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Article
Publication date: 8 March 2011

Arash Abbasalizadeh Boora, Firuz Zare and Arindam Ghosh

Multi‐level diode‐clamped inverters have the challenge of capacitor voltage balancing when the number of DC‐link capacitors is three or more. On the other hand…

Abstract

Purpose

Multi‐level diode‐clamped inverters have the challenge of capacitor voltage balancing when the number of DC‐link capacitors is three or more. On the other hand, asymmetrical DC‐link voltage sources have been applied to increase the number of voltage levels without increasing the number of switches. The purpose of this paper is to show that an appropriate multi‐output DC‐DC converter can resolve the problem of capacitor voltage balancing and utilize the asymmetrical DC‐link voltages advantages.

Design/methodology/approach

A family of multi‐output DC‐DC converters is presented in this paper. The application of these converters is to convert the output voltage of a photovoltaic (PV) panel to regulate DC‐link voltages of an asymmetrical four‐level diode‐clamped inverter utilized for domestic applications. To verify the versatility of the presented topology, simulations have been directed for different situations and results are presented. Some related experiments have been developed to examine the capabilities of the proposed converters.

Findings

The three‐output voltage‐sharing converters presented in this paper have been mathematically analysed and proven to be appropriate to improve the quality of the residential application of PV by means of four‐level asymmetrical diode‐clamped inverter supplying highly resistive loads.

Originality/value

This paper shows that an appropriate multi‐output DC‐DC converter can resolve the problem of capacitor voltage balancing and utilize the asymmetrical DC‐link voltages advantages and that there is a possibility of operation at high‐modulation index despite reference voltage magnitude and power factor variations.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 30 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 12 December 2017

Yu Tian, Jun Zhang, Zongjin Ren, Wei Liu, Zhenyuan Jia and Qingbing Chang

This paper aims to improve calibration and force measurement accuracy of multi-sensors’ piezoelectric dynamometer used in thrust measurement of rocket/air vehicle engine.

Abstract

Purpose

This paper aims to improve calibration and force measurement accuracy of multi-sensors’ piezoelectric dynamometer used in thrust measurement of rocket/air vehicle engine.

Design/methodology/approach

This paper presents a mapping solution method of sensors’ outputs based on the Kirchhoff thin plate theory, builds force-deformation differential equations with specific boundary conditions, uses finite difference (FD) method to solve the equations and analyzes outputs in offset loading forces in four-sensor square layout in main direction. The resultant force deviations calculated by the Kirchhoff theory are optimized with sequence quadratic program (SQP) method, and a calibration method of multiple loading points (MLP) based on the Kirchhoff theory is presented. Experiments of static calibration and verification are complemented to contrast the novel and single loading point (SLP) calibration method.

Findings

Experiments of static calibration and its verification show that at a loading force of 5,000N, the average resultant force deviations with MLP is 17.87N (0.35% FS) compared with single loading point method 26.45N (0.53% FS), improving calibration and measurement precision.

Originality value

A novel calibration method with MLP is presented. Force distributions of multiple sensors of main direction in piezoelectric dynamometer with offset loading force are solved with the Kirchhoff theory. The resultant force deviations calculated by Kirchhoff theory are optimized with the SQP method.

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Article
Publication date: 9 March 2020

Qingbing Chang, Jun Zhang and Zongjin Ren

The purpose of this paper is to solve the problem that the relationship between loading forces, which were applied at different positions on a plane, and output values of…

Abstract

Purpose

The purpose of this paper is to solve the problem that the relationship between loading forces, which were applied at different positions on a plane, and output values of load-sharing dynamometer is non-linear.

Design/methodology/approach

First, the analytical model of ISPM (isodynamic surface proportional mapping method) method, which is used to calibrate dynamometer, was established. Then, a series of axial force calibration tests were performed on a load-sharing dynamometer at different loading positions. Finally, according to output values, calibration forces at different loading positions were calculated by ISPM method, and corresponding distribution histogram of calibration force error was generated.

Findings

The largest error between calculated force and standard force is 2.92 per cent, and the probability of calculated force error within 1 per cent is 91.03 per cent, which verify that the ISPM method is reliable for non-linear calibration of dynamometers.

Originality/value

The proposed ISPM method can achieve non-linear calibration between measured force and output signal of load-sharing dynamometer at different positions. In addition, ISPM method can also solve some complex non-linear problems, such as prediction of plane cutting force under the influence of multiple parameters, the force measurement of multi-degree-of-freedom platform and so on.

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Article
Publication date: 1 May 1955

TIME and Motion/Work Study faces a major issue today and it has got to be solved—quickly. Either it rises in a unified manner to the tasks Industry has allotted it, or it…

Abstract

TIME and Motion/Work Study faces a major issue today and it has got to be solved—quickly. Either it rises in a unified manner to the tasks Industry has allotted it, or it expends itself in shrill quarrels about controlling its destiny.

