Fluxgate형 지자기 센서 및 응용회로 개발에 관한 연구

문태정,김재홍 慶南專門大學 2001 論文集 Vol.29 No.1

MVDC급 Fluxgate 방식 전류센서의 여자권선 턴수에 따른 선형성 분석

조주희,김수용,이승재,김병택 대한전기학회 2023 전기학회논문지 P Vol.72 No.4

Research on Medium voltage DC converter station is actively developed to construct a DC power grid. In addition, for stable operation of the converter station, sensor technology is essential to precisely measure and analyze the voltage and current of the electrical devices in the converter station. This paper is about a fluxgate-type current sensor to measure DC current in an MVDC power grid. Three-dimensional finite element analysis was applied to analyze the linearity of a fluxgate type current sensor according to the number of excitation winding turns. The number of excitation winding turns must be sufficient so that the ring core can operate with high permeability even with small changes in primary current.

자성체 코어 형상에 따른 마이크로 플럭스게이트 센서의 검출 특성

조중희,최원열 한국전기전자재료학회 2004 전기전자재료학회논문지 Vol.17 No.5

A fluxgate magnetic sensor consists of a solenoid excitation coil, pick-up coil, and magnetic core. We presents the effect of magnetic core shape in a micromachined fluxgate sensor. To observe the performance of fluxgate sensor with magnetic core side width and gap, side width of 125 ${\mu}{\textrm}{m}$, 250 ${\mu}{\textrm}{m}$, and 500 ${\mu}{\textrm}{m}$ were designed in a rectangular-ring shaped core and the gaps of 0 ${\mu}{\textrm}{m}$, 50 ${\mu}{\textrm}{m}$, and 100 ${\mu}{\textrm}{m}$ were also fabricated in a racetrack shaped core. The solenoid coils and magnetic core were separated by benzocyclobutane(BCB) which had high insulation and good planarization characters. Copper coil patterns of 10 ${\mu}{\textrm}{m}$ width and 6${\mu}{\textrm}{m}$ thickness were electroplated on Ti(300 $\AA$) / Cu(1500 $\AA$) seed layers. 3 ${\mu}{\textrm}{m}$ thick N $i_{0.8}$F $e_{0.2.}$(permalloy) film for the magnetic core was also electroplated under 2000 gauss to induce the magnetic anisotropy. The magnetic core had the high DC effective permeability of ∼1,300 and coercive field of ∼0.1 Oe. Because the magnetic cores of 500 ${\mu}{\textrm}{m}$ side width and 0 gap had a low magnetic flux leakage, high sensitivity of ∼350 V/T were measured at excitation condition of 3 $V_{P-P}$ and 2 MHz square wave. The power consumption of ∼14 ㎽ was measured. The fabricated fluxgate sensor had the very small actual size of 3.0${\times}$1.7 $\textrm{mm}^2$. When two fluxgates were perpendicularly aligned in terrestrial field, their two-axis output signals were very useful to commercialize an electronic azimuth compass for the portable navigation system.m.m.m.

