• Title, Summary, Keyword: Synchronous PI decoupling control

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Synchronous PI Decoupling Control Scheme for DVR against a Voltage Sag in the Power System

  • Kim, Myung-Bok;Lee, Seung-Hoon;Moon, Gun-Woo;Youn, Myung-Joong
    • Journal of Power Electronics
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    • v.4 no.3
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    • pp.180-187
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    • 2004
  • This paper proposes a new control strategy for the dynamic voltage restorer (DVR). It is based on a synchronous PI decoupling control strategy which features fast response time and low steady state error. Therefore, the proposed control strategy produces faster action time against voltage sag and guarantees more than enough compensation for reduced supply voltage. Experimental results, implemented with the TMS320C3${\times}$DSP control unit, are shown to validate the effectiveness of the proposed control strategy.

An Improved Stationary Frame-based Digital Current Control Scheme for a PM Synchronous Motor

  • Kim, Kyeong-Hwa;Young, Myung-Joong
    • Journal of Power Electronics
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    • v.1 no.2
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    • pp.88-98
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    • 2001
  • An improved stationary frame-based digital current control technique for a permanent magnet(PM) synchronous motor is presented. Generally, the stationary frame current controller is known to provide the advantage of a simple implementation. However, there are some unavoidable limitations such as a steady-state error and a phase delay in the steady-state. On the other hand, in the synchronous frame current regulator the regulated currents are dc quantities and a zero steady-state error can be obtained through the integral control. However, the need to transform the signals between the stationary and synchronous frames makes the implementation of a synchronous frame regulator complex. Although the PI controller in the stationary frame gives a steady-state error and a phase delay, the control performance can be greatly improved by employing the exact decoupling control inputs for the back EMF., resulting in an ideal steady-state control characteristics irrespective of an operating condition as in the synchronous PI decoupling controller. However, its steady-state response may be degraded due to the inexact cancellation inputs under the parameter variations. To improve the control performance in the stationary frame, the disturbance is estimated using the time delay control. The proposed scheme is implemented on a PM synchronous motor using DSP TMS320C31 and the effectiveness is verified through the comparative simulations and experiments.

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An Improved Stationary Frame-based Digital Current Control Scheme for a PM Synchronous Motor

  • Kim Kyeong-Hwa;Youn Myung-Joong
    • Proceedings of the KIPE Conference
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    • pp.174-178
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    • 2001
  • An improved stationary frame-based digital current control technique for a permanent magnet (PM) synchronous motor is presented. Generally, the stationary frame current controller is known to provide the advantage of a simple implementation. However, there are some unavoidable limitations such as a steady-state error and a phase delay in the steady-state. On the other hand, in the synchronous frame current regulator, the regulated currents are dc quantities and a zero steady-state error can be obtained through the integral control. However, the need to transform the signals between the stationary and synchronous frames makes the implementation of a synchronous frame regulator complex. Although the PI controller in the stationary frame gives a steady-state error and a phase delay, the control performance can be greatly improved by employing the exact decoupling control inputs for the back EMF, resulting in an ideal steady-state control characteristics irrespective of an operating condition as in the synchronous PI decoupling controller. However, its steady-state response may be degraded due to the inexact cancellation inputs under the parameter variations. To improve the control performance in the stationary frame, the disturbance is estimated using the time delay control. The proposed scheme is implemented on a PM synchronous motor using DSP TMS320C31 and the effectiveness is verified through the comparative simulations and experiments.

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A Robust Dynamic Decoupling Control Scheme for PMSM Current Loops Based on Improved Sliding Mode Observer

  • Shen, Hanlin;Luo, Xin;Liang, Guilin;Shen, Anwen
    • Journal of Power Electronics
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    • v.18 no.6
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    • pp.1708-1719
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    • 2018
  • A complete current loop decoupling control strategy based on a sliding mode observer (SMO) is proposed to eliminate the influence of current dynamic coupling and back electromotive force (EMF) in the vector control of permanent magnet synchronous motors. With this strategy, current dynamic decoupling and back EMF compensation can be simultaneously achieved. Unlike conventional methods, the proposed strategy can avoid the disturbances caused by the parametric variations of motor systems and maintain the advantages of proportional integral (PI) controllers, which are robust and easy to operate. An improved SMO, which uses a special PI regulator other than a linear saturation function as the equivalent control law in the boundary layer of a sliding surface, is proposed to eliminate the estimated errors caused by the quasi-sliding mode and obtain a satisfactory decoupling performance. The stability and parameter robustness of the proposed strategy are also analyzed. Physical experimental results are presented to verify the validity of the method.

Control characteristics of digital PI current controller for PM synchronous (영구자석 동기전동기를 위한 디지털 PI 전류제어기의 제어특성)

  • Kim, M.H.;Lim, J.G.;Chung, S.K.
    • Proceedings of the KIPE Conference
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    • pp.93-95
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    • 2009
  • The synchronous PI current controller has been widely used for the high performance PM synchronous drives and generally implemented using a digital signal processor. This paper describes the control characteristics of the digital PI current controller for PM synchronous drives. The stability of the current control system considering the sampling time is investigated and the effects of the mismatched decoupling terms in the discrete-time domain are also discussed. The simulation results are provided to verify the theoretic results.

