Required Output Characteristics Research Articles

Integrated starter-generator with a supply voltage of 48 V for the automotive industry

Integrated starter-generator (ISG) systems are being widely implemented in the automotive industry, combining two devices in one. This article describes the design of ISG type Brushless DC (BLDC) with internal permanent magnets (PM) for the automotive industry with a supply voltage of 48 V. The results of a numerical calculation of electromagnetic and thermal characteristics obtained using the ANSYS software package using 2D modeling are presented. The results obtained show the high efficiency of the proposed design, as well as obtaining the required output characteristics. Keywords: hybrid cars, integrated starters-generators, electrical machines, numerical computer simulation

Improved Model Predictive Control for Asymmetric T-Type NPC 3-Level Inverter

In this paper, a model predictive control for an asymmetric T-type NPC 3-level inverter is presented. The mathematical model and characteristics of the reduced switching topology are described. An improvement for the predicted strategy with the pre-selected candidate vectors is proposed. The simulation and experimental results are provided and show good efficiency for the proposed control algorithm. The improved algorithm greatly reduces execution time by about 18% and delivers a better load current THD than the conventional model for predictive control. For comparison, similar tests are performed on both 2-level and conventional 3-level inverters. Although the current load quality of the asymmetrical inverter is not as good as the traditional 3-level inverter, it is much better than the 2-level inverter. In addition, it has the benefits of significantly reducing overall costs, simpler hardware system design, and faster predictive processing than the conventional 3-level inverters. Therefore, this asymmetric inverter has advantages for an application with the required output characteristics like the conventional 3-level inverter and with lower cost.

Design and Characteristics Satisfying Required Output Characteristics for SynRM

Design and Characteristics Satisfying Required Output Characteristics for SynRM

Heat Power Equipment Sample Tests Using Time-Series Techniques

The article is concerned with the problem of planning of the amount of sample tests of heat power equipment components using time-series techniques. In the operation process of thermoelectric power stations (TPS) their expensive components (turbines, bearings, oil systems, generators, transformers, pipelines etc.) require securing of preset level of reliability and safety. For achievement of this aim it is necessary to develop corresponding plan of sample tests. Peculiarity of heat power equipment components is that they are devices consisting of elements’ totality of mechanical, hydraulic, pneumatic, electronic and other types. The basis of the proposed sample tests amount planning technique is the condition of test sample restorability after failure through improvements. In this case, the risk of developer (supplier) is assumed to be close to zero (α = 0). Improvement will be considered effective if carried out tests are successful in the same amount after improvement. Novelty of the proposed test amount planning technique for one preset level of reliability allows getting required output characteristics of heat power equipment in shorter period.

Estimating the parameters of ultrasonically induced mass transfer and flow of liquids in the pseudomembrane method

The main features of the effect of acoustic streaming induced in the cylindrical volume of a liquid by the radial vibrations of its walls in the ultrasonic frequency range on mass transfer and transport of liquid fractions in the axial direction have been determined. An analysis of conditions for the effective occurrence of the process under consideration has been performed, and the optimum scheme for the technological implementation of the method being developed has been designed. The problem of self-consistent distribution of liquid flows in different regions of the space occupied by the liquid where extraction occurs has been solved. Its results form a basis for the targeted regulating of the efficiency of physicochemical processes involved and the arrangement of the practical scheme of equipment with required output characteristics. The derived formulas make it possible to calculate the resonance parameters of ultrasound and equipment used, which ensure conditions for achieving the desired efficiency of the phenomenon under study, to determine the radius of droplets into which liquid fractions are broken, to calculate the rate of liquid motion along the axis of the cylinder, and to estimate the critical sizes of the process flow diagram. Formulated analytical relations and computer calculations are aimed at revealing the most significant dependencies that give crucial guidelines in the practical implementation of the technology under study.

