• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.6
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• pp.995-1000
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• 2016

Minimum Energy Performance Standard(MEPS) has been adapted in Korea since 2008. For at least 37 kW, IE3 efficiency class motors are now mandatory in Korea. IE4 level regulation is expected in a few years. Foreign companies are already selling IE4 class motors in the market, and the discussions on IE5 have already started. The efficiency standard of variable speed motors is scheduled for publication shortly. Recently, discussions are now beginning to prepare for IE5 in Korea. In this paper, author reviews the policies associated with a high efficent electric motors by reference to both domestic and international standards, and reviews the research direction to prepare for IE5.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.10a
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• pp.353-360
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• 2001

Electro Electric Systems Division of HHI is developing new series of models for industrial mid/compact size motors to satisfy the demand of costumers. Various essential technologies are required for motors to support design technology on design and development stage. Conventional motors have several things to analyze for mechanical strength and structural deformation during manufacturing process or operation. Therefore, the manufacturing cost will be reduced and the danger of accident during operation will be prevented by recognizing and revising the problems prior to actual manufacturing and operation. 112 Frame motor (3.7 kW) has been analyzed for this study and the basic analysis technology is eventually developed by analyzing other models gradually (sequence of 112, 135, 250, 200, 280, 225, 160, 180 Frame motors). Then, the developed technologies are established as main factors to support the motor design technology and competitive motors will be manufactured to satisfy the costumers.

• Journal of Power Electronics
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• v.11 no.4
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• pp.464-470
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• 2011

In this paper, the feasibility of applying a position sensorless control technique to hybrid electric vehicles (HEVs) is practically evaluated. The proposed position estimator has a straightforward structure with properties that combines the model and the saliency tracking-based rotor position estimation for interior permanent magnet synchronous motors (IPMSMs). The proposed method can be used in the event of sensor loss or sensor recovery to sustain continuity of operations. The developed system takes into account the estimated position transition between two distinct sensorless methods. The transition is enhanced by introducing a synchronized transition algorithm based on a single tracking observer. Extensive experimental results are presented to verify the principles and show a reliable estimation performance over the entire speed range including standstill under 150% load conditions.

• 전기의세계
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• v.26 no.5
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• pp.74-82
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• 1977

This study is to present a method for reductin of noise and vibration of home electric motors coupled to the mechanical load causing relatively big amplitude of vibration. The noise and vibration factors have been analysed in the divisions such as the pattern related to the armature reaction, the pattern related to the circulating current by induction and the other patterns those are affected by a dditive magnetic field and have an effect on mechanical constants. From the systematic mutual relations between the patterns and daping effects, it is possible to derive the fundamental measure for reduction of noise and vibration. Vibration measurements and analysis were carried out in accordance with the planned experimentation and thre object model was chosen randomly from the production line in a factory where home electric machines were mass-produced. Based on the above-mentioned fundamental measure, suppression effects on noise and vibration have been analysed according to the number of slots, the amount of rotor skew and the way the stator winding connection was series or parallel.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.5
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• pp.29-34
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• 2014

Cooling the in-wheel motor in electric vehicles is critical to its performance and durability. In this study, thermal flow analysis was conducted by evaluating the thermal performance of two conventional cooling models for in-wheel motors under the continuous rating base speed condition. For conventional model #1, in which cooling oil was stagnant in the lower end of the motor, the maximum temperature of the coil was $221.7^{\circ}C$; for conventional model #2, in which cooling oil was circulated through the exit and entrance of the housing and jig, the maximum temperature of the coil was $155.4^{\circ}C$. Therefore, both models proved unsuitable for in-wheel motors since the motor control specifications limited the maximum temperature to $150^{\circ}C$.

• Journal of Mechanical Science and Technology
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• v.17 no.10
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• pp.1399-1410
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• 2003

In this paper, we develop a joystick manual driving algorithm for an electric vehicle called Cycab. Cycab is developed as a public transportation vehicle, which can be driven either by a manual joystick or an automated driving mode. The vehicle uses six motors for driving four wheels, and front/rear steerings. Cycab utilizes one industrial PC with a real time Linux kernel and four Motorola MPC555 micro controllers, and a CAN network for the communication among the five processors. The developed algorithm consists of two automatic vehicle speed control algorithms for normal and emergency situations that override the driver's joystick command and an open loop torque distribution algorithm for the traction motors. In this study, the algorithm is developed using SynDEx, which is a system level CAD software dedicated to rapid prototyping and optimizing the implementation of real-time embedded applications on distributed architectures. The experimental results verify the usefulness of the two automatic vehicle control algorithms.

• Journal of Korean Elementary Science Education
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• v.17 no.1
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• pp.105-112
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• 1998

It is well known that making electric motors is very difficult in chapter 2, "Electric Current and Magnetic Field", natural science textbook 6-1 in primary school. In the present paper, we propose a new and successful method for making them. The most important point is that iron cores are not used in making electromagnets. This resolves the problem that both poles of electromagnet can be attracted by any pole of permanent magnet because of iron core in the electromagnet. The thick enamel wire is used as arms of armature so that they can support the electromagnet stably and we can reliably strip off the skin of the enamel wires, completely for one end and half for the other end of the enamel wires coming from the electromagnet. In addition, we suggest the ring-type support made of aluminum foil and the M-shaped support made of thick enamel wire that can substitute for the M-shaped copper wire support for armature. armature.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.11
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• pp.1634-1640
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• 2012

This paper develops the high-efficiency drive system of the small-size electric vehicles (EVs) driven by the brushed dc motors. A power circuit for driving the dc motor is designed with the H-bridge circuit and buck converter by considering both the efficiency and cost. In order to change smoothly the rotating direction of dc motor driven by the proposed power circuit, an operating sequence for both the field current and the armature voltage according to an accelerator pedal angle is suggested. Through the simulation studies and experimental results with the low-cost 8-bit AVR, the performances of the proposed methods are verified.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.2
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• pp.76-82
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• 2014

In this paper, an optimal power distribution algorithm is proposed for the small electric vehicle with front in-line and rear in-wheel motors. First, it is assumed that the vehicle driving torque and velocity are given conditions. And, an optimal problem is defined that finding the front and rear motor torques which minimizes the battery power. From the above optimization problem, the optimized front-rear motor torque distribution map is obtained. And, the vehicle simulations are performed to verify the performance of the optimal power distribution algorithm which is proposed in this study. The simulations are performed based on the federal urban driving schedule for two cases which are constant ratio power distribution, and optimal power distribution. From the simulation results, it is found that the optimal power distribution shows the 6.3% smaller battery energy consumption than the constant ratio power distribution.

• Proceedings of the KIEE Conference
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• 2001.07e
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• pp.95-99
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• 2001

In this paper, a drive system for multi-phase bipolar brushless DC (MPB BLDC) motor is presented. This drive system is used for an electric bicycle. In general, the maximum and minimum speed of electric bicycle are required by law. At first, the proposed controller is satisfied for the limited speed control. Secondly, the system has a technique of exited with modulation(EWM), bidirection control, and partial square wave control. Thirdly, the controller is designed for system stability Experimental results show the performance of the proposed controller of MPB BLDC motors for an electric bicycle.