For any thermal design and improvements of the motor accurate evaluation of the losses and reasons for
existence of these losses because of which they occur is very important. Experimental techniques aiming at
determining total losses and temperature rise in squirrel cage induction motors (SCIM) are expensive and their
effectiveness is often limited to specific types of motors. Accurate estimation of these losses and how they are
distributed along with feasible techniques to reduce them will result a scope to optimize the thermal design of
the motor. In the present report evaluation, categorization, distribution and methods of reduction of all losses in
SCIM Motor are presented. This has been done with relevant mathematical expressions and presenting
properties of important materials.
Iron losses in ferromagnetic enclosures of gas-insulated transmission lines u...Power System Operation
The enclosure of AC gas-insulated transmission lines
(AC-GIL) is ordinarily made of aluminium. In HVDC
systems, it can be economically and technically
reasonable to manufacture the enclosure of GIL from
steel. To check the feasibility to operate such DC-GIL
even under AC the relevant losses in the steel enclosure
must be known.
The present paper compares three different methods to
determine the specific iron losses of steel when exposed
to magnetic fields with power frequencies. The iron
losses as a function of the magnetic field strength are
measured with a pipe sample in a coaxial conductor
arrangement, a pipe sample in a toroidal core test and
with relevant strips in an Epstein frame. The results
from the three test methods are found to be in close
agreement. By calculating the iron losses in a GIL with
steel enclosure the reduction of the transmission capacity
is estimated when changing from DC to AC operation.
Mechanical behavior and statistical study of aluminum wires belonging to low...theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
This lecture describes the arc welding processes TIG, Plasma, MIG and their modifications in connection with aluminium; it explains the choice of welding parameters; it demonstrates influence of the process on macrostructure. General engineering background and basic knowledge in electrical engineering is assumed.
Evaluation of the Influence of the Welding Current on the Surface Quality of ...theijes
Welding is a metallurgical process; all aspects of a welding process can be more or less, related to metallurgy of the materials involved in welding,either base metal or electrodes. It is a rapid joining technique extensively used for joining thin assemblies in military and automotive applications. The resistance spot welding process bonds contacting metal surfaces via the heat obtained from resistance to an electrical current flow.Process parameters like welding current, time and pressure are closely controlled to obtain superior weld quality. Welding current is generally considered as a key factor affecting the weld quality. The paper deals with evaluation of welding current as the most important parameter of resistance spot welding on the surface quality of welded steel sheets.Various values of welding current were used in the experiments and consequently the marks of spot welded tips on the welded material surfaces were observed. Hot-dip galvanized steel sheets of H220PD and TRIP RAK 40/70 were used for resistance spot welding.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Specification and Use of a Flux ConcentratorFluxtrol Inc.
http://fluxtrol.com
Overview:
Basics of Magnetic Flux Control
Effect of Flux Controllers on Different Coil Styles
Materials for Magnetic Flux Control
Influence of Magnetic Permeability
Selecting the Proper Flux Concentrator
Crankshaft Hardening Inductors
Iron losses in ferromagnetic enclosures of gas-insulated transmission lines u...Power System Operation
The enclosure of AC gas-insulated transmission lines
(AC-GIL) is ordinarily made of aluminium. In HVDC
systems, it can be economically and technically
reasonable to manufacture the enclosure of GIL from
steel. To check the feasibility to operate such DC-GIL
even under AC the relevant losses in the steel enclosure
must be known.
The present paper compares three different methods to
determine the specific iron losses of steel when exposed
to magnetic fields with power frequencies. The iron
losses as a function of the magnetic field strength are
measured with a pipe sample in a coaxial conductor
arrangement, a pipe sample in a toroidal core test and
with relevant strips in an Epstein frame. The results
from the three test methods are found to be in close
agreement. By calculating the iron losses in a GIL with
steel enclosure the reduction of the transmission capacity
is estimated when changing from DC to AC operation.
Mechanical behavior and statistical study of aluminum wires belonging to low...theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
This lecture describes the arc welding processes TIG, Plasma, MIG and their modifications in connection with aluminium; it explains the choice of welding parameters; it demonstrates influence of the process on macrostructure. General engineering background and basic knowledge in electrical engineering is assumed.
Evaluation of the Influence of the Welding Current on the Surface Quality of ...theijes
Welding is a metallurgical process; all aspects of a welding process can be more or less, related to metallurgy of the materials involved in welding,either base metal or electrodes. It is a rapid joining technique extensively used for joining thin assemblies in military and automotive applications. The resistance spot welding process bonds contacting metal surfaces via the heat obtained from resistance to an electrical current flow.Process parameters like welding current, time and pressure are closely controlled to obtain superior weld quality. Welding current is generally considered as a key factor affecting the weld quality. The paper deals with evaluation of welding current as the most important parameter of resistance spot welding on the surface quality of welded steel sheets.Various values of welding current were used in the experiments and consequently the marks of spot welded tips on the welded material surfaces were observed. Hot-dip galvanized steel sheets of H220PD and TRIP RAK 40/70 were used for resistance spot welding.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Specification and Use of a Flux ConcentratorFluxtrol Inc.
http://fluxtrol.com
Overview:
Basics of Magnetic Flux Control
Effect of Flux Controllers on Different Coil Styles
Materials for Magnetic Flux Control
Influence of Magnetic Permeability
Selecting the Proper Flux Concentrator
Crankshaft Hardening Inductors
Design the High Speed Kogge-Stone Adder by UsingIJERA Editor
In this Technical era the high speed and low area of VLSI chip are very- very essential factors. Day by day number of transistors and other active and passive elements are growing on VLSI chip. In Integral part of the processor adders play an important role. In this paper we are using proposed kogge-stone adders for binary addition to reduce the size and increase the efficiency or processors speed. Proposing kogge stone adder provides less components, less path delay and better speed compare to other existing kogge stone adder and other adders. Here we are comparing the kogge stone adders of different-different word size from other adders. The design and experiment can be done by the aid of Xilinx 14.1i Spartan 3 device family.
Drilling Mud Formulation Using Potato Starch(Ipomoea Batatas)IJERA Editor
In the search for suitable local alternatives as additives in the manufacture of drilling muds which is an essential
entity in the exploration of oil and gas, some vital considerations must be put in place such as cost and
environmental effect. This study focuses on the suitability of locally processed potato starch as a viscosifier and
fluid loss agent in drilling mud. Comparative analysis of properties obtained from the prepared potato starch
mud and that formulated from Polyanionic cellulose (PAC) were carried out. Results from this investigation
showed that rheological properties (plastic viscosity and yield point) of the potato starch mud increased when
the content of both viscosifiers were equal at 1.0g/ 316.4ml of water. Plastic viscosity also increased by 13.6%
when potato starch concentration increased by 50%. Also, a combination of PAC and potato starch at a ratio of
1:1 to 0.5:1.5 gave a fluid loss of 7.1 - 7.7 ml which were very close to that of the standard mud at 6.8ml. the
pH, mud weight and specific gravity of the formulated mud samples ranged from 7.0 - 9.0, 7.0 - 9.1 and 0.83 -
1.09 respectively, which were all in line with the standard mud specifications.
Alternative Method for Determining the Elastic Modulus of ConcreteIJERA Editor
This paper presents the use of the technique of digital image correlation for obtaining the elasticity modulus of
concrete. The proposed system uses a USB microscope that captures images at a rate of five frames per second.
The stored data are correlated with the applied loads, and a stress-strain curve is generated to determine the
concrete compressive modulus of elasticity. Two different concretes were produced and tested using the
proposed system. The results were compared with the results obtained using a traditional strain gauge. It was
observed a difference in the range of 4% between the two methods, wherein this difference depends of a lot of
parameter in the case of the DIC results, as focal length and a video capture resolution, indicating that DIC
technique can be used to obtain mechanical properties of concrete.
A Mixed Approach For Nutrient Management Planning In Southeast Asian CountriesIJERA Editor
Southeast Asia (SeA) region has experienced impressive economic, population and urban growth in the last
decades. The region faces big challenges and difficult choices, between economic growth and environmental
protection, especially from water pollution, in pursuing sustainable development. Deterioration of water quality
in lakes, rivers and reservoirs in urban areas due to nutrient pollution from anthropogenic sources, either point
or non-point sources, has recently been recognized as one of the most serious environmental problems
throughout the region. The nutrient pollution problem in water environment has been well-recognized and
addressed in many developed countries, but not in developing countries, especially in the SeA region. This
paper provides a comprehensive assessment on the current status of nutrient management across the region, and
investigates possible reasons why current efforts fail to address the issue. In addition, the paper examines the
possibility of introducing a mixed approach, from planning stage using a Material Flow Analysis (MFA) tool to
implementing stage utilizing regulatory and economic incentive measures to effectively address the nutrient
pollution from both point and non-point sources.