Investigation on the Effect of Tool Coating Thickness in Pocket Milling using Austenite Ss316

Objective: This paper presents the research work done in Pocket milling operation using Stainless steel 316 materials. The most critical process parameters namely, Coating thickness (μm), Depth of Cut [DOC] (mm), Spindle Speed [SS] (rev/ min) and Feed Rate (mm/min) are taken into consideration to improve the quality of the output characteristics. The required output characteristics are Cycle time (min), Surface quality measurement, i.e., Roughness of the surface (Ra), Wear of the Tool (mm), Microhardness (HV) and Material Removal Rate (mm3/min). Methods/Analysis: The Taguchi method was used to tabulate the Design of experiments (DOE) of L9 orthogonal array. According to the study, the required Material Removal Rate is considered ‘higher the better’ and other required output characteristics are ‘lower the better.’ To determine to a most significant process parameter, Taguchi’s grey relation analysis is used. To determine the significance and shift of each parameter to the total variation observed, Signal to Noise Ratio (S/N) was used. The contributions of each process parameters to obtain the required output characteristics are studied. Findings: From the grey relation grade, the highest maximum – minimum value shows that the depth of cut is the most influential input parameter for the obtained output characteristics. The optimum input parameters are tool coating thickness of 10 μm, the speed of the spindle being 2500 rev/min, feed rate being 1000 mm/min and depth of cut being 0.7 mm. A verification test was performed conducive to determine the veritableness of the obtained optimal input parameters. The test proves that the optimum input process variables satisfy the required output characteristics for pocket milling operation in AISI Stainless Steel 316 material.

The development of an electro-hydraulic transmission control system of a high-speed tracked vehicle

The paper presents some of the results obtained by the investigations carried out in the process of development of a new control system concept (named GC TRONIC) for a high-speed tracked vehicle having two planetary gearboxes. The description and principle of operation of the GC TRONIC system are presented together with its output characteristics obtained by the experimental investigations on the corresponding test stand. The obtained results confirmed that the system provided a high degree of automation of the process of gear change under load and satisfied the required output characteristics.

Calculation model of a CO laser with a high-frequency discharge in a supersonic stream of combustion products

A calculation model was developed for a CO laser with an hf discharge in a supersonic stream of combustion products. The model can be used to determine the energy, time, and spectral parameters of a CO laser, and to optimise its construction and operation so as to ensure that the required output characteristics are obtained. The model was employed to design and construct for the first time a prototype system in which lasing was achived. A high laser efficiency was ensured by adjustment of the composition of the combustion products, selection of the duration of exposure to a discharge, and composition of the active mixture subject to the condition that the bulk of the energy supplied by the electric field was transferred to the vibrational levels of the CO molecules. In this case the other components of the active mixture acted simply as a buffer gas if the volume fraction of the nitrogen molecules did not exceed 90% and the volume fraction of the oxygen molecules was not greater than the corresponding fraction of the CO molecules in the mixture.

Design of replay audio recording heads

Manufacturers of audio replay heads for tape cassettes often require design information in response to customer specifications. This paper shows how a computer can be used to speed-up the design process. Probable output characteristics can be forecast for various designs of replay head which comply with the same basic specification. In this way designs can be quickly optimized in terms of the required output characteristics and manufacturing economy.

A Theory of Available Output and Optimum Operating Conditions for Triode Valves

The output characteristics of triode and pentode valves have been investigated in the past by many workers, using either the static method of plotting a whole family of curves, or the dynamic method of measurement with a harmonic analyzer: these have not, however, led to many simplifying generalizations, and are cumbersome and difficult methods if they are to be applied to each individual valve. In this paper, the form of the triode curves is first investigated experimentally, and the allowable limits of dynamic swing thus determined for any given per cent harmonic: on this basis, a series of expressions are mathematically developed giving the required output characteristics in terms of an easily obtained valve constant (i.e., the valve alternating-current resistance at V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">a</inf> = 100, V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">g</inf> = 0; this is the standard figure quoted by English manufacturers). Curves are given for output and correct plate current with various values of resistive load and of per cent harmonic limit, with or without conditions of limited anode dissipation. The case of the practical load with low direct-current resistance is examined, and the results are checked with a harmonic analyzer; the paper concludes with a few practical rules. It is hoped in a future paper to extend the analysis to cover push-pull circuits, the pentode valve, and the practical inductive load.