Efficiency Of Induction Motor Research Articles

Comparison of energy efficiency determination methods for the induction motors

In the paper the effects on the induction motor efficiency determination due to the introduction of the EU, USA, Canada, Japan and Russian Standards have been analyzed and discussed. Industrial induction motor has been tested and a comparison between the efficiencies determined by various National Standards has been presented. In addition, the motor efficiencies have been compared with the efficiency classes defined by the EU Standardization.

Design of Premium Efficiency (IE3) Induction Motors Using Evolutionary Optimization and Scaling Laws

Design of Premium Efficiency (IE3) Induction Motors Using Evolutionary Optimization and Scaling Laws

Uncertainty Issues in Direct and Indirect Efficiency Determination for Three-Phase Induction Motors: Remarks About the IEC 60034-2-1 Standard

Electric motors and the systems they drive are the single largest electrical end-use; it is estimated that they consume between 43% and 46% of all global electricity consumption. Recent studies show that efficiency values of induction motors can be successfully increased, with improvements up to 20%–30%. In 2009, the European Commission published a new regulation (640/2009) concerning requirements for the eco-compatible design of electric motors. In such a scenario, the experimental determination of induction motor efficiency is getting more and more important, because of the need of placing these motors in the right energy efficiency levels defined by international regulations. The correct motor classification strictly depends on the uncertainty associated with the efficiency determination. According to the IEC 60034-2-1 standard, the efficiency of three-phase induction motors can be determined by applying the direct or indirect efficiency technique. The direct procedure is suggested for low uncertainty efficiency measurements of single-phase induction motors and three-phase motors with rated power ≤1 kW. In this paper, we propose a comparative analysis between direct and indirect efficiency determination for three-phase induction motors, according to the IEC 60034-2-1 standard. The contribution of this paper consists in the comparison between the uncertainty calculations in indirect and direct efficiency determination for induction motors, to investigate the advisability of adopting the direct efficiency determination as reference method, because it is easier to implement and it has a good accuracy. This task is carried out starting from the accuracy requirements for measurement equipment, as demanded by the Guide to the Expression of Uncertainty in Measurement GUM. Some experimental results obtained with the indirect and direct efficiency determinations on a 3-kW three-phase two-pole induction motor are presented and discussed. A final suggestion related to a future version of IEC 60034-2-1 is also reported.

Energy Efficient Control of an Induction Machine Under Torque Step Changes

Methods for increasing the energy efficiency of induction motors by an appropriate control strategy have been a subject of research during the last years. Several methods for loss minimization have been developed for induction motors operated in a steady state. In recent years, some solutions for the dynamic case have been given as well either using an online or offline optimization approach, implying a certain computational burden, which is undesired in practice. This paper shows that the appropriate application of steady state techniques during transients due to a changing motor torque is a suboptimal strategy with an acceptable performance for efficiency optimization given an induction machine where saturation effects of the main inductance must be considered. The optimization problem is simplified such that a simple suboptimal solution is possible and the quality of the suboptimal solution is investigated by simulations and measurements. The proposed solution is simple, easy to implement, and does not require an online optimization. In addition, the influence of magnetizing induction saturation is considered.

유도전동기 효율향상에 따른 역률 보상 콘덴서 최적 선정에 대한 연구

유도전동기 효율향상에 따른 역률 보상 콘덴서 최적 선정에 대한 연구

Selected elements of a new method of induction motor efficiency determination

Abstract This paper presents the results of estimating method of the energy consumed by induction motors and the legal situation concerning the efficiency of electrical motors in the European Union. Three elements of a new method of induction motor efficiency determination are described: methodology of taking into account the influence of non-sinusoidal voltage and the voltage unbalance on the motor efficiency and the application of the interval arithmetic in order to determine the border error of the induction motor efficiency. It is proved that the middle of efficiency interval for the direct method of efficiency determination is always equal to or higher than the measurement result and the radius of interval is longer than the border error.

Effects of sequence voltage components on torque and efficiency of a three-phase induction motor

For quantifying voltage unbalance, some standards adopt the index provided by the ratio between the negative and positive sequence component magnitudes. In these documents, the use of an indicator that includes the zero sequence component is not obligatory. This article presents the results from evaluations of the effects of the zero, negative and positive sequence voltage components on the torque and efficiency of a three-phase induction motor. These evaluations are performed through laboratory experiments and the application of incremental sensitivity analysis. The results of this investigation allow for, among other things, identifying the consequences of the absence of the zero sequence component in unbalance quantification.

