scholarly journals Analysis of a DC Converter with Low Primary Current Loss and Balance Voltage and Current

Electronics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 439 ◽  
Author(s):  
Lin
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Low Voltage ◽  
Field Effect Transistors ◽  
Magnetic Coupling ◽  
Oxide Semiconductor ◽  
Current Loss ◽  
Control Approach ◽  
Switching Characteristics ◽  
Primary Current

A dc/dc pulse width modulation (PWM) circuit was investigated to realize the functions of reduced primary current loss and balanced voltage and current distribution. In the presented dc/dc converter, two full bridge pulse width modulation circuits were used with the series/parallel connection on the high-voltage/low-voltage side. The flying capacitor was adopted on the input side to achieve voltage balance on input split capacitors. The magnetic coupling element was employed to achieve current sharing between two parallel circuits. A capacitor-diode passive circuit was adopted to lessen the primary current at the commutated interval. The phase-shifted duty cycle control approach was employed to regulate load voltage and implement soft switching characteristics of power metal-oxide-semiconductor field-effect transistors (MOSFETs). Finally, the experimental results using a 1.68 kW prototype converter were obtained to confirm the performance and feasibility of the studied circuit topology.

Output Voltage Sampling Circuit for Discontinuous Conduction Mode Flyback Pulse-Width Modulation Controller

2016 ◽  
Vol 25 (11) ◽  
pp. 1650140 ◽  
Author(s):  
Ling-Feng Shi ◽  
Zhen-Bo Shi ◽  
Sen Chen ◽  
Jian-Hui Xun
Keyword(s):  
Pulse Width ◽  
Output Voltage ◽  
Pulse Width Modulation ◽  
Low Voltage ◽  
Low Cost ◽  
Complementary Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Cmos Process ◽  
Discharge Time ◽  
Constant Output

Primary-side controlled pulse-width modulation (PWM) flyback converter has been widely used in low-power and low-voltage products for its simple structure and low cost. This paper presents a novel output voltage sampling circuit which considers the influence of the rectifier diode current on the output voltage sampling. The output voltage sampling circuit samples the output voltage at 85% of the secondary inductance discharge time [Formula: see text] of last cycle, which improves the accuracy of the output voltage sampling circuit. Besides, the circuit can also sample the secondary inductance discharge time [Formula: see text]. Finally, a chip has been fabricated in 0.6[Formula: see text][Formula: see text]m complementary metal-oxide semiconductor (CMOS) process, which is used in the presented output voltage sampling circuit in its internal circuit to simple output voltage and achieve constant output voltage.

scholarly journals Hybrid DC Converter with Current Sharing and Low Freewheeling Current Loss

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6631
Author(s):  
Bor-Ren Lin ◽  
Guan-Yi Wu
Keyword(s):  
Phase Shift ◽  
Pulse Width Modulation ◽  
Low Voltage ◽  
Magnetic Coupling ◽  
Soft Switching ◽  
Load Range ◽  
Pwm Converter ◽  
Current Loss ◽  
Zero Voltage Switching ◽  
Voltage Balance

A new hybrid high-frequency link pulse-width modulation (PWM) converter using voltage balance capacitor and current balance magnetic coupling is proposed to realize low freewheeling current loss and wide load range of soft switching operation. Series-connected H-bridge converter is adopted for high voltage applications. In addition, a voltage balance capacitor and a current balance magnetic coupling core are employed for achieving voltage and current balance. To extend zero-voltage switching (ZVS) range of switches at lagging-leg of phase-shift PWM converter, soft switching LLC converter is linked to the lagging-leg of phase-shift PWM converter. Therefore, the wide ZVS load operation is realized in the presented hybrid converter. The other high freewheeling current disadvantage in conventional phase-shift PWM converter is improved by a snubber circuit used on low-voltage side. Thus, the primary current during the freewheeling state is decreased and close to zero. In addition, the conduction losses on primary-side components of studied converter are reduced. The secondary-sides of phase-shift PWM converter and LLC resonant converter are series-connected to achieve power transfer between input and output sides. Experimental results using a laboratory prototype are provided to demonstrate the effectiveness of the studied circuit and control algorithm.