폐자로를 형성한 마이크로 플럭스게이트 자기 센서

최원열,황준식,강명삼,최상언 한국마이크로전자및패키징학회 2002 마이크로전자 및 패키징학회지 Vol.9 No.3

본 논문은 인쇄회로 기판 (PCB)에 내장된 마이크로 플럭스게이트 자기센서 (micro fluxgate magnetic sensor)에 대한 것으로써, 센서의 제작과 폐자로 형성에 따른 자계 검출 특성 변화에 관한 것이다. 이를 위해 연자성 코아를 사각링 형태와 두개의 바 (bar)형태로 각각 구현하였다. 제작을 위해 모두 5층의 기판을 적층하였으며, 가운데 (3번째) 기판을 자성체 코아로, 자성체 코아 외부 (2번째와 4번째) 기판을 여자코일로, 최외부 (1번째와 5번째) 기판을 검출코일로 제작하였다. 연자성 코아로는 약 100,000의 큰 DC 투자율 (permeability)을 갖는 코발트 (Co)가 주성분인 아몰퍼스 재료를 사용하였으며, 여자코일과 검출코일은 구리를 사용하였다. 제작된 자기센서는 여자조건이 360 KHz, $3V_{p-p}$의 구형파일 경우에 사각링 형태의 연자성 코아를 갖는 자기센서에서는 540V/T로 매우 우수한 감도를 보이고 있으며, -100 $\mu$T~+100 $\mu$T 영역에서 매우 우수한 선형특성을 보이고 있다. 자기 센서의 크기는 $7.3 \times 5.7\textrm{mm}^2$ 이며, 소비전력은 약 8 mW이다. 이런 초소형 자기센서는 휴대용 navigation 시스템, telematics, VR 게임기 등 다양한 응용분야에 적용할 수 있다. This paper presents a micro fluxgate magnetic sensor in printed circuit board (PCB). In order to observe the effect of the closed magnetic path, the magnetic cores of rectangular-ring and two bars were each fabricated. Each fluxgate sensor consists of five PCB stack layers including one layer magnetic core and four layers of excitation and pick-up coils. The center layer as a magnetic core is made of a Co-based amorphous magnetic ribbon with extremely high DC permeability of ~100,000. Four outer layers as an excitation and pick-up coils have a planar solenoid and are made of copper foil. In case of the fluxgate sensor having the rectangular-ring shaped core, excellent linear response over the range of -100 $\mu$T to + 100 $\mu$T is obtained with 540 V/Tsensitivity at excitation square wave of 3 $V_{p-p}$ and 360 KHz. The chip size of the fabricated sensing element is $7.3 \times 5.7\textrm{mm}^2$. The very low power consumption of ~8 mW was measured. This magnetic sensor is very useful for various applications such as: portable navigation systems, telematics, VR game and so on.n.

High Sensitivity Micro-fabricated Fluxgate Sensor with a Racetrack Shaped Magnetic Core

Won-Youl Choi,김소정 한국전기전자재료학회 2005 Transactions on Electrical and Electronic Material Vol.6 No.3

We present a micro fluxgate magnetic sensor having solenoid coils and racetrack shaped magnetic core, which was designed to decrease the operating power and magnetic flux leakage. Electroplated copper coils of 6 μm thickness and the core of 3 μm thickness were separated by benzocyclobutane (BCB) having a high insulation and good planarization characters. Permalloy (Ni0.8Fe0.2) as a magnetic core was also electroplated under 2000 gauss to induce the magnetic anisotropy. The core had the high DC effective permeability of ~1,300 and coercive field of ~0.1 Oe. The fabricated fluxgate sensor had the very small actual size of 3.0 ´ 1.7 mm2. The fluxgate sensor with a racetrack shaped core had the high sensitivity of ~350 V/T at excitation condition of 3 VP-P and 2 MHz square wave. When two fluxgates were perpendicularly aligned in terrestrial field, their two-axis output signals were very useful to commercialize an electronic azimuth compass for the portable navigation system.

MEMS 공정 제작방법에 의한 솔레노이드형 여자 코일과 검출코일을 사용한 마이크로 플럭스게이트 센서

나경원,박해석,심동식,최원열,황준식,최상언 한국전기전자재료학회 2003 전기전자재료학회논문지 Vol.16 No.2

This paper describes a MEMS-based micro-fluxgate magnetic sensing element using Ni$\_$0.8/Fe$\_$0.2/ film formed by electroplating. The micro-fluxgate magnetic sensor composed of a thin film magnetic core and micro-structure solenoids for the pick-up and the excitation coils, is developed by using MEMS technologies in order to take advantage of low-cost, small size and lower power consumption in the fabrication. A copper with 20${\mu}$m width and 3${\mu}$m thickness is electroplated on Cr (300${\AA}$) / Au (1500${\AA}$) films for the pick-up (42turn) and the excitation (24turn) coils. In order to improve the sensitivity of the sensing element, we designed the magnetic core into a rectangular-ring shape to reduce the magnetic flux leakage. An electroplated permalloy film with the thickness of 3${\mu}$m is obtained under 2000 gauss to induce magnetic anisotropy. The magnetic core has the high DC effective permeability of ~1,100 and coercive field of ~0.1 Oe. The fabricated sensing element using rectangular-ring shaped magnetic film has the sensitivity of about 150 V/T at the excitation frequency of 2 MHz and the excitation voltage of 4.4 V$\_$p p/. The power consumption is estimated to be 50mW.

