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Article
Publication date: 8 February 2021

Saravanan R., Vijayshankar S., Sathyaseelan and Suresh K.

This paper aims to propose Hidden Converter (H-Converter) combined with dual portinverter for energy storage application to produce wide range of voltage. Some of the…

238

Abstract

Purpose

This paper aims to propose Hidden Converter (H-Converter) combined with dual portinverter for energy storage application to produce wide range of voltage. Some of the application required wide range of voltages, but problem from E-chopper is either boost or buck mode of operations, both modes are not possible. To overcome this drawback, H-Converter is combined with dual portinverter controlled by carrier-based pulse width modulation (CB-PWM) technique is added with zero sequence injection.

Design/methodology/approach

Hidden converter is a bidirectional DC-DC chopper used to convert fixed DC to variable DC and vice versa in both buck and boost modes of operations. Dual port inverter is combined with hidden DC-DC converter can produce wide range of voltages.

Findings

The bidirectional DC-AC converter requires less power for processing and consumes less power losses by using modest carrier built- pulse width modulation scheme through proposed zero structure addition.

Originality/value

By using this proposed strategy H-Converter can produce wide range of voltage in both the sides and mostly power is processed in the 3Ø inverter with a one stage conversion with less power loss. As a result, with one stage power conversion has more efficiency because of less power loss. This proposed converter has designed by analysis, and the real time result is tested in an experiment.

Details

Circuit World, vol. 48 no. 1
Type: Research Article
ISSN: 0305-6120

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Article
Publication date: 20 June 2020

Fossy Mary Chacko, Ginu Ann George, Jayan M.V. and Prince A.

This paper aims to propose an improved multifunctional control strategy for achieving real, reactive power flow control and the mitigation of power quality issues in grid…

105

Abstract

Purpose

This paper aims to propose an improved multifunctional control strategy for achieving real, reactive power flow control and the mitigation of power quality issues in grid integrated photovoltaic (GIPV) systems.

Design/methodology/approach

The paper proposes a dual stage, three phase, multifunctional GIPV system with modified instantaneous reactive power (IRP) theory-based and modified synchronous reference frame (SRF) theory-based control algorithms for reference template generation with continuous load power requirement tracking. The control structure is designed so as to impart virtual distribution static compensator functionality to the photovoltaic inverter. The dual mode operation in active filter and renewable power injection modes provides enhanced capability to the GIPV system. A comprehensive evaluation of the dynamic behaviour of the GIPV system is carried out for various conditions of irradiance and load under MATLAB/Simulink platform. The performance comparison is done considering an uncompensated system and the GIPV system with both proposed control algorithms.

Findings

The extensive simulation results demonstrate that the proposed modified SRF theory-based multifunctional control strategy shows superior performance in real and reactive power flow control; reduction in real and reactive burden of the utility grid; and regulation of dc bus voltage under varying scenarios of irradiance and load. Furthermore, there is improvement of grid power factor and reduction in total harmonic distortion of grid currents in compliance with the IEEE 519 standard even with highly non-linear loads at the point of common coupling.

Originality/value

The proposed modified SRF theory-based multifunctional controller offers a viable solution for power quality enhancement as well as the realization of effective real and reactive power flow control in GIPV systems. Thus, the penetration level of distributed generation can be increased in this era of global energy crisis.

Details

World Journal of Engineering, vol. 17 no. 4
Type: Research Article
ISSN: 1708-5284

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Article
Publication date: 1 February 1989

Bennett J. Price

Uninterruptible Power Supply (UPS) systems are typically designed to provide power to computers for five to thirty minutes after all utility company power has failed. In addition…

215

Abstract

Uninterruptible Power Supply (UPS) systems are typically designed to provide power to computers for five to thirty minutes after all utility company power has failed. In addition to providing blackout and brownout protection, many UPS systems also protect against spikes, surges, sags, and noise, and some also offer many of the features found in power distribution units (PDUs). The major components or subsystems of a typical UPS system are detailed, and a sample bid specification is appended. Three sidebars discuss UPSs and air conditioning, the maintenance bypass switch (MBS), and literature for further reading.

Details

Library Hi Tech, vol. 7 no. 2
Type: Research Article
ISSN: 0737-8831

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Article
Publication date: 27 July 2012

Siti Maisurah Mohd Hassan, Mohd Azmi Ismail, Nazif Emran Farid, Norman Fadhil Idham Muhammad and Ahmad Ismat Abdul Rahim

The purpose of this paper is to design and implement a fully integrated low‐phase noise and large tuning range dual‐band LC voltage‐controlled oscillator (VCO) in 0.13 μm…

212

Abstract

Purpose

The purpose of this paper is to design and implement a fully integrated low‐phase noise and large tuning range dual‐band LC voltage‐controlled oscillator (VCO) in 0.13 μm complementary metal oxide semiconductor (CMOS) technology.

