• The Transactions of the Korean Institute of Power Electronics
• /
• v.6 no.6
• /
• pp.546-555
• /
• 2001

In this paper filtering techniques to reduce the adverse effects of motor leads on high-frequency PWM inverter fed AC motor drives are presented. The filter was designed to keep the motor terminal from the cable surge impedance to reduce overvoltage reflections ringing and the dv/dt, di/dt, at the motor terminals. Specially the output filter is used to limit the rate of the inverter output voltage and reduce common mode noise to the motor, The performance of the output filter is evaluated through simulations and experiment on PWM inverter-fed AC motor drive. An experimental PWM drive system reduction of conducted EMI was implemented on an available TMS320C31 microprocessor control board Finally, experimental result shows inverter output filter reduces more common mode voltage than low pass filter also reduce overoltage and ringing at the motor terminal.

• Aerospace Engineering and Technology
• /
• v.5 no.2
• /
• pp.67-76
• /
• 2006

This paper describes the analysis method to define the system specification for conducted EMI environment and verification method to evaluate the conducted EMI performance. Conducted EMI environment is characterized by the electrical power subsystem which is mainly issued by the switching circuit noise, common ground impedance coupling. To define and control these EMI problems, EMI assesment through system analysis are preceded at the early design phase and then EMI reduction methods are applied during the unit/system development phase. System EMC should be carefully controlled and designed in the consideration of EMC safety margin and its performance is fully evaluated at the whole development period.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2003.10a
• /
• pp.115-115
• /
• 2003

최근 회전기계에 대한 세계적인 기술추세를 볼 때 해를 거듭할수록 더욱 정밀해지고 고속화에 대한 요구가 한층 증대되고 있으며 이러한 측면에서 여러 분야에 우수한 장점을 지니고 있는 능동적 자기베어링의 회전축계 활용에 대한 연구가 활발히 진행되고 있다. 특히 프랑스를 중심으로 한 미국, 일본 등이 이에 대한 연구를 활발하게 수행하여 고속 공작기계 스핀들을 비롯한 고진공 펌프 및 각종 터어빈, 압축기 등에 실용화시키는 단계에 있다. 그러나 국내 관련기술에 대한 연구는 연구소, 학계를 중심으로 실험실적인 기초연구로서 부분적으로 수행하는 단계에 있으며 관련분야 활용을 위한 본격적인 연구는 수행되지 못하고 있는 실정이고 이를 실용화시키기 위한 일환으로 능동적 자기 베어링의 회전 축계를 구성하고 있는 요소기술 중 하나인 전력 증폭기의 개발이 이뤄져야 할 필요성이 있는데 본 논문에서는 네트웍 기반 전력 증폭기 개발을 시도하였다. 전력 증폭기는 크게 리니어 앰프와 스위칭 앰프로 구분된다. 리니어 앰프의 경우 회로가 간단하고 노이즈가 비교적 작다는 장점이 있지만 전력손실 및 발열이 크기 때문에 에너지 측면에서 저 효율이라는 점과 따로 방열판을 부착해야 한다는 단점을 가지고 있고, 스위칭 앰프의 경우 전력손실이 작은 반면, 회로가 비교적 복잡하고 노이즈의 발생 가능성이 높다는 단점이 있다. 본 논문에선 위 두 가지 방식을 혼합한 혼합형 전력 증폭기로 설계하였다. 또한 기존에 전력증폭기의 경우 상위 주제어기로부터 제어량을 아날로그 신호로 통신하기 때문에 발생할 수 있는 EMI 노이즈신호에 대한 대책을 세워야 하는데 본 연구를 통해 개발된 전력증폭기는 따로 보조제어기(TMS320LF2406A)를 두어 상위 주제어기에 전력증폭기의 상태값을 궤환할 수 있도록 명령 신호체계를 전체 시스템의 샘플링 시간을 고려하여 비교적 전송 속도가 빠른 CAN(Controller Area Network)으로 구축하여 주제어기와 전력 증폭기간에 양방향 통신이 가능하도록 하였다. 이로써 전력증폭기의 상태정보를 알 수 있다. 따라서 본 논문에서는 칩 설계기술의 발전으로 가격대 성능비가 우수한 DSP(TMS320LF2406A)를 이용하여 과거의 아날로그 방식의 명령신호체계를 디지털 신호체계로 바꿈으로써 네트웍을 통해 전력증폭기의 상태진단 가능성을 검증한다.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.37 no.3
• /
• pp.84-93
• /
• 2000

In PWM voltage source inverters operated by conventional switching method, the dead time is inserted in switching signals to prevent tile short circuit of the DC voltage source. The dead time causes detrimental effects to the control performance of the inverter system. So we need to compensate the dead time effects. And the dead time minimization switching method can be considered as the best way to avoid the dead time effects fundamentally. In this paper, a new switching strategy is proposed which is a kind of dead time minimization switching methods. According to the proposed switching method, very short dead time is adopted in only once when the current polarity is changing. And the adopted dead time is equal to the turn off time of the swtiching device or shorter than it. As the proposed method can be done with the polarity information of the reference current in case that the output current of the inverter is controlled, it is easy to solve some problems in comparison with the case that the real current is used to get the polarity changing time； level detection difficulty, noise problem and so on