Friction Stir.Welding is an advance metal joining process: A ReviewIJERA Editor
The friction stir welding is recently developed solid state welding process which overcome the problem
associated with fusion welding technology. The properties achieved by friction stir welding is better than that
achieve by fusion welding technique It has been invented as a solid-state joining technique and initially applied
to aluminum alloys. FSW is used to replace rivets joints in the aeronautical industry. Recently the aircraft and
military industries widely have been using aluminum alloys particularly because of their fine strength to weight
ratio. However in compare with steels they represent welding difficulties and also lower ductility. In last years it
has been observed that Friction Stir Welding (FSW) method represents better microstructure and mechanical
properties than conventional methods in welding aluminum alloys. It has been widely investigated for mostly
low melting materials, such as Al, Mg and Cu alloys. Aluminum is the most usable material in engineering
application and a lot of improvement is needed in the area of its welding. The latest works on friction stir
welding of aluminum have been directed towards improving the quality of weld, reducing defects and applying
the process of FSW to aluminum for specific applications. This joining technique is energy efficient,
environment friendly, and versatile. In particular, it can be used to join high-strength aerospace aluminum alloys
and other metallic alloys that are hard to weld by conventional fusion welding. FSW is considered to be the
most significant development in metal joining in a last decade. The FSW of Aluminums and its alloys has been
commercialized; and recent interest is focused on joining dissimilar materials. However, in order to
commercialize the process, research studies are required to characterize and establish proper process parameters
for FSW. This paper summarizes the trends and advances of this welding processes in the field of welding.
Future aspects of the study are also discussed.
Thermal Instability of Chemically Reacting Maxwell Fluid in a Horizontal Poro...IJERA Editor
The effect of chemical reaction on the linear stability of a viscoelastic fluid saturated horizontal densely-packed
porous layer is investigated. The viscoelastic properties are given by Maxwell constitutive relations. The porous
layer is cooled from the upper boundary while an adiabatic thermal boundary condition is imposed at the lower
boundary. Linear stability analysis suggests that there is a competition between the processes of viscous
relaxation and thermal diffusion that causes the first convective instability to be oscillatory rather than stationary.
The effect of Deborah number, Darcy-Prandtl number, normalized porosity, and the Frank-Kamenetskii number
on the stability of the system is investigated. Using a weighted residual method we calculate numerically the
convective thresholds for both stationary and oscillatory instability. The effects of viscoelasticity and chemical
reaction on the instability are emphasized. Some existing results are reproduced as the particular cases of the
present study.
The Propagation and Power Deposition of Electron Cyclotron Waves in Non-Circu...IJERA Editor
By solving the plasma equilibrium equation, ray equations, and quasi-linear Fokker-Planck equation, the ray
trajectories and power deposition of EC wave has been numerically simulated in non-circular HL-2A tokamak
plasma. The results show that shaping effect and temperature profile has little influence on ECRH, while plasma
density affect propagation and power deposition obviously. when the ordinary mode of EC waves are launched
from the mid-plane and low-field-side, ray trajectories are bended as the parallel refractive index increases and
even recurve to the low-field side when the parallel refractive index reaches to a certain value. Single absorption
decreases with increasing both poloidal and toroidal injection angle, and can be 100% when poloidal injection
angle is 180o and toroidal injection angle is less than 10o.
Study of PID Controllers to Load Frequency Control Systems with Various Turbi...IJERA Editor
This paper studies the load frequency control problem for various systems under various controller design
methods. Frequency should remain nearly constant for satisfactory operation of a power system because
frequency deviations can directly impact on a power system operation, system stability, reliability and
efficiency. A Load Frequency Control (LFC) scheme basically incorporates an appropriate control system for an
interconnected power system, which is having the capability to bring the frequencies of system to original set
point values or very nearer to set point values effectively after any load change. This can be achieved by the use
of conventional and modern controllers. In this proposed paper PID controller has been applied for LFC power
systems. The parameters of the PID controller are tuned by different methods names as Ziegler-Nichols (Z-N)
Method, and IMC method for better results. We use various tuning formulae in Z-N method and certain model
approximation methods and the responses of LFC with model approximation are studied. It is seen that the
results obtained are as good as the conventional controller.
Improving Splitting Efficiency in Photonic Crystal WaveguideIJERA Editor
“Photonic Crystals (PCs)” are dielectric structures with periodic spatial alternations of refractive index on the
scale of the wavelength of light. Many optical devices, based on PCs, have been proposed. There are
multiple ways by which equal amount of power of incoming signals can be divided into two, three and
four output channels; for example using multiple coupled photonic crystal waveguides, directional coupling and
cascaded multimode PC waveguides. Ideally, the splitter should divide the input power equally into the output
channels without significant reflection or radiation losses and should be compact in size. In this thesis I
have proposed the optical power splitting using Y-junction. The optical modeling of this proposed structure
was investigated by finite difference time domain (FDTD) simulation. The goal was to achieve equal power at
each output channel with broad spectrum around the target wavelength with low loss.
Modeling of Multilayer Transmission Lines for High-Speed Digital InterconnectsIJERA Editor
In this paper, we consider the finite element modeling of multilayer transmission lines for high-speed digital
interconnects. We mainly focused on the modeling of the transmission structures with both cases of symmetric
and asymmetric geometries. We specifically designed asymmetric coupled microstrips and four-line symmetric
coupled microstrips with a two-layer substrate. We computed the capacitance matrix for asymmetric coupled
microstrips and the capacitance, inductance, and impedance matrices for four-line symmetric coupled
microstrips on a two-layer substrate. We also provide the potential distribution spectrums of the models and
their meshing analysis.
Optimal Load Dispatch Using Ant Lion OptimizationIJERA Editor
This paper presents Ant lion optimization (ALO) technique to solve optimal load dispatch problem. Ant lion
optimization (ALO) is a novel nature inspired algorithm. The ALO algorithm mimics the hunting mechanism of
ant lions in nature. Five main steps of hunting prey such as the random walk of ants, building traps, entrapment of
ants in traps, catching preys, and re-building traps are implemented. Optimal load dispatch (OLD) is a method of
determining the most efficient, low-cost and reliable operation of a power system by dispatching available
electricity generation resources to supply load on the system. The primary objective of OLD is to minimize total
cost of generation while honoring operational constraints of available generation resources. The proposed
technique is implemented on 3, 6 & 20 unit test system for solving the OLD. Numerical results shows that the
proposed method has good convergence property and better in quality of solution than other algorithms reported
in recent literature.
A New Algorithm for Inferring User Search Goals with Feedback SessionsIJERA Editor
When different users may have different search goals when they submit it to a search engine. The inference and analysis of user search goals can be very useful in improving search engine relevance and user experience. The Novel approach to infer user search goals by analyzing search engine query logs. Once the User entered the query, the Resultant URLs will be filtered and the Pseudo-Documents are generated. Once the Pseudo documents are generated the Server will apply the Clustering Mechanism to URL’s. So that the URLs are listed as different categories. Feedback sessions are constructed from user click-through logs and can efficiently reflect the information needs of user. Second, we propose a novel approach to generate pseudo documents to better represents the feedback sessions for clustering. Finally we proposed new criterion “Classified Average Precision (CAP)” to evaluate the performance of inferring user search goals. Experimental results are presented using user click-through logs from a commercial search engine to validate the effectiveness of our proposed methods. Third, the distributions of user search goals can also be useful in applications such as re ranking web search results that contain different user search goals.
Construction Cost Prediction by Using Building Information ModelingIJERA Editor
The increased interest in using Building Information Modeling (BIM) in detailed construction cost estimates calls for methodologies to evaluate the effectiveness of BIM-Assisted Detailed Estimating (BADE) tools in generating detailed construction cost estimates. The focus of this research is on developing a quantified evaluation method to measure the impact of these BADE tools. Further, in order to understand the cognitive details of the estimator, this research also tested and evaluated the impact of the visualization factor and the compound impact of the visualization factor and aggregated calculation factor on the construction cost estimating process.Two cases study were tested, building and bridge. Three methods were applied on each case study,method 1the manual estimating method, method 2 used a BADE tool without a calculation function (i.e., the quantities of the individual building components can be read as properties of the component), method 3 used a BADE tool with calculation functions that allowed the user to directly calculate/aggregate the query results of the BIM database in the MS Excel spreadsheet.Results obtained from the test cases helped to reinforce the reliability of the observations and the evaluation. Four parameters were used to evaluate the performance results individually in the first step: generality, flexibility, efficiency, and accuracy. Then a multiattribute utility model, which took into account the four individual parameters, was developed and used to evaluate the overall performance of BIM assisted estimating versus the performance of the traditional estimating method on quantity takeoffs. The research concluded that the BIM-assisted estimate demonstrated better performance over traditional estimating methods. Both the visualization and aggregation functions of the BADE tool had significant impact on the performance of the detailed estimate.
Implementation of Text To Speech for Marathi Language Using Transcriptions Co...IJERA Editor
This research paper presents the approach towards converting text to speech using new methodology. The text to
speech conversion system enables user to enter text in Marathi and as output it gets sound. The paper presents
the steps followed for converting text to speech for Marathi language and the algorithm used for it. The focus of
this paper is based on the tokenisation process and the orthographic representation of the text that shows the
mapping of letter to sound using the description of language’s phonetics. Here the main focus is on the text to
IPA transcription concept. It is in fact, a system that translates text to IPA transcription which is the primary
stage for text to speech conversion. The whole procedure for converting text to speech involves a great deal of
time as it’s not an easy task and requires efforts.
