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Low-intrusive approach for parameters estimation of induction motor using adaptive optimal design algorithm based on on-site measurements
(2013-01-01)
Chat-Uthai, C.
;
Phumiphak, P.
This paper presents a novel low-intrusive method for estimating the equivalent circuit parameters of induction motor which focuses on a simple means without expensive testing. This paper describes the use of on-site measurements data incorporated with the adaptive optimal design algorithm based on optimization process in order to estimate the best possible set of motor parameters for determining the mechanical output at each measured load. This algorithm includes the feasible boundary of design variables process for evaluating the suitable boundaries of motor parameters depending on its power rating. This proposed method has been verified by the experimental results from four low-voltage TEFC induction motors rated at 2. 2, 4. 0, 5. 5 and 7. 5 kW. The results indicate that the agreement between the estimated parameters and the calculated parameters obtained from the standard equivalent circuit method validates the proposed method over a wide range of load conditions. For comparison, the results of estimated mechanical output of actual motors are illustrated. Therefore, this simple procedure can provide the useful information for selecting the motor most suitable for its application. © 2013 Praise Worthy Prize S.r.l.-All rights reserved.
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Non-intrusive method for induction motor field efficiency estimation using on-site measurement and modified equivalent circuit
(2012-12-01)
Phumiphak, P.
;
Chat-Uthai, C.
This paper proposes a non-intrusive method for low-voltage induction motor field efficiency estimation based on the modified equivalent circuit which includes the additional stray-load loss and friction and windage loss parameters for improving accuracy. This method focuses on a simple means without the expensive testing. This paper presents the use of on-site measurement data and speed measurement scheme using the motor current signature analysis (MCSA) incorporated with the proposed adaptive optimal design algorithm based on optimization process to evaluate the optimal parameters of modified circuit. This proposed method has been verified by using the shaft torque method results of low-voltage 2.2 (6-pole) and 4 kW (4-pole) motors. The results indicate that the estimated motor field efficiencies have sufficient accuracy (within 2 %) during the normal operations. Therefore, this simple procedure can provide the useful information for energy audit. © 2012 IEEJ Industry Appl Soc.
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Energy management program for use of induction motors based on efficiency prediction
(2005-01-01)
Phumiphak, T.
;
Kedsoi, T.
;
Chat-Uthai, C.
Electric drive systems are currently responsible for the largest part of the electricity consumption. As the cost of energy increases, it is increasingly more important to remove the inefficient induction motors from operation. This paper proposes an energy management program that can help the plants to determine how much saving will be achieved by using more efficient motors. This paper focuses on the use of motor field efficiency estimation of motors without the removal of motor from service and without the output power measurement, and the use of motor efficiency prediction based on the manufacturer information. The motor efficiency evaluations are obtained from the equivalent circuit method. The test results indicate that this program is a tool of accurate economic analysis for the purchase scenario. As a result, it is possible to conduct on-site energy audits of existing motors in order to determine the potential savings and payback period with great confidence.
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Estimation of induction motor parameters based on field test coupled with genetic algorithm
(2002-01-01)
Phumiphak, T.
;
Chat-Uthai, C.
This paper proposed a technique for estimating the parameters of three-phase induction motor in order to conduct on-site energy audits of existing motors, which are then used to project a cost savings. This proposed technique uses only a few sets of data (voltage, current, speed, power factor or torque if possible) from the field test of motor (on-site), instead of the no-load and blocked rotor tests, coupled with the genetic algorithm for evaluating the equivalent circuit parameters. Once these parameters are known it is possible to obtain the operating performances (50-100%) of the motor such as efficiency, current, torque. This technique could be suitable for the general purpose drive applications when the motor cannot operate at no-load since its shaft is permanently connected to its load. To illustrate how well the performances of the estimated model matches that of the actual motor obtained from load test, the results of 3 HP and 5 HP induction motors will be presented and compared.
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A study of harmonics effect on performances of three-phase induction motor using BSRG
(2002-01-01)
Lumyong, P.
;
Chat-Uthai, C.
This paper proposes the technique of brushless synchronous reluctance generator (BSRG) combined with the utility power supply for generating a three-phase nonsinusoidal voltage waveform. The three-phase harmonic voltage waveforms obtained from the BSRG have a phase angle of 120 electrical degree of its order. The amplitude, frequency and sequence direction of three-phase harmonic voltage waveform referenced with the fundamental can be controlled. The nonsinusoidal three-phase voltage source of the fundamental combined with the 2<sup>nd</sup> to 11<sup>th</sup> order harmonic at various voltage-distortion factor (VDF) having positive or negative sequence direction is then supplied for a real load test to investigate the effect on performances of three-phase induction motor. The test results are illustrated and discussed about the order of harmonic having effect on input current and power loss of the motor.
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Shape design optimization of power frequency electromagnetic devices using numerical methods
(1997-03-01)
Ramirez, Jaime A.
;
Freeman, Ernest M.
;
Chat-Uthai, C.
;
Vasconcelos, João A.
This paper presents the mathematical formulation concerning the solution of inverse electromagnetic problems, i.e. the shape optimization of power frequency electromagnetic devices, based on a combination of numerical methods. The optimization problem is solved using deterministic methods in which the electromagnetic field problem is treated as a subproblem of the optimization process. The field problem is calculated using the finite element (FE) method. Three deterministic approaches are studied in detail, the quadratic extended penalty method (QUA), the augmented Lagrange multiplier (ALM) method and the constrained quasi-Newton method (PLBA-CR). The work highlights the advantages and drawbacks of each approach. The search direction for the optimization is found by two distinct methods, the direct differentiation of the FE matrices and the finite difference (FD) method. In total, three problems are discussed in order to show the power and applicability of the theory presented. The PLBA-CR, when combined with the direct differentiation of the FE matrices, appears to offer important advantages over the other methods.

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