• 한국시뮬레이션학회:학술대회논문집
• /
• 한국시뮬레이션학회 2001년도 The Seoul International Simulation Conference
• /
• pp.205-208
• /
• 2001

A lumped electrical circuit is an approximate representation of the field within a curtain frequency range. The finite element modelling is a synonym of the equivalent circuit. The electric conduction field and electric potential wave field have been modelled by an admittance network and an LC low-pass filter network. Here in the present paper, the equivalent magnetic circuit representation is created for a magnetostatic field by the finite element modelling in two dimension.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
• /
• pp.227-232
• /
• 2003

Usually, the thrust of a Linear Pulse Motor(LPM) is calculated by magnetic equivalent circuit modelling method. Analytical thrust deviation exists to calculating magnetic flux density by using Permeance Modelling Method, Finite Element Method, and Velocity Electric Motive Force Method. For calculating accuracy thrust by using these every method, the thrust is calculated and compared by Lorentz Force Method, Magnetic Coenergy Method, and Maxwell correspondence force Method. And that becomes important factor at the comparison of each capacity and parameter of motor. So this study wants to compare and analyze measurement data and calculating data of the static thrust of LPM. and then we can get more accuracy method, calculating the static thrust of LPM.

• Journal of Advanced Marine Engineering and Technology
• /
• 제34권8호
• /
• pp.1195-1202
• /
• 2010

2회로정수 등가회로에 의한 3상유도전동기 모델링 방식은 정격제원만으로 모의운전 특성을 효과적으로 재현하는 장점이 있으나 여자전류의 생략으로 역률 지시에서의 오차가 커지는 문제가 있다. 본 논문에서는 이러한 오차를 해소하기 위한 방안으로 정격 역률이 실제 전동기와 일치되는 조건에서 부하 크기와 관련이 없는 보상전류의 직교 성분을 해석한 후 이를 2회로정수의 부하 전류에 합성하는 방식을 제시하였다. 또한 정격제원으로부터 보상전류와 보정된 값의 전동기 전류, 토크 및 역률을 출력하는 전체적인 과정을 계산하는 연산모듈을 구성하였으며 실제 전동기의 제원을 모듈에 입력하여 나타나는 시뮬레이션 결과를 확인하였다. 이로부터 정격 운전점에서 주요 운전값이 실제 전동기와 일치할 뿐 아니라 슬립에 따른 전체 운전 영역에서 제시된 모듈의 출력 결과가 2회로정수의 경우보다 개선된 모의 특성을 나타내었다.

• Journal of Computing Science and Engineering
• /
• 제8권3호
• /
• pp.129-136
• /
• 2014

This paper presents the equivalent circuit modelling and eigenfrequency analysis of a wideband robust capacitive radio frequency (RF) microelectromechanical system (MEMS) switch that was designed using Poly-Si and Au layer membrane for highly reliable switching operation. The circuit characterization includes the extraction of resistance, inductance, on and off state capacitance, and Q-factor. The first six eigenfrequencies are analyzed using a finite element modeler, and the equivalent modes are demonstrated. The switch is optimized for millimeter wave frequencies, which indicate excellent RF performance with isolation of more than 55 dB and a low insertion loss of 0.1 dB in the V-band. The designed switch actuates at 13.2 V. The R, L, C and Q-factor are simulated using Y-matrix data over a frequency sweep of 20-100 GHz. The proposed switch has various applications in satellite communication networks and can also be used for devices that will incorporate the upcoming IEEE Wi-Fi 802.11ad protocol.

• Journal of Advanced Marine Engineering and Technology
• /
• 제34권6호
• /
• pp.887-893
• /
• 2010

기관실 시뮬레이터에서 3상유도전동기에 대한 모델링을 단순하게 처리하는 경우에는 왜곡된 특성에 의해 각종 전기 기계적 모의 성능 수준이 크게 저하된다. 한편, 전동기 특성을 1, 2차 측 파라미터로 구분하는 기존의 등가회로 방식들은 복잡한 실험을 거치거나 상세 기술 자료가 확보되지 않고는 현장 전동기에 대한 회로에서의 파라미터 값들을 확정하지 못한다는 점에서 정격제원 정도만 주어지는 기관실 시뮬레이터의 개발 작업 환경에서는 사용할 수가 없다. 이러한 문제의 해결을 위해 본 논문에서는 최소 파라미터에 의한 전원 직결의 2 회로정수 방식 등가회로를 제시하였으며 이로부터 정격제원에 의해 회로정수가 결정되기까지의 조건과 과정 및 관련 식들을 해석하였다. 또한 실제 전동기에 이를 적용하여 얻어지는 특성곡선들을 통해 임의의 전동기에 대한 근사특성과 실용성을 확인하였다.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
• /
• 제49권6호
• /
• pp.380-386
• /
• 2000