A Numerical study of Flow through Sigmoid DuctIJERA Editor
Curved diffusers are an integral component of the gas turbine engines of high-speed aircraft. These facilitate
effective operation of the combustor by reducing the total pressure loss. The performance characteristics of
these diffusers depend on their geometry and the inlet conditions. In the present investigation the distribution of
mean velocity, static pressure and total pressure are experimentally studied on a S-shape Diffusing Duct of
45°/45° angle of turn with an area ratio of 1.65 aspect ratio 3.95 keeping inlet width 55 mm with centre line
length 460 mm. The experimental results then were numerically validated with the help of Fluent. The velocity
distribution shows that generation of secondary motion in the form of counter rotating vortices within the 1st half
of the diffuser. The secondary motion changes their sense of rotation after the inflexion plane of the test
diffuser. The maximum values of the mass average static Pressure recovery and total pressure loss are 36% and
13% compared to the predicted results of 39% and 11% respectively, which shows a good agreement between
the experimental and predicted results.
Rule-based Prosody Calculation for Marathi Text-to-Speech SynthesisIJERA Editor
This research paper presents two empirical studies that examine the influence of different linguistic aspects on
prosody in Marathi. First, we analyzed a Marathi corpus with respect to the effect of syntax and information
status on prosody. Second, we conducted a listening test which investigated the prosodic realisation of
constituents in the Marathi depending on their information status. The results were used to improve the prosody
prediction in the Marathi text-to-speech synthesis system MARY.
QoS Constrained H.264/SVC video streaming over Multicast Ad Hoc NetworksIJERA Editor
Support for QoS enabled multimedia transmission over multicast ad hoc network is necessary these days.
Researchers have developed various encoding/decoding schemes which can efficiently deliver the multimedia
contents over wireless networks. In case of ad hoc networks, performance of routing protocol depends upon
different factors i.e. traffic type being used for wireless transmission, dynamic network behavior, bandwidth and
computational power of nodes etc. It is essential to investigate the performance of multicast routing protocol
using various data types because they may consume huge network resources thus results in degradation of
transmission quality. In case of multicast group communication, Audio/Video data stream can cause extra
overhead on network performance and it is quite difficult to maintain Quality of Services for such type of data.
H.264 offers a rich codec library for Scalable Video Coding, to transfer SVC video traffic efficiently over
wireless networks. In this paper, we will analyze the performance of MAODV and PUMA routing protocols
using H.264/SVC video streaming traffic under the various QoS constraints such as Throughput, PDR, Delay,
Routing Load and Jitter etc.
Fuzzy based control of Transformer less Coupled inductor based DC-DC converterIJERA Editor
Most of the industrial applications use any one of the basic DC-DC converter configurations namely buck,
boost, buck–boost, and Cuk converters. These converters are non-isolating converters. Buck-boost converters
use inductors for storing energy from the source and release the same to load or output. This results in high
stress across magnetic components. This drawback restricts usage of buck-boost converters to low power
applications. Flyback converters popularly have known as buck-boost converters uses transformers for
achieving wide range of step down and step up voltages. Coupled inductor based converters or tapped inductor
based converters are used for achieving wide input – wide output conversion ratios. Coherent transition between
step-down and step-up modes is achieved by a proper control scheme. This paper proposes fuzzy logic based
closed loop control scheme for control of converter switches. Theoretical derivations of control parameters with
their membership values, mamdani based rules for development of fuzzy rules and simulation results of a
coupled inductor based DC-DC converter using MATLAB / SIMULINK are concluded.
Dimensional and Constructional Details of Components, Fundamentals of TNM Met...IJERA Editor
For the improvement in thermal design of squirrel cage induction (SCIM) motor, it is essential to know details
of the methods for evaluation of thermal distribution in a SCIM motor. A presentation of various details of
methods of basics of heat transfer that occur in a SCIM motor is done in this report. SCIM motors have wide
applications and thus their construction is completely influenced by the starting characteristics specified by the
operating loads. General constraints of a motor and specification of 30 KW motor are presented in this report as
a case study of constraints. As the next step the Thermal Network Method (TNM) has been explained.
Effects of Operational Losses in Active Magnetic Bearing Designs.IJERA Editor
This paper studies the effects of different forms of operational losses that are associated with active magnetic
bearing designs.Active magnetic bearings are generally considered as having much lower frictional losses as
compared to fluid and roller bearings, however AMBs are considered as more complex mechatronic systems,
associated with various potential power loss mechanisms during it cycle of operation. Minimizing of losses
consist of various measures and depends largely on the requirements of the application,among all these losses,
aerodynamic losses are classified as been the more dominant in modern high speed applications and
turbomachinery especially in expanders and compressors where its working gases are considered to be under
very high pressures and temperaturesVarious forms of losses such as hysteresis, eddy current, iron, aerodynamic
have been discussed. The methods of reducing these losses in order reduce energy losses with the ultimate goal
of improving bearing efficiency haveall been discussed in this paper.
Design the High Speed Kogge-Stone Adder by UsingIJERA Editor
In this Technical era the high speed and low area of VLSI chip are very- very essential factors. Day by day number of transistors and other active and passive elements are growing on VLSI chip. In Integral part of the processor adders play an important role. In this paper we are using proposed kogge-stone adders for binary addition to reduce the size and increase the efficiency or processors speed. Proposing kogge stone adder provides less components, less path delay and better speed compare to other existing kogge stone adder and other adders. Here we are comparing the kogge stone adders of different-different word size from other adders. The design and experiment can be done by the aid of Xilinx 14.1i Spartan 3 device family.
Drilling Mud Formulation Using Potato Starch(Ipomoea Batatas)IJERA Editor
In the search for suitable local alternatives as additives in the manufacture of drilling muds which is an essential
entity in the exploration of oil and gas, some vital considerations must be put in place such as cost and
environmental effect. This study focuses on the suitability of locally processed potato starch as a viscosifier and
fluid loss agent in drilling mud. Comparative analysis of properties obtained from the prepared potato starch
mud and that formulated from Polyanionic cellulose (PAC) were carried out. Results from this investigation
showed that rheological properties (plastic viscosity and yield point) of the potato starch mud increased when
the content of both viscosifiers were equal at 1.0g/ 316.4ml of water. Plastic viscosity also increased by 13.6%
when potato starch concentration increased by 50%. Also, a combination of PAC and potato starch at a ratio of
1:1 to 0.5:1.5 gave a fluid loss of 7.1 - 7.7 ml which were very close to that of the standard mud at 6.8ml. the
pH, mud weight and specific gravity of the formulated mud samples ranged from 7.0 - 9.0, 7.0 - 9.1 and 0.83 -
1.09 respectively, which were all in line with the standard mud specifications.
Alternative Method for Determining the Elastic Modulus of ConcreteIJERA Editor
This paper presents the use of the technique of digital image correlation for obtaining the elasticity modulus of
concrete. The proposed system uses a USB microscope that captures images at a rate of five frames per second.
The stored data are correlated with the applied loads, and a stress-strain curve is generated to determine the
concrete compressive modulus of elasticity. Two different concretes were produced and tested using the
proposed system. The results were compared with the results obtained using a traditional strain gauge. It was
observed a difference in the range of 4% between the two methods, wherein this difference depends of a lot of
parameter in the case of the DIC results, as focal length and a video capture resolution, indicating that DIC
technique can be used to obtain mechanical properties of concrete.
A Mixed Approach For Nutrient Management Planning In Southeast Asian CountriesIJERA Editor
Southeast Asia (SeA) region has experienced impressive economic, population and urban growth in the last
decades. The region faces big challenges and difficult choices, between economic growth and environmental
protection, especially from water pollution, in pursuing sustainable development. Deterioration of water quality
in lakes, rivers and reservoirs in urban areas due to nutrient pollution from anthropogenic sources, either point
or non-point sources, has recently been recognized as one of the most serious environmental problems
throughout the region. The nutrient pollution problem in water environment has been well-recognized and
addressed in many developed countries, but not in developing countries, especially in the SeA region. This
paper provides a comprehensive assessment on the current status of nutrient management across the region, and
investigates possible reasons why current efforts fail to address the issue. In addition, the paper examines the
possibility of introducing a mixed approach, from planning stage using a Material Flow Analysis (MFA) tool to
implementing stage utilizing regulatory and economic incentive measures to effectively address the nutrient
pollution from both point and non-point sources.
Friction Stir.Welding is an advance metal joining process: A ReviewIJERA Editor
The friction stir welding is recently developed solid state welding process which overcome the problem
associated with fusion welding technology. The properties achieved by friction stir welding is better than that
achieve by fusion welding technique It has been invented as a solid-state joining technique and initially applied
to aluminum alloys. FSW is used to replace rivets joints in the aeronautical industry. Recently the aircraft and
military industries widely have been using aluminum alloys particularly because of their fine strength to weight
ratio. However in compare with steels they represent welding difficulties and also lower ductility. In last years it
has been observed that Friction Stir Welding (FSW) method represents better microstructure and mechanical
properties than conventional methods in welding aluminum alloys. It has been widely investigated for mostly
low melting materials, such as Al, Mg and Cu alloys. Aluminum is the most usable material in engineering
application and a lot of improvement is needed in the area of its welding. The latest works on friction stir
welding of aluminum have been directed towards improving the quality of weld, reducing defects and applying
the process of FSW to aluminum for specific applications. This joining technique is energy efficient,
environment friendly, and versatile. In particular, it can be used to join high-strength aerospace aluminum alloys
and other metallic alloys that are hard to weld by conventional fusion welding. FSW is considered to be the
most significant development in metal joining in a last decade. The FSW of Aluminums and its alloys has been
commercialized; and recent interest is focused on joining dissimilar materials. However, in order to
commercialize the process, research studies are required to characterize and establish proper process parameters
for FSW. This paper summarizes the trends and advances of this welding processes in the field of welding.
