scholarly journals A New Two Switched-Impedance Network for High Ratio Quasi-Z-Source Inverter

2021 ◽  
Vol 6 (1) ◽  
pp. 26-39
Author(s):  
Irham Fadlika ◽  
Mega Agustina ◽  
Rahmatullah Aji Prabowo ◽  
Misbahul Munir ◽  
Arif Nur Afandi
Keyword(s):  
Common Ground ◽  
High Ratio ◽  
Duty Ratio ◽  
Ground Point ◽  
Boost Factor ◽  
Power Electronics Converter ◽  
Increasing Demand ◽  
Almost All ◽  
Diode Voltage ◽  
Current Ripple

The increasing demand and widespread of renewable energy inherently compel the development of power electronics converter as an interface between consumers and the energy source/s. This paper presents a new two switched-impedance networks qZSI converter called High Ratio Two Switched-impedance quasi-Z-Source Inverter (HR2SZ-qZSI). Compared with the previous topology, this proposed HR2SZ-qZSI topology can achieve higher voltage gain with lower shoot-through duty ratio, and a higher boost factor. This paper also discusses comparative analysis between the previous topology and the proposed HR2SZ-qZSI topology. Furthermore, the simulation and experimental data are presented to prove the theoretical analysis of the proposed HR2SZ-qZSI topology. Despite the additional components needed, it accentuates that this proposed converter retains all features of qZSI: common ground point between the dc source and converter and smooth input current operation. Furthermore, almost all the devices rating including capacitor and diode voltage, and inductor current ripple are lower than the preceding relevant two switched-impedance qZSI family. Accordingly, this proposed HR2SZ-qZSI clearly a good power conditioning alternative for renewable generation system.

scholarly journals Algorithim to control output voltage and reduce the ripple of input current in quasi switched boost inverter

2021 ◽  
Vol 4 (2) ◽  
pp. first
Author(s):  
Xuan-Vinh Le ◽  
Duc-Minh Nguyen ◽  
Viet-Anh Truong ◽  
Thanh-Hai Quach
Keyword(s):  
Pulse Width ◽  
Output Voltage ◽  
Pulse Width Modulation ◽  
Short Circuit ◽  
Modulation Index ◽  
Duty Ratio ◽  
Electrical Systems ◽  
Boost Factor ◽  
Control Output ◽  
Current Ripple

In recent years, the quasi -switched boost inverter uses widely in electrical systems. This paper proposes a method to control the AC output voltage and reduce the current ripple of the booster inductor in the quasi-switched boost inverter (QSBI). The proposed technique base on carrier pulse width modulation with two triangles with phase shifts 90◦. This technique uses the offset function to expand the modulation index and the algorithm for output voltage stabilization based on the adjustment of the boost ratio. The modulation index expansion will reduce the stress voltage on the switches by an average of 16.5% under the simulated conditions. The boost factor base on the short circuit time on the DC / DC booster and the inverter on the zero vectors. So, the duty ratio (of the boost DC / DC) can reduce by the short-circuit pulses that insert in the position of zero vectors, so the inverter is responsible for both boosting and inverting. The combination helps to reduce the current ripple on the boost inductor. Besides that, reducing the short-circuit ratio of DC / DC booster will also reduce the capacity of the booster switch and thereby reduce the production cost. The analysis clarifies the proposed technique. Simulations and experiments evaluate the proposed method.

scholarly journals Analysis of Steady-State Characteristics for a Newly Designed High Voltage Gain Switched Inductor Z-Source Inverter

Electronics ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 940 ◽  
Author(s):  
Nafis Subhani ◽  
Ramani Kannan ◽  
Md. Apel Mahmud ◽  
Tushar Kanti Roy ◽  
Mohd Fakhizan Romlie
Keyword(s):  
Steady State ◽  
High Voltage ◽  
Common Ground ◽  
Experimental Studies ◽  
Voltage Source ◽  
Duty Ratio ◽  
Voltage Gain ◽  
Soft Start ◽  
High Voltage Gain ◽  
Boost Factor

This paper aims to develop a new switched inductor assisted strong boost Z-source inverter (SL-SBZSI) topology with high voltage gain and analyze the steady-state characteristics of the proposed topology. In the proposed topology, two switched inductors are used within the series impedance structure of the Z-source inverter (ZSI) in order to achieve the high voltage gain. The steady-state characteristics of the proposed topology are analyzed to disseminate its several advantages as compared to traditional ZSIs. The key advantages include the higher boost factor with lower shoot-through duty ratio and lower voltage stresses on capacitors as well as on switches of the inverter bridge. Furthermore, the proposed topology has the soft-start ability which significantly reduces the inrush start-up current while comparing with the traditional ZSI. In the proposed topology, a common ground is shared between the output AC voltage and the input DC voltage source which categorizes this topology to the doubly grounded inverter. The characteristics of the proposed SL-SBZSI are analyzed by considering two operating condition where the simple boost pulse width modulation (PWM) scheme is used to extract the shoot-through pulses. The characteristics of the proposed topology are also compared with different existing topologies along with the conventional modified capacitor assisted Z-source inverter (MCA-ZSI), whose boost factor is much closer to the proposed topology. Rigorous mathematical analyses are presented to clearly demonstrate the benefits of the proposed topology while simulation studies are carried out to demonstrate its distinct features as compared to the existing topology. Finally, experimental studies are conducted to further validate the theoretical and simulation results.

