• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.95-97
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• 2006

This paper investigates the field weakening operation of a five-phase IPMSM(inner permanent magnet synchronous motor). The five-phase motor can supply sinusoidal voltage and third harmonic voltage because of more freedom of control. This paper present field weakening algorithm and experimental results for five-phase IPMSM which has trapzoidal back-EMF and concentrate winding to prove the validity of the proposed algorithm.

• Journal of Electrical Engineering and Technology
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• v.5 no.4
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• pp.623-630
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• 2010

This paper presents the implementation and characteristic analysis of a drive system for a three-phase permanent magnet motor with independent excitation winding that is applicable for electric bicycles. The design features improves the phase current waveform, output power, and torque by using advance angle control. This adjusts the phase angle of each phase current in relation to back EMF. In addition, a DC-side PI current control is performed through PWM generation circuit using a low-cost one-chip microcontroller and a CPLD chip, resulting in reduced system costs. Finally, the validity of this control scheme for driving electric bicycles and output/torque improvement characteristics are verified through analysis and experimental results.

• Journal of Power Electronics
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• v.10 no.6
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• pp.717-723
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• 2010

This paper proposes a new torque control algorithm for BLDC motors to get the maximum torque in the high speed region. The delay of the phase currents is severe due to the stator reactance. The torque fluctuations of BLDC motors increase and the average torque is decreases due to a slow rise in the phase current when compared to the back EMF. In this paper, the phase current of BLDC motors under the high speed condition is analyzed and a torque maximization control is developed on the basis of using numerical analysis. Computer simulations and experimental results show the usefulness of the proposed control algorithm.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.610-614
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• 2000

Torque pulsation generated in every commutation period is the main drawback of BLDC motor which deteriorates the precision of BLDC motor. Many methods to solve this problem have been proposed. In this paper a new torque model considered with decaying phase back EMF is introduced and from it the cause of torque pulsation in commutation period is analyzed. Form this analysis new algorithms to reduce the torque pulsation by commutation time are proposed and with simulation the validity is verified.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.566-569
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• 1987

The primary difficulties encountered in the use of step motors are underdamped response when stopping at a specified position and dynamic instability during high-speed slewing. This paper proposes a speed and position detection scheme using the back EMF generated by the rotating permanent magnet field of a two-phase 1.8.deg. hybrid step motor, and presents its application to the state-variable feedback control of the hybrid step motor. All simulation results in a single step response show that the hybrid step motor performances such as peak overshoot and settling time are greatly improved.

• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.337-341
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• 1998

Brushless DC motors have trapezoidal back emf waveform. Generally, because it is drived by a voltage source inverter, the ideal rectangular phase current is not available and therefore produce torque ripple. In this paper, the torque ripple due to commutation is analysed and the practical method that can reduce the torque ripple is proposed. Simulation and experimental results show the effectiveness of the proposed method.

• Proceedings of the KIEE Conference
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• 2002.11d
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• pp.67-69
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• 2002

This paper present increasing of Power density of slotless PMLSM by inserting core between phase winding. PM width is changed and PM is divided into two part to reduce and eliminate high order space harmonics affecting torque ripple. Flux density, back EMF, inductance, thrust, normal and detent force are computed by 2D FEM, and analysis values are compared with each other.

• Journal of international Conference on Electrical Machines and Systems
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• v.3 no.1
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• pp.20-26
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• 2014

To enhance torque density by harmonic current injection, optimal slot/pole combinations for five-phase permanent magnet synchronous motors (PMSM) with fractional-slot concentrated windings (FSCW) are chosen. The synchronous and the third harmonic winding factors are calculated for a series of slot/pole combinations. Two five-phase PMSM, with general FSCW (GFSCW) and modular stator FSCW (MFSCW), are analyzed and compared in detail, including the stator structures, star of slots diagrams, and MMF harmonic analysis based on the winding function theory. The analytical results are verified by finite element method, the torque characteristics and phase back-EMF are also taken into considerations. Results show that the MFSCW PMSM can produce higher average torque, while characterized by more MMF harmonic contents and larger ripple torque.

• Journal of Magnetics
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• v.19 no.1
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• pp.90-100
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• 2014

Position estimation that uses only active phase voltage and current is presented, to perform high accuracy position sensorless control of a SRM drive. By extracting the amplitude of the first switching harmonic terms of phase voltage and current for a PWM period through Fast Fourier Transform (FFT), the flux-linkage and position are estimated without external hardware circuitry, such as a modulator and demodulator, which result in increased cost, as well as large position estimation error, produced when the motional back EMF is ignored near zero speed. A two-phase SRM drive system, consisting of an asymmetrical converter and a conventional closed-loop PI current controller, is utilized to validate the performance of the proposed position estimation scheme in comprehensive operating conditions. It is shown that the estimated values very closely track the actual values, in dynamic simulations and experiments.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.11
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• pp.1894-1899
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• 2016

In this paper, because the position sensor represents the important factor in BLDC (Brushless DC) motor drives, BLDC motor is necessary that the three Hall-sensors evenly be distributed around the stator circumference in case of the 3 phase motor. The Hall-sensor is set up in this motor to detect the main flux from the rotor. So the output signal from Hall-sensor is used to drive IGBT to control the stator winding current. However, in case of breakdown Hall sensor, we research that the estimation algorithm of Hall sensor signal to detect rotor position and for the speed feedback signals with BLDC motor whose six stator and two rotor designed. In addition, this paper presents a sensorless speed control of BLDC Motor using terminal voltage of the one phase. Rotor position information is extracted by indirectly sensing the back EMF from only one of the three terminal voltages for a three-phase BLDC motor.