• Title/Summary/Keyword: Full order state observer

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PLL for Unbalanced Three-Phase Utility Voltage using Positive Sequence Voltage Observer (정상분 전압 관측기를 이용한 불평형 3상 전원의 PLL)

  • Kim, Hyeong-Su;Choi, Jong-Woo
    • The Transactions of the Korean Institute of Power Electronics
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    • v.13 no.2
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    • pp.145-151
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    • 2008
  • This paper proposes the PLL method using positive sequence voltage which is estimated by full-order state observer to find an accurate phase angle under the condition of unbalanced utility voltage. The proposed method uses the full-order state observer instead of existing method(APF All Pass Filter) to find a positive sequence of a utility voltage and this proposed method improves transient response of an estimated phase angle when a three-phase utility voltage becomes unbalanced. To compare proposed method withexisting method, experiments have been done for a phase angle detection of utility voltage when a three-phase utility voltage becomes unbalanced. Their results show that transient state response of proposed method is improved.

Depth Control of Underwater Glider Using Reduced Order Observer (축소 차원 관측기를 사용한 수중 글라이더의 깊이 제어)

  • Joo, Moon-Gab;Woo, Him-Chan;Son, Hyeong-Gon
    • IEMEK Journal of Embedded Systems and Applications
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    • v.12 no.5
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    • pp.311-318
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    • 2017
  • A reduced order observer is developed for depth control of a hybrid underwater glider which combines the good aspects of a conventional autonomous underwater vehicle and a underwater glider. State variables include the center of gravity of the robot and the weight of the buoyancy bag, which can not be directly measured. By using the mathematical model and available information such as directional velocities, accelerations, and attitudes, we developed a Luenberger's reduced order observer to estimate the center of gravity and the buoyancy weight. By simulations using Matlab/Simulink, the efficiency of the proposed observer is shown, where a LQR controller using full state variables is adopted as a depth controller.

Robust Decoupling Digital Control of Three-Phase Inverter for UPS (3상 UPS용 인버터의 강인한 비간섭 디지털제어)

  • Park, Jee-Ho;Heo, Tae-Won;Shin, Dong-Ryul;Roh, Tae-Kyun;Woo, Jung-In
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.49 no.4
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    • pp.246-255
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    • 2000
  • This paper deals with a novel full digital control method of the three-phase PWM inverter for UPS. The voltage and current of output filter capacitor as state variables are the feedback control input. In addition, a double deadbeat control consisting of a d-q current minor loop and a d-q voltage major loop, both with precise decoupling, have been developed. The switching pulse width modulation based on SVM is adopted so that the capacitor current should be exactly equal to its reference current. In order to compensate the calculation time delay, the predictive control is achieved by the current·voltage observer. The load prediction is used to compensate the load disturbance by disturbance observer with deadbeat response. The experimental results show that the proposed system offers an output voltage with THD less than 2% at a full nonlinear load.

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A new scheme for discrete implicit adaptive observer and controller (이산형 적응관측자 및 제어기의 새로운 구성)

  • 고명삼;허욱열
    • 전기의세계
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    • v.30 no.12
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    • pp.822-831
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    • 1981
  • Many different schemes of the adaptive observer and controller have been developed for both continuous and discrete systems. In this paper we have presented a new scheme of the reduced order adaptive observer for the single input discrete linear time invariant plant. The output equation of the plant, is transformed into the bilinear form in terms of system parameters and the states of the state variable filters. Using the plant output equation the discrete implicit adaptive observer based on the similar philosophy to Nuyan and Carroll is derived and the parameter adaptation algorithm is derived based on the exponentially weighted least square method. The adaptive model following control system is also constructed according to the proposed observer scheme. The proposed observer and controller are rather than simple structure and have a fast adaptive algorithm, so it may be expected that the scheme is suitable to the practical application of control system design. The effectiveness of the algorithm and structure is illustrated by the computer simulation of a third order system. The simulation results show that the convergence speed is proportinal to the increasing of weighting factor alpha, and that the full order and reduced order observer have similar convergence characteristics.

