• 제목/요약/키워드: load current observer

검색결과 52건 처리시간 0.018초

직접토크제어에 의한 리럭턴스 동기전동기의 고성능 제어시스템 (A High-Performance Control System of Reluctance Synchronous Motor with Direct Torque Control)

  • 김민회
    • 전기학회논문지P
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    • 제51권2호
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    • pp.68-76
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    • 2002
  • This paper presents an implementation of high-dynamic performance control system of Reluctance Synchronous Motor (RSM) drives for an industrial servo system with direct torque control (DTC). The problems of DTC for high-dynamic performance and maximum efficiency RSM drives are the nonlinear variable flux and inductance due to a saturated stator linkage flux and nonlinear inductance curve with various load currents. The accurate estimation of the stator flux and torque are obtained using stator flux observer of which a saturated inductance Ld and Lq can be compensated by using the adapted neural network from measuring the modulus and angle of the stator current. To obtain fast torque response and maximum torque/current with varying load current, the reference command flux is ensured by imposing Ids=Iqs. This control strategy is proposed to fast response and optimal efficiency for RSM drive. In order to prove rightness of the suggested control algorithm, we have some actual experimental system using 6000 pulse/rev encoder at ${\pm}10$ and ${\pm}1500rpm$. The developed digitally high-performance control system are shown some good response characteristics of control results and high performance features using 1.0kW RSM of which has 2.57 Ld/Lq salient ratio.

외란 관측기를 이용한 BLDCM의 위치 및 속도제어 (The Position and Speed Control of the BLDC Motor Using the Disturbance Observer)

  • 전용호
    • 한국전자통신학회논문지
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    • 제15권5호
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    • pp.899-906
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    • 2020
  • 전동기의 제어에 있어서 전동기의 수학적 모델 오차와 작용하는 외란에 대해서 강건하며 정밀한 제어의 성능을 요구한다. 강건하며 정밀한 제어를 위하여 외란 관측기를 설계하여 부하변동을 추정하고, 공칭 시스템으로 설계된 백스텝핑 제어기에 적용하였다. 설계된 시스템의 제어 성능을 확인하고자 120 [W]급의 BLDCM(Brushless Direct Current Motor)에 적용하여, 위치제어 및 속도제어의 결과 외란을 극복하고 정상상태 오차가 영으로 수렴하며, 점근적 안정한 결과를 확인할 수 있다.

Robust Time Delay Compensation for DTC-Based Induction Machine Systems via Extended State Observers

  • Wang, Fengxiang;Wang, Junxiao;Yu, Li
    • Journal of Power Electronics
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    • 제18권3호
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    • pp.736-745
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    • 2018
  • This paper presents an extended state observer (ESO) based direct torque control (DTC) for use in induction motor systems to handle the issues of time delays, load torque disturbances and parameter uncertainties. Direct torque control offers an excellent torque response and it does not require a proportion integration (PI) controller in the current loop. However, a PI controller is still adopted in the outer speed loop to generate the torque reference value, which is a slow method. An ESO based compound control scheme is proposed to improve the response rate and accuracy of the torque reference signal, especially when load torque is injected. In addition, the time delay problem is analyzed and compensated for in this paper to reduce torque ripples. The proposed disturbance compensation technique based direct control scheme is shown to have good performance both in the transient and stable states via simulations and experimental results.

외란 관측기를 이용한 BLDC 전동기의 속도제어 (Speed Control of the BLDC Motor using the Disturbance Observer)

