Efficiency Of Induction Motor Research Articles

An Analytical Model of Induction Motors for Rotor Slot Parametric Design Performance Evaluation

Induction motors are commonly used in most elec-tricity generation due to their low investment cost. However, the performance of the induction motors for different applications highly depends on rotor design and machine geometry. For example, changing rotor bar height and width varies the rotor resistance and reactance, thereby leading to variation of the motor efficiency. A parametric study on rotor slot geometry parameters such as opening height, rotor slot depth, and rotor slot width, is carried out to investigate the effect of the parameters on the efficiency of a squirrel cage induction motor. The study is based on analytical model that considers a general-purpose squirrel cage induction motor with the specification of 5.5 kW, 60 Hz, and 460 V. The analytical model is developed and simulated within the MATLAB software environment. The effects of each parameter variation toward efficiency of the induction motor are investigated individually as well as all together using a 4D scatter plot. Results show that the efficiency can be improved up to 0.1%after designing a suitable setting of rotor slot parameters from the initial settings.

An Alternative Methodology for Quantifying Voltage Unbalance Based on the Effects of the Temperatures and Efficiency of Induction Motors

Many unbalanced voltage conditions, which produce different effects on electric equipment, are associated with the same voltage unbalance factor. This fact hinders the precise association between the values of this index and the effects of voltage unbalance. In the present study, an alternative methodology for quantifying voltage unbalance based on the effects of this phenomenon on the temperature and efficiency of three-phase induction motors is proposed. The application of the suggested methodology results in an index that contemplates the combined effects of the modules and angles of the positive and negative sequence voltages. Aiming to apply this methodology and evaluate its performance, we selected a comprehensive set of balanced and unbalanced voltage conditions and used it on a three-phase induction motor. The results show that the index obtained, when compared to the traditional voltage unbalance factors, reduces the uncertainties inherent to the quantification process of this phenomenon. In other words, it allows a better association between the values and effects of the voltage unbalance. For these reasons, this index is considered as a potential alternative that can be employed in industrial utilities and standards that deal with voltage unbalance.

Equivalent Circuit and Performance Investigation of Cross-Shaped Linear Induction Motor

In order to improve the thrust density and efficiency of linear induction motors (LIMs) in large load transport situations, a cross-shaped LIM (CSLIM) structure is proposed in this article. The equivalent circuit of CSLIM is built. Based on that, the electromagnetic thrust expressions are deduced, and the expressions for parameters of equivalent circuits are given. The relationship between the coupling characteristics of the secondary inductive eddy current and the condition of the motor is analyzed. Finally, the simulation results verify the validity and superiority of the proposed analysis.

Особливості розрахунку характеристик компенсованого асинхронного двигуна в програмному середовищі matlab simulink

An asynchronous electric motor with a short-circuited rotor is the most common means of converting electrical energy into mechanical energy in the electric drive of working machines in industry and agriculture. Modern methods of increasing the energy efficiency of induction motors with short-circuited rotor are aimed at finding with the help of computer technology the optimal solutions in the processes of their design, production and operation using new high-performance materials in machines. Such methods do not change the physical processes occurring in the induction motor, ie are passive. However, despite numerous improvements and scientific achievements, technical and economic indicators of induction motors still do not meet modern energy requirements. It is necessary to use ways to increase the energy efficiency of induction motors while maintaining their simplicity and reliability. It is proposed to use internal capacitive compensation of reactive power of induction motors. The aim of the research is to develop a mathematical model of an induction motor with internal capacitive reactive power compensation in the MathLab Simulink software environment for the calculation of operating and mechanical characteristics. A mathematical model of an induction motor with internal capacitive reactive power compensation in the MathLab Simulink software environment using the theory of electric circuits has been developed. The developed mathematical model allows to study the working and mechanical characteristics of an induction motor with internal capacitive compensation of reactive power. Numerical researches of characteristics of the induction motor with internal capacitive compensation of reactive power are carried out and their comparison with corresponding characteristics of the basic induction motor is carried out.

Application of Energy-Saving for an inverter feeds three-phase induction motor

Three-phase induction motors are the most prevalent AC motors used in many applications. Operation of these motors at load power less than that of the motor full-load power leads to significant power losses and reduces the motor’s efficiency. To mitigate these losses and increase the efficiency of the three-phase induction motors at light loading conditions, energy-saving techniques should be utilized. This paper investigates a voltage control technique applied to light-loaded induction motors to save the energy using an inverter. The light load selected in this paper is a fan load of power load less than the motor full load power. Theoretical analysis, computed characteristics, and experimental verifications are presented to show the effectiveness of the proposed energy-saving technique.

