scholarly journals A New Hybrid Ćuk DC-DC Converter with Coupled Inductors

Electronics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2188
Author(s):  
Ioana-Monica Pop-Calimanu ◽  
Maria Balint ◽  
Dan Lascu

This paper proposes a new hybrid Ćuk-type converter employing two inductors built on the same core which can be successfully used in applications requiring an output voltage considering higher than the input one. With few components added, in the proposed converter the static conversion ratio can be easily extended becoming wider compared to the classical Ćuk topology. At the same duty cycle range the output voltage is higher than in the classical Ćuk converter. The output voltage remains with negative polarity and with a reduced ripple. An advantage of the new converter is given by its two degrees of freedom. A DC and AC analysis is carried out, device stresses are evaluated and a comparative analysis of the proposed hybrid Ćuk topology to other indirect converters has also been performed. All the equations necessary for designing the converter are provided. The simulations performed together with the practical experiments carried out, all results confirm that the theoretical considerations are correct and validate the features that the proposed converter can provide a higher static conversion ratio without operating at high duty cycles.


Author(s):  
Mohammad Fajar Setyawan ◽  
Mohammad Zaenal Efendi ◽  
Farid Dwi Murdianto

In a battery set, there is always a voltage difference caused by charging and discharging. Therefore, it is necessary to pay attention to the condition of the battery or State of Charge (SOC) so that it is in a balanced state between the batteries. Unbalanced battery conditions result in decreased performance of the battery. For that we need a balancing circuit that works actively with the help of a DC-DC converter. DC-DC converters generally have a principle like a buck-boost converter to increase and decrease the output voltage, however the output still has a fairly large ripple in the waveform. Therefore, the CUK converter is used which is a development of the buck-boost converter topology, where the output of this CUK converter has smaller ripples because it uses two capacitors and two inductors. Of the various methods used to adjust the duty cycle of the CUK converter, a precise and accurate algorithm is needed to overcome the instability of the converter output. The method used to adjust the duty cycle uses the Adaptive Neuro-Fuzzy Inference System (ANFIS) algorithm as the development of the Fuzzy method. The system is implemented using MATLAB Simulink software. The simulation results show that the output of the CUK converter with the ANFIS method has a faster response speed reaching a set point of 1.95 × 10-4 seconds and the accuracy of the output voltage with ANFIS is 99.94% while the accuracy of the output converter current using ANFIS is 65.7%.Keywords: ANFIS, balancing, battery, CUK converter, state of charge (SOC).15



Author(s):  
Brahim Lagssiyer ◽  
Aziz Abdelhak ◽  
Aziz Abdelhak ◽  
Mohamed El Hafyani ◽  
Mohamed El Hafyani

<table class="Grilledutableau1" width="593" border="1" cellspacing="0" cellpadding="0"><tbody><tr><td valign="top" width="387"><p>Our work focuses on the design and analysis of an interleaved Boost converter DC-DC with coupled and independent inductors in terms of ripples and power. An interleaving strategy is adopted to minimize the currents in the Boost components and consequently to miniaturize them. The command shift of the switch by the X.T value (X: shift coefficient 0&lt;X&lt;1 and T: period of the command signal), minimizes the ripple of the input current and output voltage and maximizes the power extracted from the photovoltaic system. The coupling technique of inductances of interleaved Boost, furthermore reduces the ripples of the input currents and further maximizes the power extracted from the photovoltaic panels. To determine the variation of the power extracted from the PV, according to the duty cycle D and the switches command shift X.T, the duty cycle, was manually varied (Similar to a MPPT command). For this we modeled, under MATLAB/Simulink, the photovoltaic system, the power interface (DC/DC Boost interleaved). Finally, a prototype of interleaved Boost converter with coupled inductors and a shifted control of the switches was realized. Experimental results have been proposed to validate the results of simulations.</p></td></tr></tbody></table>



2020 ◽  
Vol 10 (5) ◽  
pp. 6362-6367
Author(s):  
Y. Almalaq ◽  
M. Matin

This paper introduces a two-switch high gain non-isolated Cuk converter which can be used as a high gain DC-DC converter in renewable energy, such as photovoltaic and fuel cell, applications because their output is low. As the conventional, the proposed Cuk converter provides negative output voltage but with a higher voltage in magnitude. The main advantage of the proposed converter is having lower voltage stress with the ability to maintain a higher voltage gain. By combining a switched-inductor and a switched-capacitor into the conventional Cuk converter, the proposed Cuk converter has the ability to reach 13 times the input voltage for a duty cycle D of 0.75. Also, by attaching more switched-inductors to the proposed Cuk converter, more voltage gain can be achieved. A complete theoretical analysis of the Continuous Conduction Mode (CCM) of the proposed Cuk converter is presented and the key aspects of the circuit design have been derived. Also, a comparison in terms of voltage gain and voltage stress between the proposed Cuk converter and Cuk converters using other techniques is presented. The proposed Cuk converter has been designed for 100W rated power, -152V output voltage, 50kHz switching frequency, and 75% duty cycle. The presented converter is simulated in Matlab/Simulink and the results are discussed.