  • 전용호
    • 한국전자통신학회논문지
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    • 제11권10호
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    • pp.955-962
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    • 2016
  • 본 논문은 BLDC 전동기의 정밀한 속도제어를 위하여 외란 관측기의 설계 및 영향을 제거하는 제어기 설계방법을 제안한다. BLDC 전동기의 외부에서 회전축에 작용하는 부하의 변동과 전기적인 시스템에서 발생하는 역기전력을 외란으로 가정하고, 외란은 구간에 대한 상수로 가정하여 루엔버거 관측기를 설계한다. 시스템 상태에 대한 관측기의 오차가 0으로 수렴할 수 있도록 적절한 이득을 설정하는 방법을 보이고, 추종성능을 향상시킬 수 있는 적절한 PI제어기의 이득을 설정하기 위한 방법을 제시한다. 제안된 제어기를 120W급의 BLDC 전동기에 적용하여 속도 그리고 전류 레퍼런스를 추종하는 능력을 시뮬레이션 시험하였다. 상수부하의 변동을 외란으로 적용하였고, 그 결과 설계된 제어기의 정상상태 오차가 0.1 [%] 이내를 가짐으로 상태 추종성능에 대해 유용한 제어기임을 보일 수 있었다.

An auto weather-vaning system for a DP vessel that uses a nonlinear controller and a disturbance observer

  • Kim, Dae Hyuk;Kim, Nakwan
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제6권1호
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    • pp.98-118
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    • 2014
  • An auto weather-vaning system for a Dynamic Positioning (DP) vessel is proposed. When a DP vessel is operating, its position keeping is hindered by ocean environmental disturbances which include the ocean current, wave and wind. Generally, most ocean vessels have a longitudinal length that is larger than the transverse width. The largest load acts on the DP vessel by ocean disturbances, when the disturbances are incoming in the transverse direction. Weather-vaning is the concept of making the heading angle of the DP vessel head toward (or sway from) the disturbance direction. This enables the DP vessel to not only perform marine operations stably and safely, but also to maintain its position with minimum control forces (surge & sway components). To implement auto weather-vaning, a nonlinear controller and a disturbance observer are used. The disturbance observer transforms a real plant to the nominal model without disturbance to enhance the control performance. And the nonlinear controller deals with the kinematic nonlinearity. The auto weather-vaning system is completed by adding a weather-vaning algorithm to disturbance based controller. Numerical simulations of a semi-submersible type vessel were performed for the validation. The results show that the proposed method enables a DP vessel to maintain its position with minimum control force.

Integrated Sliding-Mode Sensorless Driver with Pre-driver and Current Sensing Circuit for Accurate Speed Control of PMSM

  • Heo, Sewan;Oh, Jimin;Kim, Minki;Suk, Jung-Hee;Yang, Yil Suk;Park, Ki-Tae;Kim, Jinsung
    • ETRI Journal
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    • 제37권6호
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    • pp.1154-1164
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    • 2015
  • This paper proposes a fully sensorless driver for a permanent magnet synchronous motor (PMSM) integrated with a digital motor controller and an analog pre-driver, including sensing circuits and estimators. In the motor controller, a position estimator estimates the back electromotive force and rotor position using a sliding-mode observer. In the pre-driver, drivers for the power devices are designed with a level shifter and isolation technique. In addition, a current sensing circuit measures a three-phase current. All of these circuits are integrated in a single chip such that the driver achieves control of the speed with high accuracy. Using an IC fabricated using a $0.18{\mu}m$ BCDMOS process, the performance was verified experimentally. The driver showed stable operation in spite of the variation in speed and load, a similar efficiency near 1% compared to a commercial driver, a low speed error of about 0.1%, and therefore good performance for the PMSM drive.

Design and Stability Analysis of a Fuzzy Adaptive SMC System for Three-Phase UPS Inverter

  • Naheem, Khawar;Choi, Young-Sik;Mwasilu, Francis;Choi, Han Ho;Jung, Jin-Woo
    • Journal of Power Electronics
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    • 제14권4호
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    • pp.704-711
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    • 2014
  • This paper proposes a combined fuzzy adaptive sliding-mode voltage controller (FASVC) for a three-phase UPS inverter. The proposed FASVC encapsulates two control terms: a fuzzy adaptive compensation control term, which solves the problem of parameter uncertainties, and a sliding-mode feedback control term, which stabilizes the error dynamics of the system. To extract precise load current information, the proposed method uses a conventional load current observer instead of current sensors. In addition, the stability of the proposed control scheme is fully guaranteed by using the Lyapunov stability theory. It is shown that the proposed FASVC can attain excellent voltage regulation features such as a fast dynamic response, low total harmonic distortion (THD), and a small steady-state error under sudden load disturbances, nonlinear loads, and unbalanced loads in the existence of the parameter uncertainties. Finally, experimental results are obtained from a prototype 1 kVA three-phase UPS inverter system via a TMS320F28335 DSP. A comparison of these results with those obtained from a conventional sliding-mode controller (SMC) confirms the superior transient and steady-state performances of the proposed control technique.

