• The Transactions of The Korean Institute of Electrical Engineers
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• v.68 no.1
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• pp.44-51
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• 2019

Tunnel Boring Machine's Technology has depends mostly on imports, currently domestic technology development was proceeding. There are many technologies in this field, above all, the large-capacity motor drive technology required for excavation is one of the core technologies. In particular, when several large motors are simultaneously starting, there are many problems due to a large starting current at that time, and it is difficult to design and operate a power receiving facility. In this paper, A method of reducing the starting current by using the regenerative power generated by the deceleration of the motor has been studied. To verify this proposal, we designed the induction motor controller using CAE based power simulation tool and verified the results of the proposed method by applying the reduced model. As a result, it is possible to reduce the maximum starting current and shorten the start-up time. Moreover, even if several motors are connected to one bank, it is proved that the method can be efficiently operated by using the sequential braking / starting sequence. In the case of a power system in which a large capacity electric motor such as a tunnel excavation system is driven, the results of this study are expected to be a stable and effective method for solving the start-up current problem and designing the power receiving facility.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.34-37
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• 2000

This paper presents the power compensation by wound-rotor induction motor with a Fly-wheel. In the wound-rotor induction motor the primary power is controlled by AC excitation which used the secondary power conversion. Based on theory this paper describes the dynamic response analysis of the would-rotor induction motor with Fly-wheel. Simulation and experimental results are performed to verify the proposed control method

• 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 the Korean Society for Precision Engineering
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• v.30 no.11
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• pp.1187-1192
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• 2013

In the case of 4 wheel drive (4-WD) type car, power switching occurs to 4-WD by operating lever or switch that operates power switching device attached in transfer case which can operate motor by electric signal. So if the RPM of motor is high, power switching will not exactly occur and can cause damage to gear in transfer case according to circumstances. So in this study, we applied 2 level of planet gear type motor spindle of motor drive part of a power train. And conducted decelerating to increase torque to switch power safe and accurately. Also, we researched efficiency of gear by designing reduction gear ratio and gear type and by calculating contact stress and bending strength. Based on researched content, we made drive head of power switching device and a reduction module which uses type that uses motor spindle as sun gear and ring gear as cover.

• Journal of Power Electronics
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• v.13 no.2
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• pp.256-263
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• 2013

This paper presents an IHQRR (Integrated High Quality Rectifier Regulator) BIFRED (Boost Integrated Flyback Rectifier Energy Storage DC-DC) converter fed BLDC (Brushless DC) motor drive. A reduced sensor topology is derived by utilizing a BIFRED converter to operate in a dual DCM (Discontinuous Conduction Mode) thus utilizing a voltage follower approach for the PFC (Power Factor Correction) and voltage control. A new approach for speed control is proposed using a single voltage sensor. The speed of the BLDC motor drive is controlled by varying the DC link voltage of the front end converter. Moreover, fundamental frequency switching of the VSI's (Voltage Source Inverter) switches is used for the electronic commutation of the BLDC motor which reduces the switching losses in the VSI. The proposed drive is designed for a wide range of speed control with an improved power quality at the AC mains which falls within the recommended limits imposed by international power quality standards such as IEC 61000-3-2.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.1
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• pp.52-60
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• 2018

The winding of the motor stator coil is broken due to external stress and various factors. If the proper current is not injected when interturn fault(ITF) occurs, the fault can easily be expanded and the motor can be finally destroyed, resulting in many problems with time costs and safety. In this paper, the power loss limit concept, which is the inherent durability of each motor, is applied to secure safety by controlling the total power loss of the motor within the limits. So, we propose an algorithm that can control maximum torque per minimum power loss based on constant torque curve and power loss limit. To verify the proposed method, the simulation and experimental results with an Interior permanent magnet synchronous motor(IPMSM) having an ITF are shown.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.7
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• pp.868-875
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• 1999

In this paper, digital motor control center using protection relay is developed in order to protect power systems by means of timely fault detection and diagnosis during operation for induction motor which have various load environments and capacities in power systems. Digital motor control center is employed by power supervisory control systems without separate remote terminal unit and transducers adding communicational ability. Also we develope a maximum demand controller to control the load effectively at peak status and a power factor controller to minimize real power losses and improve the power factor. Therefore, when using the developed controller, real time computation is possible by loading DSP in hardware and applying real-time kernel which can convert each algorithm to task module.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.2
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• pp.92-100
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• 2010

A new class of electronically commutated brushless motor, the flux-switching motor(FSM) is gradually emerging in power tools and household appliances especially fan and pump application because of green policy. This motor offers advantages of high-power density and relatively high efficiency compare with induction motor, low cost and simple motor structure compare with bldc motor. This paper presents the principle of the FSM and design of the 12/6 pole FSM drive system for fan application. Finally, test results of the prototype motor are provided to verify a validity of the fan application with TMS320F2812 DSP and inverter.

• Journal of Power System Engineering
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• v.20 no.1
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• pp.57-62
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• 2016

In this study, design the core part of the driving of the robot. The power of the driving is window motor for automobiles obtained by using a method of directly to the motor shaft of the worm gear type. The decelerator consists of a worm gear to receive power from the motor shaft, Helical gear contact to worm gear, a pinion gear to be connected in line with the helical gear, and an output shaft to be engaged to the pinion gear. Drive system by using the power from the motor shaft based on the deceleration gear designed by the gear ratio set by the gear teeth increases the torque.

• Journal of Power System Engineering
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• v.12 no.6
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• pp.83-87
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• 2008

EPS(Electric Power Steering) system, which has replaced the hydraulic steering system(HPS or HPAS) in many passenger cars recently, have many merits such as low energy consumption, easy mounting, light weight and improvement of environmental pollution. However, EPS system has the problem of motor noise when motor is rotated, which can make a driver feel uncomfortable. There are many techniques to solve those problems, but they are not clear. It is necessary to evaluate the mechanical noise in steering systems, because an EPS has vibration sources such as at the motor gear reducer, manual gears and intermediate joints. In this paper, reduction technique of EPS motor noise is introduced.