Design/methodology/approach

Two parallel‐connected single‐band VCOs are designed to implement the proposed VCO. Adopting a simple and straight‐forward architecture, the dual‐band VCO is configured to operate at two frequency bands, which are from 1.48 GHz to 1.78 GHz and from 2.08 GHz to 2.45 GHz. A band selection circuit is designed to perform band selection process based on the controlling input signal.

Findings

The proposed VCO features phase noise of −104.7 dBc/Hz and −108.8 dBc/Hz at 1 MHz offset frequency for both low corner and high corner end of the low‐band operation. For high‐band operation, phase‐noise performance of −101.1 dBc/Hz and −110.4 dBc/Hz at 1 MHz offset frequency are achieved. The measured output power of the dual‐band VCO ranges from −8.4 dBm to −5.8 dBm and from −9.6 dBm to −8.0 dBm for low‐band and high‐band operation, respectively. It was also observed that the power differences between the fundamental spectrum and the nearby spurious tone range from −67.5 dBc to −47.7 dBc.

Originality/value

The paper is useful to both the academic and industrial fields since it promotes the concept of multi‐band or multi‐standard system which is currently in demand in the telecommunication industry.

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Article
Publication date: 1 September 1963

TEN THOUSAND AND NINETY gallons of usable fuel are carried in six integral type tanks, three in each wing, the individual tank capacities per wing being: No. 1 Tank (Inner) 2,865…

105

Abstract

TEN THOUSAND AND NINETY gallons of usable fuel are carried in six integral type tanks, three in each wing, the individual tank capacities per wing being: No. 1 Tank (Inner) 2,865 gallons, No. 2 Tank (Centre) 1,750 gallons, No. 3 Tank (Outer) 430 gallons. Each tank is equipped with two booster pumps mounted in canisters which permit pump replacement without draining the tanks.

Details

Aircraft Engineering and Aerospace Technology, vol. 35 no. 9
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 12 October 2021

Augusto Romero

The purpose of this study is to explore the optimum design of bending plate compliant mechanisms subjected to pure mechanical excitations using topological-derivative-based…

78

Abstract

Purpose

The purpose of this study is to explore the optimum design of bending plate compliant mechanisms subjected to pure mechanical excitations using topological-derivative-based topology optimization. The main objective is to design the reinforcement in a plate of base material.

Design/methodology/approach

The optimum design is performed by means of a level-set representation method guided by topological derivatives. Kirchhoff and Reissner–Mindlin models are used to solve the linear bending plate problem. A qualitative comparison has been carried out between the optimal obtained topologies for each model.

Findings

The proposed methodology was able to design reinforcement in a plate of the base material. The obtained reinforcements notably improve the device’s behavior. The shape and topology of the reinforcements vary depending on the mechanical plate model considered. In fact, in the Reissner–Mindlin solutions, very thin flexo-torsional hinges connecting big zones of the reinforcement material are designed.

Originality/value

Up to date, the synthesis of ortho-planar mechanisms by means of continuum topology optimization was only boarded within a multi-physics context. In this work, the optimal design of pure ortho-planar compliance actuators is addressed. The best performance is found by analyzing the results for two classical mechanical plate models.

Details

Engineering Computations, vol. 39 no. 1
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 10 September 2019

Shilpi Birla

Major area of a die is consumed in memory components. Almost 60-70% of chip area is being consumed by “Memory Circuits”. The dominant memory in this market is SRAM, even though…

115

Abstract

Purpose

Major area of a die is consumed in memory components. Almost 60-70% of chip area is being consumed by “Memory Circuits”. The dominant memory in this market is SRAM, even though the SRAM size is larger than embedded DRAM, as SRAM does not have yield issues and the cost is not high as compared to DRAM. At the same time, the other attractive feature for the SRAM is speed, and it can be used for low power applications. CMOS SRAM is the crucial component in microprocessor chips and applications, and as the said major portion of the area is dedicated to SRAM arrays, CMOS SRAM is considered to be the stack holders in the memory market. Because of the scaling feature of CMOS, SRAM had its hold in the market over the past few decades. In recent years, the limitations of the CMOS scaling have raised so many issues like short channel effects, threshold voltage variations. The increased thrust for alternative devices leads to FinFET. FinFET is emerging as one of the suitable alternatives for CMOS and in the region of memory circuits.

Design/methodology/approach

In this paper, a new 11 T SRAM cell using FinFET technology has been proposed, the basic component of the cell is the 6 T SRAM cell with 4 NMOS access transistors to improve the stability and also makes it a dual port memory cell. The proposed cell uses a header scheme in which one extra PMOS transistor is used which is biased at different voltages to improve the read and write stability thus, helps in reducing the leakage power and active power.