scholarly journals Design and development of PWM switching for 5-level multiphase interleaved DC/DC boost converter using FPGA

2020 ◽  
Vol 17 (1) ◽  
pp. 131
Author(s):  
A. F. H. A. Gani ◽  
A. A. Bakar ◽  
A. Ponniran ◽  
M. Hussainar ◽  
M. A. N. Amran
Keyword(s):  
Pulse Width Modulation ◽  
Technological Development ◽  
Boost Converter ◽  
Switching Frequency ◽  
Switching Scheme ◽  
Digital Controllers ◽  
Electric Drives ◽  
Field Programmable ◽  
Increasing Demand ◽  
Current Ripple

<p>The continuously increasing demand for control on electric power equipment has led to the rapid technological development in various applications such as renewable energy, electric drives, and communication. Pulse Width Modulation (PWM) switching is an important technique to control the output voltage. PWM signals can either be generated using digital controller or analog controller. Digital controllers are widely used to generate PWM signals due to their reliability in solving complex algorithms within short amount of time. Multiphase boost converter is capable to overcome high input current ripple, current stress and semiconductor losses in conventional boost converter. This paper proposes a PWM switching scheme for multiphase interleaved converter using Field Programmable Gate Array (FPGA). The proposed switching scheme uses PWM switching technique that is implemented by programming Altera DE2-70 board. The duty cycle can be easily adjusted using assigned switches on the Altera board. For validation, switching frequency was set to 100 kHz, and then switching signal was observed using oscilloscope.</p>

The Ethics of Medical Tourism

2015 ◽  
pp. 79-88
Author(s):  
Nader Ghotbi
Keyword(s):  
Cosmetic Surgery ◽  
Assisted Suicide ◽  
Common Ground ◽  
Medical Tourism ◽  
Ethical Decision Making ◽  
Ethical Issues ◽  
Moral Issues ◽  
Therapeutic Massage ◽  
Life Saving ◽  
Almost All

Medical tourism is rapidly growing. There are various reasons for this form of travel; from having life-saving surgery, receiving organ transplants and other vital operations, to therapeutic massage, using hot spas, and cosmetic surgery, and from receiving assistance with infertility to assisted suicide services at particular destinations. Some forms of medical tourism have strong ethical issues attached to them, but there are also ethical issues that may apply to almost all cases, and these can be discussed in a general way. This chapter discusses fundamental definitions of the concepts and general ethical issues in medical tourism, and then explains in more detail some of the moral issues in medical tourism that need to be examined from an ethical standpoint. The chapter establishes common ground for discussion based on broadly accepted principles that can be used almost universally as general guidelines for ethical decision-making in medical tourism activities.

Low Input Current Ripple Quasi-Single-Stage Power Supply Based on Double Resonant Tank LLC Converter for Maglev Control System Applications

2016 ◽  
Vol 25 (06) ◽  
pp. 1650064 ◽  
Author(s):  
Hongbo Ma ◽  
Junhong Yi ◽  
Jie Shuai ◽  
Jie Yang
Keyword(s):  
Power Supply ◽  
Low Voltage ◽  
Magnetic Levitation ◽  
High Reliability ◽  
Input Voltage ◽  
Single Stage ◽  
Input Current ◽  
Duty Ratio ◽  
Low Input ◽  
Current Ripple

High input voltage, multiple low voltage outputs and high working temperature are the main design challenges for magnetic levitation (maglev) control power supply. The traditional solutions have several problems, such as the uncontrolled duty ratio, the poor cross-regulation capability and low reliability. In order to solve these problems, a quasi-single-stage solution employing the double resonant tank LLC topology is proposed and developed in this paper. The proposed solution can increase significantly the overall conversion efficiency because of the achieved soft-switching over the entire operation range. Moreover, the low input current ripple, high magnetic utilization and high reliability can be achieved. Experimental results of a 210-W laboratory prototype with 220–380[Formula: see text]V input and four outputs are presented to demonstrate the declared features.

scholarly journals Differential Evolution Based Algorithm for Optimal Current Ripple Cancelation in an Unequal Interleaved Power Converter

Mathematics ◽  
2021 ◽  
Vol 9 (21) ◽  
pp. 2755
Author(s):  
Julio C. Rosas-Caro ◽  
Pedro M. García-Vite ◽  
Alma Rodríguez ◽  
Abraham Mendoza ◽  
Avelina Alejo-Reyes ◽  
...  
Keyword(s):  
Differential Evolution ◽  
Differential Evolution Algorithm ◽  
Power Converter ◽  
Input Current ◽  
Switching Frequency ◽  
Duty Cycles ◽  
Numerical Experimentation ◽  
Evolution Algorithm ◽  
Power Electronics Converter ◽  
Current Ripple