scholarly journals Hybrid DC-DC Converter with Low Switching Loss, Low Primary Current and Wide Voltage Operation

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2536
Author(s):  
Bor-Ren Lin ◽  
Yi-Kuan Lin
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Input Voltage ◽  
Resonant Circuit ◽  
Switching Loss ◽  
Voltage Range ◽  
Current Loss ◽  
Zero Voltage Switching ◽  
Energy Applications ◽  
Multi Stage

A full-bridge converter with an additional resonant circuit and variable secondary turns is presented and achieved to have soft-switching operation on active devices, wide voltage input operation and low freewheeling current loss. The resonant tank is linked to the lagging-leg of the full bridge pulse-width modulation converter to realize zero-voltage switching (ZVS) characteristic on the power switches. Therefore, the wide ZVS operation can be accomplished in the presented circuit over the whole input voltage range and output load. To overcome the wide voltage variation on renewable energy applications such as DC wind power and solar power conversion, two winding sets are used on the output-side of the proposed converter to obtain the different voltage gains. Therefore, the wide voltage input from 90 to 450 V (Vin,max = 5Vin,min) is implemented in the presented circuit. To further improve the freewheeling current loss issue in the conventional phase-shift pulse-width modulation converter, an auxiliary DC voltage generated from the resonant circuit is adopted to reduce this freewheeling current loss. Compared to the multi-stage DC converters with wide input voltage range operation, the proposed circuit has a low freewheeling current loss, low switching loss and a simple control algorithm. The studied circuit is tested and the experimental results are demonstrated to testify the performance of the resented circuit.

Analytical Evaluation of Switching Characteristics in Five-Phase Drives with Discontinuous Space Vector Pulse Width Modulation Techniques

EPE Journal ◽  
2013 ◽  
Vol 23 (2) ◽  
pp. 24-33 ◽  
Author(s):  
Joel Prieto ◽  
Federico Barrero ◽  
Sergio Toral ◽  
Emil Levi ◽  
Martin Jones ◽  
...  
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Analytical Evaluation ◽  
Space Vector ◽  
Modulation Techniques ◽  
Switching Characteristics

scholarly journals Novel Intelligent and Sensorless Proportional Valve Control with Self-Learning Ability

2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
Bayram Akdemir
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Control Method ◽  
Low Voltage ◽  
Control Unit ◽  
Control Signal ◽  
Learning Ability ◽  
Learning Abilities ◽  
Valve Control ◽  
Self Learning

Linear control is widely used for any fluid or air flows in many automobile, robotics, and hydraulics applications. According to signal level, valve can be controlled linearly. But, for many valves, hydraulics or air is not easy to control proportionally because of flows dynamics. As a conventional solution, electronic driver has up and down limits. After manually settling up and down limits, control unit has proportional blind behavior between two points. This study offers a novel valve control method merging pulse width and amplitude modulation in the same structure. Proposed method uses low voltage AC signal to understand the valve position and uses pulse width modulation for power transfer to coil. DC level leads to controlling the valve and AC signal gives feedback related to core moving. Any amplitude demodulator gives core position as voltage. Control unit makes reconstruction using start and end points to obtain linearization at zero control signal and maximum control signal matched to minimum demodulated amplitude level. Proposed method includes self-learning abilities to keep controlling in hard environmental conditions such as dust, temperature, and corrosion. Thus, self-learning helps to provide precision control for hard conditions.

scholarly journals Research on Modified Hybrid Frequency Modulation Technology of Type-III Asymmetric CHB Multilevel Inverters

