• 제목/요약/키워드: Speed estimator

검색결과 263건 처리시간 0.022초

MRAS Based Speed Estimator for Sensorless Vector Control of a Linear Induction Motor with Improved Adaptation Mechanisms

  • Holakooie, Mohammad Hosein;Taheri, Asghar;Sharifian, Mohammad Bagher Bannae
    • Journal of Power Electronics
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    • 제15권5호
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    • pp.1274-1285
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    • 2015
  • This paper deals with model reference adaptive system (MRAS) speed estimators based on a secondary flux for linear induction motors (LIMs). The operation of these estimators significantly depends on an adaptation mechanism. Fixed-gain PI controller is the most common adaptation mechanism that may fail to estimate the speed correctly in different conditions, such as variation in machine parameters and noisy environment. Two adaptation mechanisms are proposed to improve LIM drive system performance, particularly at very low speed. The first adaptation mechanism is based on fuzzy theory, and the second is obtained from an LIM mechanical model. Compared with a conventional PI controller, the proposed adaptation mechanisms have low sensitivity to both variations of machine parameters and noise. The optimum parameters of adaptation mechanisms are tuned using an offline method through chaotic optimization algorithm (COA) because no design criterion is given to provide these values. The efficiency of MRAS speed estimator is validated by both numerical simulation and real-time hardware-in-the-loop (HIL) implementations. Results indicate that the proposed adaptation mechanisms improve performance of MRAS speed estimator.

역기전력 추정기를 이용한 전류 모델 기반의 SPMSM 센서리스 벡터제어 (Current Model based SPMSM Sensorless Vector Control using Back Electro Motive Force Estimator)

  • 이정효;유재성;공태웅;이원철;원충연
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2007년도 추계학술대회 논문집
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    • pp.7-10
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    • 2007
  • The current model based sensorless method has many benefits that it can be robust control for large load torque. However, this method should determine a coefficient of back electro motive force(back-emf). This coefficient is varied by load torque and speed. Also, the coefficient determining equation is not exist, so it is determined only by experiment. On the other hands, using only back-emf estimatior method can not drive in low speed area and it has weakness in load variation. For these problems, this paper suggests the hybrid sensorless method that mixes the back-emf estimator regarding saliency and the current based sensorless model. This estimator offers not only non-necessary coefficient for current sensorless model, but also wide speed area operating in no specific transition method.

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왕복동 압축기의 부드러운 정지 제어를 위한 속도 맥동 기반의 기계 각 추정 방식 (Speed Ripple Based Mechanical Angle Estimation Scheme for Smooth Stop Control of Reciprocating Compressor)

  • 이광운
    • 전력전자학회논문지
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    • 제26권4호
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    • pp.298-301
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    • 2021
  • A mechanical angle estimator is presented in this study to achieve the sensorless control of permanent magnet synchronous motor (PMSM) used in driving a reciprocating compressor. Braking the PMSM at a specific mechanical angular position is critical for the silent stoppage of the reciprocating compressor. The performance of conventional mechanical angle observers used in reciprocating compressor drives can be seriously affected according to gains of the speed controller because such observers rely on the magnitude of current ripples. A speed ripple-based mechanical angle estimator is proposed to solve this problem. Experimental results showed the effectiveness of the proposed method.

새로운 MRAS에 의한 유도전동기의 센서리스 속도제어 (Novel MRAS Based Sensorless Speed Control of Induction Motor)

  • 김덕기;김종수;김성환
    • Journal of Advanced Marine Engineering and Technology
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    • 제24권6호
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    • pp.102-109
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    • 2000
  • In this industrial induction motor speed and torque controlled drive system, the closed loop control usually requires the measurement of speed or position of amotor. However a sensorless drive of an induction motor has several advantages ; low cost and mechanical simplicity. Thus this paper investigates a field oriented control method without speed and flux sensors. The proposed control strategy is based on the Model Reference Adaptive System(MRAS) using a new flux estimator which replaces integrators with two lag circuits as the reference model. This algorithm may overcome several shortages of conventional MRAS such as integrator problems, small EMF at low speed. The simulation and experimental results indicate good speed responses.

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차량 전복 방지를 위한 강건한 롤 상태 추정기 설계 (Design of a Robust Estimator for Vehicle Roll State for Prevention of Vehicle Rollover)

  • 박지인;이경수
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회A
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    • pp.1103-1108
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    • 2007
  • This paper describes a robust model-based roll state estimator for application to the detection of impending vehicle rollover. The roll state estimator is based on a 2-D bicycle model and a roll model to estimate the maneuver-induced vehicle roll motion. The measurement signals are lateral acceleration, yaw rate, steering angle, and vehicle speed. Vehicle mass is adapted to obtain robust performance of the estimator. Computer simulation is conducted to evaluate the proposed roll state estimator by using a validated vehicle simulator. It is shown that the roll state estimator shows robust performance without exact vehicle mass information.