Future aspects of the study are also discussed.
Thermal Instability of Chemically Reacting Maxwell Fluid in a Horizontal Poro...IJERA Editor
The effect of chemical reaction on the linear stability of a viscoelastic fluid saturated horizontal densely-packed
porous layer is investigated. The viscoelastic properties are given by Maxwell constitutive relations. The porous
layer is cooled from the upper boundary while an adiabatic thermal boundary condition is imposed at the lower
boundary. Linear stability analysis suggests that there is a competition between the processes of viscous
relaxation and thermal diffusion that causes the first convective instability to be oscillatory rather than stationary.
The effect of Deborah number, Darcy-Prandtl number, normalized porosity, and the Frank-Kamenetskii number
on the stability of the system is investigated. Using a weighted residual method we calculate numerically the
convective thresholds for both stationary and oscillatory instability. The effects of viscoelasticity and chemical
reaction on the instability are emphasized. Some existing results are reproduced as the particular cases of the
present study.
The Propagation and Power Deposition of Electron Cyclotron Waves in Non-Circu...IJERA Editor
By solving the plasma equilibrium equation, ray equations, and quasi-linear Fokker-Planck equation, the ray
trajectories and power deposition of EC wave has been numerically simulated in non-circular HL-2A tokamak
plasma. The results show that shaping effect and temperature profile has little influence on ECRH, while plasma
density affect propagation and power deposition obviously. when the ordinary mode of EC waves are launched
from the mid-plane and low-field-side, ray trajectories are bended as the parallel refractive index increases and
even recurve to the low-field side when the parallel refractive index reaches to a certain value. Single absorption
decreases with increasing both poloidal and toroidal injection angle, and can be 100% when poloidal injection
angle is 180o and toroidal injection angle is less than 10o.
Study of PID Controllers to Load Frequency Control Systems with Various Turbi...IJERA Editor
This paper studies the load frequency control problem for various systems under various controller design
methods. Frequency should remain nearly constant for satisfactory operation of a power system because
frequency deviations can directly impact on a power system operation, system stability, reliability and
efficiency. A Load Frequency Control (LFC) scheme basically incorporates an appropriate control system for an
interconnected power system, which is having the capability to bring the frequencies of system to original set
point values or very nearer to set point values effectively after any load change. This can be achieved by the use
of conventional and modern controllers. In this proposed paper PID controller has been applied for LFC power
systems. The parameters of the PID controller are tuned by different methods names as Ziegler-Nichols (Z-N)
Method, and IMC method for better results. We use various tuning formulae in Z-N method and certain model
approximation methods and the responses of LFC with model approximation are studied. It is seen that the
results obtained are as good as the conventional controller.
Improving Splitting Efficiency in Photonic Crystal WaveguideIJERA Editor
“Photonic Crystals (PCs)” are dielectric structures with periodic spatial alternations of refractive index on the
scale of the wavelength of light. Many optical devices, based on PCs, have been proposed. There are
multiple ways by which equal amount of power of incoming signals can be divided into two, three and
four output channels; for example using multiple coupled photonic crystal waveguides, directional coupling and
cascaded multimode PC waveguides. Ideally, the splitter should divide the input power equally into the output
channels without significant reflection or radiation losses and should be compact in size. In this thesis I
have proposed the optical power splitting using Y-junction. The optical modeling of this proposed structure
was investigated by finite difference time domain (FDTD) simulation. The goal was to achieve equal power at
each output channel with broad spectrum around the target wavelength with low loss.
Modeling of Multilayer Transmission Lines for High-Speed Digital InterconnectsIJERA Editor
In this paper, we consider the finite element modeling of multilayer transmission lines for high-speed digital
interconnects. We mainly focused on the modeling of the transmission structures with both cases of symmetric
and asymmetric geometries. We specifically designed asymmetric coupled microstrips and four-line symmetric
coupled microstrips with a two-layer substrate. We computed the capacitance matrix for asymmetric coupled
microstrips and the capacitance, inductance, and impedance matrices for four-line symmetric coupled
microstrips on a two-layer substrate. We also provide the potential distribution spectrums of the models and
their meshing analysis.
Optimal Load Dispatch Using Ant Lion OptimizationIJERA Editor
This paper presents Ant lion optimization (ALO) technique to solve optimal load dispatch problem. Ant lion
optimization (ALO) is a novel nature inspired algorithm. The ALO algorithm mimics the hunting mechanism of
ant lions in nature. Five main steps of hunting prey such as the random walk of ants, building traps, entrapment of
ants in traps, catching preys, and re-building traps are implemented. Optimal load dispatch (OLD) is a method of
determining the most efficient, low-cost and reliable operation of a power system by dispatching available
electricity generation resources to supply load on the system. The primary objective of OLD is to minimize total
cost of generation while honoring operational constraints of available generation resources. The proposed
technique is implemented on 3, 6 & 20 unit test system for solving the OLD. Numerical results shows that the
proposed method has good convergence property and better in quality of solution than other algorithms reported
in recent literature.
A New Algorithm for Inferring User Search Goals with Feedback SessionsIJERA Editor
When different users may have different search goals when they submit it to a search engine. The inference and analysis of user search goals can be very useful in improving search engine relevance and user experience. The Novel approach to infer user search goals by analyzing search engine query logs. Once the User entered the query, the Resultant URLs will be filtered and the Pseudo-Documents are generated. Once the Pseudo documents are generated the Server will apply the Clustering Mechanism to URL’s. So that the URLs are listed as different categories. Feedback sessions are constructed from user click-through logs and can efficiently reflect the information needs of user. Second, we propose a novel approach to generate pseudo documents to better represents the feedback sessions for clustering. Finally we proposed new criterion “Classified Average Precision (CAP)” to evaluate the performance of inferring user search goals. Experimental results are presented using user click-through logs from a commercial search engine to validate the effectiveness of our proposed methods. Third, the distributions of user search goals can also be useful in applications such as re ranking web search results that contain different user search goals.
Construction Cost Prediction by Using Building Information ModelingIJERA Editor
The increased interest in using Building Information Modeling (BIM) in detailed construction cost estimates calls for methodologies to evaluate the effectiveness of BIM-Assisted Detailed Estimating (BADE) tools in generating detailed construction cost estimates. The focus of this research is on developing a quantified evaluation method to measure the impact of these BADE tools. Further, in order to understand the cognitive details of the estimator, this research also tested and evaluated the impact of the visualization factor and the compound impact of the visualization factor and aggregated calculation factor on the construction cost estimating process.Two cases study were tested, building and bridge. Three methods were applied on each case study,method 1the manual estimating method, method 2 used a BADE tool without a calculation function (i.e., the quantities of the individual building components can be read as properties of the component), method 3 used a BADE tool with calculation functions that allowed the user to directly calculate/aggregate the query results of the BIM database in the MS Excel spreadsheet.Results obtained from the test cases helped to reinforce the reliability of the observations and the evaluation. Four parameters were used to evaluate the performance results individually in the first step: generality, flexibility, efficiency, and accuracy. Then a multiattribute utility model, which took into account the four individual parameters, was developed and used to evaluate the overall performance of BIM assisted estimating versus the performance of the traditional estimating method on quantity takeoffs. The research concluded that the BIM-assisted estimate demonstrated better performance over traditional estimating methods. Both the visualization and aggregation functions of the BADE tool had significant impact on the performance of the detailed estimate.
Implementation of Text To Speech for Marathi Language Using Transcriptions Co...IJERA Editor
This research paper presents the approach towards converting text to speech using new methodology. The text to
speech conversion system enables user to enter text in Marathi and as output it gets sound. The paper presents
the steps followed for converting text to speech for Marathi language and the algorithm used for it. The focus of
this paper is based on the tokenisation process and the orthographic representation of the text that shows the
mapping of letter to sound using the description of language’s phonetics. Here the main focus is on the text to
IPA transcription concept. It is in fact, a system that translates text to IPA transcription which is the primary
stage for text to speech conversion. The whole procedure for converting text to speech involves a great deal of
time as it’s not an easy task and requires efforts.
A Numerical study of Flow through Sigmoid DuctIJERA Editor
Curved diffusers are an integral component of the gas turbine engines of high-speed aircraft. These facilitate
effective operation of the combustor by reducing the total pressure loss. The performance characteristics of
these diffusers depend on their geometry and the inlet conditions. In the present investigation the distribution of
mean velocity, static pressure and total pressure are experimentally studied on a S-shape Diffusing Duct of
45°/45° angle of turn with an area ratio of 1.65 aspect ratio 3.95 keeping inlet width 55 mm with centre line
length 460 mm. The experimental results then were numerically validated with the help of Fluent. The velocity
distribution shows that generation of secondary motion in the form of counter rotating vortices within the 1st half
of the diffuser. The secondary motion changes their sense of rotation after the inflexion plane of the test
diffuser. The maximum values of the mass average static Pressure recovery and total pressure loss are 36% and
13% compared to the predicted results of 39% and 11% respectively, which shows a good agreement between
the experimental and predicted results.