3ph High Efficiency Induction Motors with IFOC Applied to a Wheelchair by Joystick

Most of the wheelchair's drive systems uses direct-current (DC) motors as propulsion. However, such motors have several drawbacks aspects, as higher cost and maintenance, resulting in its gradual disuse. An option already consolidated in the industrial area is the high efficiency squirrel-cage induction motor, which has high energy efficiency and low maintenance, compared to DC motors. The use of induction motors applied to wheelchair tend to increase with the advancement of microelectronics and power electronics. This paper presents a relevant proposal in drive and control of power wheelchairs through three-phase induction with vector control. The system's power supply comes from batteries, which are suitable for the static converter. A digital signal controller (DSC) performs the reading joystick and vector control of three-phase induction motor. Experimental results with wheelchair developed denote viability and functionality for paraplegic patients.

Induction Motor Efficiency Evaluation Using a New Concept of Stator Resistance

This paper presents an air-gap torque (AGT)-based method for efficiency estimation of induction motors. A new concept of stator resistance that includes the mechanical losses effect is proposed. This new stator resistance is estimated through a particle swarm optimization approach based on the stator flux equations and minimization of torque error at the rated operation point. Then, the obtained stator resistance is used in the AGT equations to estimate the shaft torque and then the efficiency. Moreover, the rotor speed is estimated using induction motor current signature analysis. Thus, the proposed methodology for induction motor efficiency estimation relies only on line currents, line voltages, and nameplate data, being appropriate for in-service applications. Finally, the simulation and experimental results are presented to validate the proposed method at different load conditions.

A Model-Based Suboptimal Control to Improve Induction Motor Efficiency

This paper proposes a control strategy for energy efficiency improvement of three-phase induction motors (TIM). The main control is based on the indirect field-oriented approach. A loss model-based controller is proposed in order to reduce the cooper and iron losses of TIM for different load values. A nonlinear equation based only on quadrature currents is derived and used to obtain suboptimal flux reference in steady-state conditions. Thus, for dynamic implementation (motor transient), a low-pass filter is included and designed based on the rotor time constant. MATLAB simulations are performed to test the proposed strategy for several operation conditions. To verify the approach in real situations, a 4hp motor drive platform was implemented using F28069 DSP. The effectiveness of the proposed model is demonstrated through simulations and experimental results.

Optimization of Three-phase Squirrel Cage Induction Motor Drive System Using Minimum Input Power Technique

The efficiency of induction motor drives operating under variable conditions can be improved by predicting the optimum flux that minimizes the losses. In this study, a Loss-Minimization Controller (LMC) and a Search Controller (SC) are combined. The output from the controllers would drive the field oriented control inverter in order to achieve the optimum flux in the motor that minimizes the losses. For this purpose, a mathematical model for calculating the total power losses as a function of magnetic flux and a factor to obtain feedback as a function of optimum flux were discussed. An LMC-SC vector-controlled induction motor drive system was modelled, simulated and tested. The results have validated the effectiveness of this system in minimizing the motor operating losses, especially at light and medium loads. The proposed controller can be implemented in adjustable speed induction motor drive systems with variable loads, operating below rated speed.

High Accuracy Measurement of Total Losses in Fractional Horsepower Induction Motors

Large and small single-phase and three-phase induction motors are commonly used in industrial applications. The present work represents an attempt towards the design of a high accuracy system for the measurement of fractional horsepower (FHP) induction motor losses and efficiency. The calorimeter designed and built is capable of measuring heat losses of up to 1 kW with an overall accuracy better than 3%. During all tests, ambient temperature, humidity, motor speed and motor frame temperature were recorded using precise digital instruments. The inlet, outlet temperatures and resulting losses were recorded automatically using a high accuracy 12-bit data acquisition system. The preliminary results obtained demonstrate the suitability of the designed calorimeter for the accurate measurement of losses in FHP induction motors.

A Novel <italic>In Situ</italic> Efficiency Estimation Algorithm for Three-Phase IM Using GA, IEEE Method F1 Calculations, and Pretested Motor Data

The precise estimation of efficiency of induction motors is crucial in industries for energy savings, auditing, and management. This paper presents a novel method for in situ induction motors efficiency estimation by applying the genetic algorithm and utilizing IEEE Form F2-Method F1 calculations with pretested motor data. The method requires a dc test, full-load operating point rms voltages, currents, input power, and speed measurements. The proposed algorithm uses a sensorless technique to determine motor speed. The algorithm is not only an in situ tool; it can also be used as an on-site efficiency estimation tool that might replace the expensive dynamometer procedure. The method was validated by testing 30 induction motors.

