• 전력전자학회논문지
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• 제18권6호
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• pp.523-529
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• 2013

A sensorless speed control of a permanent magnet synchronous motor(PMSM) which utilizes MRAS based scheme to estimate rotor speed and position is presented. Considering an error between real and estimated rotor position values, a state equation of PMSM in the synchronous d-q reference frame is represented. A state equation of model system which uses estimated speed and nominal parameter values is expressed. To minimize the errors between the derivatives of d-q axis currents of real and model system, MRAS based adaptation mechanisms for the estimation of rotor speed and position are derived. On the other hand, for the acceleration stage of motor just before the sensorless operation, an acceleration scheme using only d-axis current control is proposed. To show the validity of the proposed scheme, experimental works are carried out and evaluated. During acceleration stage, the acceleration scheme using only d-axis current command shows good acceleration performance and controlled current level. For the sensorless operation, at low speed (5% of rated speed), a good performance is observed.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.720-723
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• 2005

Ship motion is a complex controlled process with several hydrodynamic parameters that vary in wide ranges with respect to ship load condition, speed and surrounding conditions (such as wind, current, tide, etc.). Therefore, to effectively control ships in a designed track is always an important task for ship masters. This paper presents an effective adaptive autopilot ships that ensure the optimal accuracy, economy and stability characteristics. The PID control methodology is modified and parameters of a PID controller is designed to satisfy conditions for an optimal objective function that comprised by heading error, resistance and drift during changing course, and loss of surge velocity or fuel consumption. Designing of the controller for course changing process is based on the Model Reference Adaptive System (MRAS) control theory, while as designing of the automatic course keeping process is based on the Self Tuning Regulator (STR) control theory. Simulation (using MATLAB software) in various disturbance conditions shows that in comparison with conventional PID autopilots, the designed autopilot has several notable advantages: higher course turning speed, lower swing of ship bow even in strong waves and winds, high accuracy of course keeping, shorter time of rudder actions smaller times of changing rudder direction.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제51권7호
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• pp.399-405
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• 2002

This paper presents an implementation of digital high-performance Position sensorless motion control system of an induction motor drives with Direct Torque Control(DTC). The system consist of closed loop stator flux and torque observer, speed and torque estimators, two hysteresis controller, optimal switching look-up table, IGBT voltage source inverter, and TMS320C31 DSP board. The stator flux observer is based on the combined current and voltage model with stator flux feedback adaptive control of which inputs are current and voltage sensed on motor terminal for wide speed range. The speed observer is using the model reference adaptive system(MRAS) with rotor flux linkages for speed turning signal. The simulation and experimental results are provided to evacuate the consistency and the performance of the suggested position sensorless control algorithm. The developed position sensorless system are shown a good motion control response characteristic and high performance features using 2.2[kw] general purposed induction motor.

• Journal of Electrical Engineering and Technology
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• 제8권3호
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• pp.530-543
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• 2013

This paper describes a control scheme of speed sensorless fuzzy direct torque control (FDTC) of permanent magnet synchronous motor for electric vehicle (EV). Electric vehicle requires fast torque response and high efficiency of the drive. Speed sensorless FDTC In-wheel PMSM drives without mechanical speed sensors at the motor shaft have the attractions of low cost, quick response and high reliability in electric vehicle application. This paper presents a new approach to estimate the speed of in-wheel electrical vehicles based on Model Reference Adaptive System (MRAS). The direct torque control suffers in low speeds due to the effect of changes in stator resistance on the flux measurements. To improve the system performance at low speeds, a PI-fuzzy resistance estimator is proposed to eliminate the error due to changes in stator resistance. High performance sensorless drive of the in-wheel motor based on MRAS with on line stator resistance tuning is established for four motorized wheels electric vehicle and the whole system is simulated by matalb/simulink. The simulation results show the effectiveness of the new control strategy. This proposed control strategy is extensively used in electric vehicle application.

• 전기학회논문지P
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• 제51권1호
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• pp.18-27
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• 2002

This paper presents an implementation of digital high-performance speed sensorless control system of an induction motor drives with Direct Torque Control(DTC). The system consists of closed loop stator flux and torque observer, speed and torque estimators, two hysteresis controllers, an optimal switching look-up table, IGBT voltage source inverter, and TMS320C31 DSP controller board. The stator flux observer is based on the combined current and voltage model with stator flux feedback adaptive control for wide speed range. The speed estimator is using the model reference adaptive system(MRAS) with rotor flux linkages for speed turning signal estimation. In order to prove the suggested speed sensorless control algorithm, and to obtain a high-dynamic robust adaptive performance, we have some simulations and actual experiments at low(20rpm) and high(1000rpm) speed areas. The developed speed sensorless system are shown a good speed control response characteristic, and high performance features using 2.2[kW] general purposed induction motor.