Rule-based Prosody Calculation for Marathi Text-to-Speech SynthesisIJERA Editor
This research paper presents two empirical studies that examine the influence of different linguistic aspects on
prosody in Marathi. First, we analyzed a Marathi corpus with respect to the effect of syntax and information
status on prosody. Second, we conducted a listening test which investigated the prosodic realisation of
constituents in the Marathi depending on their information status. The results were used to improve the prosody
prediction in the Marathi text-to-speech synthesis system MARY.
QoS Constrained H.264/SVC video streaming over Multicast Ad Hoc NetworksIJERA Editor
Support for QoS enabled multimedia transmission over multicast ad hoc network is necessary these days.
Researchers have developed various encoding/decoding schemes which can efficiently deliver the multimedia
contents over wireless networks. In case of ad hoc networks, performance of routing protocol depends upon
different factors i.e. traffic type being used for wireless transmission, dynamic network behavior, bandwidth and
computational power of nodes etc. It is essential to investigate the performance of multicast routing protocol
using various data types because they may consume huge network resources thus results in degradation of
transmission quality. In case of multicast group communication, Audio/Video data stream can cause extra
overhead on network performance and it is quite difficult to maintain Quality of Services for such type of data.
H.264 offers a rich codec library for Scalable Video Coding, to transfer SVC video traffic efficiently over
wireless networks. In this paper, we will analyze the performance of MAODV and PUMA routing protocols
using H.264/SVC video streaming traffic under the various QoS constraints such as Throughput, PDR, Delay,
Routing Load and Jitter etc.
Fuzzy based control of Transformer less Coupled inductor based DC-DC converterIJERA Editor
Most of the industrial applications use any one of the basic DC-DC converter configurations namely buck,
boost, buck–boost, and Cuk converters. These converters are non-isolating converters. Buck-boost converters
use inductors for storing energy from the source and release the same to load or output. This results in high
stress across magnetic components. This drawback restricts usage of buck-boost converters to low power
applications. Flyback converters popularly have known as buck-boost converters uses transformers for
achieving wide range of step down and step up voltages. Coupled inductor based converters or tapped inductor
based converters are used for achieving wide input – wide output conversion ratios. Coherent transition between
step-down and step-up modes is achieved by a proper control scheme. This paper proposes fuzzy logic based
closed loop control scheme for control of converter switches. Theoretical derivations of control parameters with
their membership values, mamdani based rules for development of fuzzy rules and simulation results of a
coupled inductor based DC-DC converter using MATLAB / SIMULINK are concluded.
Dimensional and Constructional Details of Components, Fundamentals of TNM Met...IJERA Editor
For the improvement in thermal design of squirrel cage induction (SCIM) motor, it is essential to know details
of the methods for evaluation of thermal distribution in a SCIM motor. A presentation of various details of
methods of basics of heat transfer that occur in a SCIM motor is done in this report. SCIM motors have wide
applications and thus their construction is completely influenced by the starting characteristics specified by the
operating loads. General constraints of a motor and specification of 30 KW motor are presented in this report as
a case study of constraints. As the next step the Thermal Network Method (TNM) has been explained.
Effects of Operational Losses in Active Magnetic Bearing Designs.IJERA Editor
This paper studies the effects of different forms of operational losses that are associated with active magnetic
bearing designs.Active magnetic bearings are generally considered as having much lower frictional losses as
compared to fluid and roller bearings, however AMBs are considered as more complex mechatronic systems,
associated with various potential power loss mechanisms during it cycle of operation. Minimizing of losses
consist of various measures and depends largely on the requirements of the application,among all these losses,
aerodynamic losses are classified as been the more dominant in modern high speed applications and
turbomachinery especially in expanders and compressors where its working gases are considered to be under
very high pressures and temperaturesVarious forms of losses such as hysteresis, eddy current, iron, aerodynamic
have been discussed. The methods of reducing these losses in order reduce energy losses with the ultimate goal
of improving bearing efficiency haveall been discussed in this paper.
Study of Optimization of Squirrel Cage Induction Motor Using DCR Technologypaperpublications3
Abstract: Induction motors are versatile electric motors suited best for industrial applications as well as low-power application in domestic equipment because of their unique advantage compared to other types such as dc and synchronous motors. Electric motors do not transfer 100% of the input electrical energy into kinetic mechanical energy. A certain percentage of electrical energy is “lost” during the conversion to mechanical energy. These losses, in motor windings, core and rotating mechanical parts reduces the energy efficiency of motors. In today’s power crisis condition it is very important to manufacture the motors which are more efficient than the standard motors which are already available. The AC induction motor has been continuously improved by optimising stator and rotor design and electric material properties and quantities. With given exterior motor dimensions, the potential efficiency gain is limited and costly. DCR technology is a new development to reduce losses by using copper instead of aluminium for the conductor bars and end rings in rotors to enhance its efficiency and performance. This paper reviews the historical development in squirrel cage rotor designs, importance of energy efficient motors, efficiency improvement, adoption of DCR technology and the optimization of 3- phase squirrel cage induction motor.
Automatic procedure and detailed multi-disciplinary analysis for an electric traction motor - Seminario Spin all'Università dell'Aquila su software, elettrificazione e nuove frontiere della ricerca
Design and Simulation of a Fractal Micro-TransformerIJERA Editor
Due to advancement in smart technologies, the issues like renewable energy integrations into the existing power
systems, reduced weight and size of power equipments is required. In this regard, this work is focused on the
study and design of fractal type micro-transformer for day-to-day applications. An air core transformer is
designed using finite element modeling. The obtained results showed far better implementation parameters in
comparison to the macro transformers.
Design and analysis of a premium efficiency (ie3) induction motoreSAT Journals
For designing an induction motor complete dimension of all the parts of the machine must be known in order to satisfy the
customers required specifications. This paper presents the calculation of following design details. (a) The dimensions of the stator
that includes stator packet length and diameter. (b) Details of stator windings and stator slots. (c) Design details of rotor and
rotor slots. (d) Finally, the performance of motor. In order to get the above design details the designer needs the required
customer specifications such as rated power output, rated voltage, speed, frequency, type of stator winding and its connection,
type of rotor winding, working conditions, shaft extension and dimension details etc. The design example of 45kW cage motor is
presented and various tests are also performed.
Keywords: Induction Motor; Designing; Premium Efficiency Motor; Efficiency; Losses; IEC 60034-30-1; IEC 60034-
1 standard.
A Comparative Performance Analysis DCR and DAR Squirrel Cage 3-Phase Inductio...paperpublications3
Abstract: The importance of energy saving in induction motor was emphasized about 15 years ago, in academic area, but the motor manufacturer’s interest is focussed only on maximum benefit. As a customer, it is better to take into account not only the motor price, but also the cost of the used energy during the whole lifetime of the motor. The new requirement to improve the motor efficiency is a serious research subject, which must be about the possibility of loss minimization in the induction motor.
On an average the cost of energy consumed by the motor is nearly 80 – 100 times the initial cost of the initial manufacturing cost of the motor. So the efficiency of motor is of great importance whether during the selection or during the operation. Small increase in motor efficiency can make an overall significant difference in total energy consumption.
The slightly higher initial cost of DCR motors is often misunderstood as a demerit. It is not all true. The increase in initial cost is offset by the energy saving.
This paper presents the comparative analysis of performance of a DCR motor and DAR motor. The method of analysis is based upon testing results. The only change in design is that the Die cast aluminium rotor is replaced by die cast copper rotor. The other design parameters like stator core, winding, air gap length etc are remains same.
Compatibility Design of Non Salient Pole Synchronous Generatorijtsrd
This paper is focused design calculation of 30 MVA, 11 kV, 50 Hz, two pole non salient poles synchronous generator that use in gas turbine power plant. The choices of specific loadings are magnetic loading and electric loading are involved in that design calculation. The number of rotor slot selection main considered in order to avoid the undesirable effects of harmonics in the flux density wave forms. The rotors are cylindrical in shape having parallel slots on it to place rotor windings. The design system is compatibility based on where specific magnetic loading or specific electric loading with synchronous generator generate more electrical power and to get better performance. The relation between specific loading and volume of the generator, short circuit ratio and air gap length, comparison design data and efficiency due to load changing are mainly emphasized studying in this paper. Thant Zaw Oo | Aye Myo Thant ""Compatibility Design of Non-Salient Pole Synchronous Generator"" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-4 , June 2019, URL: https://www.ijtsrd.com/papers/ijtsrd24026.pdf
Paper URL: https://www.ijtsrd.com/engineering/electrical-engineering/24026/compatibility-design-of-non-salient-pole-synchronous-generator/thant-zaw-oo
Investigation into the Performance of Aluminum Wound Distribution TransformersLeonardo ENERGY
Highlights:
* Looks into stresses responsible for transformer failures.
* Reasons include hot spot temperature, creep behavior of aluminum conductor, and frequent switching of distribution transformers in the field.
