Step-skew is a common technique for eliminating the cogging torque of target harmonic order in permanent magnet synchronous motors (PMSMs). However, when step-skew applied to rotor, not completely eliminated due 3-D leakage flux. Therefore, flux should be considered designing PMSM with reduction. The most accurate way consider perform finite element analysis (FEA), but it has disadvantage high computation time. To resolve this challenge, article proposes design method that utilizes transfer...

Urban lightweight electric vehicles (EVs) for personal mobility have the advantage of being convenient and economical. Vehicles with low vibrations high energy efficiency are suitable use as urban vehicles. The torque ripple motor that induces vibration EV can be improved by reducing harmonics magnetic flux density. an increasing at main operating points (MOPs) considering driving cycle. Through proposed design process, optimization was performed to improve harmonic characteristics a...

A magnetic field communication system utilizes induction to transmit data, providing a high quality wireless service in harsh environment whereas the previous has many problems. In general, is used surrounded by soil, metal, and fluid. power transfer transfers energy between coils at transmitter side receiver side. this paper, we propose new which consists of system.

In this study, the radial vibration of fractional-slot concentrated winding (FSCW) permanent magnet synchronous motor (PMSM) was analyzed according to pole/slot combination considering phase relationship modulated radial, tangential forces, and moment. First, calculate forces moment combination, amplitude force converted by air-gap electromagnetic density (AEFD) are analytically derived. Since lever arm effect varies tooth length, translated on yoke an equivalent Subsequently, analyze caused...

A new wireless communication system using a low frequency signal transmitted by current loop antennas is proposed. The range relatively small (about several meters) so that the included in near field of carrier signal. use magnetic fields makes it possible to provide high quality an unfavorable environment where metal or fluids are present. In addition, algorithms for transceivers this proposed carefully deal with energy consumption and interference which changes dramatically according...

This paper introduces the concept of a magnetic field area network (MFAN), which uses low-frequency magnetic-field signals by loop antennas. It has two layers, data link layer and physical layer. The properties enable these systems to operate through soil, rock, water medium boundary as well air although strength falls off rapidly. Additionally, Loop antennas make it possible implement communication systems. We have designed functions system including ARM7TDMI, FPGA, several peripheral devices.

최근 가축 전염병에 대한 확산과 인체 감염에 위험성 증대로 말미암아 질병 관리의 중요성이 커짐에 따라 생체 내의 상황을 실시간 감시할 수 있는 삽입형 센서 태그 기반 이력 관리 시스템에 관심이 커지고 있다. 이에 축사의 열악한 환경에서도 무선통신과 동시에 무선전력전송이 가능한 MFAN 기술과 배터리 없이 내에 삽입된 태그로부터 무선으로 데이터를 수집할 900MHz RFID 기술을 융합하여 MFAN/RFID 시스템을 개발하였다. 시스템은 융합 UHF 태그를 삽입하여 외부 환경의 영향을 받지 않고 체온 등 가축의 변화를 모니터링하는 시스템으로, 태그에게 공급할 전력을 확보하기 위해서 목 부위에 설치하는 통신 및 전력전송을 위한 중계기를 사용한다. 코디네이터는 노드와 리더가 융합된 거쳐 태그와 데이터 송수신한다. 코디네이터에 수집된 데이터는 인터넷을 통해 시스템으로 전달되어 관리된다. 본 시스템의 개발을 관리에 문제가 크게 개선될 것이라 기대된다. With the recent...

본 논문은 유도 모터의 진동을 저감하기 위한 최적의 동심 권선 구성 적용방법을 제안한다. 우선 진동 발생 원인을 규명하고 일반적으로 사용되는 중권 배치와 동심권 배치의 구조적 특징과 장단점을 설명했다. 또한, 동심권의 슬롯당 턴 수를 유지하면서 코일의 비율을 조절함에 따라 특성이 어떻게 바뀌는지 비교하였다. 이를 통해 저감을 배치가 결정되었다. 저감 효과를 검증하기 위해 기존의 중권과 제안된 동심권이 각각 적용된 37 ㎾급 모터에 대해 2차원 유한요소해석을 수행했다. 마지막으로 배치에 따른 전자기 성능 및 특성 비교를 검증하였다.

A wireless communication system using magnetic fields is a new technology for in harsh environments. The utilizes current loop antennas radiating on which signal loaded. target application of this monitoring the status buildings, bridges, underground pipes, etc. amount data required to be transferred not huge. However, property applications requires fast between coordinators and nodes are facilitated buildings bridges. So, multiple detection at one broadcasting from coordinator very crucial...

A more realistic and robust resource allocation mechanism for wireless networks is proposed which enables network systems to communicate efficiently combat harsh channels. In order a central spectrum moderator (CSM) allocate stations (WSTAs), overhead information requisite. new iterative version of the VCG (Vickrey-Clarke-Groves)-Kelly introduced in reduce amount by appropriate selection initial value bids playing an important role convergence performance. This uses prediction bid next...

The light-duty electric vehicles for personal mobility have a short driving range, but since they are city cars, convenience and economy must be considered. Therefore, the vibration of vehicle should small, energy efficiency high. torque ripple motor, which is one causes in vehicles, can reduced by improving harmonic characteristics motor. In this study, optimum design process proposed to improve high-efficiency vehicle, performed applying stator chamfer rotor notch structures. method shows...

우선 센서 네트워크 기술이 환경 감시나 재난 감시와 같은 다양한 용용 분야에 적용되면서 지중 환경에서의 무선통신에 대한 필요성이 증가하고 있다. 특히, 지중에서는 기존의 전자기파를 이용한 통신 방식이 비효율이기 때문에 그 대안으로서 자기장을 제시되었고, 최근 들어 자기장 국내 KS 규격으로 제정되었다. 본 논문에서는 제정된 매체 접근 제어(Media Access Control) 프로토콜의 성능을 분석 및 시뮬레이션 방법을 통해서 분석한다. As wireless sensor networks are applied to various applications such as environment monitoring and disaster sensing system, there increased needs for communication in underground environment. Since the previous technology using electromagnetic wave...

This paper discusses about the characteristics of magnetic field. Experiments are run to examine received signal strength in soil and metals compare rate attenuation field that electromagnetic wave. The results reveal has much lower path loss than