Findings

The cell shows improvement in RSNM (read static noise margin) with LP8T by 2.39× at sub-threshold voltage 2.68× with D6T SRAM cell, 5.5× with TG8T. The WSNM (write static noise margin) and HM (hold margin) of the SRAM cell at 0.9 V is 306 mV and 384  mV. It shows improvement at sub-threshold operation also. The leakage power is reduced by 0.125× with LP8T, 0.022× with D6T SRAM cell, TG8T and SE8T. The impact of process variation on cell stability is also discussed.

Research limitations/implications

The FinFet has been used in place of CMOS even though the FinFet has been not been a matured technology; therefore, pdk files have been used.

Practical implications

SRAM cell has been designed which has good stability and reduced leakage by which we can make an array and which can be used as SRAM array.

Social implications

The cell can be used for SRAM memory for low power consumptions.

Originality/value

The work has been done by implementing various leakage techniques to design a stable and improved SRAM cell. The advantage of this work is that the cell has been working for low voltage without degrading the stability factor.

Details

Circuit World, vol. 45 no. 4
Type: Research Article
ISSN: 0305-6120

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Article
Publication date: 27 May 2022

Faruk Yalcin, Ugur Arifoglu and Irfan Yazici

This paper aims to present the design and implementation of a new general-purpose single-phase buck-type inverter.

158

Abstract

Purpose

This paper aims to present the design and implementation of a new general-purpose single-phase buck-type inverter.

Design/methodology/approach

The operation of the proposed inverter is based on the general-purpose buck converter. The proposed buck-type inverter topology is designed with reduced numbers of passive and active elements to minimize design cost and complexity. Also, an efficient hybrid control technique based on the proportional‐integral‐derivative (PID) supported by open-loop control signal is offered for the control of the proposed inverter. The proposed hybrid control method improves the performance of the PID controller during the change of inverter operation parameters. A close to single-phase sine wave output voltage with low total harmonic distortion (THD) can be produced by the proposed inverter in a wide range of voltage and frequency lower than the inverter input voltage value.

Findings

Simulation and experimental test studies are applied to the proposed inverter. The experimental laboratory setup is built for 0–50 Hz, 0–100 Vp, 0.5 kW. Both the simulation and the experimental test results show that the single-phase inverter can produce close to sine wave output voltage with THD level under 5% in a wide range of frequency for various operating conditions and for different loads.

Originality/value

In this paper, a new topology and a new hybrid control technique that are patented by the corresponding author are implemented for a single-phase buck-type inverter through a scientific project. The operating results of the study reveal the efficient operating capability with a simple topology structure.

Details

Circuit World, vol. 48 no. 3
Type: Research Article
ISSN: 0305-6120

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Article
Publication date: 1 August 1965

A Description of the Crew Compartment Layout and Instruments, and Details of the Hydraulic, Power Plant, Fuel, Fire Protection, Flight Control, Wing Flap, Air Conditioning and…

41

Abstract

A Description of the Crew Compartment Layout and Instruments, and Details of the Hydraulic, Power Plant, Fuel, Fire Protection, Flight Control, Wing Flap, Air Conditioning and Pressurization, Ice and Rain Protection, Electrical and Radio Systems. WITH the crew compartment situated above the main freight compartment, the layout presented few problems from a space point of view. Height was restricted due to the need to keep the frontal area of the fuselage within reason but there was ample width to allow the pilots plenty of elbow room. Most of the work in settling the layout was conducted on the full‐size mock‐up and in view of the fact that this was the first civil aircraft to be designed by the company for some years, a review of modern airliner cockpits was undertaken, and consultations took place between the firm, the British Airline Pilots' Association, and the Air Registration Board before too many of the features were settled.

Details

Aircraft Engineering and Aerospace Technology, vol. 37 no. 8
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 1 August 1966

R.F.W. Guest

BECAUSE of relatively high power to weight factor, general compactness with low frontal area, competitive specific fuel consumption and general ruggedness, the horizontally…

76

Abstract

BECAUSE of relatively high power to weight factor, general compactness with low frontal area, competitive specific fuel consumption and general ruggedness, the horizontally opposed engines manufactured by Continental Motors Corporation have been used by small aircraft over the past twenty‐five years. The manufacture of the four and six cylinder versions of these engines has been undertaken by the Rolls‐Royce Ltd, who have participated with Beagle in providing a sophisticated installation on the B.206 aircraft.

Details

Aircraft Engineering and Aerospace Technology, vol. 38 no. 8
Type: Research Article
ISSN: 0002-2667

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