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Design of a Fuzzy Model-Based State Observer Using GAs (유전알고리즘에 의한 퍼지모델기반의 상태관측기 설계)

  • 이현식;손영득;김종화;유영호;하윤수;진강규
    • Journal of Advanced Marine Engineering and Technology
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    • v.25 no.1
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    • pp.162-170
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    • 2001
  • This paper presents a scheme for designing a fuzzy model-bsaed state observer for nonlinear system. For this scheme, a Tagaki-Sugeno type fuzzy model whose consequent part is of the state space form is obtained. In describes the locally linear input/output relationship of a system. The parameters of the fuzzy model are adjusted using a genetic algorithm. Then. fuzzy full-order and reduced-order state observers are designed based on the fuzzy model. A set of simulation works is carried out to demonstrate the effectiveness of the proposed scheme.

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Design of Full-Order Observer-based SM-MF Controller including CLF for Power System Stabilizer : Part 4 (전력계통안정기를 위한 폐-루우프 피이드백을 가진 전-차수 관측기에 기준한 SM-MF 제어기 설계 : Part4)

  • Lee, Sang-Seung;Park, Jong-Keun
    • Proceedings of the KIEE Conference
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    • 1997.07c
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    • pp.1171-1173
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    • 1997
  • This paper presents the sliding mode observer-model following(SMO-MF) power system stabilizer(PSS) for unmeasurable plant state variables. This SMO-MF PSS can be obtained by combining the sliding mode-model following(SM-MF) including closed-loop feedback(CLF) with the linear foil-order observer(LFOO).

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Design of Position Estimator for Propulsion Inverter Driving Long Stator LSM in High Speed Maglev

  • Jo, Jeong-Min;Lee, Jin-Ho;Han, Young-Jae;Lee, Chang-Young
    • Journal of international Conference on Electrical Machines and Systems
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    • v.3 no.3
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    • pp.252-255
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    • 2014
  • In the case of long-stator linear drives, unlike rotative drives for which speed or position sensors are a single unit attached to the shaft, these sensors extend along the guideway. The position signal transmitted from maglev vehicle can't meet the need of the real-time propulsion control. In this paper the position estimator for propulsion inverter driving long stator linear synchronous motor (LSLSM) in high speed maglev train is proposed. In order to get the higher resolution of the position information transmitted from vehicle, Full order state observer is proposed for position estimator.

Improvement of Control Performance of PMSM in the low Speed Range (영구자석형 동기전동기의 저속도 영역에서 제어 성능 개선)

  • Won, Chung-Yuen;Yu, Jae-Sung;Jun, Bum-Su;Hwang, Sun-Mo;Kim, Yuen-Chung;Lee, Song-Seok
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.19 no.1
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    • pp.70-79
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    • 2005
  • In this paper, improvement method of control performance by a full-order observer using reduced-order state equation is proposed in the low speed range. Full-order observer using reduced-order state equation is the motor speed and the disturbance torque observer. The proposed algorithm is very stable in the low speed range about 1.9[rpm]. The disturbance torque in the motor drive system degrades speed control performance in the low speed range. The proposed algorithm estimated both motor speed and disturbance torque. The estimated disturbance torque is used as a feedforward value in output of the speed controller, As a result, it improves the response of load torque in the low speed range(1.9rpm).

A New Dynamic Residual Generator for Process Fault Detection (프로세스고장검출을 위한 새로운 잔차발생기구)

  • 이기상;이상문
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.52 no.10
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    • pp.575-582
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    • 2003
  • A new FDOs (fault diagnostic observers) and the residual generation schemes using the FDOs are suggested for the process fault detection and isolation of linear (control) systems. The design method of the FDO is described, first, for the full measurement systems. Then it is extended for the systems with unmeasurable state variables. An unknown input observer is proposed and applied for the extension. The size of the observer bank may be the smallest, specially in full measurement systems, because the order of the proposed FDO is very low. In spite of the simplicity, the scheme provides the same information for the detection and isolation of the anticipated faults as the conventional multiple observer based schemes. The residuals may be structured so that fault isolation can be performed by pre-selected logic. An FDIS using the proposed scheme is constructed for the model of the four-tank system. Simulation results show the practical feasibility of the proposed scheme.