
Power Imbalance ◽  
Fast Switching ◽  
Multiple Input ◽  
In Series ◽  
Input Transformer

High-capacity power-supply systems using a large input voltage typically improve efficiency and can be miniaturized by dividing the input voltage into multiple small voltages, thereby minimizing the stress on the switching element and thus materializing a fast switching function. When a large input voltage is divided into small voltages in series through a DC link capacitor, power is supplied to each converter and the power of each LLC (Inductor-Inductor-Capacitor) converter can be divided and converted. However, such LLC converters, which are configured by the division of the input voltage, have power imbalance due to the parameter variation between active and passive elements of the power board, which results in an increase in the stress and heat of a particular element. As this problem of power balance necessitates a design for securing a power margin and as the heated element increases its volume, the efficiency and reliability of the LLC converter are degenerated. Accordingly, this study attempted to solve the problem of the power imbalance of LLC converters at each level using a coupled shunt inductor and multiple-input transformers sharing magnetic coupling.

scholarly journals Evaluating Alternative Seed-Cotton Reclaimers for High-Speed Roller Ginning

2020 ◽  
Vol 36 (3) ◽  
pp. 245-256
Author(s):  
Carlos B. Armijo ◽  
Derek P. Whitelock ◽  
Paul A. Funk ◽  
Joe W. Thomas
Keyword(s):  
Upland Cotton ◽  
High Speed ◽  
High Capacity ◽  
Seed Storage ◽  
List Type ◽  
Seed Cotton ◽  
Seed Loss ◽  
Pima Cotton ◽  
Full Speed ◽  
In Series

HighlightsExperimental high-capacity seed-cotton reclaimers were evaluated for the growing high-speed roller-ginning industry.The experimental reclaimers minimized the amount of seed-cotton loss compared to the conventional reclaimer, but had more seed loss than a conventional reclaimer.The conventional reclaimer had the lowest combined seed and lint loss when processing Pima cotton.An experimental reclaimer based on a current cotton gin machine had seed and lint losses nearly $10 per cotton bale less than the conventional reclaimer when processing Upland cotton.Abstract. In a roller ginnery, a reclaimer machine removes partially-ginned or unginned seed cotton (carryover) from the mixture of carryover and ginned cottonseed that is expelled from the roller-gin stand during operation and returns the carryover to the gin stand for re-ginning. Conventional seed-cotton reclaimers are marginally adequate in their capacity to handle the increased carryover that high-speed roller ginning produces. Overloading a reclaimer often leads to choke-ups and downtime for the ginnery. The objective of this study was to develop and test high-capacity reclaimers. A modified 3-saw cylinder stick machine and a modified 2-saw cylinder gin-stand feeder were tested and compared to a conventional reclaimer. The saw-cylinders in the modified machines were operated at standard full speed, 1/2 of full speed, and 3/4 of full speed. Both Pima and Upland cotton were included in this study because there is a sizable amount of roller-ginned Upland cotton. Results showed that the experimental reclaimers reclaimed more carryover than the conventional reclaimer. An effective reclaimer will 1) reclaim carryover without also capturing residual seed that will likely be removed with cotton trash when returned to the gin stand feeder (seed loss) and 2) allow seed to pass through to the seed storage while minimizing the amount of residual carryover that escapes with the seed (carryover loss). The experimental reclaimers minimized the amount of residual carryover loss, but they had more residual seed loss than the conventional reclaimer. Increasing the saw-cylinder speeds of the experimental reclaimers decreased the residual seed loss but increased the residual carryover loss. Estimates of the value of the lost seed and of the lint on the lost carryover revealed that the conventional reclaimer had the lowest combined loss of $3.56 per bale when processing Pima cotton and the experimental 2-saw feeder with saw-cylinders operating at full speed had the lowest combined loss of $6.89 per bale when processing Upland cotton. The results suggest that losses of lint and seed may be further reduced by using a combination in series of different types of reclaimers to take advantage of each of their respective best features. Keywords: Cotton ginning, Roller ginning, Seed-cotton reclaimer.

scholarly journals A Single-Phase Nine-Level Boost Inverter

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 394 ◽  
Author(s):  
Dai-Van Vo ◽  
Minh-Khai Nguyen ◽  
Duc-Tri Do ◽  
Youn-Ok Choi
Keyword(s):  
Output Voltage ◽  
Single Phase ◽  
Simple Structure ◽  
Input Voltage ◽  
Maximum Output ◽  
Power Switches ◽  
In Series ◽  
Simulation And Experiment ◽  
Laboratory Prototype ◽  
Circuit Configuration