* Suggests recommendations for procuring reliable aluminum and copper wound distribution transformers.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Optimization of Process Parameters in Wire Electrical Discharge Machining of ...IJERA Editor
Wire electrical discharge machining (WEDM) is a specialized thermal machining process capable of accurately machining parts with varying hardness or complex shapes, which have sharp edges that are very difficult to be machined by the main stream machining processes. This practical technology of the WEDM process is based on the conventional EDM sparking phenomenon utilizing the widely accepted non-contact technique of material removal. Since the introduction of the process, WEDM has evolved from a simple means of making tools and dies to the best alternative of producing micro-scale parts with the highest degree of dimensional accuracy and surface finish quality. Metal matrix composites are advanced materials having high specific strength, good wear resistance, and high thermal expansion coefficient. To achieve this task, machining parameters such as pulse on time, pulse off time, peak current, servo voltage, wire feed, wire tension etc. of this process should be selected such that optimal value of their performance measures like Material Removal Rate (MRR), Surface Roughness (SR), Gap current, Dimensional deviation, etc. can be obtained or improved. In past decades, intensive research work had been carried out by different researchers for improvement and optimization of WEDM performance measures using various optimization techniques like Taguchi, Response Surface Methodology (RSM), Artificial Neural Network (ANN), Genetic Algorithm (GA), etc. This paper also highlights the feasibility of the different control strategies of obtaining the optimal machining conditions. This literature review helps to identify the suitable process parameters and their ranges in machining of metal matrix composites.
Finite element analysis of aluminium alloys for their vibration characteristicseSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Similar to Evaluation, Categorization, Distribution and Methods of Reduction of Losses to Improve Thermal Design of SCIM Motor (20)
Hierarchical Digital Twin of a Naval Power SystemKerry Sado
A hierarchical digital twin of a Naval DC power system has been developed and experimentally verified. Similar to other state-of-the-art digital twins, this technology creates a digital replica of the physical system executed in real-time or faster, which can modify hardware controls. However, its advantage stems from distributing computational efforts by utilizing a hierarchical structure composed of lower-level digital twin blocks and a higher-level system digital twin. Each digital twin block is associated with a physical subsystem of the hardware and communicates with a singular system digital twin, which creates a system-level response. By extracting information from each level of the hierarchy, power system controls of the hardware were reconfigured autonomously. This hierarchical digital twin development offers several advantages over other digital twins, particularly in the field of naval power systems. The hierarchical structure allows for greater computational efficiency and scalability while the ability to autonomously reconfigure hardware controls offers increased flexibility and responsiveness. The hierarchical decomposition and models utilized were well aligned with the physical twin, as indicated by the maximum deviations between the developed digital twin hierarchy and the hardware.
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
Using recycled concrete aggregates (RCA) for pavements is crucial to achieving sustainability. Implementing RCA for new pavement can minimize carbon footprint, conserve natural resources, reduce harmful emissions, and lower life cycle costs. Compared to natural aggregate (NA), RCA pavement has fewer comprehensive studies and sustainability assessments.
6th International Conference on Machine Learning & Applications (CMLA 2024)ClaraZara1
6th International Conference on Machine Learning & Applications (CMLA 2024) will provide an excellent international forum for sharing knowledge and results in theory, methodology and applications of on Machine Learning & Applications.
NO1 Uk best vashikaran specialist in delhi vashikaran baba near me online vas...Amil Baba Dawood bangali
Contact with Dawood Bhai Just call on +92322-6382012 and we'll help you. We'll solve all your problems within 12 to 24 hours and with 101% guarantee and with astrology systematic. If you want to take any personal or professional advice then also you can call us on +92322-6382012 , ONLINE LOVE PROBLEM & Other all types of Daily Life Problem's.Then CALL or WHATSAPP us on +92322-6382012 and Get all these problems solutions here by Amil Baba DAWOOD BANGALI
#vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore#blackmagicformarriage #aamilbaba #kalajadu #kalailam #taweez #wazifaexpert #jadumantar #vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore #blackmagicforlove #blackmagicformarriage #aamilbaba #kalajadu #kalailam #taweez #wazifaexpert #jadumantar #vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore #Amilbabainuk #amilbabainspain #amilbabaindubai #Amilbabainnorway #amilbabainkrachi #amilbabainlahore #amilbabaingujranwalan #amilbabainislamabad
Governing Equations for Fundamental Aerodynamics_Anderson2010.pdf
Evaluation, Categorization, Distribution and Methods of Reduction of Losses to Improve Thermal Design of SCIM Motor
1. A Ravi Prasad Int. Journal of Engineering Research and Applications www.ijera.com
ISSN: 2248-9622, Vol. 5, Issue 9, (Part - 3) September 2015, pp.36-42
www.ijera.com 36 | P a g e
Evaluation, Categorization, Distribution and Methods of
Reduction of Losses to Improve Thermal Design of SCIM Motor
A Ravi Prasad, Dr. K Prahlada Rao
Retired Scientific Officer (F), Bhabha Atomic Research Centre, Trombay, Mumbai-40085 Former In-charge
Head, Department of Nuclear Energy, Pandit Deendayal Petroleum University, Gandhinagar, Gujarat
Professor, Department of Mechanical Engineering, JNTUA College of Engineering
Anantapur- 515002 India
Abstract
For any thermal design and improvements of the motor accurate evaluation of the losses and reasons for
existence of these losses because of which they occur is very important. Experimental techniques aiming at
determining total losses and temperature rise in squirrel cage induction motors (SCIM) are expensive and their
effectiveness is often limited to specific types of motors. Accurate estimation of these losses and how they are
distributed along with feasible techniques to reduce them will result a scope to optimize the thermal design of
the motor. In the present report evaluation, categorization, distribution and methods of reduction of all losses in
SCIM Motor are presented. This has been done with relevant mathematical expressions and presenting
properties of important materials.
I. INTRODUCTION
In the process of energy conversion taking place
in a SCIM motor, certain amount of energy gets lost
in the form of heat. These losses can be called as
stable losses [1] occurring without charge changing
and losses depending on charge changing in line with
square of the armature current. Stable losses include
iron, friction and wind losses and copper losses
resulting from magnetizing current. Charge depended
losses are primarily those stemming from copper
losses. By means of thermal classification of
insulating materials used in cooling of the SCIM
motor, it was rendered possible to make the working
temperature of certain parts of the SCIM motor
stable. Every insulating material has a certain
working temperature complying with expected life of
SCIM motor and allowing the SCIM motor to safely
function within this expected period. Even a small
increase in temperature beyond the permitted values
can considerably decrease working life of insulating
material.
It is well known that experimental techniques
aiming at determining total losses and temperature
rise in electric induction motors are expensive and
their effectiveness is often limited to specific types of
motors. It is, therefore, important to estimate
analytically or numerically power losses of motor in
order to use the loss estimations obtained as input
parameters for thermal modeling.
Fig. 1 Power flow of a SCIM motor
II. MECHANISM OF HEAT
GENERATION INSIDE AN
INDUCTION MOTOR [1]
Losses in SCIM motors can be categorized
according to the causes or phenomena that produce
them. For performance analysis of any motor, one
important parameter to be considered is the motor
loss. Determination of efficiency of motor and
investigation of safe operating thermal mechanisms
of heat generation in induction electric motors are
generally divided in to four groups, related mainly to
the places where they occur.
These are Joule losses, iron losses, stray load
losses and mechanical losses. Each one of these kinds
of energy conversion from electric to thermal energy
is detailed below.
The importance of study surrounds from the
magnitude of these losses and the ability of known
techniques to reduce within the limitations of motor
capabilities.
RESEARCH ARTICLE OPEN ACCESS
2. A Ravi Prasad Int. Journal of Engineering Research and Applications www.ijera.com
ISSN: 2248-9622, Vol. 5, Issue 9, (Part - 3) September 2015, pp.36-42
www.ijera.com 37 | P a g e
Table I
Losses and Methods of Their Reductions in SCIM
Motors
Limits in turn influence the operating cost,
determines the heating of given motor which gives
the motor rating without the deterioration of
insulation and for accounting the voltage drops or
current component associated with cause of losses.
A. Copper Loss or Ohmic Loss or Joule Losses or
Resistive Losses
Copper Loss or Ohmic Loss is I2
Re loss which is
caused when a current I flows through the winding
(copper in most cases) having a resistance Re.
This mechanism corresponds to the conversion
of electric energy into thermal energy in electrical
conducting media. The type of losses are directly
related to the electric resistance of the conductor and
changes proportionally to the square of the current,
i.e. Pj = I² ReEnergy conversion by Joule effect in
squirrel cage induction electric motors occurs in the
stator (copper windings) and in the squirrel cage
(aluminum bars). The fundamental resistive losses of
the stator and rotor are given by
P Cus = 3 Re,s Is
2
………(1)
P Cur = 3Re,r Ir
2
…….….(2)
Where Re and I are the electrical resistance and
current per phase, respectively, and the indices s and r
stand for the stator and rotor, respectively. For the
small wire diameter used in the stator windings of
smaller TEFC motors, the skin effect of the stator
windings can be neglected when the supply voltage is
sinusoidal. Concerning the resistive losses in the
rotor, it is assumed that the skin effect can be
neglected for the fundamental rotor current.
Correction for the resistance [9] change with
temperature for aluminum or copper can be made by
(The constant value K is 245 for Aluminum and 235
for Cu bars)
Re = Re,0 …………(3)
The I2
Re (copper) loss in stator is divided between the
slot winding and end windings, nodes corresponding
to rotor bar and rotor end ring in proportion to the
quantity of conductor in each component. In rotor to
separate the losses of end rings from losses of the
bars, the following ratio of bar losses to ring losses
can be used
= 2 sin2
……..(4)
Where p is the number of pole pairs, S2 is the number
of rotor slots, Ab and lb are the area and lengths of a
rotor bar, respectively. Ar and lr are the area and
lengths of a ring segment (i.e. between two bars),
respectively.
