• Proceedings of the KIPE Conference
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• 2019.11a
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• pp.180-181
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• 2019

This paper proposes a method for improving the power quality of PMSG-based wind energy conversion system based on model predictive control in DC Microgrid. The MPC has a fast dynamic response. However, a large torque ripple deteriorating power quality is generated by a large and fixed switching period. On the other hand, the proposed method improves the power quality by setting the sampling time having zero torque error. The validity of the proposed method is verified through PSIM simulation.

• Journal of Electrical Engineering and Technology
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• v.4 no.1
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• pp.79-86
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• 2009

This paper presents a flyback technology in power conversion aimed at increasing efficiency and power density, reducing cost and using minimum components in AC-DC conversion. The proposed converter provides these features for square waveforms and constant frequency PWM. It is designed to operate in a wide input voltage range of 75-265VAC RMS with two output voltages of 5V and 20V respectively and full load output power of 5W. The proposed converter is suitable for high efficiency and high power density application such as LCDs, TV power modules, AC adapters, motor control, appliance control, telecom and networking products.

• Proceedings of the KIEE Conference
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• summer
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• pp.956-958
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• 2004

이 논문에서, 우리는 PMLSM(permanent magnet linear synchronous motor) 시스템에서 발생하는 detent force의 ripple 저감을 위한 진동보상 모델과 제안한 구조에 대한 제어기 설계 방법을 제시한다. 본 논문에서 고려되어진 제어기는 feedforward 보상기, PID feedback 보상기, 그리고 adaptive feedforward 보상기의 세 부분으로 구성된 제어기를 사용한다. 특히, PMLSM의 위치 정밀성 향상에 관한 연구를 위한 정밀 위치 제어의 문제는 PM으로 인해 발생하는 detent force이며, 이를 해결하기 위해 출력신호를 웨이블릿 변환하여 추출 후 이를 보상하였다.

• Journal of Power Electronics
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• v.14 no.4
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• pp.687-694
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• 2014

This paper focuses on the analysis and compensation of thrust ripples in permanent magnet linear synchronous motors (PMLSM). The main drawback in PMLSMs is the presence of thrust ripples, which are mainly due to the interaction between the permanent magnets and armature slotted core. These thrust ripples reduce the performance of the drive system in high precision applications especially at low speeds. This paper analyzes thrust ripples using the discrete wavelet transform. These undesired thrust ripples are compensated by using an adaptive feed forward controller. It is observed that this novel controller reduces about 65 percent of the thrust ripples. An extensive simulation is performed through MATLAB and it is validated through experimental results using a d-SPACE system with a DS1104 control board.

• Journal of Power Electronics
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• v.6 no.2
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• pp.114-120
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• 2006

This paper compares two types of direct torque controllers for permanent magnet synchronous motors(PMSMs). These controllers both use a single-chip FPGA(Field Programmable Gate Array) but have differing hardware configurations. One of the controllers was constructed by programming a soft-core CPU and hardware logic circuits written in VHDL(Very high speed IC Hardware Description Language), while the other was constructed of only hardware logic circuits. The characteristics of these two controllers were compared in this paper. The results show the controller constructed of only hardware logic circuits was able to shorten the control period and it was able to suppress the low torque ripple.

• Proceedings of the KIPE Conference
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• 2015.07a
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• pp.239-240
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• 2015

본 논문에서는 가정용 단상 계통연계 인버터의 전압손실과 직류링크측 맥동 전압을 고려한 배터리 공칭전압 설계법을 제안한다. 일반적으로 가정용 단상 계통연계 인버터는 3kWh 정도의 낮은 에너지용량을 갖는 배터리팩의 수명 관리상 배터리의 공칭전압은 48V정도로 낮게 설계된다. 단상계통연계형 인버터의 직류링크전압에는 필연적으로 기본주파수의 2배에 해당하는 맥동성분이 포함된다. 이 맥동성분은 계통연계시 전원측 전류에 저차 고조파를 생성하여 전력품질의 저하를 초래하게 된다. 따라서 직류링크측 맥동성분 간섭을 제거하기위한 피드포워드 제어방식을 채택한 단상계통연계형 인버터의 제어시스템을 수립하고, 인버터의 전압손실과 직류링크측 맥동전압을 고려한 배터리 공칭전압 설계법을 제안하며, 시뮬레이션을 통해 타당성을 검증한다.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.910-915
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• 2003

This paper describes the design of a 2-phase stepping motor driver using CPLD(Complex Programmable Logic Device). The driver IC such as L297 (SGS-Thomson Microelectronics), which is mostly used has some problems in PWM control because of the switching noise of power MOSFETs. It causes current ripple and acoustic noise. To improve theses characteristics, we proposed a new current control method that the output PWM frequency is almost constant using a digital filter. Also we proposed constant current method for 1-2 phase(half step) excitation. The proposed method is implemented with CPLD(Xilinx, XC9572-PC44). Experimental results show the effectiveness of the proposed method.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.6
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• pp.39-46
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• 2010

Linear induction motor is adopted as an actuator of the planar stage. An inherently poor characteristic at zero or ultra-low speed zone of the induction motor is remarkably improved due to a recent development of power electronic semiconductor technology and a spatial vector control theory. At present, a servo response speed of the induction motor reaches 90 percent of one of PM synchronous or BLDC motor. Specially, as a secondary of the induction motor can be constructed using uniform conducting sheets, there is no periodic force ripple as in PM motors. So, the induction motor can be superior to another driving means under a certain condition. This paper discusses the overall development procedure of non-contact planar stage with a big workspace using linear induction motors.

• Journal of Power Electronics
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• v.18 no.6
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• pp.1866-1878
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• 2018

This paper presents a neutral point deviation and ripple compensation control method for application to 3-level NPC converters. The neutral point deviation and its harmonic components are analyzed with a focus on the average current flowing through the neutral point of the dc-link. This paper also proposes a control scheme to compensate for the neutral point deviation and dominant harmonic components under generalized unbalanced grid operating conditions. The positive and negative sequence components of the pole voltages and ac input currents are employed to accurately explain the behavior of 3-level NPC converters. Simulation and experimental results are presented to verify the validity of the proposed method.

• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.396-397
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• 2019

본 논문은 유한요소 모델예측제어(FCS-MPC)의 샘플링 시간을 가변하여 표면부착형 영구자석 동기 전동기(SPMSM)의 토크 리플을 개선하고 스위칭 손실을 저감하는 가변 샘플링 시간이 적용된 모델예측제어 기법을 제안한다. 기존 FCS-MPC는 토크 리플을 저감하기 위해 고정 샘플링 시간을 짧게 설정하였다. 고정 샘플링 시간을 짧게 설정함에 따라, 전압벡터의 변경횟수가 증가하여 스위칭 손실이 증가하였다. 본 논문은 이러한 문제점을 해결하기 위해 가변 샘플링 시간이 적용된 FCS-MPC를 통해 토크 리플을 저감하고, 전압벡터의 변경횟수를 감소시켜 스위칭 손실을 저감하였다. 본 논문에서 제안하는 기법은 시뮬레이션을 통해 증명되었다.