scholarly journals A Modified Step-Up DC-DC Flyback Converter with Active Snubber for Improved Efficiency

Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2066 ◽  
Author(s):  
Cristian Pesce ◽  
Javier Riedemann ◽  
Ruben Pena ◽  
Werner Jara ◽  
Camilo Maury ◽  
...  
Keyword(s):  
Output Voltage ◽  
High Efficiency ◽  
Controller Design ◽  
Current Mode ◽  
Input Voltage ◽  
Input Power ◽  
Good Efficiency ◽  
Main Research ◽  
Flyback Converter ◽  
Wide Range

The research on DC-DC power converters has been a matter of interest for years since this type of converter can be used in a wide range of applications. The main research is focused on increasing the converter voltage gain while obtaining a good efficiency and reliability. Among the different DC-DC converters, the flyback topology is well-known and widely used. In this paper, a novel high efficiency modified step-up DC-DC flyback converter is presented. The converter is based on a N-stages flyback converter with parallel connected inputs and series-connected outputs. The use of a single main diode and output capacitor reduces the number of passive elements and allows for a more economical implementation compared with interleaved flyback topologies. High efficiency is obtained by including an active snubber circuit, which returns the energy stored in the leakage inductance of the flyback transformers back to the input power supply. A 4.7 kW laboratory prototype is implemented considering four flyback stages with an input voltage of 96 V and an output voltage of 590 V, obtaining an efficiency of 95%. The converter operates in discontinuous current mode then facilitating the output voltage controller design. Experimental results are presented and discussed.

scholarly journals Slope Compensation Design for a Peak Current-Mode Controlled Boost-Flyback Converter

2018 ◽  
Author(s):  
Juan-Guillermo Muñoz ◽  
Guillermo Gallo ◽  
Fabiola Angulo ◽  
Gustavo Osorio
Keyword(s):  
High Voltage ◽  
High Efficiency ◽  
Power Converters ◽  
Mathematical Expression ◽  
Current Mode ◽  
Input Voltage ◽  
Switching Frequency ◽  
Peak Current ◽  
Flyback Converter ◽  
Coupled Inductors

Power converters with coupled inductors are very promising due to the high efficiency and high voltage gain. Apart from the aforementioned advantages, the boost-flyback converter reduces the voltage stress on the semiconductors. However, to obtain good performance with high voltage gains, the controller must include two control loops (current and voltage), and a compensation ramp. One of the most used control techniques for power converters is the peak current-mode control with compensation ramp. However, in the case of a boost-flyback converter there is no mathematical expression in the literature, to compute the slope of the compensation ramp. In this paper, a formula to compute the slope of the compensation ramp is proposed in such a way that a stable period-1 orbit is obtained. This formula is based on the values of the circuit parameters, such as inductances, capacitances, input voltage, switching frequency and includes some assumptions related to internal resistances, output voltages, and some other electrical properties related with the physical construction of the circuit. The formula is verified numerically using the saltation matrix and experimentally using a test circuit.

scholarly journals Impact of Transformer Turns Ratio on the Power Losses and Efficiency of the Wide Range Isolated Buck–Boost Converter for Photovoltaic Applications

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5645
Author(s):  
Hamed Mashinchi Maheri ◽  
Dmitri Vinnikov ◽  
Andrii Chub ◽  
Vadim Sidorov ◽  
Elizaveta Liivik
Keyword(s):  
High Efficiency ◽  
Input Voltage ◽  
Power Losses ◽  
Efficient Operation ◽  
Wide Range ◽  
Photovoltaic Applications ◽  
Theoretical Predictions ◽  
Converter Topology ◽  
Isolation Transformer ◽  
The Impact

In this paper, the impact of transformer turns ratio on the performance of the quasi-Z-source galvanically isolated DC-DC converters is studied. Embedded buck–boost functionality enables these converters to regulate the input voltage and load in a wide range, which makes them suitable for such demanding application as photovoltaic microconverters. The isolation transformer here plays a central role as its turns ratio defines the point of transition between the boost and buck modes and overall capability of the converter to regulate the input voltage in a wide range at high efficiency. The studied quasi-Z-source galvanically isolated DC-DC converter is benchmarked in terms of power loss of components and weighted power conversion efficiency for three different turns ratios of isolation transformer to achieve the best and optimized turns ratio lead to the efficient operation. Operation in a wide range of input voltage at high efficiency is the main criterion for assessing the effect of turns ratio on the efficiency of the converter. The proposed loss model and theoretical predictions of the efficiency were validated with the help of a 300 W experimental prototype of the photovoltaic microconverter based on the quasi-Z-source galvanically isolated DC-DC converter topology.

