• 해양환경안전학회지
• /
• 제25권6호
• /
• pp.802-808
• /
• 2019

직류전동기는 속도제어가 간단하고, 출력 토크특성이 우수한 장점으로 윈치나 카고 펌프 모터 등으로 선박에서 많이 사용되었으며, 전기추진선박이 도입된 초기에는 선박용 추진전동기로도 적용되었다. 하지만 브러시와 정류기와 같은 기계적 정류장치의 단점으로 인해 최근에는 직류전동기와 전기적인 특성은 매우 유사하지만 기계적인 정류장치를 설치하지 않고 반도체 소자를 이용한 전자적인 정류장치를 사용하는 브러시리스 직류전동기의 사용이 증가하고 있다. 기존의 브러시리스 직류전동기를 구동하기 위한 인버터 시스템은 2상여자방식을 사용하므로 역기전력파형이 사다리꼴모양으로 되며, 이로인해 전류가 흐르는 권선이 바뀌는 상전류 전환 구간에서 고조파와 토크리플이 발생하게 된다. 이러한 고조파와 토크리플을 저감하기 위한 다양한 방안이 연구되어 발표되었으며, 본 연구에서는 전력분석프로그램을 이용하여 브러시리스 직류전동기의 구동회로에 비례적분 속도전류제어기 알고리즘을 구현한 Cascaded H-Bridge 멀티레벨 인버터를 적용하였다. 모델링한 브러시리스 직류전동기의 시뮬레이션을 통해 제안하는 전동기의 구동방식을 적용하는 경우에 기존의 구동방식에 비해 전동기 입력측 전압파형 개선과 고조파 및 토크리플이 현저히 저감되는 결과를 확인할 수 있었다.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 1996년도 창립기념 전력전자학술발표회 논문집
• /
• pp.13-16
• /
• 1996

A new instantaneous torque control technique is presented for a high performance control of a permanent magnet synchronous motor. Using the model reference adaptive system technique, the linkage flux of the motor is estimated and the torque is instantaneously controlled by the proposed torque controller combining with a variable structure control and space vector PWM. The proposed torque control provides the advantage of reducing the torque pulsation caused by the flux harmonics. This control strategy is applied to the high torque PM synchronous motor drives for direct drive systems and is implemented by using a software of the DSP TMS320C30. The experiments are carried out for this system and the results well demonstrate the effectiveness of the proposed control.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 하계학술대회 논문집 B
• /
• pp.1206-1208
• /
• 2001

Direct torque control(DTC) of AC motor has the fast torque and flux dynamic responses even though it has very simple scheme to implement. DTC is also very simple in its implementation because it needs only two hysteresis comparators and switching vector table for both flux and torque control. The amplitude of hysteresis band greatly influences on the drive performance such as flux and torque ripple, switching frequency and current harmonics. Therefore, authors analysis flux and torque hysteresis bands is suggested considering switching frequency and harmonic distortion of currents.

• 대한전기학회논문지
• /
• 제40권2호
• /
• pp.162-172
• /
• 1991

In proportion to the capacity enlargement of the induction motor system controlled by current source inverter, the capacitance of the commutating capacitor is enlarged and then the spike value of output voltage is increased at the moment of charge and discharge. Moreover, the output currnet includes a number of harmonic components. Such voltage spike and harmonics generate the torque ripple and lead to bad effects on the performance of the induction motor. In this study, all the harmonics excluding 17th and 19th harmonics were mostly elimunated by adopting 18-phase Triple High Frequency Current Source Inverter(HFCSI), and the spike component of output voltage was reduced by adding the Voltage Clamping Circuit(VCC). As a result, the torque ripple and the commutation loss were reduced and the performance of the system was improved. Experiments for speed control were carried out in the tripple current source inverter system for induction motor drive. Overall system was controlled by ONE CHIP MICROCOMPUTER(INTEL 8751). Control circuits were simplified and good experimental results in the constant V/F control were obtained due to the flexibility of the microcomputer.