Details

Work Study, vol. 4 no. 5
Type: Research Article
ISSN: 0043-8022

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Article
Publication date: 1 June 1960

Electrohydraulic servos have been widely applied to the task of precisely positioning heavy loads. Common examples from the military field are radar antenna and rocket…

Abstract

Electrohydraulic servos have been widely applied to the task of precisely positioning heavy loads. Common examples from the military field are radar antenna and rocket engine swivelling drives. In the commercial area large machine tool position controls are a prime example. Even with relatively substantial driving linkages, the inertia of these loads frequently results in low natural frequency of the output load‐driver structure. Very commonly this is combined with extremely small natural damping forces. Natural frequencies from 5 to 20 c.p.s. with damping ratios in the oder of 0·05 critical are typical. This combination of resonance with low damping creates a severe stability and performance problem for the electrohydraulic servo drive. Efforts to deal with this problem have centred on introducing artificial damping. In the past this has been done either by use of a controlled piston by‐pass leakage path or by use of a load force feedback path. The former technique is simple but wasteful with respect to power and inherently involves serious performance compromises. The latter technique can be arranged to be unassailable on theoretical grounds. However, it leads to severe system complication and large incremental hardware requirements. Questions of a reliability penalty are raised. A new technique has been developed which possesses all the performance advantages of load feedback without serious increase in complexity. Called Dynamic Pressure Feedback, this technique involves only a modification of servo valve component. It utilizes for feedback purposes the inherently high load forces developed as piston differential pressures, insuring reliable operation. The pressures needed are already available at the valve. No new hydraulic or electrical connexions are added. The performance advantages adduced for the Dynamic Pressure Feedback Servo Valve have been confirmed in carefully controlled comparative tests on a typical load system. Correspondence of test data with analytical prediction is good. A sufficient number of Dynamic Pressure Feedback Servo Valves have been produced on a pilot production line and installed in several applications in the field to insure producibility and design reliability.

Details

Aircraft Engineering and Aerospace Technology, vol. 32 no. 6
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 1 February 1937

B. Sykes

IN this article it is proposed to deal with the broad principles of operation of the various systems of control of aircraft electrical generators which are in common use…

Abstract

IN this article it is proposed to deal with the broad principles of operation of the various systems of control of aircraft electrical generators which are in common use, rather than with the detail design features and the many minor variations adopted by different manufacturers of this type of equipment.

Details

Aircraft Engineering and Aerospace Technology, vol. 9 no. 2
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 30 March 2010

Chen Mei

The purpose of this paper is to develop a capacitance vehicle weighing device. The key part of this device is the capacitance vehicle weighing sensor. This paper discusses…

Abstract

Purpose

The purpose of this paper is to develop a capacitance vehicle weighing device. The key part of this device is the capacitance vehicle weighing sensor. This paper discusses the static and dynamic performance test of capacitance vehicle weighing sensor with emphasis, and provides theoretical analysis, in order to provide the tests and theoretical basis for the popularization and application of the vehicle weighing device.

Design/methodology/approach

The paper gives an introduction to the weighing sensor in respects of the structure design and measuring principles, with the emphasis on the static and dynamic performance of the testing processes. Then, the paper provides the corresponding testing processes and data with theoretical analysis.

Findings

This weighing sensor can be applied to static as well as dynamic tests thus the capacitance vehicle weighing device is practical and worthy of promotion and popularization.

Originality/value

The capacitance vehicle weighing device is characterized by its simple structure, simple measuring circuits, strong reliability in anti‐interference, small size and low cost. The static performance is of little repetitive error, and the use of software may efficiently solve the problems of non‐linearity and hysteresis. In dynamic measurement, the speed, acceleration and vibration of the vehicle produce little effect on the result, which can be neglected, thus being able to overcome the disadvantages of the traditional weighing method which is of low speed and great errors.

Details

Sensor Review, vol. 30 no. 2
Type: Research Article
ISSN: 0260-2288

Keywords

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Article
Publication date: 25 January 2021

Rekha Yoganathan, Jamuna Venkatesan and William Christopher I.

This paper intent to design, develop, and fabricate a robust cascaded controller based on the dual loop concept i.e. Fuzzy Sliding Mode concept in the inner loop and…

Abstract

Purpose

This paper intent to design, develop, and fabricate a robust cascaded controller based on the dual loop concept i.e. Fuzzy Sliding Mode concept in the inner loop and traditional Proportional Integral controller in the outer loop to reduce the unknown dynamics and disturbances that occur in the DC-DC Converter.