Application of Ring Winding in Induction Motor

To solve the low power factor and efficiency of the conventional induction motor (IM), ordinary single-layer windings are changed to ring windings (RW) to improve motor performance. Firstly, structural features of RW are described. Then a dual-rotor ring winding induction motor (DRRWIM) is proposed, and the structure, magnetic circuit and circuit characteristics of DRRWIM are analyzed. Based on the analysis result, the motor design method for DRRWIM is proposed. The basic size is determined through the proposed method, and the electromagnetic performance of DRRWIM is calculated. Finally, a comparison between DRRWIM and the Y-type traditional IM with the same power and poles number proves that DRRWIM is more efficient and energy- saving.

Variable Voltage Control of Three-Phase Induction Motor for Energy Saving

Energy saving is one of the most important factor for industrial and commercial applications. In the industries, Induction motors are the mostly preferred due to their reliability, robustness, price and rugged construction. The largest percentage of consumed energy in industrial is consumed by induction motors. So, Energy conservation in induction motor drive leads to reduction in power consumption and electricity cost. This paper describes energy saving technique for squirrel cage induction motor. The energy saving is achieved by controlling the voltage applied to the stator winding using the three phase AC voltage controller. The simulation verifications are done in MATLAB/Simulink. The results show that the proposed scheme gives rise to the considerable energy-savings The rated efficiency of an induction motor is high when it operates under the full load. In general, the rated efficiency is larger than 75%. Although, the operating efficiency of the induction motor drive system will be low if an induction motor is operating at light loads or does not selected correctly. So, that the improvement in the energy efficiency of induction motor drives refers to huge energy saving

Comparison of Analytical and Software Based Design of Energy Efficient Induction Motor

Energy Efficient Induction motor is playing a vital role in current scenario. Due to rising electrical energy demand, increased awareness of global warming, and rising fossil fuel prices, energy efficiency has become increasingly important. Apart from adding capacity, the only practical approach to deal with this situation is to make optimal use of the available energy, which may be done by using energy efficient Motors. The main objective of this paper is to calculate and Compare the Analytical and Electromagnetic Software based design for a 5HP Energy Efficient Motor.

Design and Force Analysis of Salient Single-Sided Linear Induction Motor

The linear induction motors, due to their unique features, utilize in various applications. The most crucial drawback of the linear induction motors is the large air gap between secondary and primary. This problem deteriorates the performance of linear induction motor, increases power loss, and causes to low efficiency. In this paper, a novel structure of single-sided linear induction motor is proposed to reduce the magnetic air gap. This structure consists of ladder-slit sheets and salient back iron for secondary of single-sided linear induction motor. The salient parts of back iron fill the slits of sheet, and therefore, the effective magnetic air gap can be decreased owing to partial form. Also, the electromagnetic aspects of the proposed secondary such as z-component of air gap flux density, y-component of aluminum eddy current density, and three components of Lorentz force are analyzed. Also, the finite element method and the analytical method is used for the 3 D analysis of the edge effects as well as the end effects. To show the advantages of the proposed structure, the results are compared with other secondary structures. The results show that the thrust and efficiency of the salient single-sided linear induction motor increased in comparison with other ones.

Design and Development of Energy Efficient Single Phase Induction Motor For Ceiling Fan Using Taguchi's Orthogonal Arrays

The conventional single phase induction motor (SPIM)-based ceiling fans are difficult to design using the analytical procedure because of inherent nonlinearities in the electromagnetic construction. The high skewing of rotor bars to eliminate low-order harmonics makes the analytical solution based on a 2D magnetic circuit, which is quite inaccurate. This article deals with the systematic design and experimental validation of the energy-energy efficient SPIM for ceiling fan application. A systematic approach starting from the existing SPIM motor is presented for improvement in the efficiency of the motor using 2D finite element analysis (FEA). The process involves the design validation of the existing ceiling fan motor followed by a set of experiments (2D multislice time-stepping transient FEA) to obtain the energy-efficient motor. Taguchi's orthogonal arrays are used for the improvement in the performance of the motor. Finally, the achieved optimal design is developed and tested for the improvement in the performance.

