• Proceedings of the KIEE Conference
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• summer
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• pp.791-793
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• 2004

Voltage unbalance is generated by the load and impedance mismatching at the 3-phase 4-wire system of customer load. Voltage unbalance factor can be changed by the voltage amplitude or phase angle, and both. A small voltage unbalance is connected to high current unbalance. If the voltage unbalance is generated at the joint system of 1-phase and 3-phase load, Induction motor due to the current unbalance increase is generated loss, noise and torque ripple. In order to analyze the effect by voltage unbalance, it is necessary to the consideration of amplitude and phase angle. In this paper, We analyzed the effects that induction motor is affected by asymmetric voltage unbalance

• Journal of Electrical Engineering and Technology
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• v.12 no.2
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• pp.761-768
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• 2017

This paper deals with the performance analysis of three phase induction motor considering its stator side faults and operating thermal limits. The speed control of induction motor using three phase boost converter operated by a MOSFET switch and a PI controller is demonstrated and presented in this article. IGBTs switches are used for inverter drive mechanism. The experimental result of speed control of induction motor using voltage control technique clearly shows better accuracy than conventional methods of speed control. A three phase 1HP 415V 0.78 kW 4 Pole induction motor is designed using motor solver software. Based on the parameters used in the software thermal analysis of induction motor is done and torque variation with conductor area, efficiency, output curve, losses in different parts of motor has been obtained. Also different types of faults namely under voltage, over voltage, stator imbalanced voltage, turn to turn, locked rotor bar, wrong alignment of rotor bar with respect to stator are studied and fault analysis is performed. Hence comparison is made based upon the results obtained before and after faults.

• Proceedings of the KIEE Conference
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• 2004.11b
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• pp.63-65
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• 2004

The recent advancement in the power electronic technique has increased the use of induction motor fed by inverter using high-frequency switching devices. Also the tendency is toward larger size and higher voltage. Therefore, The IGBT (Insulated-Gate Bipolar Transistor) that is high switching frequency element has been using increase. But, The switching surge voltage was occurred by high switching frequency of inverter has appeared a voltage doubling in the motor input terminal due to mismatching of cable characteristic impedance and motor characteristic impedance. Actually, The Switching surge voltage became the major cause to occur the insulation failure by serious voltage stress in the stator winding of induction motor. The short during rise time of switching surge and cable length is increased, the maximum transient voltage seen at the motor terminals increases. In this paper, Analyzed switching surge transient voltage of power cable pulling is used EMTP(Electromagnetic Transient Program) at the induction motor terminal and in cable.

• Journal of the Korean Society of Industry Convergence
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• v.6 no.1
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• pp.3-10
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• 2003

Application of matrix converter to vector control of induction motor using simplified Venturini algorithm which is capable of achieving the maximum output voltage is developed. This algorithm simplifies the control algorithm and therefor reduces the digital implementation time. Matrix converter is used as voltage-referenced voltage fed vector controlled induction motor drive. This paper describes the performance of vector controlled induction motor with four quadrant capability employing a matrix converter power circuit. The advantage of this system over the conventional rectifier-inverter arrangement are capability for regeneration into the utility, sinusoidal supply currents and minimum passive components. The steady-state and transient performance of the induction motor drive under the vector control technique is demonstrate with simulation and experiment results.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.3
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• pp.61-68
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• 2015

When medium and large induction motors are driven by 2-level inverters with low switching frequency, induction motors provoke deteriorated performances resulted from large torque ripples, flux ripples, and large current distortion. Model predictive torque control(MPTC) for a fast torque control of induction motors is also suffered from large torque ripples when the induction motors are fed by 2-level inverters that are based on 6 active voltage vectors with low switching frequency restricted. To solve this problem, this paper proposes a new MPTC method based on both a 12 active voltage vector and an optimized duty ratio calculation. The proposed control strategy illustrates its effectiveness under the various operating conditions through simulation works.

