• Proceedings of the KIEE Conference
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• 1993.11a
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• pp.47-49
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• 1993

The squirrel cage three-phase induction motor has been used in all types of industry for a number of years. A series of noise components were identied analytically from the expressions for the node numbers and frequencies of the magnetic force waves, taking into account the stator and rotor sldtting, eccentricity, asymmetric and iron saturation. A method is presented for calculating the magnetic energy distribution of eccentrical and asymmetric the squirrel cage induction motor.

• 전기의세계
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• v.30 no.6
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• pp.366-374
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• 1981

In most cases, simulation of induction machines under dynamic conditions have been based on two-phase models using constant circuit parameters. Squirrel cage induction machines with double rotor bars which are made for high starting torgue have lower rotor bars of sufficient depth they cannot be accurately represented by a constant rotor resistance under all operating condition. In this paper, the circuit of three-phase symmetrical induction machines is represented in two-axis model by tensor. A method for simulating three-phase squirrel cage induction machines in a dynamic conditions is presented, and the current distribution in double rotor bars is calculated under dynamic conditions.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.2
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• pp.231-236
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• 2012

This paper presents the MPPT(Maximum Power Point Tracking)control method of the PMSG wind generation system using the turbine model with a squirrel cage induction motor. The torque of squirrel cage induction turbine model is controlled by mathematization of speed characteristics of real blade. In this paper, maintenance and cost issues into consideration, except for previous method using information of the velocity of the wind speed sensor, the algorithm is presented. The algorithm is controlled by tracking the optimal point, the generator speed and maximum grid power. The vector controls of the generator side converter and the grid side converter are controlled respectively to obtain maximum torque and regulate unity power factor. With Psim simulations and experiments, the efficiency of squirrel cage induction turbine model and the validity of control algorithm are verified.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.2
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• pp.289-294
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• 2007

This paper describes the effects of rotor eccentricity in squirrel cage induction machines. Asymmetric electro-magnetic force caused by the frictional worn bearing, rotor misalignment and unbalanced rotor etc. generates an asymmetrical operation, vibration and electro-magnetic noise. The need for detection of these rotor eccentricities has pushed the development of monitoring methods with increasing sensitivity and noise immunity. In this paper, we focus on investigating the asymmetrical operation considering of unbalanced magnetic pull in squirrel-cage induction motor with 380 [V], 7.5 [kW], 4P, 1,768 [rpm]. The effects of the non-symmetric rotor and magnetic force are simulated by finite element method (FEM) and tested using search coils for measuring the actual air-gap flux.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.825-830
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• 2001

Many techniques have been developed to evaluate the structural integrity for the traction motor with squirrel cage. However, the former approaches are not appropriate to our problems and there is no reliable specification for evaluation of squirrel cage motor. In this study, an improved boundary condition and the criteria for evaluation are proposed. Using 3-dimensional solid element, finite element model is generated. The number of meshes can be reduced by considering the symmetry of geometry. Stress analyses are carried out for three types of traction motors.

• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.299-301
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• 1998

The torque characteristic of an induction motor is affected greatly by the slot shape at which the conductors of the rotor are located. In this paper, the three analysis model; general type, deep slot type, double squirrel-cage type, of which the slot shapes are different, were analyzed by FEM at no load, at rated load, and at standstill respectively. The flux distribution and air-gap flux density were also obtained. From the above result, it was confirmed that the analysis models of deep slot and double squirrel-cage had more desirable characteristics than those of general squirrel-cage.

• Journal of the Korean Magnetics Society
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• v.26 no.2
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• pp.67-69
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• 2016

Recently, cost of rare-earth magnets has been raised, because rare-earth magnets are monopolized and the export is also regulated in China. For this reason, the induction motor is operated without the rare-earth magnets. The efficient development of induction motor is more important for economical scheme. A torque of the induction motor is computed and the correlation between dimension and resistance of the squirrel cage rotor is investigated. Also, the correlation between leakage reactance and torque was analyzed with respect to the same dimension of rotor with different shapes. Therefore, this paper proposes the method of improvement for squirrel cage rotor.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.05a
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• pp.418-422
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• 2001

This paper presents a developed squired cage induction motor for axial flow fan. The developed squirrel cage induction noter for axial flow fan is exchanged the position, rotor and stater. In this method a fan blade is attached to outside rotor. So we can protect the motor from rain and reduce noise, and there is no need to have bending duct to locate the fan motor. Carried out experimental test with this induction motor, and the results were as follows. Starting torque was 21kgㆍcm@120V, maximum efficiency was 0.84@120V. The characteristics of tests were the same as double squirrel-cage type IM.

• Transactions on Electrical and Electronic Materials
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• v.16 no.6
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• pp.328-333
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• 2015

Squirrel cage induction motors have mostly been used for their small capacity because the starting torque is smaller than the starting current during start-up. However, as more and more mid-to-large capacity motors are developed, the demands for improvements in performance characteristics have also increased. In this study, the starting characteristics of squirrel cage induction motors were analyzed based on the rotor materials and shapes using a finite element method to provide design data suitable for different use purposes and capacities. We further completed analysis by combining electromagnetic equations deduced from Maxwell’s equations and the circuit equations of stators and rotors. A moving coordinator was introduced to rotate the rotor during the analysis, and the torques calculated via the finite element method were combined with the motion equations to calculate the position and angular velocity of the rotors at the next time, thereby analyzing the transient characteristics. The analysis results of the transient characteristics were applied to a 3-phase 4-pole 5-hp induction motor to calculate the starting torque, speed, and rotation angle of the rotors. In the reference model, the materials and shapes of the rotor slot were changed to copper and silicon copper and a deep slot, shallow slot, and long-neck-shaped slot.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.2
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• pp.49-55
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• 1999

This paper proposes an efficient 2D Finite Element Method(FEM) taking into account the end-ring of three phase squirrel-cage induction motors. The parameters of the squirrel-cage induction motor such as conductivity of secondary conductor have an effect on the characteristics of a motor. Especially, if the characteristic analysis is done without considering the end-ring, the good results can not be obtained. Therefore, we calculated a new resistivity of the secondary conductor including the end-ring's resistance to apply the 2D FEM. Then, the performances of the motors are analyzed by using the new resistivity of secondary conductor which contains the end-ring resistivity. The validity of the proposed method is verified by comparing the numerical results with experimental ones.