Maximum Torque Per Watt (MTPW) field-oriented control of induction motor

A new field-oriented control strategy for induction motor is proposed in the paper. It is called Maximum Torque Per Watt (MTPW) and allows obtaining the minimum value of the sum of the stator and rotor losses due to joule effect, and of the iron losses, for a given value of the reference torque and of the motor speed. Iron losses have been modeled according to Steinmetz equation, separating hysteresis and eddy currents and taking into account the dependence both on the frequency and on the peak value of the flux density. Numerical and experimental results are presented to confirm the validity of the proposed approach, which allows achieving significant improvements in the efficiency of induction motor drive.

Structural Optimizations of High-efficiency Direct-On-Line Synchronous Reluctance Motors for Metal Industry Applications

To meet the severe operating conditions in the metal industry, more thorough design and operational assessments about those implemented electric motors for specific applications must be emphasized. With its inherent robust structure, the induction motor is generally adopted to fulfill such driven objective. However, due to global warming and energy conservation concerns, those strictly enforced regulations have potentially increased the complexity and cost of high efficiency induction motor. Since the synchronous reluctance motor (SynRM) has relatively simpler structure with no copper loss in its rotor, it is a very attractive alternative for accomplishing the high-efficiency objectives of those common hoist, punch, roller, and pump applications. In addition, to eliminate drive circuits that can further reduce the overall system construction costs, the rotor barriers of the SynRM can be equipped with direct-on-line capability (DOL_SynRM) with conductors filled in. The impacts to the operational performance of these DOL_SynRMs for different applications will all be thoroughly investigated. The competitive high-efficiency DOL_SynRMs for driving various metal industry equipment can thus be offered.

Theoretical Analysis of the Voltage Unbalance Factor to Characterize Unbalance Problems in Induction Motors

Voltage Unbalance (VU) is one of the most common power quality problems in industrial electrical systems and it is a subject of systematic study. This problem affects the operation and the efficiency of Induction Motors (IMs), which are the loads that demand more energy in the industrial sector with around 68%. The Voltage Unbalance Factor (VUF), defined by the international IEC standard, is the main factor used to characterize this problem. This article aims to present a theoretical analysis of VUF focused on its limitations for characterizing the effects of VU on IMs. As a result of the analysis, it is shown that the use of the VUF indicator only is insufficient since it does not consider other aspects that affect the operation of the IMs such as voltage variation. As an alternative, the use of the Complex Voltage Unbalance Factor and the Equivalent Voltage Magnitude Factor are suggested as parameters that, together with the VUF, allow deepening the characterization of the effects of the UV on the IMs.

Effects of Geometric Dimension Variations on Efficiency of 3-phase Squirrel Cage Induction Motors Considering Economic Evaluation

There are different approaches to improve the efficiency of induction motors. In this paper, the considered approaches include, design of the rotor slot, rotor slot shape, and stator and rotor diameters which are applied on a 30-kW 3-phase, 4-poles, 48-stator slots, and 44-rotor squirrel cage induction motor. Comparison of analytical, simulation and experimental results confirm the proposed FEM-based model of set-up induction motor. The sensitivity analysis of efficiency considering the variations of rotor slot dimensions, stator outer diameter, and stator and rotor diameters have been applied on the case-study. The results of the GA-based optimal design of the rotor slot dimensions showed a 0.32% improvement in motor efficiency. On the other hand, changing the motor core diameters has more effects on motor efficiency so that, when the stator and rotor outer diameters were increased simultaneously, the efficiency was increased by 0.55%. However, if the stator outer diameter just increased, motor efficiency increased by 0.76%. Finally, the economic evaluation was accomplished to validate the optimal approach of motor design for three cases of electricity consumption per kWh.

Effect of chording on the efficiency of induction motor supplied by PWM inverter

The increasing usage of theinverter fed three-phase induction motor due to latest technological innovations in the industry demands for designing a high efficiency motor. Three-phase induction motor stator coils were short pitched and tested with pulsewidth modulation (PWM) inverter voltage supply at various switching frequencies. Various loads were varied using eddy current brake and torque is measured using torque gauge. The effect of short pitching on the efficiency of novel winding designed motor were quantified and found that the shortest pitched coil radically improves the efficiency of the motor due to attenuation of lower order harmonics and reduced copper losses.

Mechanical Cutting Effect of Electrical Steel on the Performance of Induction Motors

This paper investigates the mechanical cutting effect on the performance of induction motors. Numerical modeling of cutting effect is described in this paper. The approach inverts the degradation of the permeability model for inclusion of it into magnetic vector potential formula by Newton method. The effect of cutting on iron losses is implemented in finite element simulation. The simulation results are compared with experimental results of prototype IE4 efficiency induction motors rated at 2.2 kW. One of them was manufactured with annealed electrical steel lamination to highlight the cutting effect on the performance of the motor. The notable effect of cutting was measured in increased stator current; however, negligible differences were found in measured iron losses. The presented model in this paper follows the measurements.

