DC-Modulated AC/AC Converters

2013 ◽  
Vol 341-342 ◽  
pp. 1317-1325
Author(s):  
Lin Luo Fang

Traditional methods of AC/AC converters have general drawbacks: output voltage is lower than input voltage, the input side THD is poor and output voltage frequency is lower than input voltage frequency by using voltage regulation method and cycloconverters. We introduce the novel approach - DC-modulated AC/AC converters in this paper, which successfully overcomes the drawbacks. Simulation and experimental results of the DC-modulated AC/AC converter are the evidences to verify our design. These methods will be very widely used in industrial applications.

2014 ◽  
Vol 15 (4) ◽  
pp. 327-333 ◽  
Author(s):  
Mohamad R. Banaei ◽  
M. R. Jannati Oskuee ◽  
F. Mohajel Kazemi

Abstract In this paper, a new advanced topology of stacked multicell inverter is proposed which is generally suitable for high number of steps associated with a low number of switches. Compared with traditional flying capacitor multicell and stacked multicell (SM) inverters, doubling the number of output voltage levels and the RMS value, ameliorating the output voltage frequency spectrum, decreasing the number and rating of components, stored energy and rating of flying capacitors are available with the proposed inverter. These improvements are achieved by adding only four low-frequency switches to the traditional SM inverter’s structure. The suggested topology is simulated using MATLAB/SIMULINK software, and simulation results are presented to indicate well-performance of the novel converter. In addition, the experimental results of proposed topology prototype have been presented to validate its practicability.


2006 ◽  
Vol 3 (3) ◽  
pp. 143-150 ◽  
Author(s):  
S. Guo ◽  
Y. Okuda ◽  
W. Zhang ◽  
X. Ye ◽  
K. Asaka

There has been a great demand, in the medical field and in industrial applications, for a novel micro biped robot with multiple degrees of freedom that can swim smoothly in water or in aqueous medium. The fish-like micro-robot studied is a type of miniature device that is installed with sensing and actuating elements. This article describes the new structure and motion mechanism of a hybrid type of underwater micro-robot using an ion-conducting polymer film (ICPF) actuator, and discusses the swimming and floating characteristics of the micro-robot in water, measured by changing the voltage frequency and the amplitude of the input voltage. Results indicate that the swimming speed of the proposed underwater micro-robot can be controlled by changing the frequency of the input voltage, and the direction (upward or downward) can be manipulated by changing the frequency of the electric current applied and the amplitude of the voltage.


2021 ◽  
Author(s):  
Palash K. Banerjee

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.


2015 ◽  
Vol 781 ◽  
pp. 414-417
Author(s):  
Yutthana Kanthaphayao ◽  
Chalermpol Reaungepattanawiwat

This paper illustrates a fuzzy gain scheduling of PI plus derivative controller. The proposed control technique improves the transient response of a DC/DC converter. The proposed control system is easy to implement based on an STM32F4 microcontroller. The performance evaluation was done by an experiment through a boost DC/DC converter, with a 24W load, a 12V input voltage, and a 24V output voltage, respectively. The system operation achieves tight output voltage regulation, both for the steady-state and transient responses.


2020 ◽  
Vol 8 (3) ◽  
pp. 32-39
Author(s):  
Richard Zelnik ◽  
Michal Prazenica

DC-DC converters are mainly used to provide required output voltage by suitably controlling the pulse width modulated (PWM) signal given to the gate of the fast-acting power electronics switches. The flyback converter is one such popular isolated DC-DC converter topology used to obtain regulated output voltage in low power applications. They are used as power supply systems in space technology and in many other industrial power electronics systems, where having constant voltage is very much essential. This paper presents the practical implementation of multiple output Flyback converter with MOSFET as a switching device. The designed converter is observed to have a good output voltage regulation and higher efficiency for the wide input voltage range.


2021 ◽  
Author(s):  
Elisa Verna ◽  
Gianfranco Genta ◽  
Maurizio Galetto ◽  
Fiorenzo Franceschini

Abstract Increased assembly complexity is one of the main challenges in manufacturing. Complexity can induce increased assembly cost and time, operational issues, costly defects and quality losses. Several approaches have been proposed in the literature to predict product defects by using assembly complexity as predictor. Despite defect prediction is of utmost importance from the early stages of product and related quality inspection design, most approaches are not directly applicable because they rely on the operators' prior subjective knowledge and are designed for specific industrial applications. To overcome this issue, the present research proposes a novel approach to predict product defects from a more objective evaluation of complexity. This is one of the first attempts to predict product defects and improve its quality with a purely objective assessment of the complexity of the assembled product, without the need for operators' evaluations and assembly experience. Defect rates in the model are predicted by using a recent conceptual paradigm of complexity that considers only structural properties of assembly parts and their architectural structure. The novel model is applied to a real assembly process in the electromechanical field and is compared with one of the most accredited in the literature, i.e. the Shibata-Su model. Empirical results show that, despite the super-linear relationship between defect rates and complexity in both models, the objective approach used in the novel model leads to more accurate and precise predictions of defectiveness rates, as it does not include the variability introduced by operators' subjective assessments. Adopting this novel model can effectively improve the estimate of product defects and support designers’ decisions for assembly quality-oriented design and optimization, especially in early design phases.


2020 ◽  
Vol 1 (2) ◽  
pp. 144-149
Author(s):  
Muldi Yuhendri ◽  
Randy Setiawan

Direct current (dc) voltage sources are one of the voltage sources most widely used for various purposes. Dc voltage can be obtained from a dc generator or by converting an ac voltage into a dc voltage using a power converter. There are several dc voltage levels that are commonly used by electrical and electronic equipment. To get a dc voltage that can be used for various equipment, then a dc voltage source must be varied according to the required. One way to get a variable dc voltage is to use a dc-dc converter. This research proposes a dc-dc boost converter that can increase the dc voltage with varying outputs. The boost converter is proposed using Arduino Uno as a controller with an input voltage of 12 volts. The converter output voltage regulation is implemented through Arduino programming using Matlab simulink. The experimental results show that the boost converter designed in this study has worked well as intended. This can be seen from the boost converter output voltage which is in accordance with the reference voltage entered in the Matlab simulink program


Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7643
Author(s):  
Lingling Cao ◽  
Jiefeng Lin ◽  
Shikai Chen ◽  
Yuanmao Ye

Multilevel inverters have been widely used in various industrial applications such as renewable energy generation and electric vehicles. An improved circuit of symmetrical cascaded switched-capacitor multilevel inverter is proposed so that the reactive power is absorbed by its power supply instead of capacitors. Then, a special hybrid pulse width modulation strategy combing level-shifted pulse width modulation (LS-PWM) and phase-shifted pulse width modulation (PS-PWM) was developed for the inverter. With this modulation algorithm, the power between cascaded units is automatically balanced, and the voltage of the capacitor in each unit is also automatically balanced to the dc input voltage. In addition, the optimized capacitor voltage ripple makes it possible to use a smaller capacitor to produce a better output voltage waveform. Theoretical analysis, simulation and experimental results show that the equivalent switching frequency of the cascaded multilevel inverter is twice the original frequency so that the output voltage harmonics are only distributed near even multiples of the carrier frequency.


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