Electronics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 263
Author(s):  
Manyuan Ye ◽  
Wei Ren ◽  
Qiwen Wei ◽  
Guizhi Song ◽  
Zhilin Miao
Keyword(s):  
Pulse Width ◽  
Output Voltage ◽  
Pulse Width Modulation ◽  
Low Voltage ◽  
Output Line ◽  
Line Voltage ◽  
Multilevel Inverters ◽  
Type Iii ◽  
Hybrid Frequency ◽  
Frequency Pulse

Asymmetric Cascaded H-bridge (ACHB) level inverters can output more voltage waveforms with fewer cascaded units while ensuring the quality of output voltage waveforms, so they have attracted more and more attention. Taking the topology of Type-III asymmetric CHB multilevel inverters as the research object, a Modified Hybrid Frequency Pulse Width Modulation (MHF-PWM) strategy is proposed in this paper. This modulation strategy overcomes the local overshoot of low-voltage unit in the presence of traditional Hybrid Frequency Pulse Width Modulation (HF-PWM), thus completely eliminating the low frequency harmonics in the output voltage waveform of Type-III ACHB nine-level inverters, and the Total Harmonic Distortion (THD) of output line voltage of the modulation strategy is lower than that of PS-PWM strategy in the whole modulation degree, which effectively improves the quality waveform of the output line voltage. At the same time, the strategy can also improve the problems of current backflow and energy feedback caused by the high-voltage unit pouring current to the low-voltage unit, thereby reducing the imbalance of the output power of the high-voltage and low-voltage units. Finally, the Matlab/Simulink simulation model and experimental platform are established to verify the validity and practicality of the modulation strategy.

1.4kV Double-Implanted MOSFETs Fabricated on 4H-SiC(000-1)

2011 ◽  
Vol 679-680 ◽  
pp. 607-612 ◽  
Author(s):  
Hiroshi Kono ◽  
Takuma Suzuki ◽  
Kazuto Takao ◽  
Masaru Furukawa ◽  
Makoto Mizukami ◽  
...  
Keyword(s):  
Room Temperature ◽  
Dielectric Breakdown ◽  
Field Effect Transistors ◽  
Oxide Semiconductor ◽  
Gate Bias ◽  
Drain Voltage ◽  
Mos Capacitor ◽  
Time Dependent Dielectric Breakdown ◽  
Blocking Voltage ◽  
Switching Characteristics

1.2 mm × 1.2 mm and 2.7 mm × 2.7 mm silicon carbide double-implanted metal-oxide-semiconductor field-effect transistors (DIMOSFETs) were fabricated on 4H-SiC (000-1) carbon face. 1.2 mm × 1.2 mm DIMOSFETs were characterized from room temperature to 150°C. At room temperature, the specific on-resistance of this MOSFET was 5.7 mΩcm2 at a gate bias of 20 V and a drain voltage of 1.0 V. The blocking voltage of this MOSFET was 1450 V based on the avalanche current. At 150 °C, the specific on-resistance increased from 5.7 mΩcm2 to 9.1 mΩcm2 and the threshold voltage decreased from 4.9 V to 4.1 V. The blocking voltage increased from 1450V to 1500V. 2.7 mm × 2.7 mm DIMOSFETs were also characterized at room temperature. They showed a specific on-resistance of 8.0 mΩcm2 at a gate bias of 20 V and a drain voltage of 1 V. The blocking voltage of this device was 1550 V, which was determined by the avalanche current. The time-zero dielectric breakdown (TZDB) and time-dependent dielectric breakdown (TDDB) characteristics of 180 μm × 180 μm MOS capacitor were estimated. At room temperature (RT), TZDB was 9.3 MV/cm and the charge to breakdown value of 63% cumulative failure (Qbd) was 72 C/cm2. The temperature dependence of Qbd measurements showed that it deceased from 72 C/cm2 at RT to 14 C/cm2 at 250 °C. Switching characteristics of 1.2 mm × 1.2 mm DIMOSFETs were obtained by the double-pulse measurements. The turn-on time and the turn-off time were 36 nsec and 53 nsec, respectively.

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