Design/methodology/approach

The proposed Fuzzy sliding mode approach combines the merits of both SMC and Fuzzy logic control. FSMC approach reduces the chattering phenomena that commonly occurs in the sliding mode control and speed up the response of the controller.

Findings

In most of the research work, the inner current loop of cascaded controller was designed by sliding mode control. In this paper FSMC is proposed and its efficacy is confirmed with SMC -PI. In most uncertainties, FSMC-PI produces null maximum peak overshoot and a very less settling time of 0.0005 sec.

Originality/value

The presence of Fuzzy SMC in the inner loop ensure satisfactory response against all uncertainties such as steady state, circuit parameter variations and sudden line and load disturbances.

Details

Circuit World, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0305-6120

Keywords

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Article
Publication date: 19 October 2020

Xin Rui, Junying Wu, Jianbin Zhao and Maryam Sadat Khamesinia

Based on the positive features of the shark smell optimization (SSO) algorithm, the purpose of this paper is to propose a method based on this algorithm, dynamic voltage…

Abstract

Purpose

Based on the positive features of the shark smell optimization (SSO) algorithm, the purpose of this paper is to propose a method based on this algorithm, dynamic voltage and frequency scaling (DVFS) model and fuzzy logic to minimize the energy consumption of integrated circuits of internet of things (IoT) nodes and maximize the load-balancing among them.

Design/methodology/approach

Load balancing is a key problem in any distributed environment such as cloud and IoT. It is useful when a few nodes are overloaded, a few are under-loaded and the remainders are idle without interrupting the functioning. As this problem is known as an NP-hard one and SSO is a powerful meta-hybrid method that inspires shark hunting behavior and their skill to detect and feel the smell of the bait even from far away, in this research, this study have provided a new method to solve this problem using the SSO algorithm. Also, the study have synthesized the fuzzy logic to counterbalance the load distribution. Furthermore, DVFS, as a powerful energy management method, is used to reduce the energy consumption of integrated circuits of IoT nodes such as processor and circuit bus by reducing the frequency.

Findings

The outcomes of the simulation have indicated that the proposed method has outperformed the hybrid ant colony optimization – particle swarm optimization and PSO regarding energy consumption. Similarly, it has enhanced the load balance better than the moth flame optimization approach and task execution node assignment algorithm.

Research limitations/implications

There are many aspects and features of IoT load-balancing that are beyond the scope of this paper. Also, given that the environment was considered static, future research can be in a dynamic environment.

Practical implications

The introduced method is useful for improving the performance of IoT-based applications. We can use these systems to jointly and collaboratively check, handle and control the networks in real-time. Also, the platform can be applied to monitor and control various IoT applications in manufacturing environments such as transportation systems, automated work cells, storage systems and logistics.

Originality/value

This study have proposed a novel load balancing technique for decreasing energy consumption using the SSO algorithm and fuzzy logic.

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Article
Publication date: 5 May 2021

Aditya Kolakoti

This study aims to improve the performance and to regulate the harmful emission from the diesel engine. For this purpose, palm oil biodiesel (POBD), waste cooking…

Abstract

Purpose

This study aims to improve the performance and to regulate the harmful emission from the diesel engine. For this purpose, palm oil biodiesel (POBD), waste cooking biodiesel (WCBD) and animal fat biodiesel (AFBD) are used for examination.

Design/methodology/approach

The transesterification process was followed to convert the three raw oils into biodiesels and the experiments are conducted at various loads with fixed 25 rps. Diesel as a reference fuel and three neat biodiesels are tested for emissions and performance. By training the experimental results in an artificial neural network (ANN), the best biodiesel was predicted.

Findings

The biodiesels are tested for significant fuel properties with the American Society for testing and materials standards and observed that kinematic viscosity, density and cetane number are recorded higher than diesel fuel. The fatty acid composition (FAC) from chromatography reveals the presence of unsaturated FAC is more in POBD (70.89%) followed by WCBD (57.67%) and AFBD (43.13%). The combustion pressures measured at every degree of crank angle reveal that WCBD and AFBD exhibited on far with diesel fuel. Compared to diesel fuel WCBD and AFBD achieved maximum brake thermal efficiency of 31.99% and 30.93% at 75% load. However, there is a penalty in fuel consumption and NOx emissions from biodiesels. On the other hand, low carbon monoxide, unburnt hydrocarbon emissions and exhaust smoke are reported for biodiesels. Finally, WCBD was chosen as the best choice based on ANN modeling prediction results.

Originality/value

There is no evident literature on these three neat biodiesel applications with the mapping of ANN modeling.

Details

World Journal of Engineering, vol. 18 no. 5
Type: Research Article
ISSN: 1708-5284

Keywords

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