PCB 기판에 내장된 마이크로 플럭스게이트 센서

최원열,황준식,강명삼,최상언 한국전기전자재료학회 2002 전기전자재료학회논문지 Vol.15 No.8

This paper presents a micro fluxgate sensor in printed circuit board (PCB). The fluxgate sensor consists of five PCB stack layers including one layer magnetic core and four layers of excitation and pick-up coils. The center layer as a magnetic core is made of a micro patterned amorphous magnetic ribbon and the core has a rectangular-ring shape. The amorphous magnetic core is easily saturated due to the low coercive field and closed magnetic path for the excitation field. Four outer layers as an excitation and pick-up coils have a planar solenoid structure. The chip size of the fabricated sensing element is 7.3$\times$5.7$\textrm{mm}^2$. Excellent linear response over the range of -100$\mu$T to +100$\mu$T is obtained with 540V/T sensitivity at excitation square wave of 3 $V_{p-p}$ and 360kHz. The very low power consumption of ~8mW was measured. This magnetic sensing element, which measures the lower fields than 50$\mu$T, is very useful for various applications such as: portable navigation systems, military research, medical research, and space research.h.

Optimization of Operation Frequency of Orthogonal Fluxgate Sensor Fabricated with Co Based Amorphous Wire

Young-Hak Kim,Yongmin Kim,Chang-Seob Yang,Kwang-Ho Shin 한국자기학회 2013 Journal of Magnetics Vol.18 No.2

We present how to optimize the operation condition including frequency of the orthogonal fluxgate sensor in this paper. The orthogonal fluxgate sensor was fabricated with a Co-based amorphous wire with 10 mm long and 100 μm in the diameter and a 270-turn pickup coil wound on the amorphous wire. In order to investigate the frequency dependence of the sensitivity, output spectra of the sensor which was connected by using a coaxial cable with various lengths of 0.5-5 m were measured with a RF lock-in amplifier. The maximum sensitivities were obtained at different frequencies according to coaxial cable lengths. It was found that the optimal operation frequencies, at which maximum sensitivities were appeared, were almost identical to the frequencies of impedance resonance. The maximum sensitivity and optimal operation frequency were 1.1 V/Oe (? 11000 V/T) and 1.25 MHz respectively.

High Sensitivity Micro-fabricated Fluxgate Sensor with a Racetrack Shaped Magnetic Core

Choi, Won-Youl,Kim, So-Jung The Korean Institute of Electrical and Electronic 2005 Transactions on Electrical and Electronic Material Vol.6 No.3

We present a micro fluxgate magnetic sensor having solenoid coils and racetrack shaped magnetic core, which was designed to decrease the .operating power and magnetic flux leakage. Electroplated copper coils of $6\;{\mu}m$ thickness and the core of $3\;{\mu}m$ thickness were separated by benzocyclobutane (BCB) having a high insulation and good planarization characters. Permalloy $(Ni_{0.8}Fe_{0.2})$ as a magnetic core was also electroplated under 2000 gauss to induce the magnetic anisotropy. The core had the high DC effective permeability of $\~1,300$ and coercive field of $\~0.1$ Oe. The fabricated fluxgate sensor had the very small actual size of $3.0\times1.7\;mm^2$. The fluxgate sensor with a racetrack shaped core had the high sensitivity .of $\~350$ V/T at excitation condition of 3 $V_{P-P}$ and 2 MHz square wave. When two fluxgates were perpendicularly aligned in terrestrial field, their two-axis output signals were very useful to commercialize an electronic azimuth compass for the portable navigation system.

Orthogonality Correction for Concentric Tri-axis Fluxgate Magnetometer

Xuan Thang Trinh,Jen-Tzong Jeng,Chih-Cheng Lu,Van Su Luong 한국자기학회 2019 Journal of Magnetics Vol.24 No.2

In this work, a compact tri-axis fluxgate magnetometer comprising a single magnetic core was implemented and the effectiveness of the orthogonality correction algorithm was demonstrated. The vector magnetometer consists of a tube-shaped soft magnetic flux chopper with a toroidal coil and three concentric pick-up coils. The tube-shaped flux chopper with magnet wires has the total dimension of 10 mm × 10 mm. The number of turns of the pick-up coils X-, Y-, and Z- are 110, 110 and 150, respectively. The center of flux chopper is also the geometric center of the three pick-up coils, of which the sensing directions are aligned along the Cartesian axes. The concentric design ensures a single field point for the three sensing axes. When using the tri-axis fluxgate magnetometer as an electronic compass, the geomagnetic field components converted from the demodulated outputs of the sensing coils shows high accuracy by using the voltage-to-field transfer matrix. The proposed fluxgate system is suitable for applications related to high-accuracy static magnetic field measurement, e.g. geomagnetic field monitoring, electronic compass, and magnetic field mapping.