This paper presents the mathematical modelling analysis of Brushless Synchronous Motor(BLSM). The dynamic and the steady state characteristics of BLSM are simulated and analyzed : electromagnetic torque, speed, line voltage, and current. We used mathematical modelling to model of BLSM with sinusoidal back EMF, namely the shaft transformation referencing rotor frame from a, b, c three to produce constant torque like synchronous motor. The experiment result has already similar to compare with simulation result : torque error about 7%, speed error about 5%. The validity of proposed modelling and analysis was confirmed by the experimental result.

• 전기학회논문지
• /
• 제66권4호
• /
• pp.629-635
• /
• 2017

Free-Flooded Ring (FFR) transducer array for use in Sonar system can be driven with large amplitude in a wide frequency band due to its structural characteristics, in which two resonances of a ring mode (1st radial mode) and an inner cavity vibration mode occur in a low frequency band. Since its sound wave generation characteristics are not influenced by the water pressure, the FFR transducer array is widely used in the deep sea. So FFR has been recognized as a low-frequency active sound source and has received much attention ever since. In order to utilize the FFR transducer array for SONAR systems in military and industrial applications, its equivalent electric circuit model is necessary especially to design the matching circuit between the driving power amplifier and the FFR transducer array. Thus this paper proposes the equivalent electric circuit model of FFR transducer array by using measured values of parameter, and suggest the improved method of parameter identification. Finally it verifies the effectiveness of the proposed circuit model of FFR transducer array by experimental measurements.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1994년도 하계학술대회 논문집 C
• /
• pp.1431-1434
• /
• 1994

The annular induction electromagnetic pump with maximum flowrate of $60{\ell}/min$ for the sodium coolant system of liquid metal fast breeder reacters has been designed using the equivalent circuit method. The final optimum values of geometrical and electromagnetic parameters were obtained for an annular induction pump from the relation of the electrical variables giving the developing force to the fluid and the pressure drops between both sides of the pump. The physical properties of the core, coil condoctor materials in the high temperature and pump cooling systems under operation have been taken into account in the design of the pump. The structural material were also selected considering the reaction with sodium and the magnetic field distortion.

• 센서학회지
• /
• 제15권1호
• /
• pp.34-39
• /
• 2006

This study provides the electrical model of combustible catalytic gas sensor. Physical characteristics such as thermal behavior, resistance change were included in this model. The finite element method analysis for sensor device structure showed that the thermal behavior of sensor is expressed in a simple electrical equivalent circuit that consists of a resistor, a capacitor and a current source. This thermal equivalent circuit interfaces with real electrical circuit using two parts. One is 'power to heat' converter. The other is temperature dependent variable resistor. These parts realized with the analog behavior devices of the SPICE library. The gas response tendency was represented from the mass transferring limitation theory and the combustion theory. In this model, Gas concentration that is expressed in voltage at the model, is converted to heat and is flowed to the thermal equivalent circuit. This model is tested in several circuit simulations. The resistance change of device, the delay time due to thermal capacity, the gas responses output voltage that are calculated from SPICE simulations correspond well to real results from measuring in electrical circuits. Also good simulation result can be produced in the more complicated circuit that includes amplifier, bios circiut, buffer part.

• 한국정보통신학회논문지
• /
• 제7권7호
• /
• pp.1514-1519
• /
• 2003

본 논문은 Custom Power의 입력 전압 Sag 보상을 위해 사용되는 3상 PWM Boost AC-AC 컨버터의 정적특성 및 동적 특성의 모델링 및 해석을 다룬다. 특히 회로 DQ 변환 기법을 사용하여 기본파 영역에서 시스템의 특성을 모두 포함하는 등가회로를 구하고, 전압이득과 입력 역률에 대한 해석적인 결과를 도출한다. 또한, 제어의 관점에서 유용한 일정한 동작 점 하에서의 선형화 된 상태방정식을 구한다. 끝으로, PSIM 시뮬레이션을 통하여 제안된 등가회로 모델링과 해석이 타당함을 확인하였다.