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The Gringorten estimator revisited

  • Cook, Nicholas John;Harris, Raymond Ian
    • Wind and Structures
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    • 제16권4호
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    • pp.355-372
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    • 2013
  • The Gringorten estimator has been extensively used in extreme value analysis of wind speed records to obtain unbiased estimates of design wind speeds. This paper reviews the derivation of the Gringorten estimator for the mean plotting position of extremes drawn from parents of the exponential type and demonstrates how it eliminates most of the bias caused by the classical Weibull estimator. It is shown that the coefficients in the Gringorten estimator are the asymptotic values for infinite sample sizes, whereas the estimator is most often used for small sample sizes. The principles used by Gringorten are used to derive a new Consistent Linear Unbiased Estimator (CLUE) for the mean plotting positions for the Fisher Tippett Type 1, Exponential and Weibull distributions and for the associated standard deviations. Analytical and Bootstrap methods are used to calibrate the bias error in each of the estimators and to show that the CLUE are accurate to better than 1%.

PC 기반의 순시속도 검출에 의한 서보 모터의 저속 제어 (PC-based low speed control of a servo motor using instantaneous speed detection)

  • 류재규;박정일;이석규
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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    • pp.377-382
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    • 1993
  • The low speed control of a servo motor using instantaneous speed detection method is described. To estimate the instantaneous speed from the average speed, the speed estimator of the first or second order is used. We confirm that these estimatorsimprove the speed control performance of a servo system with experiments.

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위상지연필터를 이용한 리니어 모터 피스톤 진폭 추정기의 구현 (Implementation of Linear Motor Piston Amplitude Estimator Using Phase Lag Filter)

  • 오준태;김규식
    • 전자공학회논문지
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    • 제50권4호
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    • pp.212-218
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    • 2013
  • 본 논문에서는 위상지연필터를 이용한 리니어 모터 피스톤 진폭 추정기를 구현하였다. 리니어 컴프레서가 적용된 냉장고나 에어컨의 냉각능력을 제어하기 위해서는 단위시간동안 피스톤의 움직인 거리, 즉 피스톤의 속도를 제어해야 하는데 이때 리니어 모터의 주파수나 스트로크를 조정함으로써 가능하다. 이때, 주파수를 고정하고 스트로크를 변화시키는 것이 일반적이다. 스트로크, 즉 피스톤 진폭을 정확하게 추정하는 것이 리니어 컴프레서의 동특성을 좌우하는데, 본 연구에서는 위상지연필터를 이용한 피스톤 진폭 추정기를 제안하고 성능이 우수함을 모의실험을 통해 확인하였다.

Sensorless Vector Control of Induction Motors for Wind Energy Applications Using MRAS and ASO

  • Jeong, Il-Woo;Choi, Won-Shik;Park, Ki-Hyeon
    • Journal of Electrical Engineering and Technology
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    • 제9권3호
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    • pp.873-881
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    • 2014
  • Speed sensorless modes of operation are becoming standard solution in the area of electric drives. This paper presents flux estimator and speed estimator for the speed sensorless vector control of induction motors. The proposed sensorless methods are based on the model reference adaptive system (MRAS) observer and adaptive speed observer (ASO). The proposed speed estimation algorithm can be employed in the power control of grid connected induction generator for wind power applications. Two proposed schemes are verified through computer simulation PSIM and compared their simulation results.

유도 전동기 센서리스 제어를 위한 동기 각속도 오차 보상기를 갖는 향상된 Programmable LPF 자속 추정기 (Improved Programmable LPF Flux Estimator with Synchronous Angular Speed Error Compensator for Sensorless Control of Induction Motors)

  • 이상수;박병건;김래영;현동석
    • 전력전자학회논문지
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    • 제18권3호
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    • pp.232-239
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    • 2013
  • This paper proposes an improved stator flux estimator through ensuring conventional PLPF to act as a pure integrator for sensorless control of induction motors. Conventional PLPF uses the estimated synchronous speed as a cut-off frequency and has the gain and phase compensators. The gain and phase compensators are determined on the assumption that the estimated synchronous angular speed is coincident with the real speed. Therefore, if the synchronous angular speed is not same as the real speed, the gain and phase compensation will not be appropriate. To overcome the problem of conventional PLPF, this paper analyzes the relationship between the synchronous speed error and the phase lag error of the stator flux. Based on the analysis, this paper proposes the synchronous speed error compensation scheme. To achieve a start-up without speed sensor, the current model is used as the stator flux estimator at the standstill. When the motor starts up, the current model should be switched into the voltage model. So a stable transition between the voltage model and the current model is required. This paper proposes the simple transition method which determines the initial values of the voltage model and the current model at the transition moment. The validity of the proposed schemes is proved through the simulation results and the experimental results.