A Stable Mode-Selectable Oscillator with Variable Duty Cycle and High-Efficiency

2015 ◽  
Vol 24 (09) ◽  
pp. 1550132 ◽  
Author(s):  
Li-Ye Cheng ◽  
Xin-Quan Lai
Keyword(s):  
Duty Cycle ◽  
High Efficiency ◽  
Dynamic Performance ◽  
Operation Mode ◽  
Charge Pump ◽  
Input Voltage ◽  
Cmos Process ◽  
Pump Efficiency ◽  
Stable Mode ◽  
Wide Range

A mode-selectable oscillator (OSC) with variable duty cycle for improved charge pump efficiency is proposed in this paper. The novel OSC adjusts its duty cycle according to the operation mode of the charge pump, thus improves the charge-pump efficiency and dynamic performance. The control of variable duty cycle is implemented in digital logic hence it provides robust noise immunity and instantaneous response. The OSC and the charge-pump have been implemented in a 0.6-μm 40-V CMOS process. Experimental results show that the peak efficiency is 92.7% at 200-mA load, the recovery time is less than 25 μs and load transient is 15 mV under 500-mA load variation. The system is able to work under a wide range of input voltage (V IN ) in all modes with low EMI.

A HIGH EFFICIENCY ADAPTIVE CURRENT MODE STEP-UP/STEP-DOWN DC–DC CONVERTER WITH FOUR MODES FOR SMOOTH TRANSITION

2014 ◽  
Vol 23 (07) ◽  
pp. 1450097 ◽  
Author(s):  
YANZHAO MA ◽  
SHAOXI WANG ◽  
SHENGBING ZHANG ◽  
XIAOYA FAN
Keyword(s):  
Transient Response ◽  
Output Voltage ◽  
High Efficiency ◽  
Current Mode ◽  
Smooth Transition ◽  
Maximum Efficiency ◽  
Cmos Process ◽  
Voltage Ripple ◽  
Transition Modes ◽  
Step Down

This paper presents a current mode step-up/step-down DC–DC converter with high efficiency, small output voltage ripple, and fast transient response. The control scheme adaptively configures the converter into the proper operation mode. The efficiency is improved by reducing the switching loss, wherein the converter operates like a buck or boost converter, and conduction loss, wherein the average inductor current is reduced in transition modes. The output voltage ripple is significantly reduced by incorporating two constant time transition modes. A fast line transient response is achieved with small overshoot and undershoot voltage. An adaptive substrate selector (ASS) is introduced to dynamically switch the substrate of PMOS power transistors to the highest on-chip voltage. A lossless self-biased current sensor with high-speed and high-accuracy is also achieved. The proposed converter was designed with a standard 0.5 μm CMOS process, and can regulate an output voltage within the input voltage ranged from 2.5 V to 5.5 V. The maximum load current is 600 mA, and the maximum efficiency is 94%. The output voltage ripple is less than 15 mV in all operation modes.

scholarly journals Modelling of three phase SVPWM AC-AC converter using unity power factor control

2019 ◽  
Vol 10 (4) ◽  
pp. 1823
Author(s):  
Saidah Saidah ◽  
Hari Sutiksno ◽  
Bambang Purwahyudi ◽  
Taufik Taufik
Keyword(s):  
Power Factor ◽  
Pulse Width Modulation ◽  
High Efficiency ◽  
Input Voltage ◽  
Input Power ◽  
Current Waveform ◽  
Unity Power Factor ◽  
Dc Voltage ◽  
Three Phase ◽  
Power Factor Control

This paper introduces the modelling of a novel three phase AC-AC converter with indirect use of a capacitor as DC voltage link. The proposed converter has high efficiency because it uses Space Vector PWM (SVPWM) technique at both rectificier and inverter stages to operate the pulse width modulation in IGBT switches. The novel converter is equipped with a power factor control to shape the rectifier input current waveform to be sinusoidal and to be in phase with the input voltage. To keep the DC voltage stable, the converter utilizes PI controllers. Simulations are conducted for output voltage from 120 to 300 Volts with output frequency ranging from 30 Hz to 60 Hz. The simulation results show that the converter is able to maintain stable the DC voltage and current. Furthermore, the model demonstrates the benefits of proposed converter in terms of acquiring high input power factor and sinusoidal current waveform at the output side of the inverter.

scholarly journals AC-AC voltage regulation by switch mode PWM Cûk voltage controller with improved performance

2021 ◽  
Author(s):  
Palash K. Banerjee
Keyword(s):  
Output Voltage ◽  
Supply Voltage ◽  
Input Voltage ◽  
Voltage Regulation ◽  
Control Circuit ◽  
Voltage Regulator ◽  
Error Signal ◽  
Constant Voltage ◽  
Wide Range ◽  
Switching Devices