A Novel Algorithm for Estimating Refurbished Three-Phase Induction Motors Efficiency Using Only No-Load Tests

Induction motors fail due to many reasons, and many are rewound two or more times during their lifetimes. It is generally assumed that a rewound motor is not as efficient as the original motor. Precise estimation of efficiency of a refurbished motor or any existing motor is crucial in industries for energy savings, auditing, and management. Full-load and partial-load efficiency can be measured by using the dynamometer. This paper presents a novel technique for estimating refurbished induction motors’ full-load and partial-load efficiencies from only no-load tests. The technique can be applied in any electric motor workshop and eliminates the need for the dynamometer procedure. It also eliminates the need for the locked-rotor test. Experimental and field results of testing eight induction motors are presented, and the degree of accuracy is shown by comparing the estimated efficiencies against the measured values. To provide the necessary credits to the proposed technique, an error analysis is conducted to investigate the level of uncertainty through testing three induction motors, and the results of uncertainty of the direct measurements and no-load measurements using the proposed technique are presented.

Labeling and efficiency of induction motors, IEC on chilean case

This article presents the historical development of a labeling program, particularly in Chile, the criteria chosen for the experiments, the participants of the process and the difficulties found during its execution. It also discussed the methodology used, which considered the IEC 60034-2-1 norm for direct and indirect measurements of the performance of three-phase induction motors. Finally, the results obtained by measuring the performance of one motor. Furthermore, not only the results are presented in a labeling context but also the criteria that they should meet for this class of program are suggested.

Torque Ripple and Harmonic Density Current Study in Induction Motor: Two Rotor Slot Shapes

The variation of the rotor slot geometry causes diminution of joule losses, noise and vibrations, which improves Induction Motor IM performance and efficiency. In this paper, we propose a comparative study of the two IM design structures by varying the slot shapes based on the Finite Element Method (FEM). This software is used to estimate the magnetic field density, the magnetic flux and the harmonic current densities Simulation results prove that the optimal form of rotor slots is the round shape since the gain in torque ripple peak to peak may reach 40% compared to rectangular one.

Multi-objective Design of Induction Motor using Harmony Search Optimization

paper presents a Harmony Search Optimization (HSO) based design methodology for maximizing both the starting torque and the efficiency of Induction Motor (IM). HSO is inspired the musical process of searching for a perfect state of harmony. The harmony in music is analogous to the optimization solution vector, and the musician's improvisations are analogous to local and global search schemes in optimization techniques. Among the number of design variables of the IM, seven variables are identified as primary design variables and the HSO based design methodology is tailored to optimize the chosen primary variables with a view to obtain the global best design. The optimal design obtained by the developed methodology for two IMs are presented with a view of illustrating the superiority.

New criteria for energy efficiency of induction motors with squirrel-cage rotor winding

New criteria for energy efficiency of induction motors with squirrel-cage rotor winding

Procedure for Determining Induction Motor Efficiency Working Under Distorted Grid Voltages

In electric power systems, it is very common to find problems of power quality. The flow of harmonics significantly affect the operation of three-phase induction motors, and its energy characterization becomes difficult. There are different methods in situ to estimate motor efficiency. However, it is necessary to deepen the in situ efficiency analysis under nonsinusoidal voltage conditions. In this paper, a procedure is presented based on the equivalent circuits with losses segregation and using a bacterial foraging algorithm (BFA). It allows induction motors' energy efficiency determination in field conditions with low invasiveness and working under harmonic distortion. The method was successfully tested on a 1.5 kW motor fed with significant levels of voltage harmonic.

A Ultra -Super Efficiency Induction Motor Based on the Finite Element Analysis

In order to increase the cost and material conditions as little as possible for improving the efficiency of the motor, and reduce the losses of the motor. This paper have YE3-132S-6X3 super-efficient motor loss analysis first. According to the characteristics of its loss analysis, this paper change the motor slot coordination, and through the finite element analysis, further has carried on the design of slot type and winding. Finally, in order to further reduce iron loss, this paper uses the new type of silicon steel, and then by comparing with the finite element analysis and experimental tests found YE3-132S-6X3 motor efficiency have achieved the purpose of the ultra-super efficient, and other performance parameters can also meet the requirements.