B. Core Loss
Core loss also highly affects the performance of
the SCIM motor. This loss is due to the conversion
of electric energy into thermal energy in the iron
(core) of the SCIM motor as the name depicts. In
simple words, it is caused due to the presence of time
varying i.e. pulsating or rotating magnetic field in the
magnetic material. There are two kinds of core losses
namely hysteresis losses and eddy current losses.
Copper Losses:
Core
Losses/
Iron
losses
Stray
Load
losses:
Wind-
age and
Friction
Losses:
Stator Rotor
Explanation of the loss in section
III A III
B,C,D
IV A,B V A,B,C
Approximate magnitude of the loss as % of total
losses
36 24 24 10 6
Loss depends on
Condu
ctor
area,
mean
length
of turn
Bar
and
end
ring
area
and
materia
l
Material
of
laminati
on steel,
air gap,
magneti
c
saturatio
n
intensity
Manufa
cturing
process
, slot
design,
air gap
and
other
parame
ters
Fan
efficienc
y,
Lubricati
on,
bearing,
power
consume
d by fan
Methods to reduce losses (more details of losses by
strategic techniques in table IV)
Using
higher
conductivi
ty copper
in the
windings
and
increasing
conductor
cross-
sectional
area for
decreasing
primary
losses.
Cha
nge
of
rotor
bar
mate
rial
and
end
ring
from
alum
inum
to
copp
er.
Better
grades
and
thinner
gages
of steel
laminat
ions
also
reduce
losses
.Therm
al
treatme
nt,
rotor
bar
insulati
on, non
machin
ing of
rotor
surface
etc.
Methods
such as
improved
fans and
bearing
performa
nces,
reduced
air gaps
and
closer
machinin
g
tolerance
s are also
used for
building
of more
efficient
motors
3. A Ravi Prasad Int. Journal of Engineering Research and Applications www.ijera.com
ISSN: 2248-9622, Vol. 5, Issue 9, (Part - 3) September 2015, pp.36-42
www.ijera.com 38 | P a g e
C. Hysteresis Losses
Hysteresis losses are proportional to frequency
and proportional to Bmax
1.6-2.4
(depending on
saturation) where Bmax is the peak flux density. In
practice, hysteresis losses are commonly assumed to
be proportional to Bmax. Hysteresis loss is the loss
because of hysteresis produced by time varying
magnetic field in the magnetic material
D. Eddy Current Loss
Eddy current losses are Joule losses that occur in
iron due to flow of an induced electric current. When
a conductor is placed in a changing magnetic field,
due to the relative motion
Table II
PROPERTIES OF IRON CORE MATERIALS
Fig.2 Plot of the Electric Induction (B) Versus
Magnetic Field (H) for the Iron
of field and conductor or time variation of magnetic
field, a current is induced in the conductor which
circulates over the conductor body. These circulating
currents cause heating in conductor core and also
induce magnetic field which may oppose or add to
the original field. It also causes the skin effect which
is the phenomena where the current density is
distributed towards the peripheral surface of the
conductor.
III. General Expression - Iron Losses In
Magnetic Materials Of Motor
The eddy current loss varies with square of the
flux density (Bmax), the frequency (f), and thickness of
the lamination (Δ).
Under normal condition, the eddy current loss can be
approximately expressed as
Pe = Ke (Bmax f )2
………..(5)
Where Ke is the proportionality constant and core
losses per mass unit are
Q = (kHy f + k Ft f 2
) B2
max ……..(6)
Where kHy and kFt are loss factors of the material for
Hysterisis and eddy currents.
The eddy current loss factor is given below:[7]
k Ft = …..(7)
Where ρe is the resistivity, ρ the density of
lamination material. The sum of the eddy current
losses and hysteresis losses is usually available from
Epstein tests at 50 or 60 Hz. However, the real losses
of a stator core can be 50–100 % larger than the
calculated ones. The losses are increased due to
harmonics of the field variation and due to
manufacturing (e.g. punching of the sheets).
Temperature also affects the losses.
The magnetic fluxes and magnetic flux densities
of the yoke (By) and teeth (Bt) respectively, are
determined by means of equivalent circuit, winding
data and geometry of SCIM motor in usual way.
TABLE III
EXPRESSIONS FOR CORE LOSSES
Report
2,3
Expression for total core losses
(kHy f + k Ft f 2
) Bmax
2
Hysterisis losses Eddy current losses
kHy f Bmax
2
k Ft f 2
Bmax
2
More detailed expression for total core losses is
Report
4
c [α + (1- α) [ Vi
Hysterisis losses
c α Bx
ΔVi
Eddy current losses
c (1- α ) [ ΔVi
kHy = c [α ] ΔVi
KFt = c (1- α )
[ ΔVi =
c=constant is a good approximation
The exponent x of B is equal to 1 for very low
flux densities and 1.5 to 2 for the usual densities
Sl. No Property Symbol Units Value
Repo
rt [7]
Report [3]
M270-
35 A
Silicon
Iron Lami
nation
1 Hysteresis
coefficient
Kh [Ws/T2
/
m3
]
118.6 93.89
2 Electric
conductivit
y
σ [(Ώm)-1
] 1.92
x106
2.22 x106
3 Lamination
sheet
thickness
Δ [m] 0.35x
10-3
0.35x10-3
4 Excess loss
coefficient
ke [W/(TS-
1
)3/2
/m3
]
0.74 1.33
5 Packing
factor
kf 0.98 0.98
6 Density ρ [Kg/m3
] 7650 7650
4. A Ravi Prasad Int. Journal of Engineering Research and Applications www.ijera.com
ISSN: 2248-9622, Vol. 5, Issue 9, (Part - 3) September 2015, pp.36-42
www.ijera.com 39 | P a g e
of SCIM motors. Calculations with x =
1.5/1.8/2.0 and α = 0.7/0.5/0.3 are carried out
generally.
Where: f is the frequency (in Hz), c a lamination
factor (in W/kg), ΔVi~ the element volume (in
m3
),
B the flux density (in Tesla) and 0 <α <1.
B = By if the element i is at yoke and B = Bt if it
is at teeth.
A. Stray Load Losses or Additional Losses [6]
The Stray Load Loss (also called additional
losses) is one kind of losses in electrical SCIM
motors. Stray load loss arises from the non-uniform
distribution of current in winding and additional core
losses produced in the iron due to distortion of the
magnetic flux caused by the load current.
However the stray load losses are minor losses in
the electric motor operation and at the same time their
quantification is very difficult. They include the
losses due to the skin effect, high frequency, among
others, that are unknown not easily quantified.
B. Causes for the Stray Load Losses
Slots in SCIM motors cause permeance waves
that produce no load stray losses both in stator and
rotor. The non sinusoidal mmf distribution in air gap
and the saturation of the magnetic circuit further add
to space harmonics. Some of the no load stray losses
are caused by eddy currents in the rotor teeth. These
losses are usually divided into surface losses and
tooth pulsation losses, where the surface losses are
treated separately because they only appear in a thin
surface layer, while the pulsation losses penetrate
deeper. Penetration depth of pulsations depends on
design of rotor cage.
Since each rotor tooth is surrounded by short-
circuited rotor bars, circulating currents will occur
which limit the penetration depth of the permeance
waves. Surface losses are influenced by finish of the
rotor surface. Magnitude and nature of stray losses
depend on whether rotor bars are skewed or not.
Additional losses are the total load losses minus
the fundamental resistive losses. They are basically of
the same kind as the no-load stray losses, but much
increased due to the mmf waves occurring at load. A
part of the additional losses is also the end losses,
which depend on axial leakage flux that penetrates
the rotor and stator ends and to a certain extent the
end shields and the frame. The end losses are
influenced by the distance between the end windings
and other conducting SCIM motor details.
In summary these losses are due to the non
uniform current distribution in the copper and the
additional core losses produced in the iron by
distortion of the magnetic flux by the load current.
The stray load losses consist of the following
components- especially when the motor is operated at
high frequency.
1. Surface losses in the stator
2. Surface losses in the rotor
3. Pulsation losses in the stator teeth
4. Pulsation losses in the rotor teeth
5. Losses in the squirrel cage winding
6. Losses due to skewing with un insulated cast
aluminum squirrel cage windings.
IV. MECHANICAL LOSSES
The two main mechanical losses found in electric
machines are the bearing and windage losses. Bearing
loss is caused by friction between the moving parts of
the bearing, i.e. between the balls and sleeves in the
case of ball bearings. Lubrication is used to lower the
frictional loss, but the viscosity of the lubrication also
influences the total bearing loss. Other factors that
influence bearing loss are shaft speed, bearing type
and bearing load. The latter is composed of static and
dynamic loading, the former is associated with
gravitational forces and the latter with dynamic
effects like unbalance forces and rotor dynamics. The
bearing loss (P) can be calculated using:
Bearing Losses due to a) friction in bearing b)
viscous losses due to air gap friction and c) windage
together are considered as mechanical losses.
A. Friction Losses in Rolling Bearings
Friction losses are losses in rolling bearings
(balls/rings interface) and bearing seals. Viscous
losses are small compared to the fan losses. Losses
due to the seals may in fact be larger than the actual
bearing losses. Bearing friction torque consists of a
constant part that depends on the bearing forces and a
hydro dynamical part, which is strongly temperature-
dependent and speed-dependent. The hydro
dynamical part is usually dominant over the constant
part.