In this research project, an AC Cûk voltage regulator has been proposed for maintaining constant voltage across the load during wide range of input voltage fluctuations. The proposed AC Ck voltage regulator made of practical IGBT switches has been investigated for both manual and automatic control circuit. A fraction of the output voltage is taken as the input voltage of the control circuit and produce the error signal if any changes occur in the output voltage. The modified error signal is used to make PWM signals for switching devices as per output voltage of regulator. The PWM controls the ON/OFF time (Duty cycle) of switching devices (IGBTs) of the proposed regulator. As a result the regulator is maintaining a constant voltage across the load during any change in supply voltage. The simulation waveforms and the calculated total harmonics distortion (THD) values are compared with previously studied AC Buck-Boost regulator. The observed simulated waveforms of output voltage, output current and input current and THD values have been improved in case of proposed AC Cûk voltage regulator.

scholarly journals A Structure-Reconfigurable Soft-Switching DC-DC Converter for Wide-Range Applications

Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2905 ◽  
Author(s):  
Xianxu Huo ◽  
Ke Xu ◽  
Ruixin Liu ◽  
Xi Chen ◽  
Zhanchun Li ◽  
...  
Keyword(s):  
Direct Current ◽  
High Efficiency ◽  
Zero Point ◽  
Input Voltage ◽  
Optimal Switching ◽  
Peak Efficiency ◽  
Loss Analysis ◽  
Wide Range ◽  
Analysis Calculation ◽  
Current Converter

In this paper, a structure-reconfigurable resonant DC-DC (direct current – direct current) converter is presented. By controlling the state of the auxiliary switch, the converter could change the resonant structure to acquire a high efficiency and wide voltage gain range simultaneously. The characteristics of the LLC (inductor-inductor-capacitor) resonant converter are firstly analyzed. Based on this, through introducing additional resonant elements and adopting the topology morphing method, the proposed converter can be formed. Moreover, a novel parameter selection method is discussed to satisfy both working states. Then, a detailed loss analysis calculation is conducted to determine the optimal switching point. In addition, an extra resonant zero point is generated by the topology itself, and the inherent over-current protection is guaranteed. Finally, a 500 W prototype is built to demonstrate the theoretical rationality. The output voltage is constant at 400 V even if the input voltage varies from 160 to 400 V. A peak efficiency of 97.2% is achieved.

Power Feedback Control in Cylindrical Traverse Grinding

2000 ◽  
Author(s):  
Rogelio L. Hecker ◽  
Steven Y. Liang
Keyword(s):  
Controller Design ◽  
Velocity Model ◽  
Input Power ◽  
Open Architecture ◽  
System Response ◽  
Grinding Wheel ◽  
Wide Range ◽  
Grinding Machine ◽  
Power Response ◽  
Traverse Grinding

Abstract This paper describes the design of a power controller in cylindrical traverse grinding (CTG), where the power consumed by the grinding wheel is controlled by regulation of the traverse velocity. A mathematical model relating the power to the traverse velocity was developed and quantified with machining data. The controller design was based on the power-velocity model developed and it was tuned to fulfill time response specifications including settling time and overshoot. An inner velocity loop was also designed and implemented inside the power close loop to guaranty a stable power response. The controller was implemented and tested on an open architecture cylindrical grinding machine. The results show that the controlled system response can be regulated to meet the requirements of time specifications, over a wide range of cutting depth and input power reference.

Research of Modeling and Simulation of Aviation Ignition Equipment

2013 ◽  
Vol 690-693 ◽  
pp. 2906-2911
Author(s):  
Kang Song ◽  
Jun Bi Liao ◽  
Qian Yang
Keyword(s):  
Output Voltage ◽  
High Efficiency ◽  
Circuit Simulation ◽  
Input Voltage ◽  
Simulation Software ◽  
Ignition Energy ◽  
Charge Voltage ◽  
Important Conclusion ◽  
Switching Power ◽  
Air Jet

Ignition energy of aviation ignition equipment is an important parameter for reliable launch of air jet. The factors are quite more that influence ignition energy and increasing the charge voltage of capacitance with high efficiency is an approach which increasing ignition energy efficiently. The charge voltage is the output voltage of switching power of ignition device. A mathematic model was constructed for switching power, and a mathematic expression were deduced about output voltage uo with input voltage ui and other elements parameters of switching power supply. An important conclusion were obtained which uo mainly depended on input voltage ui, load RL, dynatron collector peak current ICM on certain condition through a smart transform. When increasing ui, RL, ICM , uo increasing observably. The PSpice circuit simulation software is used for simulation, and the results show that the above conclusion is valid and feasible.

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