• 한국산학기술학회논문지
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• 제15권2호
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• pp.1044-1050
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• 2014

매입형 영구자석 동기전동기의 제어기법으로 많이 사용되는 단위전류 당 최대 토크제어기법이 제대로 적용되려면 전동기의 고정자 저항, 인덕턴스의 값, 그리고 영구자석에 의해 형성되는 쇄교 자속과 같은 전동기 상수들의 값을 정확히 알아야 한다. 이러한 상수들의 값은 내부 온도 및 전류 등의 변화에 따라 계속 변하기 때문에 정확하게 추정하기가 매우 어렵다. 본 논문에서는 적응제어기법을 이용하여 이러한 상수들의 값을 추정하는 알고리즘을 제시한다. 제시하는 알고리즘은 MRAS(Model Reference Adaptive System)기법으로 실제 전류의 값을 이용하여 상수들을 추정하게 된다. 제시하는 알고리즘의 우수성은 시뮬레이션을 통해 입증하도록 한다.

• 전력전자학회논문지
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• 제19권1호
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• pp.71-79
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• 2014

In this paper, a new grid voltage estimation algorithm without voltage sensors is proposed for the three-phase vienna rectifier. Generally, input voltage sensor circuits increase size and cost of the PWM rectifier In order to reduce the cost and size and in order to increase reliability from the electrical noise, grid voltage estimation scheme without input voltage sensor is highly required. In this paper, the grid voltage estimation algorithm is proposed by a simple MRAS(Model Reference Adaptive System) observer without input voltage sensors. The validity of the proposed method is proven by simulation and experiment on the three-phase vienna rectifier system.

• 한국산학기술학회논문지
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• 제19권5호
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• pp.389-398
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• 2018

상호인정협약(MRA)은 무역기술장벽(TBT) 극복을 위한 WTO 틀 내의 중요한 정책수단이다. MRA의 경제적 효과와 관련된 연구는 대부분 인터뷰와 간단한 설문조사를 통해 그 효과를 확인하거나 MRA체결을 통해 면제되는 제품의 심사비용이 명확하고 계량분석이 가능한 데이터가 축적된 정보통신산업 등에서 제한적으로 계량 분석을 통해 비용절감 효과와 수출에 미치는 영향을 제시한다. 이러한 연구결과는 모두 MRA 체결이 긍정적 경제효과를 가져오는 것으로 분석되었다. 그러나 제약 산업의 MRA체결에 대해 직접 경제적 효과를 분석한 연구는 없다. 따라서 본 논문에서는 EFTA와의 GMP 실사 면제 MRA체결의 경제효과를 비시장재의 가치 추정 방법인 조건부가치평가법(CVM)을 통해 분석하였다. 먼저 제약 기업을 대상으로 EFTA권역과의 MRA 체결 의의와 효과를 설명하고, 가상의 시장을 설정하여 GMP 실사 면제에 대한 연회비 형태의 지불의사를 이중경계양분형질문을 통해 조사하였다. 이를 Hanemann(1984)이 제시한 효용차이모형을 통해 중간값 WTP와 절단된 평균 WTP를 산출하였고, 이를 바탕으로 전체기업의 경제효과를 산출한 결과 연간 최소 70.3억에서 최대 약 158억의 경제적 효과가 있는 것으로 분석되었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.163-165
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• 2006

This paper presents a implementation of speed sensorless vector control algorithm of induction motor using MATLAB/SIMULINK amd dSPACE DSl104 R&D board. The estimation of rotor flux linkage and rotor speed is carried out using model reference adaptive system(MRAS) method. Estimated rotor speed is used to speed controller of induction motor. Simulation results are presented to confirm speed sensorless vector control algorithm.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1995년도 Proceedings of the Korea Automation Control Conference, 10th (KACC); Seoul, Korea; 23-25 Oct. 1995
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• pp.207-210
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• 1995

In this paper, two representative schemes for vector control of induction motor without speed sensor are studied. First, the two sensorless systems which are implemented by voltage and current source are presented with new ideas and interpretations. Then a linear model around an operating point is proposed. Finally, the stability improvement of these systems are studied and evaluated by computing the trajectories of poles and zeros.