A 3-D Simulation of a Single-Sided Linear Induction Motor with Transverse and Longitudinal Magnetic Flux

This paper presents a novel and improved configuration of a single-sided linear induction motor. The geometry of the motor has been modified to be able to operate with a mixed magnetic flux configuration and with a new configuration of paths for the eddy currents induced inside the aluminum plate. To this end, two slots of dielectric have been introduced into the aluminum layer of the moving part with a dimension of 1 mm, an iron yoke into the primary part, and lastly, the width of the transversal slots has been optimized. Specifically, in the enhanced motor, there are two magnetic fluxes inside the motor that circulate across two different planes: a longitudinal magnetic flux which goes along the direction of the movement and a transversal magnetic flux which is closed through a perpendicular plane with respect to that direction. With this new configuration, the motor achieves a great increment of the thrust force without increasing the electrical supply. In addition, the proposed model creates a new spatial configuration of the eddy currents and an improvement of the main magnetic circuit. These novelties are relevant because they represent a great improvement in the efficiency of the linear induction motor for low velocities at a very low cost. All simulations have been made with the finite elements method—3D, both in standstill conditions and in motion in order to obtain the characteristic curves of the main forces developed by the linear induction motor.

Efficiency Assessment of Induction Motors Drives Operating Under Shaft Misalignment Conditions

Historically, the negative effects of misalignment between the motor shaft and the load on the electric drives are well known. Vibrations, loss of life of couplings and deterioration of efficiency are some of these effects. Regarding this last point, the literature offers contradictory opinions. Some studies consider that the loss of efficiency in cases of misalignment is undesirable; while others consider that it has significant importance. In this paper, experimental results show in which cases the misalignment has a significant effect on efficiency and in which cases it can be neglected. For this, radial and angular misalignment cases are studied with four of the most used flexible couplings in the industry. The obtained results are analysed in relation to the actual regulations on energy efficiency in induction motors. The reached conclusions offer new tools for the correct selection of flexible couplings tending to the improvement of energy efficiency.

IMPLEMENTATION OF FRACTIONAL PI CONTROLLER FOR OPTIMAL SPEED CONTROL OF INDUCTION MOTOR FED WITH QUASI Z-SOURCE CONVERTER

Recently, Induction motor are extensively used in many application and are present in almost all production processes. Trouble in induction motor results in reducing the machine speed, large amount of intake of current and operational disaster which causes economic and human losses. To have a better efficiency in induction motor, this proposed work focuses with the efficient control technique. The objective of this proposed work is to find effective technique to sustain at a steady state and dynamic analysis and to determine the parameters and performance of the machine. Quasi Z-source network is employed to boost up the source voltage and transformation from AC to DC is performed. To drive the induction motor at a standard speed, some controllers were analogized and the well performing fractional PI controller was chosen to perform at a top notch level. Analogizing fractional PI controller with other controllers like PI controller, and fuzzy logic controller, Fractional PI controller performs well in solving the problem faced by other controllers. The experimental result shows the torque, rise time, settling time, and peak time are measured and obtains the better result as compared with the PI, Fuzzy and FO-PID approach. The torque results to 1.1Nm on proposed method; steady state error is reduced from 2.4 to 1.1 and the peak time settling time and rise time is reduced near 1.93 to 0.85 ranges of settling time; 1.66 to 0.79 of peak time; 1.55 to 1.62 of rise time. The entire system is manipulated using DSPIC and the simulation results are performed using MATLAB.

Estimation efficiency of rewound induction motors in situ using a numerical model

This paper presents an effective technique for determining the impact of rewinding practices on the motor efficiency and characterizing the efficiency reduction when electrical motors are rewound several times. This technique focuses on a new approach and a statistical study to find a numerical model for the estimation efficiency of rewound induction motors in the field. The experimental results from 101 induction motor tests are analyzed. A numerical model is determined and compared with different methods: separate losses method, modified current method and simple current method. An error analysis is conducted to examine the level of uncertainty by testing three asynchronous motors at 110 kW, 160 kW, and 300 kW. The results show that this approach can predict and estimate the efficiency reduction in rewound motors without expensive tests and can help the energy manager make effective cost decisions in replacing the rewound motors with more efficient ones by using an assessment of overconsumption and maintenance costs. Another advantage of this model is that it can be used to improve the software tools and can also be a very strong indicator to audit the repair quality