Bearing friction loss can be calculated as
Pbearing= 0.5 ω kf r F dBearing ……………….(8)
Where kfr is the frictional co-efficient of the bearing,
F is the dynamic bearing load and dBearing is the inner
diameter of the bearing.
The bearing load is greatly increased when a
bearing needs to carry loads in a direction it was not
designed for, e.g. axial loading in a bearing designed
for radial operation. The second important
mechanical loss mechanism is windage loss. The
mechanical air gap in an electric machine is filled
with a fluid, usually air. The fluid is moving at the
same speed as the rotor on the rotor surface and on
the stator surface, it is stationary. This results in a
drag torque and frictional loss.
5. A Ravi Prasad Int. Journal of Engineering Research and Applications www.ijera.com
ISSN: 2248-9622, Vol. 5, Issue 9, (Part - 3) September 2015, pp.36-42
www.ijera.com 40 | P a g e
B. Losses in Air Gap or Viscous Losses
A narrow air gap requires less no-load current
than a wide air gap, so motor designs incorporate the
narrowest air gaps possible. This improves efficiency
and power factor.
However, if the air gap is too small there is a
danger that the rotor may actually contact the stator,
short circuiting it. Maintaining precise air gap
requires precision rotor bearings
The windage loss
Pwind = ks CM π ρa ω3
L)
…………..(9) Where ks is the surface roughness
coefficient (usually between 1-1.4), CM is the torque
coefficient, ρa is the air density, dbearing is the rotor
outside diameter and L is the active length of the
motor.
TABLE IV
METHODS FOR REDUCTION OF LOSSES
Improvement technique Reduction of losses
1 Increased stator slot fill factor Reduction of stator copper losses because of higher
dimension of stator conductors or reduced total insulation
content in slots.
2 Coating laminations with
higher thermal conductivity
material
Effective dissipation of heat leading to reduction of overall
losses.
3 Increased diameter Less magnetic and electric specific values and thus reduction
of losses for the higher size motors.4 Core axial lengthening
5 Rotor bars insulation Rotor slots are insulated before the casting, highly increasing
the inter-bar resistance and reducing the inter-bar currents.
6 Non-machining of rotor
surface
Reduced surface losses and thus reduction of eddy current
losses
7 Low-loss electrical steel
Reduction of core losses
8 Decreased lamination thickness
9 Heat shock /Thermal treatment
10 Slot dimensions
Optimized dimensions of these two techniques will reduce
core losses
11 Core dimensions or lamination
sizes
12 Annealing
13 Magnetic/semi-magnetic
wedges
Reduced leakage flux and reduction of losses14 Reduction of air gap
15 Amorphous steel
16 Stator magnetic insulation
17 Current densities Number of stator conductors is more -current density
required will be less since amp conductors/surface area is
flux density (Bav). Product of Bav and ac/m of circumference
will be decreased for higher values of D2
L and vice versa for
same performance of motor.
18 No. of Stator conductors
19 Conductor insulation (material
and thickness)
Better materials need thinner insulations and improved heat
transfer thus less rise in temperature leading to lower losses.
20 Manufacturing methods Uniform and precise air gap to reduce flux leakage and
reduced losses
21 Copper rotor bars Reduced specific resistance and reduced stator copper losses
22 Use of combination of Al/Cu
rotor bars
Optimization of starting current and reduction of rotor losses
is possible.
6. A Ravi Prasad Int. Journal of Engineering Research and Applications www.ijera.com
ISSN: 2248-9622, Vol. 5, Issue 9, (Part - 3) September 2015, pp.36-42
www.ijera.com 41 | P a g e
Table V
DISTRIBUTION OF LOSSES
The torque coefficient is dependent on the Reynolds
number and can be calculated
CM = 10 Re <64 ……..(10)
and careful machining.
C. Windage Losses [11]
CM =2 64<Re <5 x 102
……..(11)
CM = 1.03 5 x 102
< Re <5 x 104
……..(12)
CM = 0.065 5 x 104
< Re (13)
Where lg is air gap length
The stator must draw extra current to increase the
flux density of its magnetic field and bridge the air
gap.
V. CATEGORISATION AND
DISTRIBUTION OF MOTOR
LOSSES
The core (iron) loss is distributed among the
stator and rotor components in such a way that the
majority of the loss occurs in the components
(corresponding nodes) that model the stator teeth and
combined rotor bars and teeth. Mechanical losses are
generally included as heat generation in the shaft.
A. Contribution of Each Category Of Loss [5]
For the correct modeling, it is important to
quantify the suitable value and location of the heat
generation. In general, the quantification of the losses
is directly related to the location where these losses
occur in the electric motor, excepting the stray losses.
Power loss classification based on the location of the
losses is as below:
TABLE VI
BREAK UP OF TOTAL LOSS
The total loss is separated into the five separate bulk
regions indicated as above:
Copper loss (both in stator and rotor) was
subdivided based on the respective length of
conductor in the slot and end winding regions in the
lumped models where an extra node is provided for
the end winding regions and rotor copper losses are
distributed as given in the equation (4).
Table VII
SUMMARY OF MOTOR LOSSES
Iron
losses
Copper
losses
Mechanical
losses
Additional
losses
Stator
SCIM motor
yoke, PFe (s)
Y.
Iron losses
in the stator
teeth, PFe(S,T)
Embed
ded
Windin
gs and
end
windin
gs
Windage
losses do not
add to heat
Viscous
losses get
added to rotor
and stator
teeth
proportionately
a) 40% is
added to
Stator
windings
b) 30% of
additional
losses is
added to
stator teeth
and
Rotor
Iron
losses in
the rotor
laminatio
ns, PFe R.
Bars
End rings
Bearing
losses get
added to the
shaft
c) 30% of
additional
losses is
added to
rotor iron
Stator
yoke
Tooth
body
Stator slot
winding
End
winding
Rotor
bars and
End rings
Total losses
Load losses(current dependent) No Load Losses (voltage dependent)
Stray Load losses Copper losses Mechanical losses Iron Losses
Skew leakage losses Surface losses Windage losses Hysterisis losses
End leakage losses Slot leakage flux losses Friction losses Eddy current losses
Losses due to leakage flux
Rotor pulsation and copper loss due to
zig-zag mmf
Load losses (current dependent) No-load losses (voltage dependent)
Losses at sinusoidal supply voltage Losses at non-sinusoidal supply
voltage
(a) resistive losses in the stator
winding
(b) resistive losses in the rotor
The dominating harmonic losses
are
a) Resistive losses in the stator
The following losses can be expected
at no load with sinusoidal supply
(a) Core losses in the stator teeth and
7. A Ravi Prasad Int. Journal of Engineering Research and Applications www.ijera.com
ISSN: 2248-9622, Vol. 5, Issue 9, (Part - 3) September 2015, pp.36-42
www.ijera.com 42 | P a g e
REFERENCES
[1] PH Mellor, D Roberts, DR Turner, Lumped
parameter thermal model for electrical IEE
PROCEEDINGS-B/ Vol. 138, No. 5, 1/205-
218/machines of TEFC design 1991
SEPTEMBER 1991
[2] Thermal modeling of small cage induction
motors Gunnar Kyalandar 1995
[3] Rafal Wrobel, Adrian Mlot, and Phil H.
Mellor, Contribution of End-Winding
Proximity Losses to Temperature Variation
in Electromagnetic Devices 2012, IEEE
TRANSACTIONS ON INDUSTRIAL
ELECTRONICS, VOL. 59, NO. 2,
FEBRUARY 2012
[4] J.Xypteras, V. Hazithansion, Thermal
analysis of an electrical machine. taking
into account the iron losses and the deep-bar
Transactions on Energy conversion, Vol.14,
No. 4, December 1999
[5] Cassiano antunes cezário Transient thermal
analysis of an induction electric motor, 18th
International Congress of Mechanical
Engineering by ABCM Ouro Preto, MG
November 6-11, 2005
[6] Popove Lyudmila, Combined
electromagnetic and thermal design platform
for totally enclosed induction machines
master’s thesis
[7] Rafal Wrobel, Phil Mellor, Derrick Holliday
Department of Electrical and Electronic
Engineering,University of Bristol, UK
Thermal Analysis of a Segmented Stator
Winding Design
[8] A Book on Losses in Electrical Machines of
permanent magnet type, chapter 2, collected
from internet (Does not bear any author’s
name)
winding
(c)Additional losses due to leakage
flux and m.m.f. space harmonics.
The additional losses consist of
similar components as the no-load
stray losses.
End losses and losses due to the skew
leakage flux are also part of the
additional losses.
and rotor windings caused by the
harmonic currents and by skin
effect
b) Core losses and surface losses
caused by the harmonic flux. It is
often assumed that the harmonic
losses are of the no-load type, but
the harmonic losses increase with
the load. This effect is due to
saturation of the harmonic
leakage flux path, which
decreases the leakage reactance
and thus increases the harmonic
currents.
yoke, due to the main flux
(b) No-load stray losses
(c) Losses due to friction and wind-
age:
The term no load stray losses is here
used for losses that are due to space
harmonics and consequently are not
of fundamental frequency. These are
tooth pulsation losses, surface losses,
losses due to inter bar currents and
circulating currents in the rotor.
Apart from the terms (a) to (c), there
are of course also some resistive
losses due to the no-load current.