MRAS를 이용한 유도 전동기의 시정수 보상을 갖는 속도 센서리스 벡터제어 (Sensorless Vector Control System with Compensated Time Constant of Induction Motor Using a MRAS)

  • 임태윤;김동희;황돈하;김민회
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 1999년도 전력전자학술대회 논문집
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    • pp.540-543
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    • 1999
  • This paper describes a speed sensorless algorithm for vector control system with compensated stator resistance and rotor time constant of induction motor using a model reference adaptive system(MRAS). The system are composed of two MRAC, one is a rotor speed estimation and a stator resistor identification by back-EMF observer, other is used to identify rotor time constant by magnetizing current observer, so that the estimation can be cover a very low speed range with a robust control. The suggest control strategy and estimation method have been validated by simulation study. In the simulation using Matlab/Simulik, the proposed speed sensorless vector control system are shown to operate very well in spite of variable rotor time constant and load fluctuation.

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Sensorless Sine-Wave Controller IC for PM Brushless Motor Employing Automatic Lead-Angle Compensation

  • Kim, Minki;Heo, Sewan;Oh, Jimin;Suk, Jung-Hee;Yang, Yil Suk;Park, Ki-Tae;Kim, Jinsung
    • ETRI Journal
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    • 제37권6호
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    • pp.1165-1175
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    • 2015
  • This paper presents an advanced sensorless permanent magnet (PM) brushless motor controller integrated circuit (IC) employing an automatic lead-angle compensator. The proposed IC is composed of not only a sensorless sine-wave motor controller but also an isolated gate-driver and current self-sensing circuit. The fabricated IC operates in sensorless mode using a position estimator based on a sliding mode observer and an open-loop start-up. For high efficiency PM brushless motor driving, an automatic lead-angle control algorithm is employed, which improves the efficiency of a PM brushless motor system by tracking the minimum copper loss under various load and speed conditions. The fabricated IC is evaluated experimentally using a commercial 200 W PM brushless motor and power switches. The proposed IC is successfully operated without any additional sensors, and the proposed algorithm maintains the minimum current and maximum system efficiency under $0N{\cdot}m$ to $0.8N{\cdot}m$ load conditions. The proposed IC is a feasible sensorless speed controller for various applications with a wide range of load and speed conditions.

전원전압의 불평형 및 왜곡 보상기능을 갖는 3상 PWM 정류기의 전류제어기 (A Current Controller with the Compensation of the Input Voltage Unbalance and Distortion for Three Phase PWM Rectifier)

  • 신근희;김학원;조관열;임병국
    • 전력전자학회논문지
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    • 제16권6호
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    • pp.594-601
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    • 2011
  • 본 논문은 상용의 전원 전압이 불평형 및 왜곡을 갖는 경우, 전원전압 불평형 및 왜곡 보상기능을 갖는 전류제어기를 제안한다. 일반적으로 3상 전원 시스템은 공통 입력 단자 (Point of Common Coupling)에 단상 부하 및 비선형 부하가 3상 부하와 같이 연결될 수 있어, 종종 불평형과 왜곡이 발생한다. 이런 조건하에서 3상 PWM 정류기를 일반적인 전류 제어기로 제어 할 경우, 3상 PWM 정류기 입력 전류가 불평형 및 왜곡을 갖는 문제가 발생한다. 본 논문에서는 간단한 모델 기반 적응 제어 시스템(Model Reference Adaptive System)기법을 이용하여 3상 입력 전압의 불평형 및 왜곡을 관측하고 전향 보상하는 전류 제어기를 제안하며, 모의해석과 실험을 통하여 그 효용성을 입증한다.