• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.717-719
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• 2003

In terms of induction motor analysis, magnetic energy conversion takes place into mechanical energy in air gap. Therefore, flux distribution in air Sap has to be analyzed in detail more than other place of induction motor. In this paper, the air gap permeance of induction motor, which was effected by means of skewed angle and fringing, was analyzed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.4
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• pp.1777-1783
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• 2012

In this paper, a new motor driving circuit is designed to improve the output performance of DC motor, and a controller is developed with the designed circuit. By the designed driving circuit, a controller can continuously drive DC motors by a transformer which has switching signals of a self-generated circuit to operate it. And while the DC motor have a maximum velocity, the reference voltage can be maintained higher value than that of triangle voltage and it makes the DC motor driving transistor ON and maximum power. A 24V-500W DC motor controller is developed with the proposed motor driving circuit, and also a small electric car is made and the driving test of it is executed. The test results shows that it can continuously control go and back speed of motor with 12A driving current. And also, it is verified that the over current and heat detecting function is operating correctly and the rest value of the used battery can be displayed as 6 step from 20 to 100%.

• Journal of Drive and Control
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• v.12 no.1
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• pp.9-14
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• 2015

In the early of 1950, the high response magnetic torque motor was developed for driving electro-hydraulic servo valves. Since then it has been broadly used for industrial application and the research of development or improvement of the torque motor is still being conducted. The purpose of this study is to present useful design criteria for the torque motor design. For this, torque motor is modelled and linearized. The static characteristics of the torque motor are investigated by direct computation of the derived linearlized equations. The dynamic characteristics of the torque motor are investigated with the derived transfer function by using Matlab and compared with the results of the linearlized analysis by using AMESim simulation with actual values of the physical parameters. Finally, the design criteria obtained from the analysis are reviewed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.8
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• pp.82-87
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• 2011

Induction motor is most widely used as the driving power in the industrial site. Induction motor current is composed of two parts, magnetizing current and load current. Load current uses energy what is doing the work. Load current varies with load variance but magnetizing current is constant, regardless of load variation. Magnetizing current needs for establishing the rotating magnetic field of induction motor and lags behind the voltage. Generally capacitor is used for power-factor compensation of inductive load. Self-excitation occurs when the capacitive reactive current from the capacitor is greater than the magnetizing current of the induction motor. When this occurs, excessive voltages can result on the terminals of the motor. This excessive voltage can cause insulation degradation and ultimately result in motor insulation failure. In this paper, we analyzed that how the magnetizing current and condenser current is operating at the allowable limit by the load variation. Condenser current is below allowable limit of magnetizing current but magnetizing current is above allowable limit at the lower load operation condition.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.47 no.2
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• pp.1-9
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• 2024

New motor development requires high-speed load testing using dynamo equipment to calculate the efficiency of the motor. Abnormal noise and vibration may occur in the test equipment rotating at high speed due to misalignment of the connecting shaft or looseness of the fixation, which may lead to safety accidents. In this study, three single-axis vibration sensors for X, Y, and Z axes were attached on the surface of the test motor to measure the vibration value of vibration. Analog data collected from these sensors was used in classification models for anomaly detection. Since the classification accuracy was around only 93%, commonly used hyperparameter optimization techniques such as Grid search, Random search, and Bayesian Optimization were applied to increase accuracy. In addition, Response Surface Method based on Design of Experiment was also used for hyperparameter optimization. However, it was found that there were limits to improving accuracy with these methods. The reason is that the sampling data from an analog signal does not reflect the patterns hidden in the signal. Therefore, in order to find pattern information of the sampling data, we obtained descriptive statistics such as mean, variance, skewness, kurtosis, and percentiles of the analog data, and applied them to the classification models. Classification models using descriptive statistics showed excellent performance improvement. The developed model can be used as a monitoring system that detects abnormal conditions of the motor test.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.784-785
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• 2015

This paper proposes a new structure of coil to maximize the conductor occupting ratio(conductor cross sectional area than the cross sectional area inside the slot) of the magnetic core. Further, assuming a case in which the 3-D coil is applied to a real motor. Analyze the current density distribution of the coil conductor by electromagnetic analysis method. Finally the AC resistance was measured according to the frequency of the coils. This expereiment is to calculate a optimal operating frequency to obtain high efficiency operational frequency range of motor.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.217-221
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• 2002

In this research a Matlab/Simulink/RTW - based on the realtime control system was developed for an induction motor vector control. On the Simulink window, the control system is designed In the form of block diagrams, program codes are produced automatically with the RTW(Real Time Workshop), then a DSP c compiler complies the program codes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4751-4756
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• 2012

Blushes are known to generate unwanted nano particles of dust and harm elements in various electro-mechanical home appliances. Subsequently, the blushless type is proposed as an eco-friendly alternative to replace the brushes. Further, the expensive magnetized rotor of the Blush-less DC (BLDC) is to be replaced in SRM, which requires complex control not to overflow the switching current the system within a budget. This paper introduces an approach to implement an efficient yet, cost-effective controller for high-speed rotation control, employing Switched Reluctance Motor (SRM) BLDC motor.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.2
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• pp.816-821
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• 2013

This paper proposes the design method of low-cost vector control system for induction motor using the ARM Cortex-M4 microcontroller. This MCU can be used instead of expensive DSP to control the home appliances such as refrigerator, air conditioner, washing machine and so on. This paper explains the major features of Cortex-M4 for motor control and how to realize a vector-controlled inverter using it. The developed system is applied to 3-phase induction motor of 200[W] and experimental results show good performance similar to the system using TMS320F28335 DSP.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.565-568
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• 2002

A lot of rotating machines are being used in the industrial world and electric motor and generator take the most part of it. When it comes to the electric motor and generator, we can not help thinking about the eddy current because it brings a loss of electric and can be a important reason of the heat generation. To attenuate eddy current. laminated silicon steel sheets are being used in general. Especially, laminated rotor is being used for rotating part of the electric motor and generator and it decreases electrical loss and heat generation but we can be faced with another problem. In general, most of the motor and generator can be normally operated under 3600rpm because they are designed to have the first critical speed more than that speed. But nowadays, they should be operated more than the first critical speed as usual with the trend of high speed. large scale and high precision in industrial world. The critical speed can be determined from the inertia and stiffness for the rotor and bearing of rotating systems. The laminated rotor stiffness can be hardly determined because it can be derived a lot factors for instance rotor material and shape. lamination material and shape. insulation material. lamination force and so on. In this paper, the change of the natural frequency of the motor was examined with the change of the lamination force as an experimental method.