A novel single-phase nine-level boost inverter is proposed in this paper. The proposed inverter has an output voltage which is higher than the input voltage by switching capacitors in series and in parallel. The maximum output voltage of the proposed inverter is determined by using the boost converter circuit, which has been integrated into the circuit. The proposed topology is able to invert the multilevel voltage with the high step-up output voltage, simple structure and fewer power switches. In this paper, the circuit configuration, the operating principle, and the output voltage expression have been derived. The proposed converter has been verified by simulation and experiment with the help of PSIM software and a laboratory prototype. The experimental results match the theoretical calculation and the simulation results.

scholarly journals A new kind of solid-state Marx generator based on transformer type magnetic switches

2013 ◽  
Vol 31 (2) ◽  
pp. 239-248 ◽  
Author(s):  
Yu Zhang ◽  
Jinliang Liu
Keyword(s):  
Solid State ◽  
Life Time ◽  
Input Voltage ◽  
Magnetic Core ◽  
Marx Generator ◽  
Magnetic Switch ◽  
Transformer Type ◽  
In Series ◽  
New Type ◽  
High Level

AbstractIn this paper, a new kind of solid-state Marx generator based on synchronous transformer type magnetic switches (TTMS) is put forward, and the TTMSs with new winding structures are used to substitute all the spark gaps in the traditional Marx generator for the purposes of solidification and long life time. As the new type of TTMS with high step-up ratio and low saturated inductances is employed, the proposed Marx generator becomes a compact combination of pulse transformer, magnetic switch, and Marx capacitors. The stages of the Marx capacitors can be synchronously charged in parallel before the magnetic core saturates, and these Marx capacitors also can synchronously discharge in series. The establishing time of the proposed Marx generator is at ns range. As the new type of self-reset TTMS is used, the input voltage of the Marx generator decreases to a low level less than 1 kV while the output voltage can easily reach a high level ranging from dozens of kV to hundreds of kV.

scholarly journals Dual Active Bridge (DAB) DC-DC converter for multilevel propulsion converters for electrical multiple units (EMU)

2018 ◽  
Vol 180 ◽  
pp. 04002
Author(s):  
Marek Adamowicz ◽  
Zbigniew Krzemiński ◽  
Paweł Stec
Keyword(s):  
Input Voltage ◽  
Regenerative Braking ◽  
Power Electronic ◽  
Power Devices ◽  
Medium Frequency ◽  
Pwm Inverter ◽  
Fast Switching ◽  
Dual Active Bridge ◽  
Power Modules ◽  
Multiple Units

Semiconductor 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) 3.3-kV SiC MOSFET-based three-level PWM inverter with regenerative braking and (ii) 6.5-kV IGBT-based fourquadrant power electronic traction transformer (PETT). The former has successfully reached optimized dimensions and efficiency but still requires a bulky line frequency transformer for multisystem applications. The latter characterizes inherent galvanic isolation from AC traction, which is realized by cascaded system of power electronic cells containing medium frequency transformers (MFT). The downsizing of the 6.5-kV IGBT-based cells is, however, problematic. The present paper proposes a different approach, that involves the use of a fast switching 1.2-kV SiC MOSFETS. The SiC-based PETT proposed in the paper is dedicated first for the DC traction. For multi-system application the input voltage of the proposed PETT can be adjusted using weight-optimized adjusting autotransformer. Thanks to utilization of fast-switching SiCbased power modules the weight and size of the power electronic cells can be optimized in a convenient way.

The Application of a Portable DMFCs Stack With Fractal Current Collectors Using Hilbert Geometry for a Charger System

2009 ◽  
Author(s):  
Shah-Rong Lee ◽  
Yean-Der Kuan ◽  
Min-Feng Sung ◽  
Jing-Yi Chang ◽  
Shi-Min Lee
Keyword(s):  
Plate Thickness ◽  
Input Voltage ◽  
Bipolar Plate ◽  
Power Balance ◽  
Third Order ◽  
Current Collectors ◽  
Hilbert Geometry ◽  
Direct Methanol ◽  
System Output ◽  
Methanol Fuel Cell

The study develops a portable charger platform that contains a direct methanol fuel cell (DMFC) consisting of a set of planar DMFCs with current collectors, Fractal Hilbert Geometry and a power balance plant (BOP). The third order Hilbert geometry is used for the 35×35 mm2 current collectors. The system output design is set at 5V controlled by a power balance plant applied to 3C low power products. This paper discusses the Methanol feed rate, air flow rate, bipolar plate thickness and power balance plant layout for DMFC performance. To evaluate the reliability and efficiency of the DMFC power source, a data acquisition (DAQ) system connected to a real time monitor is used to assess the current and voltage output from the DMFC system while running different parameters. The results show the current of the charger system obtain 84 mA and 103 mA under 2V and 3V input voltage converters respectively. The transform efficiency for power balance plant is up to about 84% for 3V input voltage converter.