Mathematics ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 1247
Author(s):  
Alma Rodríguez ◽  
Avelina Alejo-Reyes ◽  
Erik Cuevas ◽  
Francisco Beltran-Carbajal ◽  
Julio C. Rosas-Caro

In the past years, the interest in direct current to direct current converters has increased because of their application in renewable energy systems. Consequently, the research community is working on improving its efficiency in providing the required voltage to electronic devices with the lowest input current ripple. Recently, a hybrid converter which combines the boost and the Cuk converter in an interleaved manner has been introduced. The converter has the advantage of providing a relatively low input current ripple by a former strategy. However, it has been proposed to operate with dependent duty cycles, limiting its capacity to further decrease the input current ripple. Independent duty cycles can significantly reduce the input current ripple if the same voltage gain is achieved by an appropriate duty cycle combination. Nevertheless, finding the optimal duty cycle combination is not an easy task. Therefore, this article proposes a new pulse-width-modulation strategy for the hybrid interleaved boost-Cuk converter. The strategy includes the development of a novel mathematical model to describe the relationship between independent duty cycles and the input current ripple. The model is introduced to minimize the input current ripple by finding the optimal duty cycle combination using the differential evolution algorithm. It is shown that the proposed method further reduces the input current ripple for an operating range. Compared to the former strategy, the proposed method provides a more balanced power-sharing among converters.



1978 ◽  
Vol 21 (2) ◽  
pp. 295-308
Author(s):  
Terry L. Wiley ◽  
Raymond S. Karlovich

Contralateral acoustic-reflex measurements were taken for 10 normal-hearing subjects using a pulsed broadband noise as the reflex-activating signal. Acoustic impedance was measured at selected times during the on (response maximum) and off (response minimum) portions of the pulsed activator over a 2-min interval as a function of activator period and duty cycle. Major findings were that response maxima increased as a function of time for longer duty cycles and that response minima increased as a function of time for all duty cycles. It is hypothesized that these findings are attributable to the recovery characteristics of the stapedius muscle. An explanation of portions of the results from previous temporary threshold shift experiments on the basis of acoustic-reflex dynamics is proposed.



Author(s):  
Shima Sadaf ◽  
Nasser Al-Emadi ◽  
Atif Iqbal ◽  
Mohammad Meraj ◽  
Mahajan Sagar Bhaskar

DC-DC power converters are necessary to step-up the voltage or current with high conversion ratio for many applications e.g. photovoltaic and fuel cell energy conversion, uninterruptible power supply, DC microgrid, automobile, high intensity discharged lamp ballast, hybrid vehicle, etc. in order to use low voltage sources. In this project, a modified SIBC (mSIBC) is proposed with reduced voltage stress across active switches. The proposed mSIBC configuration is transformerless and simply derived by replacing one diode of the classical switched inductor structure with an active switch. As a result, mSIBC required low voltage rating active switches, as the total output voltage is shared between two active switches. Moreover, the proposed mSIBC is low in cost, provides higher efficiency and required the same number of components compared to the classical SIBC. The experimental results are presented which validated the theoretical analysis and functionality, and the efficiency of the designed converter is 97.17%. The proposed mSIBC converter provides higher voltage conversion ratio compared to classical converters e.g. boost, buck-boost, cuk, and SEPIC. The newly designed configurations will aid the intermediate power stage between the renewable sources and utility grid or high voltage DC or AC load. Since, the total output voltage is distributed among the two active switches, low voltage rating switches can be employed to design the power circuit of the proposed converter. The classical boost converter or recently proposed switched inductor based boost converter can be replaced by the proposed mSIBC converter in real-time applications such as DC microgrid, DC-DC charger, battery backup system, UPS, EV, an electric utility grid. The proposed power circuitry is cost effective, compact in size, easily diagnostic, highly efficient and reliable.



In this paper, a single switch single stage switched inductor based cuk converter with power factor correction control techniques is proposed. The main features of the proposed converter is low current stress, high voltage conversion ratio, reduction of components, high efficiency, low THD, etc., The operation of the proposed converter is explained in several modes along with the design of the converter. The performance of the proposed converter with different loads such as resistive, battery and motor loads with CC and CV control is analyzed and various factors such as power factor, efficiency and THD are compared. The Simulation work is carried out in MATLAB/Simulink software.



Author(s):  
Mohamed A Hegazi ◽  
Andreas Hoffrichter ◽  
Jeffrey L Andrews ◽  
Gordon Lovegrove

Switcher locomotives operate in railway yards where they shunt railcars and assemble trains. Shunting railcars requires frequent aggressive acceleration and deceleration events in order for the locomotive to push or pull railcars onto specific tracks. As a result, switcher locomotives rarely sustain tractive power for any significant period of time. Given that all switchers in North America rely on diesel-electric propulsion; the result is rapid and frequent transitions in engine power leading to a very low engine efficiency and high levels of emissions. Any attempt to quantify or remedy these issues will face a lack of a representative profile or test cycle. A locomotive duty cycle is a breakdown of time spent at each power level of the locomotive’s engine. A major drawback of current duty cycles is that they only account for steady power. Such cycles are not representative of real switcher locomotive operation. This paper presents a real-world transient duty cycle for switcher locomotives that accounts for the rapid power transitions and is argued to be more statistically representative of actual operations. The methodology adopted relies on real-time data collection, microtrip based trip segmentation, and a finite mixture model-based clustering algorithm. Measurements were collected on a EMD 16-645 GP9 locomotive. The duty cycle developed herein is representative of switching operations in Southern Railway of British Columbia’s New Westminster Yard as an example of the methodology which can be repeated in other cases as well.



2019 ◽  
Vol 15 (2) ◽  
pp. 138-144
Author(s):  
Adnan Diwan ◽  
Khalid Abdulhasan

voltage sags represent the greatest threat to the sensitive loads of industrial consumers, the microprocessor based-loads, and any electrical sensitive components. In this paper, a special topology is proposed to mitigate deep and long duration sags by using a modified AC to AC boost converter with a new control method. A boost converter is redesigned with a single switch to produces an output voltage that is linearly proportional to the duty cycle of the switch. On the other hand, the proposed control system is based on introducing a mathematical model that relates the missing voltage to the duty cycle of the boost converter switch. The simulation results along with the system analysis are presented to confirm the effectiveness and feasibility of the proposed circuit.



Sign in / Sign up

Export Citation Format

Share Document