• Journal of information and communication convergence engineering
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• v.6 no.3
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• pp.305-309
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• 2008

This paper presents an innovative prototype of a new conceptual electromagnetic induction eddy current based fluid heating appliance using voltage-fed quasi resonant zero voltage soft switching PWM high-frequency inverter using IGBTs, which can operate at a constant frequency variable power regulation scheme. The promising simple high efficient low noise inverter type electromagnetic induction eddy current based pipeline fluid heating appliance is proposed for saturated steam generator, superheated steam generator, hot water and hot air producer, metal catalyst heating for exhaust gas cleaning in engine. Under these technological backgrounds, a novel electromagnetic induction eddy current Dual Packs Heater(DPH) based pipeline fluid heating incorporates thin metal layer type package for continuous fluid heating appliances applying two types of voltage-fed quasi load resonant ZVS-PWM high frequency inverter. The unique features of a novel electromagnetic induction eddy current DPH based continuous pipeline fluid heating appliance is illustrated on the basis of simulation and discussed for the steady state operating characteristics and experimental results.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.57 no.3
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• pp.225-230
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• 2008

Reactor starting method has the advantage of simplicity and closed transition in spite of lower starting torque per kVA. This method allows a smooth start with almost no observable disturbance on transition and is suitable for applications such as centrifugal pumps or fans. Reactive power doesn't contribute to work but needs to sustain the electromagnetic field required for the induction motor to operate. Starting power factor of induction motor is specially lower than running power factor. Power factor application is needed to compensate for the lower power factor of induction motor. This power factor compensation systems is occasionally being hit by the effects of the starting reactor connection position at the starting, stopping of high-voltage induction motor. This paper describes voltage and current stress affected by the installation position of power factor compensation application at the reactor starting method.

• International Journal of Control, Automation, and Systems
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• v.6 no.5
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• pp.670-676
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• 2008

While the matrix converter has many advantages that include bi-directional power flow, a size reduction, a long lifetime, and sinusoidal input currents, it is vulnerable to the input voltage disturbances, because it directly exchanges the input voltage to the output voltage. So, in this paper, a critical evaluation of the effect of various abnormal voltage conditions like unbalanced power supply, balanced non-sinusoidal power supply, input voltage sags and short time blackout of power supply on matrix converter fed induction motor drives is presented. The operation under various abnormal conditions has been analyzed. For this, a 230V, 250VA three phase to three phase matrix converter (MC) fed induction motor drive prototype is implemented using DSP based controller and tests have been carried out to evaluate and improve the stability of system under typical abnormal conditions. Digital storage oscilloscope & power quality analyzer are used for experimental observations.

• 전기의세계
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• v.15 no.5
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• pp.32-39
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• 1966

This voltage Regulator, which regulates voltage in different way from the conventional regulator, is constructed by circular-plate core type stators and controllers (are similar to rotor of conventional). The principle of this Voltage Regulator is based on the rotating magnetic field theory including peculiar homopolar and heteropolar concept. Comparing with the conventional induction regulator, this regulator need not to have short windings and can cancel armature reaction. Moreover, it is able to decrease the machine noise and control the phase of it freely. And it's efficiency can become more than 95% which almost the same as that of transformer's. By increasing numbers of cores of the same size, the output power can be increased, the insulation can be decreased and high Voltage can directly be connected because applied voltage is distributed to each core. This Voltage Regulator can be also used as a current regulator, a starter a induction motor and a phase transformer etc.

• Proceedings of the KIPE Conference
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• 2019.11a
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• pp.96-97
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• 2019

Pulse Width Modulation (PWM) is a widely adopted technique to drive the motor using the voltage source inverters. Since they generate high frequency Common Mode (CM) Voltage, a high shaft voltage in induction motor is induced which leads to parasitic capacitive currents causing adverse effects such as premature deterioration of ball bearings and high levels of electromagnetic emissions. This paper presents an Active Cancellation Circuit (ACC) which can significantly reduce the CM voltage hence the common mode current in the three phase induction motor drives. In the proposed method the CM voltage is detected by the capacitors and applied to the frame of the motor to cancel the CM voltage hence the CM current. Unlike the conventional methods the proposed method does not insert the transformer in between the inverter and motor, a high power rating three phase transformer is not required and no losses associated with it. In addition the proposed method is applicable to any kind of PWM motor drives regardless of their PWM methods. The effectiveness of the proposed method is proved by the experiments with a three phase induction motor (1.1kW 415V/60Hz) combined with a three phase voltage source inverter modulated by the Space Vector Modulation (SVM).