• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.635-637
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• 2001

The faults of the squirrel cage induction motor is grew increasingly complex as the faults resulting in the shorting of a stator winding and the broken rotor bar or cracked rotor end ring, bearing faults, and so on. The users of electrical machines initially relied on simple protections such as over-current, over-voltage, earth-fault, etc. to ensure safe and reliable operation. but this method cause heavy financial losses and the threat of safety therefore it has now become very important to diagnose faults at there very inception. in this paper, we are going to discuss the detection method of broken rotor bar of squirrel cage induction motor by the motor current signal analysis(MCSA) and the opening terminal voltage signal analysis.

• 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.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.323-326
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• 2006

This paper shows the comparison of operating characteristics between squirrel cage induction generator and DFIG(Double Fed Induction Generator). Because squirrel cage induction generator consume the reactive power due to magnetizing reactance, the capacitor is need to compensate the reactive power. Otherwise, two back-to-back PWM voltage-fed inverters connected between the stator and the rotor allow sub/super synchronous operation with low distortion currents. In this paper, the response characteristics of squirrel cage induction generator and DFIG, were analyzed and investigated using PSCAD/EMTDC.

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.404-406
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• 2001

This paper is about designing the magnetizing system which is used for magnetizing the NdFeB magnet in a squirrel cage rotor. It propose the shape of the magnetizing yoke, the number of coil turn and the capacitor discharging circuit parameter. In case of magnetizing the NdFeB magnet assembled with a squirrel cage rotor, the eddy current which is produced during magnetizing becomes a disturbance in magnetizing NdFeB magnet. Hence in this paper, we try to design optimized magnetizing system with eddy current considered by FEM(Finite Element Method).

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.61 no.4
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• pp.199-205
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• 2012

This paper propose a improved parameter estimations of five-phase squirrel-cage induction motor(IM) for speed control system on field oriented control(FOC). In order to high performance control of ac the motors using a FOC and DTC(direct torque control) algorithm, there are required precise motor parameters for slip calculation, flux observer, controller gain, rotor position and speed estimation, and so on. We are suggest a estimation method of the motor parameters that developing five-phase squirrel-cage IM have a stator of concentrated winding for experimental. There are results of stator winding test, no-load test, locked rotor test, and obtained equivalent circuits using manufactured experimental apparatus. For presenting the superior performance of the speed control system in adapted the parameters, experimental results are presented using a 32-bit fixed point TMS320F2812 DSP with 1.5[KW] IM.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.63 no.4
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• pp.241-247
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• 2014

This paper propose a variable parameter estimations of five-phase squirrel-cage induction motor(IM) for speed control system. In order to high performance control of AC motor using a field oriented control(FOC) and direct torque control(DTC) algorithm, there are required precise motor parameters for slip calculation, flux observer, controller gain, rotor position, speed estimation, and so on. We are suggest a analyzed estimation results of the motor parameters that developing five-phase squirrel-cage IM have a stator of concentrated winding for experimental of variable input power frequency. There are results of stator winding test, no-load test, locked-rotor test, variable actual load test, and estimated parameters of equivalent circuits using manufactured experimental apparatus by IEEE Standard Test Procedure for Polyphase Induction Motors and Generators 112-2004.

• Journal of Power Electronics
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• v.1 no.2
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• pp.127-132
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• 2001

This paper describes two different systems which can compensate harmonic currents generated in a power system. As non-linear loads increase gradually in industry fields, harmonic current generated in the electric power network system also increases. Harmonic current makes a power network current distorted and generates heat, vibration and noise in the power machinery. Many approaches have been applied to compensate harmonic currents generated in the power system. Among various approaches, in this paper, two kinds are compared and evaluated. They are flywheel compensators bases on secondary excitation of WRIM(wounded rotor induction motor) and SCIM(squirrel cage induction motor). Both systems have a common structure. They use a flywheel as an energy storage device and use PWM inverters. The main differences are the size and rating of the converter used.

• Journal of the Korean Society for Railway
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• v.4 no.1
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• pp.16-22
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• 2001

This paper describes two different systems which can compensate harmonic currents generated in the power system. As non-linear loads increase gradually in industry fields, harmonic current generated in the electric power network system also increases. Harmonic current makes a power network current distorted and generates heat, vibration, noise in the power machinery. Many approaches have been applied to compensate harmonic currents generated in the power network system. Among various approaches, in this paper, two kinds of approaches are compared and evaluated. They are flywheel compensator based on secondary excitation of wounded rotor induction motor(WRIM) and primary excitation of squirrel cage induction motor(SCIM). Both systems have a common structure. They use a flywheel as a energy storage device and use PWM inverters.

• Journal of Electrical Engineering and Technology
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• v.6 no.5
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• pp.666-670
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• 2011

In this paper, a method for detecting broken rotor bar and stator winding fault in a low voltage squirrel-case induction motor using an air-gap flux variation analysis is proposed to develop a simple and low cost diagnosis technique. To measure the leakage flux in radial direction, a radial flux sensor is designed as a search coil and installed between stator slots. The proposed method is able to identify two kinds of motor faults by calculating load condition of motors and monitoring abnormal signals those are related with motor faults. Experimental results obtained on 7.5kW three-phase squirrel-cage induction motors are discussed to verify the performance of the proposed method.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.872-873
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• 2007

This paper proposes a calculating method of resistance and inductance of end ring of squirrel cage induction motor for 2D finite element analysis. The squirrel cage of induction motor consists of bars and end rings. The resistance and inductance of end ring have an effect on the result of the finite element calaculation. If the end ring were excluded from the analysis, the good result could not be obtained. Therefore, we first simulate an axisymmetric magnetodynamic analysis for the end ring, and then calculate the interbar resistance and the end ring inductance. The calculated values are put into the external circuit of 2D finite element model of the induction motor. The proposed method is verified by comparing the numerical results with the experimental ones.