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.19 no.4
• /
• pp.1024-1030
• /
• 2015

Safety and security system have been internationally enhanced in a field of shipping logistics. Accordingly, techniques for safety and security have been studied steadily. The need of portable radiation detection device is increasing by the search of the container is enhanced. In this paper, we propose a study to improve the life of the system and the realization of portable radiation detection device based on Cortex-A9. Configuration of a portable radiation detection device is configured largely to an analog board and the digital platform and the sensor module. The power used in each stage of the analog board is varied. Uses a switching regulator to use various power supply thereby to generate an error result and cause the switching noise. It is proposed to reduce the power consumption reducing technique for the study.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.19 no.7
• /
• pp.100-106
• /
• 2005

Generally, high frequency switching DC-DC converter that DC power supply for discharge lamp drive to generate ultraviolet rays(UV) is acted by hard switching mode is used. Therefore in this paper, wish to mix first existent first-side status phase shift PWM DC-DC converter and posing secondary-side status phase shift PWM DC-DC converter by high frequency link DC-DC converter that use soft switching circuit technology and develop DC power supply for discharge lamp drive. DC power supply driving Discharge lamp proposed describe validity through simulation and an experiment.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.8 no.1
• /
• pp.89-97
• /
• 2003

High frequency common mode voltage produced by PWM inverter fed Induction motor is a major cause of conducted EMI, creation motor ground currents, bearing currents and other harmful products. The zero switching states of inverter control invoke large in comparison with the non-zero switching state of Inverter control. We proposed a common mode voltage reduction method based on sinusoidal PWM technique. PWM signal are generated by comparing respective sinusoidal reference signal with three triangular carrier wave displaced of 120$^{\circ}$. Simulation and experimenta1 result show that common mode voltages in the proposed PWM technique are reduced by approximate 66% more than conventional FWM technique.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.52 no.12
• /
• pp.99-108
• /
• 2015

The embedded microcontroller which is operated by the logic gates synchronized on the clock pulse, is gradually used as main controller of mission-critical systems. Severe electrical situations such as high voltage/frequency surge may cause malfunctioning of the clock source. The tolerant system operation is required against the various external electric noise and means the robust design technique is becoming more important issue in system clock failure problems. In this paper, we propose on-chip backup clock change architecture for the automatic clock failure detection. For the this, we adopt the edge detector, noise canceller logic and glitch-free clock changer circuit. The implemented edge detector unit detects the abnormal low-frequency of the clock source and the delay chain circuit of the clock pulse by the noise canceller can cancel out the glitch clock. The externally invalid clock source by detecting the emergency status will be switched to back-up clock source by glitch-free clock changer circuit. The proposed circuits are evaluated by Verilog simulation and the fabricated IC is validated by using test equipment electrical field radiation noise

• Journal of Advanced Marine Engineering and Technology
• /
• v.18 no.2
• /
• pp.75-82
• /
• 1994

The existence of peroodic impulse noises in distribution line carrier (DLC) communication system is known to be the most serious obstacle for improving DLC communication quality in reliability and capacity. From the spectral points, impulse noises can be divided into baseband type and modulation type the noise width of whichs are much different each other. With each nose type, this study presents the basic characteristics in relation to what they originate from and how their spectrum properties are revealed. The baseband type impulse noise is normally caused from thyristor circuit running with low switching speed and the modulation type noise from the circuit of switching power supply. The base wave of modulation noise is shown to be the pulsuatic charging current to primary condenser in switching power circuit. The study result indicates also that placing the DLC carrier frequency away the band predominated by modulated noise especially from RCC type switching power circuit is very important in DLC design.

• Proceedings of the KIEE Conference
• /
• 2003.07b
• /
• pp.1145-1147
• /
• 2003

본 논문에서는 신경망을 이용한 리럭턴스 동기 전동기(Reluctance Synchronous Motor, RSM)의 자속 보상에 대한 알고리즘을 제시한다. 리럭턴스 동기 전동기의 안정적인 운전을 위해서는 자속 정보가 필수적이다. 그러나 실질적으로 추정된 자속은 스위칭 노이즈 등의 성분을 포함하고 있어서 정밀한 전동기 제어에 많은 문제점을 야기하고 있다. 특히 속도 센서없는 전동기의 운전이나 직접토크제어(Direct torque control, DTC) 등의 제어에 있어서는 자속의 노이즈 성분을 제거하기 위해서 여러 가지 필터들이 사용되고 있지만, 이러한 필터들은 위상지연과 진폭 보상이 필연적으로 이루어져야한다. 이에 따라 본 연구에서는 1.0[Kw] RSM의 자속보상을 위해 신경망을 사용하고, 제시된 자속 보상방법의 타당성을 위해서 속도센서없는 직접토크 제어를 이용하여 전동기의 동특성을 검증하였다.