• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.3
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• pp.59-65
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• 2008

High-speed electrical motor has been studied for several applications, i.e. for direct-drive systems of centrifugal compressors and turbo blowers. This paper deals with a design consideration of electromagnetic, mechanical and thermal limits of high-speed induction motor for turbo blower. Basic design concept of high-speed motor was proposed. As the motor is to be operated at high speed, the losses are quite different from conventional low-speed machines. Especially, the increases of rotor eddy current and friction losses could lead to an overheated motor. So, we suggested a special cooling system to reduce temperature rise. And, based upon this design concept, the prototype induction motor(37[kW], 45,000[rpm]) for high-speed turbo blower was designed and 2-D electromagnetic field analysis was implemented. Finally, criteria to evaluate the characteristics of high-speed induction motor have been proposed and tested.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.807-808
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• 2006

This paper covers start-up characteristic of three phase induction motor. When three phase induction motor is started, the inrush current occurs. There are several ways of reducing starting current of a three phase motor. In this paper will explain and propose the types of part windings in order to reduce the starting current.

• Proceedings of the KIPE Conference
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• 2001.12a
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• pp.3-6
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• 2001

This paper designs a drive for high efficiency of the 3-phase IM (induction motor) for FCU(Fan Coil Unit). The speed control system of 3-phase IM for FCU has been implemented by a TMS320LF2406 DSP chip. The DSP TMS320LF2406, which include the most peripheral circuit for control of the Industrial motor suitable for AC motor drive. This type of the controller can be obtained low cost and high reliance. The proposed drive system of the 3-phase IM for the FCU is verified by simulation. The results show the speed control characteristics of the control strategy Proposed for 3-Phase IM drive.

• The Transactions of the Korean Institute of Power Electronics
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• v.7 no.4
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• pp.322-331
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• 2002

In this paper, a single-phase to three-phase PWM converter topology using a single-phase half-bridge PWM rectifier and a 2-leg inverter for low cost three-phase induction motor drives is proposed. In addition, the source voltage sensor is eliminated with a state observer which controls the deviation between the model current and the system current to be zero. The converter topology is of lower cost than the conventional one, which gives sinusoidal input current, unity power factor, dc output voltage control, bidirectional power flow and VVVF output voltage. The experimental results for V/F control of 3Hp induction motor drives have been shown.

• Proceedings of the KIEE Conference
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• 2007.10c
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• pp.98-100
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• 2007

This paper presents a analysis on the torque and power characteristics of standard 3-phase induction motor. An induction motor changes its characteristics parameters under the operation condition with the same capacity. In this paper, we analyzed that how the power and torque characteristics of induction motor would be changed according to the change of these parameters.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.7
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• pp.475-482
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• 2000

This paper presents a novel power-factor correction method using customer STATCOM which generally improves the power quality of electric customers. Customer STATCOM detects the reactive currents of a induction motor(IM) and so injects compensation currents which is in 180$^{\circ}$ phase with load currents that the reactive power of IM is compensated. In particular, the paper proposes the general compensation current references in the synchronous coordinate system and makes converter output voltages using space-vector PWM. The compensation effect of customer STATCOM is confirmed through the simulation according to the operation condition of an induction motor (at no load and full load).

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.05a
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• pp.361-365
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• 2004

This paper describes the various characteristics of voltage sags which can affect the functions of three-phase induction motors that are mostly used in the power distribution systems. These assorted characteristics include motor speed losses, voltage recovery, motor reacceleration, and transient characteristics. An experimental study on the induction motor behaviors was also carried out to confirm these impacts. In addition sequential voltage sags with short durations were considered and investigated. The results show that the occurrence of the second voltage sag after the first one may affects the induction motor adversely.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.38 no.2
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• pp.93-99
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• 1989

This paper describes Sinusoidal Wave-Variable Voltage Variable Fequency (SW-VVVF) system for the high efficiency drive of a 3-phase induction motor. SW-VVVF system consists of a 3-phase 24-pulse converter and a SPWM inverter. The converter with additional 2 tap diode circuits in interphase reactor reduces harmonics in input current. The SPWM inverter consists of an improved PLL system and a V/F controller, which reduces harmonics in output current and performs a high efficiency algorithm by maintaining a constant slip frequency and compensating for the velocity variation of the induction motor with the change of load. Therefore, this system reduces harmonics in input and output currents, and also can drive an induction motor with high efficiency in an economical way. We have proved its utility through experiment.

• Proceedings of the KIEE Conference
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• summer
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• pp.45-47
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• 2004

This paper describes the various characteristics of voltage sags which can affect the functions of three-phase induction motors that are mostly used in the power distribution systems. These assorted characteristics include motor speed losses, voltage recovery, motor reacceleration, and transient characteristics. An experimental study on the induction motor behaviors was also carried out to confirm these impacts. In addition, sequential voltage sags with short durations were considered and investigated. The results show that the occurrence of the second voltage sag after the first one may affects the induction motor adversely.

• Journal of Power Electronics
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• v.3 no.2
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• pp.99-114
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• 2003

This paper presents a feasible development on a highly accurate quick response adjustable speed drive implementation fur general purpose induction motor which operates on the basis of sensorless slip frequency type vector controlled sine-wave PWM inverter with an automatic tuning machine parameter estimation schemes. In the first place, the sensorless vector control theory on the three-phase voltage source-fed inverter induction motor drive system is developed in slip frequency based vector control principle. In particular, the essential procedure and considerations to measure and estimate the exact stator and rotor circuit parameters of general purpose induction motor are discussed under its operating conditions. The speed regulation characteristics of induction motor operated by the three-phase voltage-fed type current controlled PWM inverter using IGBT's is illustrated and evaluated fur machine parameter variations under the actual conditions of low frequency and high frequency operations for the load torque. In the second place, the variable speed induction motor drive system, employing sensorless vector control scheme which is based on three -phase high frequency carrier PWM inverter with automatic toning estimation schemes of the temperature -dependent and -independent machine circuit parameters, is practically implemented using DSP-based controller. Finally, the dynamic speed response performances for largely changed load torque disturbances as well as steady state speed vs. torque characteristics of this induction motor control implementation are illustrated and discussed from an experimental point of view.