scholarly journals Detecting Load Resistance and Mutual Inductance in Series-Parallel Compensated Wireless Power Transfer System Based on Input-Side Measurement

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Longzhao Sun ◽  
Mingui Sun ◽  
Dianguang Ma ◽  
Houjun Tang
Keyword(s):  
Wireless Power Transfer ◽  
Input Voltage ◽  
Load Resistance ◽  
Mutual Inductance ◽  
Input Current ◽  
Power Transfer ◽  
Wireless Power ◽  
Direct Measurements ◽  
Input Side ◽  
In Series

In wireless power transfer (WPT) system, the variations in load resistance and mutual inductance influence the output voltage and output current, making the system deviate from its desirable operating condition; hence, it is essential to monitor load resistance and mutual inductance. Using input-side measurement to detect load resistance and mutual inductance has great advantages, because it does not need any direct measurements on the receiving side. Therefore, it can remove sensors on the receiving side and eliminate communication system feeding back the load measurements. This paper investigates load resistance and mutual inductance detection method in series-parallel compensated WPT system. By measuring input current and input voltage, the equation for calculating load resistance is deduced; when the operating frequency is lower than or equal to the receiving-side resonant frequency, the rigorous mathematical derivations prove that load resistance can be uniquely determined by using only one measurement of input current and input voltage. Furthermore, the analytical expressions for identifying load resistance and mutual inductance are deduced. Experiments are conducted to verify the proposed method.

scholarly journals Radio Vortex–Multiple-Input Multiple-Output Communication Systems With High Capacity

IEEE Access ◽  
2015 ◽  
Vol 3 ◽  
pp. 2456-2464 ◽  
Author(s):  
Qibiao Zhu ◽  
Tao Jiang ◽  
Daiming Qu ◽  
Da Chen ◽  
Nanrun Zhou
Keyword(s):  
Communication Systems ◽  
Multiple Input Multiple Output ◽  
High Capacity ◽  
Multiple Input ◽  
Input Multiple Output

scholarly journals Energy and noise characteristics of a SEPIC buck-boost converter with unipolar and bipolar output

2021 ◽  
Vol 9 (4) ◽  
pp. 9-19
Author(s):  
V. P. Babenko ◽  
V. K. Bityukov
Keyword(s):  
Output Voltage ◽  
Circuit Simulation ◽  
Spectral Characteristics ◽  
Magnetic Coupling ◽  
Input Voltage ◽  
Boost Converter ◽  
Practical Implementation ◽  
Noise Characteristics ◽  
Wide Range ◽  
Negative Output

Some advantages of the SEPIC buck-boost converter makes it stand out from other configurations. It makes possible to obtain from a unipolar input voltage both unipolar and bipolar output voltage with a good symmetry between positive and negative output voltages. It also provides efficient performance as well as circuit simplicity in unipolar and bipolar topology owing to the use of a single switch which can be operated by available integrated controllers of boost converters. The article considers the topologies of a SEPIC buck-boost converter built according to the traditional scheme (with two inductors) and according to the scheme on magnetically coupled chokes. To analyze the processes and factors affecting the converter operation efficiency, a circuit simulation has been done using the Electronics Workbench. The results of the investigation of a pulsed DC converter of input voltage to unipolar or bipolar output voltage using SEPIC buck-boost topology are presented. The circuit simulation enables to specify the switching process characteristics, to estimate the ripple level of the input current and its spectral characteristics, and to develop recommendations concerning the choice of parameters of converters elements and generation of control signals. Based on the simulation results, the load, control, and noise characteristics of the converter are obtained. The level of symmetry of positive and negative output voltage is investigated for the converter on discrete and magnetically coupled chokes. The assessment of the effect of leakage inductance on converters with magnetic coupling of inductive elements is given. Examples of practical implementation of converters built according to the SEPIC topology are shown. It is found that the resistance of the choke windings, which is less than 0.5 Ohm, has practically no effect on the efficiency of the converter, retaining the factor of about 0.9 in a wide range of load currents, while the main source of conversion losses is a passive diode switch. Synchronous converter circuits of a number of manufacturers are more efficient, but require more complex controllers for active switches with elements for protection against through currents.

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