• 대한전기학회논문지
• /
• 제38권4호
• /
• pp.269-278
• /
• 1989

When the induction motor is operated by CSI, the commutation capacitance in the CSI circuit is increased according to the increase of large capacitor system. The output voltage spikes are generated at the moment of charge and discharge of the commutation capacitor. Also, since output current comprise a great number of harmonics, torque ripples of the motor are generated, having bad effects on the motor. In this study, by adopting the 18-phase multiple high Frequency Current Source Inverter (HFCSI), torque ripples generated by the voltage spikes are mostly eliminated except the 17th and 19th harmonics. To reduce the voltage spikes comprised in the output voltage, particularly, the methods of eliminating the cause of bad effect upon the motor are proposed in this paper. In the proposed method, by using additional voltage Clamping Curcuit (VCC), it is possible to select the values of commutation capacitor energy loss in commutating, the commutating capacitor, and the capacitor in the clamping circuit.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.135-137
• /
• 2001

In slotless synchronous motor for precise position and speed control, eccentricity of rotor mass cause torque ripple, speed ripple and harmonics of back emf. This paper deals with magnetic field and characteristic analysis for ring type slotless synchronous motor by using analytical method. And then, speed and back emf harmonics are analysed.

• Journal of Magnetics
• /
• 제19권4호
• /
• pp.411-417
• /
• 2014

This paper presents the shape optimization of a permanent magnet synchronous motor to reduce the torque ripple and iron loss. Specifically, the harmonics of the electromotive force and cogging torque are decreased by adjusting the permanent magnet arrangement and non-uniform air gap length. In addition, an additional flux path along the q-axis is proposed with a unique rotor shape to increase the q-axis inductance and reluctance torque. The improvement in the performance of the proposed model is verified with simulated and experimental results.

• 전력전자학회논문지
• /
• 제7권2호
• /
• pp.137-148
• /
• 2002

직접토크제어 기법은 벡터제어계 설계 및 운전시 요구되는 복잡한 좌표변환과 전류제어루프가 불필요하며, 빠른 토크응답을 얻을 수 있기 때문에 벡터제어 기법에 버금가는 유도전동기의 고성능 제어기법으로 인정되고 있다. 본 논문에서는 직접토크제어 기법 적용시 중요한 어려움의 하나로 지적되고 있는 저속영역에서의 자속저하 및 이로 인한 전류고조파의 증가 문제를 해결하기 위한 대책으로서 퍼지 가변 스위칭섹터 기법과 이 기법의 실시간 적용을 위한 실현방법을 제안하였다. 제안된 스위칭섹터 기법을 포함한 유도전동기 제어시스템의 실험적 성능을 고찰하기 위하여 DSP를 이용한 제어보드를 제작하였다. 시뮬레이션과 실험 결과는 제안된 퍼지 가변스위칭 섹터 기법을 도입함으로서 유도전동기 드라이브의 성능이 현저히 개선됨을 보여준다.

• 전력전자학회논문지
• /
• 제18권6호
• /
• pp.573-578
• /
• 2013

In the case of the Back EMF voltage contains the harmonics, the motor torque ripple and vibration is occurred by the current pulsation, because IPMSM control algorithm is the model which is assumed that it contains a sinusoidal Back EMF voltage. To improve ride quality, in the case of IPMSM for EV, improving the torque control characteristics is necessary. Therefore, there is a need to minimize the influence of the harmonics. In this paper, the investigation to decrease the current distortion factor has been performed for improving torque control characteristics by applying the non-sinusoidal Back EMF to IPMSM model.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
• /
• 제48권11호
• /
• pp.646-654
• /
• 1999

This paper deals with PWM patterns for harmonic reduction in inverter fed traction motors and the gear changing techniques for the variable speed drive of traction motor. GTOs are used as switching device of inverter because traction motor is a large load. To derive PWM rattern which can minimize the harmonics with the limited switching frequency, the output current and torque characteristic of SPWM and SHE PWM was analyzed. GTO inverter used for traction motor drive includes harmonics in the output current and torque by the limitation of switching frequency. However, the hybrid PWM method that adopt SPWM in the range of low frequency and SHE PWM in upper frequency range can achieve less harmonic characteristics in GTO inverters. If the traction motor is driven in variable speed by the proposed PWM pattern, 7 times of gear changing is needed. At the instant of the mode change, magnetic flux and torque may be altered and the large current flow. To reduce such an undesirable transient behavior, it is also presented the technique for the gear changing of inverter fed traction motor drive operated with the hybrid PWM. The results are verified by simulations and experiments.