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Precise Position Synchronous Control of Two-Axes System Using Two-Degree-of-Freedom PI Controller in BLDC Motor (2자유도 PI 제어기를 이용한 2축 BLDC 모터 시스템의 정밀 위치동기 제어)

  • Yoo, S.K.;Jeong, S.K.
    • Journal of the Korea Society For Power System Engineering
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    • v.5 no.3
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    • pp.104-113
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    • 2001
  • This paper describes a precise position synchronous control of two axes rotating system using BLDC motors and a cooperative control based on decoupling technique and PI control law. The system is required performances both good speed following and minimum position synchronous errors simultaneously. To accomplish these goals, the three kinds of controllers are designed. At first, the current and speed controller are designed very simply to compensate the influences of disturbances and to follow up speed references quickly. Especially, the two degree of freedom PI controller is used considering both good tracking for speed reference input and quick rejection of disturbances in speed controller. Finally, a position synchronous controller is designed as a simple proportional controller to minimize position synchronous errors. The validity of the proposed method is confirmed through some numerical simulations. Moreover, the results are compared to the conventional master-slave control ones to show the effectiveness of the proposed system.

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A method of utilizing the predicted current in the high performance PI current controller with a control time delay (제어 시지연이 있는 고성능 PI 전류제어기에 대한 예측전류의 적용방법)

  • Lee Jin-Woo
    • Proceedings of the KIPE Conference
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    • pp.1-3
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    • 2006
  • This paper deals with a novel utilization method of the predicted current in the high performance PI current controller with a control time delay. The inevitable error of the predicted current in the linear servo drive using a permanent magnet linear synchronous motor is analyzed and a modified cross-coupling decoupling synchronous frame PI current controller is proposed in order to improve the current control response under the control time delay. Simulation and experimental results show that the proposed current controller has an improved current control performance under both the electrical uncertainties of a servo drive system and the control time delay.

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Complex Vector Current Control of Grid Connected Inverter Robust for Inductance Variation (인덕턴스 변화에 강인한 계통연계형 인버터의 복소 벡터 전류제어기)

  • Lee, Taejin;Jo, Jongmin;Shin, Changhoon;Cha, Hanju
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.10
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    • pp.1648-1654
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    • 2016
  • This paper analyzes complex vector current control for the enhanced cross-coupling compensation in accordance with parameter variation in grid-connected inverter system, and verifies through simulation and experiment. Complex vector current control is performed in the synchronous reference frame through d-q transformation. It generates cross-coupling components with rotating nominal angular frequency. In general, cross-coupling elements are compensated by decoupling terms added to output of conventional decoupling PI controller. But, it is impossible to compensate them perfectly which transient response is especially deteriorated such as large overshoot and slow tracking, when variation of grid impedance or measurement error occurs. However, complex vector current control can improve stability and response characteristic of current control regardless of the situation as before. Decoupling controller and complex vector controller are represented through complex forms, and these controllers are analyzed by using frequency response in s-domain, respectively. It is verified that complex vector controller has more superior response characteristic than decoupling controller through MATALB, PSIM and experimental in 5kW grid-connected inverter when L filter parameter is varied from 1.1mH to increase double, 2.2mH.

A Novel Utilization Method of the Predicted Current in the High Performance PI Current Controller with a Control time delay (제어 시지연이 있는 고성능 PI 전류제어기에 대한 예측전류의 적용방법)

  • Lee, Jin-Woo
    • The Transactions of the Korean Institute of Power Electronics
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    • v.11 no.5
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    • pp.426-430
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    • 2006
  • This paper deals with a novel utilization method of the predicted current in the high performance PI current controller with a control time delay. The inevitable error of the predicted current in the linear servo drive using a permanent magnet linear synchronous motor is analyzed and a modified cross-coupling decoupling synchronous frame PI current controller is proposed in order to improve the current control response under both the control time delay and the inevitable current prediction error. Simulation and experimental results show that the proposed current controller has an improved current control performance under both the control time delay and the inevitable current prediction error in the servo drive system.

Active Disturbance Rejection Control for Single-Phase PWM Rectifier with Current Decoupling Control

  • Yan, Ruitao;Wang, Ping
    • Journal of Electrical Engineering and Technology
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    • v.13 no.6
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    • pp.2354-2363
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    • 2018
  • This paper proposed a novel double closed control strategy for single-phase voltage source pulse width modulation (PWM) rectifier based on active disturbance rejection control (ADRC) and dq current decoupling control. First, the mathematical model of the single-phase PWM rectifier in the d-q axis synchronous rotating reference frame is established by constructing a virtual component using a second-order generalized integrator (SOGI). Then, the mathematical model is simplified according to the active power conservation, and the first-order equation of single-phase PWM rectifier voltage outer loop is acquired. A linear auto-disturbance rejection controller is used to design the voltage outer loop according to the first-order equation. Finally, the proposed control strategy and the traditional PI control are compared and verified by simulation and physical experiments. Both simulation and experimental results confirm that the proposed control strategy has excellent dynamic performance and strong rejection ability to disturbances.