This paper proposes an optimal methodology based on the Differential Evolution algorithm for obtaining the set of duty cycles of a recently proposed power electronics converter with input current ripple cancelation capability. The converter understudy was recently introduced to the state-of-the-art as the interleaved connection of two unequal converters to achieve low input current ripple. A latter contribution proposed a so-called proportional strategy. The strategy can be described as the equations to relate the duty cycles of the unequal power stages. This article proposes a third switching strategy that provides a lower input current ripple than the proportional strategy. This is made by considering duty cycles independently of each other instead of proportionally. The proposed method uses the Differential Evolution algorithm to determine the optimal switching pattern that allows high quality at the input current side, given the reactive components, the switching frequency, and power levels. The mathematical model of the converter is analyzed, and thus, the decision variables and the optimization problem are well set. The proposed methodology is validated through numerical experimentation, which shows that the proposed method achieves lower input current ripples than the proportional strategy.

From Paris to Katowice: cop-24 Tackles the Paris Rulebook

2019 ◽  
Vol 16 (2) ◽  
pp. 165-190
Author(s):  
Charlotte Streck ◽  
Moritz von Unger ◽  
Nicole Krämer
Keyword(s):  
Kyoto Protocol ◽  
Common Ground ◽  
Paris Agreement ◽  
Carbon Markets ◽  
Additional Time ◽  
International Climate Policy ◽  
International Climate ◽  
Mitigation Action ◽  
Almost All

The adoption of the “Paris rulebook” at Katowice in late 2018 marks the most significant milestone in international climate policy making since the adoption of the Paris Agreement in 2015. Through a package of decisions, Parties to the Paris Agreement fulfilled almost all of the Paris mandate and moved towards the full implementation of the treaty. With the exception of the discussion on the future of carbon markets, negotiators managed to find common ground across negotiation items ranging from mitigation action to ensuring transparency and follow-up, including through “global stocktakes”, climate finance and technology transfer. Most obligations will apply to all countries, replacing the “bifurcation” of the Kyoto Protocol with a common set of rules for all Parties. Developing countries can make the case for additional time and assistance to comply with the full set of requirements. Several matters are left for future sessions – concerning, in particular, the harmonization of the timeframes of mitigation goals, markets and finance mobilization– and structural challenges – not least concerning the integration of non-state actors – remain. However, in building on accountability, trust, and compliance through facilitation, the new Paris rules may ultimately prove decidedly more robust and sustainable than those of the Kyoto Protocol.

Nanostructured Materials for the Realization of Electrochemical Energy Storage and Conversion Devices

2017 ◽  
pp. 1719-1758
Author(s):  
Imran Shakir ◽  
Zahid Ali ◽  
Usman Ali Rana ◽  
Ayman Nafady ◽  
Mansoor Sarfraz ◽  
...  
Keyword(s):  
Energy Storage ◽  
High Performance ◽  
Structural Characteristics ◽  
Lithium Ion ◽  
Modern World ◽  
Energy Storage And Conversion ◽  
Maximum Output ◽  
Increasing Demand ◽  
Almost All ◽  
Electrocatalyst Materials

One of the greatest challenges for the modern world is the ever-increasing demand of energy, which may soon outstrip the amount of natural resources that can be obtained using currently known energy conversion and energy storage technologies such as solar cells, fuel cells, lithium ion batteries, and supercapacitors. It appears that the maximum output efficiencies of these devices have already reached the intrinsic limits of almost all electrocatalyst materials. Hence, it is a high time to think about new material architectures by controlling size, shape, and geometry, as well as composition that can potentially make a significant improvement in the performance of these electrochemical devices. Among several known electrocatalyst materials are nanomaterials and their composites due to their unique electrical, mechanical, physical, chemical, and structural characteristics. These materials have opened a whole new territory of possibilities in designing high performance energy storage and conversion devices. In this chapter, the authors review the recent progress in energy storage and conversion devices that utilize various nanomaterials and their composite materials and identify future directions in which the field is likely to develop.

A New Isolated Boost Converter with Coupling Inductors

2013 ◽  
Vol 392 ◽  
pp. 394-397
Author(s):  
Hai Ming Zhang ◽  
Xiao Zhong Liao
Keyword(s):  
Boost Converter ◽  
Input Current ◽  
Zero Voltage Switching ◽  
Zero Voltage ◽  
Diode Voltage ◽  
Current Ripple ◽  
Voltage Switching

This paper proposes a new improved zero-voltage switching isolated boost converter with coupling inductors. With the traditional advantages of smaller input current ripple, low diode voltage rating, and low transformer turns ratio of boost half bridge topology [ being retained, the proposed converter makes it much easier to realize zero voltage switching of primary switches compared with conventional converters.

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