• Proceedings of the KSR Conference
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• 한국철도학회 2002년도 추계학술대회 논문집(I)
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• pp.427-433
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• 2002

An inverter-driven induction motor is usually adapted to the traction motor for a high speed drive system requiring safety, reliability, performance, compact size owing to the space and weight alloted for attaching to train, etc. and AC Traction motor for G7 train will be operated in the worst condition such as mechanical vibration, limited mounting space, severe thermal stress, inverter with non-sinusoidal voltage waveform, dust and so on. therefore, design procedure must be carefully carried out wi th considering the motor size, vibration and thermal expansion of rotor bars, insulation system, reliability of frame, as well as output characteristics. In this paper, we will inform the characteristics and design of the traction motor for G7 train and also analyze the test result of it.

• The Transactions of the Korean Institute of Electrical Engineers
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• 제37권9호
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• pp.600-608
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• 1988

Although the structure of brushless dc motor is similar to that of a Permanent magnet synchronous motor, its torque-speed characteristcis are the same as those of a permanent magmet dc motor. The brushless dc motor drive systemcomposed of power converter including inverter, rotor positioning sensor and controller has been investigated for the purpose of position control when the motor is fed by a current controlled voltage source inverter. The equivalent transformation of a brushless dc motor into an separately exited dc motor has been possible with the vector control (field oriented control) technique. It is shown in this paper that the position control of a brushless dc mitor can be done fairly accurately only using q-axis current.

• Journal of KIEE
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• 제11권1호
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• pp.62-68
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• 2001

In this paper it is proposed an advanced modified sliding mode control of a rotor field oriented control of induction motor. The application of this unconventional control has very good results, such as disturbance rejection and nice dynamic properties. Stability can be guaranteed even in the worst situation. A conventional "sliding mode" controller is characterised by fast switching control signal, which causes the chattering of the drive system. To overcome this problem, a modified law is used, by introducing a hysteresis band and a continuous control, which modifies the conventional law. The control is accomplished with dual TMS320C44 floating-point digital signal processor. The validity of the proposed method was verified by experiment on the propulsion system simulator, used for the development of Korean High-Speed Railway Train(KHSRT).in(KHSRT).

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제3B권4호
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• pp.173-178
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• 2003

The rotational force of ultrasonic motors is able to get from the frictional force of elliptical vibration by contact between rotor and stator. Generally, ultrasonic motors are suitable for driving at resonant frequencies of about 20∼80［KHz］. The driving characteristics of ring type ultrasonic motors are the object of this study. A two-phase driving signal is delivered to the tested ultrasonic motor, which has a $90^0$ phase difference respectively with both sine and cosine voltage waveforms. The driving frequency is almost equal to the mechanical resonant frequency for the proper operation, and the driving signal is supplied by the two-phase parallel resonant inverter. The validity of the proposed driving method is verified by experimental results with stable operation.

• Proceedings of the KIEE Conference
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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• pp.2255-2257
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• 2001

This paper introduces a indirect rotor position and speed estimation algorithm for the SRM(switched reluctance motor) sensorless control, based on the sliding mode observer. The information of position and speed is generally provided by encoder or resolver. However, the position sensor not only adds complexity, cost, and size to the whole drive system, but also causes limitation for industrial applications. In this paper, in order to eliminate the position sensor, indirect position sensing method using sliding mode observer is used for SRM drives. And this observer parameters are optimized by evolutionary algorithm. PI controller is also optimized for the SRM to track precisely using evolutionary algorithm.

• Proceedings of the KIEE Conference
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.896-898
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• 2004

The lagging reactive power should be supplied for the excitation of isolated squirrel-cage induction generators by external circuit. This paper deals with a technique to drive the equations for analysis of the excitation characteristics and performance of an isolated squirrel-cage induction generator from the conventional equivalent circuit of induction machine, transform the equations into d-q coordinates to use vector control technique, and carry out the simulation of an induction generator system with various conditions using MATLAB. The results of the simulation indicate that moderate reactive power can be controlled effectively to maintain constant voltage over a wide range of the rotor speeds and loads.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제4B권3호
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• pp.114-121
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• 2004

Switched reluctance motors have received much attention as a driving means for various industrial applications because they have simple construction, low cost and high efficiency. Nevertheless, the requirements of drive converters make it difficult to lower the overall system cost as compared with the DC motor application. Single phase switched reluctance motors (SPSRMs) provide a solution to the high cost problem since the number of switching power devices can be reduced and consequently the trials for application are increased. However, research involving SPSRMs, especially in the area of design work, is insufficient. This paper introduces a novel design methodology of single phase SRM. The design work for SPSRM comprises the determination of many variables such as stator and rotor pole arc as well as on, off and so on. Managing all variable combinations leads to lengthy computation time and a fault in the design process. For that reason, a reliable technique and brief procedure term are required in SPSRM design.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제3B권3호
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• pp.133-138
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• 2003

In this paper, a BLDC motor and its controller are developed for treadmill application. Motor size and structure are restricted in the design stage due to the limited and enclosed space of the treadmill. The shape of the rotor magnet is analyzed using FEM with restricted design conditions. Manufacturing, cost and performance are also considered. A biomechanical analysis of human locomotion with the change of velocity is considered in the design of the controller. For stable operation of the treadmill, current and temperature are to be detected by the DSP controller. The prototype BLDCM and its controller are tested to verify its performances.

• Proceedings of the KIPE Conference
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• 전력전자학회 2007년도 하계학술대회 논문집
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• pp.226-228
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• 2007

SRM drive systems are designed to meet operating standards such as low cost, constant torque independent of rotor position, a desired operating speed range, high efficiency, and high performance. In applications using small motors, low cost and high performance with self-starting capabilities are highly desired. This paper discusses a novel two phase SRM (TPSRM) that has high performance characteristics with self-starting capability, low manufacturing cost with a two phase inverter and simple magnetic structure, and high efficiency. The principle of operation, analysis, and simulation for design are presented. The machine design is verified using finite element analysis (FEA) software. Analysis and simulation results are given to validate the TPSRM design.

• Proceedings of the KIPE Conference
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• 전력전자학회 2007년도 하계학술대회 논문집
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• pp.391-393
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• 2007

The rotor speed and flux information is most important in the vector control. The accuracy of flux observers for induction machine inherently depends on parameter sensitivity. The control strategy is using online flux observer for flux estimation. In the proposed system, the speed control characteristics using a online flux observer control isn't affected by a load torque parameter disturbance. Simulation results are presented to prove the effectiveness of the adaptive sliding mode controller for the drive variable load of induction motor.